Segment Reporting Footnote Tagging (Details)	3 Months Ended	6 Months Ended						6 Months Ended		3 Months Ended
	Mar. 31, 2013 segments properties	Jun. 30, 2012 Integer	Mar. 31, 2013 Tax-exempt mortgage revenue bonds [Member] Unit	Mar. 31, 2013 MF Properties [Member] Unit	Mar. 31, 2013 Consolidated VIEs [Member] Unit Integer	Dec. 31, 2012 Public housing capital fund trusts [Member] Integer	Jun. 30, 2012 Public housing capital fund trusts [Member] Integer	Jun. 30, 2012 Unconsolidated Available for Sale Securities [Member] Integer	Jun. 30, 2012 Consolidated VIEs [Member] Integer	Mar. 31, 2013 Segment, Discontinued Operations [Member] Unconsolidated Available for Sale Securities [Member] Integer	Mar. 31, 2013 Consolidated Properties [Member] properties	Mar. 31, 2013 Consolidated Properties [Member] MF Properties [Member] entities
Segment Reporting Information [Line Items]
Number of Reportable Segments	5
Number of Available for Sale Securities		25						20	3	2
Number of Units in Real Estate Property			4,656	1,346	650
Number of Available for Sale Securities, Public Housing Authorities						3	3
Number of Real Estate Properties											7	7
Number of Variable Interest Entities	5				3