| **INVESTMENTS IN OPERATING PARTNERSHIPS (Tables)**                                          | 3 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|---------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
||
| **Equity Method Investments and Joint Ventures [Abstract]**                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| Schedule Of Number Of Operating Partnerships [Table Text Block]                             | At June 30, 2013 and  2012, the Partnership had limited partnership interests in 6 and 7  Operating Partnerships, respectively, which own operating apartment  complexes as follows: Series 2013 2012 1  -  - 2  -  - 3  6  7 4  -  - 5  -  - 6  -  -    6  7                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| Schedule Of Summarized Statement Of Operations In Operating Partnerships [Table Text Block] | The combined condensed  unaudited summarized statements of operations of the Operating  Partnerships for the three months ended March 31, 2013 and 2012 are  as follows:        2013 2012         Revenues       Rental $297,259 $351,073 Interest and other  5,792  12,509            303,051  363,582         Expenses       Interest  29,616  30,167 Depreciation and amortization  70,083  78,181 Operating expenses  249,614  308,931            349,313  417,279         NET LOSS $(46,262) $(53,697)         Net loss allocated to Boston Capital Tax Credit Fund Limited  Partnership * $(45,799) $(53,160)         Net loss allocated to other Partners $(463) $(537)  * Amounts include  $45,799 and $53,160 for 2013 and 2012, respectively,  of loss not recognized under the equity method of  accounting.   The Partnership  accounts for its investments using the equity method of accounting.  Under the equity method of accounting, the Partnership adjusts its  investment cost for its share of each Operating Partnership's  results of operations and for any distributions received or  accrued. However, the Partnership recognizes individual operating  losses only to the extent of capital contributions. Excess losses  are suspended for use in future years to offset excess  income.    Series  1     2013 2012         Revenues       Rental $- $- Interest and other  -  -            -  -         Expenses       Interest  -  - Depreciation and amortization  -  - Operating expenses  -  -            -  -         NET LOSS $- $-         Net loss allocated to Boston Capital Tax Credit Fund Limited  Partnership * $- $-         Net loss allocated to other Partners $- $-  * Amounts include  $0, for both 2013 and 2012, of loss  not recognized under the equity method of  accounting.   The Partnership  accounts for its investments using the equity method of accounting.  Under the equity method of accounting, the Partnership adjusts its  investment cost for its share of each Operating Partnership's  results of operations and for any distributions received or  accrued. However, the Partnership recognizes individual operating  losses only to the extent of capital contributions. Excess losses  are suspended for use in future years to offset excess  income.    Series  2     2013 2012         Revenues       Rental $- $- Interest and other  -  -            -  -         Expenses       Interest  -  - Depreciation and amortization  -  - Operating expenses  -  -            -  -         NET LOSS $- $-         Net loss allocated to Boston Capital Tax Credit Fund Limited  Partnership * $- $-         Net loss allocated to other Partners $- $-    * Amounts include  $0, for both 2013 and 2012, of loss  not recognized under the equity method of  accounting.   The Partnership  accounts for its investments using the equity method of accounting.  Under the equity method of accounting, the Partnership adjusts its  investment cost for its share of each Operating Partnership's  results of operations and for any distributions received or  accrued. However, the Partnership recognizes individual operating  losses only to the extent of capital contributions. Excess losses  are suspended for use in future years to offset excess  income.      Series  3   2013 2012         Revenues       Rental $297,259 $351,073 Interest and other  5,792  12,509            303,051  363,582         Expenses       Interest  29,616  30,167 Depreciation and amortization  70,083  78,181 Operating expenses  249,614  308,931            349,313  417,279         NET LOSS $(46,262) $(53,697)         Net loss allocated to Boston Capital Tax Credit Fund Limited  Partnership * $(45,799) $(53,160)         Net loss allocated to other partners $(463) $(537)    * Amounts include  $45,799 and $53,160 for 2013 and 2012, respectively,  of loss not recognized under the equity method of  accounting.   The Partnership  accounts for its investments using the equity method of accounting.  Under the equity method of accounting, the Partnership adjusts its  investment cost for its share of each Operating Partnership's  results of operations and for any distributions received or  accrued. However, the Partnership recognizes individual operating  losses only to the extent of capital contributions. Excess losses  are suspended for use in future years to offset excess  income.     Series  4   2013 2012         Revenues       Rental $- $- Interest and other  -  -            -  -         Expenses       Interest  -  - Depreciation and amortization  -  - Operating expenses  -  -            -  -         NET LOSS $- $-         Net loss allocated to Boston Capital Tax Credit Fund Limited  Partnership * $- $-         Net loss allocated to other Partners $- $-    * Amounts include  $0, for both 2013 and 2012, of loss  not recognized under the equity method of  accounting.   The Partnership  accounts for its investments using the equity method of accounting.  Under the equity method of accounting, the Partnership adjusts its  investment cost for its share of each Operating Partnership's  results of operations and for any distributions received or  accrued. However, the Partnership recognizes individual operating  losses only to the extent of capital contributions. Excess losses  are suspended for use in future years to offset excess  income.       Series  5   2013 2012         Revenues       Rental $- $- Interest and other  -  -            -  -         Expenses       Interest  -  - Depreciation and amortization  -  - Operating expenses  -  -            -  -         NET LOSS $- $-         Net loss allocated to Boston Capital Tax Credit Fund Limited  Partnership * $- $-         Net loss allocated to other Partners $- $-    * Amounts include  $0, for both 2013 and 2012, of loss  not recognized under the equity method of  accounting.   The Partnership  accounts for its investments using the equity method of accounting.  Under the equity method of accounting, the Partnership adjusts its  investment cost for its share of each Operating Partnership's  results of operations and for any distributions received or  accrued. However, the Partnership recognizes individual operating  losses only to the extent of capital contributions. Excess losses  are suspended for use in future years to offset excess  income.       Series  6   2013 2012         Revenues       Rental $- $- Interest and other  -  -            -  -         Expenses       Interest  -  - Depreciation and amortization  -  - Operating expenses  -  -            -  -         NET LOSS $- $-         Net loss allocated to Boston Capital Tax Credit Fund Limited  Partnership * $- $-         Net loss allocated to other Partners $- $-    *Amounts include  $0, for both 2013 and 2012, of loss  not recognized under the equity method of  accounting. |

| X                                                                                                                                                                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Tabular disclosure for number of operating partnerships.
+ References
No definition available.
+ Details**Name:**bctc_ScheduleOfNumberOfOperatingPartnershipsTableTextBlock**Namespace Prefix:**bctc_**Data Type:**nonnum:textBlockItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                        |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Tabular disclosure for summarized statement of operations in operating partnerships.
+ References
No definition available.
+ Details**Name:**bctc_ScheduleOfSummarizedStatementOfOperationsInOperatingPartnershipsTableTextBlock**Namespace Prefix:**bctc_**Data Type:**nonnum:textBlockItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                   |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_EquityMethodInvestmentsAndJointVenturesAbstract**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |