Organization	12 Months Ended
Mar. 31, 2013
Accounting Policies [Abstract]
Business Description and Basis of Presentation [Text Block]	1. Organization Boston Financial Tax Credit Fund VIII, A Limited Partnership (the "Fund") is a Massachusetts limited partnership organized to invest in other limited partnerships or limited liability companies (collectively, "Local Limited Partnerships") which own and operate apartment complexes (each, a “Property”) which are eligible for low income housing tax credits (“Tax Credits”) that may be applied against the federal income tax liability of an investor. The Fund’s objectives are to: (i) provide investors with annual Tax Credits which they may use to reduce their federal income tax liability; (ii) preserve and protect the Fund’s capital; (iii) provide cash distributions from the operations of Local Limited Partnerships; and(iv) providecash distributions from sale or refinancing transactions. Arch Street VIII Limited Partnership ("Arch Street L.P."), a Massachusetts limited partnership consisting of Arch Street VIII, Inc., a Massachusetts corporation ("Arch Street, Inc.") as the sole general partner, ALZA Corporation as Class A limited partner (90%) and Boston Financial BFG Investments, LLC, as Class B limited partner (9%), is the sole General Partner of the Fund. Arch Street L.P. and Arch Street, Inc. are affiliates of Boston Financial Investment Management, LP (“Boston Financial”). The fiscal year of the Fund ends on March 31. The Partnership Agreement authorizes the sale of up to 200,000 units of limited partnership interest ("Units") at $1,000 per Unit in series. The first series offered 50,000 Units. On August 31, 1994, the Fund held its final investor closing. In total, the Fund received $36,497,000 of capital contributions from investors admitted as Limited Partners, for a total of 36,497 Units. The General Partner initially designated 5% of the Gross Proceeds as Reserves, as defined in the Partnership Agreement. The Reserves were established to be used for working capital of the Fund and contingencies related to the ownership of Local Limited Partnership interests. The General Partner may increase or decrease such Reserves, from time to time, as it deems appropriate. At March 31, 2013 and 2012, approximately $604,000 and $37,000 respectively, has been designated as Reserves. Generally, profits, losses, tax credits and cash flows from operations are allocated 99% to the Limited Partners and 1% to the General Partner. Net proceeds from a sale of the Fund’s interest in a Local Limited Partnership or refinancing of a Local Limited Partnership’s debt will be allocated 95% to the Limited Partners and 5% to the General Partner, after certain priority payments. The General Partner may have an obligation to fund deficits in its capital accounts, subject to limits set forth in the Partnership Agreement. However, to the extent that the General Partner’s capital accounts are in a deficit position, certain items of net income may be allocated to the General Partner in accordance with the Partnership Agreement.

Organization

12 Months Ended

Mar. 31, 2013

Business Description and Basis of Presentation [Text Block]

1. Organization

Boston Financial Tax Credit Fund VIII, A Limited Partnership (the "Fund") is a Massachusetts limited partnership organized to invest in other limited partnerships or limited liability companies (collectively, "Local Limited Partnerships") which own and operate apartment complexes (each, a “Property”) which are eligible for low income housing tax credits (“Tax Credits”) that may be applied against the federal income tax liability of an investor. The Fund’s objectives are to: (i) provide investors with annual Tax Credits which they may use to reduce their federal income tax liability; (ii) preserve and protect the Fund’s capital; (iii) provide cash distributions from the operations of Local Limited Partnerships; and(iv) providecash distributions from sale or refinancing transactions. Arch Street VIII Limited Partnership ("Arch Street L.P."), a Massachusetts limited partnership consisting of Arch Street VIII, Inc., a Massachusetts corporation ("Arch Street, Inc.") as the sole general partner, ALZA Corporation as Class A limited partner (90%) and Boston Financial BFG Investments, LLC, as Class B limited partner (9%), is the sole General Partner of the Fund. Arch Street L.P. and Arch Street, Inc. are affiliates of Boston Financial Investment Management, LP (“Boston Financial”). The fiscal year of the Fund ends on March 31.

The Partnership Agreement authorizes the sale of up to 200,000 units of limited partnership interest ("Units") at $1,000 per Unit in series. The first series offered 50,000 Units. On August 31, 1994, the Fund held its final investor closing. In total, the Fund received $36,497,000 of capital contributions from investors admitted as Limited Partners, for a total of 36,497 Units.

The General Partner initially designated 5% of the Gross Proceeds as Reserves, as defined in the Partnership Agreement. The Reserves were established to be used for working capital of the Fund and contingencies related to the ownership of Local Limited Partnership interests. The General Partner may increase or decrease such Reserves, from time to time, as it deems appropriate. At March 31, 2013 and 2012, approximately $604,000 and $37,000 respectively, has been designated as Reserves.

Generally, profits, losses, tax credits and cash flows from operations are allocated 99% to the Limited Partners and 1% to the General Partner. Net proceeds from a sale of the Fund’s interest in a Local Limited Partnership or refinancing of a Local Limited Partnership’s debt will be allocated 95% to the Limited Partners and 5% to the General Partner, after certain priority payments. The General Partner may have an obligation to fund deficits in its capital accounts, subject to limits set forth in the Partnership Agreement. However, to the extent that the General Partner’s capital accounts are in a deficit position, certain items of net income may be allocated to the General Partner in accordance with the Partnership Agreement.