Investments in Partnerships - Assets Held for Sale or Transfer and Completed Sales (Details) (USD $)	12 Months Ended							0 Months Ended	12 Months Ended					0 Months Ended	12 Months Ended			3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Local Partnerships [Member]	Dec. 31, 2011 Local Partnerships [Member]	Dec. 31, 2010 Local Partnerships [Member]	Dec. 31, 2012 Westport Village [Member]	Dec. 31, 2011 Westport Village [Member]	Dec. 20, 2012 Fairway Park [Member]	Dec. 31, 2012 Fairway Park [Member]	Dec. 31, 2011 Fairway Park [Member]	Dec. 31, 2011 Mary Allen West Tower [Member]	Dec. 31, 2012 Madison Square [Member]	Dec. 31, 2011 Madison Square [Member]	Mar. 15, 2010 Hale Ohana [Member]	Dec. 31, 2012 Hale Ohana [Member]	Dec. 31, 2010 Hale Ohana [Member]	Dec. 31, 2012 CRI, Inc [Member] Fairway Park [Member]	Mar. 31, 2012 CRI, Inc [Member] Mary Allen West Tower [Member]
Schedule of Equity Method Investments [Line Items]
Investment in partnerships held for sale or transfer	$ 0	$ 4,767,709	$ 0	$ 4,767,709	$ 2,348,551	$ 0	$ 0
Property sale price								8,710,000						3,875,000
Sale proceeds								8,710,000
Basis in Partnership									0	0	4,767,709	0	0
Acquisition fees and property purchase costs									8,294	4,130		0	0
Gain on disposition of investment									8,282,016							1,603,594
Distributions received from Local Partnerships	774,234	415,550	0	0											50,916
Fee for services provided in connection with sale																	$ 415,560	$ 70,000