6. Investment in Local Partnerships: Combined Statements of Operations of the Local Partnerships (Details) (Combined Statements of Operations, USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Combined Statements of Operations
Rental	$ 4,551,556	$ 4,834,032	$ 4,790,746
Interest and other	280,671	303,156	263,948
TOTAL REVENUE	4,832,227	5,137,188	5,054,694
Administrative	1,260,668	1,088,411	1,110,818
Utilities	752,113	778,210	732,869
Operating and maintenance	1,267,607	1,186,236	1,147,203
Taxes and Insurance	409,213	442,146	454,494
Financial	759,462	810,269	810,922
Depreciation and amortization	953,628	1,078,681	1,089,127
TOTAL EXPENSES	5,402,691	5,383,953	5,345,433
LOSS BEFORE LOSS ON SALE OF PROPERTY	(570,464)	(246,765)	(290,739)
LOSS ON SALE OF PROPERTY	(232,801)
NET LOSS	(803,265)	(246,765)	(290,739)
Net Income (Loss) Attributable To American Tax Credit Trust, Series I	176,491	84,853	231,447
Net Income (Loss) Attributable To General Partners and other limited partners (includes $1,016,695, $619,937 and $640,634 of Trust losses in excess of investment and specially allocated income of $44,987, $290,801 and $121,375)	$ (979,756)	$ (331,618)	$ (522,186)