| **INVESTMENTS IN OPERATING PARTNERSHIPS (Details 1) (USD $)** | 6 Months Ended |
|---------------------------------------------------------------|----------------|
||
| Operating Partnership Interest Transferred                    | 3              |
| Sale of Underlying Operating Partnership                      | 0              |
| Partnership Proceeds from Disposition                         | $ 0            |
| Gain/(Loss) on Disposition                                    | 0              |
| Series One [Member]                                           |           |
| Operating Partnership Interest Transferred                    | 0              |
| Sale of Underlying Operating Partnership                      | 0              |
| Partnership Proceeds from Disposition                         | 0              |
| Gain/(Loss) on Disposition                                    | 0              |
| Series Two [Member]                                           |           |
| Operating Partnership Interest Transferred                    | 0              |
| Sale of Underlying Operating Partnership                      | 0              |
| Partnership Proceeds from Disposition                         | 0              |
| Gain/(Loss) on Disposition                                    | 0              |
| Series Three [Member]                                         |           |
| Operating Partnership Interest Transferred                    | 3              |
| Sale of Underlying Operating Partnership                      | 0              |
| Partnership Proceeds from Disposition                         | 0              |
| Gain/(Loss) on Disposition                                    | 0              |
| Series Four [Member]                                          |           |
| Operating Partnership Interest Transferred                    | 0              |
| Sale of Underlying Operating Partnership                      | 0              |
| Partnership Proceeds from Disposition                         | 0              |
| Gain/(Loss) on Disposition                                    | 0              |
| Series Five [Member]                                          |           |
| Operating Partnership Interest Transferred                    | 0              |
| Sale of Underlying Operating Partnership                      | 0              |
| Partnership Proceeds from Disposition                         | 0              |
| Gain/(Loss) on Disposition                                    | 0              |
| Series Six [Member]                                           |           |
| Operating Partnership Interest Transferred                    | 0              |
| Sale of Underlying Operating Partnership                      | 0              |
| Partnership Proceeds from Disposition                         | 0              |
| Gain/(Loss) on Disposition                                    | $ 0            |

| X                                                                                                                                                                                                                                                                                   |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The number of operating partnership interest transferred.
+ References
No definition available.
+ Details**Name:**bctc_OperatingPartnershipInterestTransferred**Namespace Prefix:**bctc_**Data Type:**xbrli:integerItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                              |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The number of sale of underlying operating partnership.
+ References
No definition available.
+ Details**Name:**bctc_SaleOfUnderlyingOperatingPartnership**Namespace Prefix:**bctc_**Data Type:**xbrli:integerItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 9 -Article 5Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=16385135&loc=d3e33749-111570Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.12) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 11 -Article 7
+ Details**Name:**us-gaap_IncomeLossFromEquityMethodInvestments**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash inflow associated with the sale of equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Investing Activities -URI http://asc.fasb.org/extlink&oid=6516133Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3179-108585
+ Details**Name:**us-gaap_ProceedsFromSaleOfEquityMethodInvestments**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |