| **INVESTMENTS IN OPERATING PARTNERSHIPS (Details 1) (USD $)**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           | 3 Months Ended |
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| **Revenues**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |           |  |   |  |
| Rental                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | $ 351,073      |  | $ 1,057,752 |  |
| Interest and other                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | 12,509         |  | 80,421 |  |
| Operating Partnerships Revenues                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 363,582        |  | 1,138,173 |  |
| **Expenses**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |           |  |   |  |
| Interest                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 30,167         |  | 254,226 |  |
| Depreciation and amortization                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           | 78,181         |  | 257,357 |  |
| Operating expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | 308,931        |  | 944,727 |  |
| Operating Partnerships Total Expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | 417,279        |  | 1,456,310 |  |
| NET LOSS                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | (53,697)       |  | (318,137) |  |
| Net loss allocated to Boston Capital Tax Credit Fund Limited Partnership *                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              | (53,160)       | [1] | (314,956) | [1] |
| Net loss allocated to other Partners                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | (537)          |  | (3,181) |  |
| Series One [Member]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |           |  |   |  |
| **Revenues**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |           |  |   |  |
| Rental                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 0              |  | 186,264 |  |
| Interest and other                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | 0              |  | 6,291 |  |
| Operating Partnerships Revenues                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 0              |  | 192,555 |  |
| **Expenses**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |           |  |   |  |
| Interest                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 0              |  | 24,661 |  |
| Depreciation and amortization                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           | 0              |  | 50,886 |  |
| Operating expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | 0              |  | 169,423 |  |
| Operating Partnerships Total Expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | 0              |  | 244,970 |  |
| NET LOSS                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 0              |  | (52,415) |  |
| Net loss allocated to Boston Capital Tax Credit Fund Limited Partnership *                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              | 0              | [2] | (51,891) | [2] |
| Net loss allocated to other Partners                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 0              |  | (524) |  |
| Series Two [Member]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |           |  |   |  |
| **Revenues**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |           |  |   |  |
| Rental                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 0              |  | 201,823 |  |
| Interest and other                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | 0              |  | 37,467 |  |
| Operating Partnerships Revenues                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 0              |  | 239,290 |  |
| **Expenses**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |           |  |   |  |
| Interest                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 0              |  | 93,022 |  |
| Depreciation and amortization                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           | 0              |  | 41,468 |  |
| Operating expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | 0              |  | 186,138 |  |
| Operating Partnerships Total Expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | 0              |  | 320,628 |  |
| NET LOSS                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 0              |  | (81,338) |  |
| Net loss allocated to Boston Capital Tax Credit Fund Limited Partnership *                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              | 0              | [3] | (80,525) | [3] |
| Net loss allocated to other Partners                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 0              |  | (813) |  |
| Series Three [Member]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |           |  |   |  |
| **Revenues**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |           |  |   |  |
| Rental                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 351,073        |  | 415,010 |  |
| Interest and other                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | 12,509         |  | 9,031 |  |
| Operating Partnerships Revenues                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 363,582        |  | 424,041 |  |
| **Expenses**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |           |  |   |  |
| Interest                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 30,167         |  | 50,590 |  |
| Depreciation and amortization                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           | 78,181         |  | 98,971 |  |
| Operating expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | 308,931        |  | 373,940 |  |
| Operating Partnerships Total Expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | 417,279        |  | 523,501 |  |
| NET LOSS                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | (53,697)       |  | (99,460) |  |
| Net loss allocated to Boston Capital Tax Credit Fund Limited Partnership *                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              | (53,160)       | [4] | (98,465) | [4] |
| Net loss allocated to other Partners                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | (537)          |  | (995) |  |
| Series Four [Member]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |           |  |   |  |
| **Revenues**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |           |  |   |  |
| Rental                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 0              |  | 142,405 |  |
| Interest and other                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | 0              |  | 6,794 |  |
| Operating Partnerships Revenues                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 0              |  | 149,199 |  |
| **Expenses**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |           |  |   |  |
| Interest                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 0              |  | 34,216 |  |
| Depreciation and amortization                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           | 0              |  | 42,968 |  |
| Operating expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | 0              |  | 111,700 |  |
| Operating Partnerships Total Expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | 0              |  | 188,884 |  |
| NET LOSS                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 0              |  | (39,685) |  |
| Net loss allocated to Boston Capital Tax Credit Fund Limited Partnership *                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              | 0              | [5] | (39,288) | [5] |
| Net loss allocated to other Partners                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 0              |  | (397) |  |
| Series Five [Member]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |           |  |   |  |
| **Revenues**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |           |  |   |  |
| Rental                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 0              |  | 112,250 |  |
| Interest and other                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | 0              |  | 20,838 |  |
| Operating Partnerships Revenues                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 0              |  | 133,088 |  |
| **Expenses**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |           |  |   |  |
| Interest                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 0              |  | 51,737 |  |
| Depreciation and amortization                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           | 0              |  | 23,064 |  |
| Operating expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | 0              |  | 103,526 |  |
| Operating Partnerships Total Expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | 0              |  | 178,327 |  |
| NET LOSS                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 0              |  | (45,239) |  |
| Net loss allocated to Boston Capital Tax Credit Fund Limited Partnership *                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              | 0              | [6] | (44,787) | [6] |
| Net loss allocated to other Partners                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 0              |  | (452) |  |
| 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 $53,160 and $314,956 for 2012 and 2011, respectively, of loss not recognized under the equity method of accounting.[2]Amounts include $0 and $51,891 for 2012 and 2011, respectively, of loss not recognized under the equity method of accounting.[3]Amounts include $0 and $80,525 for 2012 and 2011, respectively, of loss not recognized under the equity method of accounting.[4]Amounts include $53,160 and $98,465 for 2012 and 2011, respectively, of loss not recognized under the equity method of accounting.[5]Amounts include $0 and $39,288 for 2012 and 2011, respectively, of loss not recognized under the equity method of accounting.[6]Amounts include $0 and $44,787 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 |
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