| **INVESTMENTS IN OPERATING PARTNERSHIPS (Details 2) (USD $)**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               | 6 Months Ended |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------|
||
| **Revenues**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |           |  |   |  |
| Rental                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | $ 652,776      |  | $ 1,917,273 |  |
| Interest and other                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          | 22,542         |  | 112,559 |  |
| Operating Partnerships Revenues                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             | 675,318        |  | 2,029,832 |  |
| **Expenses**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |           |  |   |  |
| Interest                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 63,067         |  | 483,149 |  |
| Depreciation and amortization                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               | 156,328        |  | 464,775 |  |
| Operating expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          | 567,549        |  | 1,602,694 |  |
| Operating Partnerships Total Expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | 786,944        |  | 2,550,618 |  |
| NET LOSS                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | (111,626)      |  | (520,786) |  |
| Net loss allocated to Boston Capital Tax Credit Fund Limited Partnership *                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | (110,510)      | [1] | (515,577) | [1] |
| Net loss allocated to other Partners                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | (1,116)        |  | (5,209) |  |
| Series One [Member]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |           |  |   |  |
| **Revenues**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |           |  |   |  |
| Rental                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | 0              |  | 249,303 |  |
| Interest and other                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          | 0              |  | 8,802 |  |
| Operating Partnerships Revenues                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             | 0              |  | 258,105 |  |
| **Expenses**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |           |  |   |  |
| Interest                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 0              |  | 33,384 |  |
| Depreciation and amortization                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               | 0              |  | 71,856 |  |
| Operating expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          | 0              |  | 222,791 |  |
| Operating Partnerships Total Expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | 0              |  | 328,031 |  |
| NET LOSS                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 0              |  | (69,926) |  |
| Net loss allocated to Boston Capital Tax Credit Fund Limited Partnership *                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 0              | [2] | (69,227) | [2] |
| Net loss allocated to other Partners                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | 0              |  | (699) |  |
| Series Two [Member]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |           |  |   |  |
| **Revenues**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |           |  |   |  |
| Rental                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | 0              |  | 412,218 |  |
| Interest and other                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          | 0              |  | 45,016 |  |
| Operating Partnerships Revenues                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             | 0              |  | 457,234 |  |
| **Expenses**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |           |  |   |  |
| Interest                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 0              |  | 186,044 |  |
| Depreciation and amortization                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               | 0              |  | 82,936 |  |
| Operating expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          | 0              |  | 357,539 |  |
| Operating Partnerships Total Expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | 0              |  | 626,519 |  |
| NET LOSS                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 0              |  | (169,285) |  |
| Net loss allocated to Boston Capital Tax Credit Fund Limited Partnership *                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 0              | [3] | (167,592) | [3] |
| Net loss allocated to other Partners                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | 0              |  | (1,693) |  |
| Series Three [Member]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |           |  |   |  |
| **Revenues**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |           |  |   |  |
| Rental                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | 652,776        |  | 735,635 |  |
| Interest and other                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          | 22,542         |  | 19,093 |  |
| Operating Partnerships Revenues                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             | 675,318        |  | 754,728 |  |
| **Expenses**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |           |  |   |  |
| Interest                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 63,067         |  | 92,036 |  |
| Depreciation and amortization                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               | 156,328        |  | 177,919 |  |
| Operating expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          | 567,549        |  | 621,624 |  |
| Operating Partnerships Total Expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | 786,944        |  | 891,579 |  |
| NET LOSS                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | (111,626)      |  | (136,851) |  |
| Net loss allocated to Boston Capital Tax Credit Fund Limited Partnership *                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | (110,510)      | [4] | (135,482) | [4] |
| Net loss allocated to other Partners                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | (1,116)        |  | (1,369) |  |
| Series Four [Member]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |           |  |   |  |
| **Revenues**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |           |  |   |  |
| Rental                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | 0              |  | 290,850 |  |
| Interest and other                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          | 0              |  | 14,611 |  |
| Operating Partnerships Revenues                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             | 0              |  | 305,461 |  |
| **Expenses**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |           |  |   |  |
| Interest                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 0              |  | 68,211 |  |
| Depreciation and amortization                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               | 0              |  | 85,937 |  |
| Operating expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          | 0              |  | 201,884 |  |
| Operating Partnerships Total Expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | 0              |  | 356,032 |  |
| NET LOSS                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 0              |  | (50,571) |  |
| Net loss allocated to Boston Capital Tax Credit Fund Limited Partnership *                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 0              | [5] | (50,065) | [5] |
| Net loss allocated to other Partners                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | 0              |  | (506) |  |
| Series Five [Member]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |           |  |   |  |
| **Revenues**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |           |  |   |  |
| Rental                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | 0              |  | 229,267 |  |
| Interest and other                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          | 0              |  | 25,037 |  |
| Operating Partnerships Revenues                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             | 0              |  | 254,304 |  |
| **Expenses**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |           |  |   |  |
| Interest                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 0              |  | 103,474 |  |
| Depreciation and amortization                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               | 0              |  | 46,127 |  |
| Operating expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          | 0              |  | 198,856 |  |
| Operating Partnerships Total Expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | 0              |  | 348,457 |  |
| NET LOSS                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 0              |  | (94,153) |  |
| Net loss allocated to Boston Capital Tax Credit Fund Limited Partnership *                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 0              | [6] | (93,211) | [6] |
| Net loss allocated to other Partners                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | 0              |  | (942) |  |
| Series Six [Member]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |           |  |   |  |
| **Revenues**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |           |  |   |  |
| Rental                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | 0              |  | 0 |  |
| Interest and other                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          | 0              |  | 0 |  |
| Operating Partnerships Revenues                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             | 0              |  | 0 |  |
| **Expenses**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |           |  |   |  |
| Interest                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 0              |  | 0 |  |
| Depreciation and amortization                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               | 0              |  | 0 |  |
| Operating expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          | 0              |  | 0 |  |
| Operating Partnerships Total Expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | 0              |  | 0 |  |
| NET LOSS                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 0              |  | 0 |  |
| Net loss allocated to Boston Capital Tax Credit Fund Limited Partnership *                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 0              | [7] | 0 | [7] |
| Net loss allocated to other Partners                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | $ 0            |  | $ 0 |  |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| [1]Amounts include $110,510 and $515,577 for 2012 and 2011, respectively, of loss not recognized under the equity method of accounting.[2]Amounts include $0 and $69,227 for 2012 and 2011, respectively, of loss not recognized under the equity method of accounting.[3]Amounts include $0 and $167,592 for 2012 and 2011, respectively, of loss not recognized under the equity method of accounting.[4]Amounts include $110,510 and $135,482 for 2012 and 2011, respectively, of loss not recognized under the equity method of accounting.[5]Amounts include $0 and $50,065 for 2012 and 2011, respectively, of loss not recognized under the equity method of accounting.[6]Amounts include $0 and $93,211 for 2012 and 2011, respectively, of loss not recognized under the equity method of accounting.[7]Amounts include $0, for both 2012 and 2011, of loss not recognized under the equity method of accounting. |

| X                                                                                                                                                |
|--------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                                                                                                                                                                                                |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of depreciation and amortization by an operating partnerships of the entity.
+ References
No definition available.
+ Details**Name:**bctci_OperatingPartnershipsDepreciationAndAmortization**Namespace Prefix:**bctci_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                        |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of interest and other income by an operating partnerships of the entity.
+ References
No definition available.
+ Details**Name:**bctci_OperatingPartnershipsInterestAndOtherIncome**Namespace Prefix:**bctci_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                         |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of interest expenses by an operating partnerships of the entity.
+ References
No definition available.
+ Details**Name:**bctci_OperatingPartnershipsInterestExpenses**Namespace Prefix:**bctci_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of net loss by an operating partnerships of the entity.
+ References
No definition available.
+ Details**Name:**bctci_OperatingPartnershipsNetLoss**Namespace Prefix:**bctci_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                            |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of net loss allocated to other partners by an operating partnerships of the entity.
+ References
No definition available.
+ Details**Name:**bctci_OperatingPartnershipsNetLossAllocatedToOtherPartners**Namespace Prefix:**bctci_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                             |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of net loss allocated to parent by an operating partnerships of the entity.
+ References
No definition available.
+ Details**Name:**bctci_OperatingPartnershipsNetLossAllocatedToParent**Namespace Prefix:**bctci_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                           |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of operating expenses by an operating partnerships of the entity.
+ References
No definition available.
+ Details**Name:**bctci_OperatingPartnershipsOperatingExpenses**Namespace Prefix:**bctci_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                  |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of rental income by an operating partnerships of the entity.
+ References
No definition available.
+ Details**Name:**bctci_OperatingPartnershipsRentalIncome**Namespace Prefix:**bctci_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                         |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of revenues by an operating partnerships of the entity.
+ References
No definition available.
+ Details**Name:**bctci_OperatingPartnershipsRevenues**Namespace Prefix:**bctci_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of total expenses by an operating partnerships of the entity.
+ References
No definition available.
+ Details**Name:**bctci_OperatingPartnershipsTotalExpenses**Namespace Prefix:**bctci_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                    |
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