Public Housing Capital Fund Trusts Narrative Tagging (Details) (USD $)							3 Months Ended		3 Months Ended																					12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011	Dec. 31, 2012 Public housing capital fund trusts [Member] Integer	Sep. 30, 2012 Public housing capital fund trusts [Member] Integer	Jun. 30, 2012 Public housing capital fund trusts [Member]	Dec. 31, 2012 Trust Portfolio--MBS Bonds [Member]	Sep. 30, 2012 Trust Portfolio--MBS Bonds [Member]	Sep. 30, 2012 LIFERS [Member]	Sep. 30, 2012 LIFERS [Member] Public housing capital fund trusts [Member]	Jun. 30, 2012 LIFERS [Member] Public housing capital fund trusts [Member]	Dec. 31, 2012 LIFERS [Member] Trust Portfolio--MBS Bonds [Member]	Sep. 30, 2012 SPEARS [Member] Public housing capital fund trusts [Member]	Jun. 30, 2012 SPEARS [Member] Public housing capital fund trusts [Member]	Dec. 31, 2012 SPEARS [Member] Trust Portfolio--MBS Bonds [Member]	Dec. 31, 2012 Effective rate - minimum [Member]	Dec. 31, 2012 Effective rate - minimum [Member] Public housing capital fund trusts [Member]	Dec. 31, 2012 Effective rate - minimum [Member] Trust Portfolio--MBS Bonds [Member]	Dec. 31, 2012 Effective rate - maximum [Member]	Dec. 31, 2012 Effective rate - maximum [Member] Public housing capital fund trusts [Member]	Dec. 31, 2012 Effective rate - maximum [Member] Trust Portfolio--MBS Bonds [Member]	Sep. 30, 2012 10% adverse [Member] Public housing capital fund trusts [Member]	Sep. 30, 2012 10% adverse [Member] Trust Portfolio--MBS Bonds [Member]	Dec. 31, 2012 10% adverse [Member] Effective rate - minimum [Member]	Dec. 31, 2012 10% adverse [Member] Effective rate - minimum [Member] Public housing capital fund trusts [Member]	Dec. 31, 2012 10% adverse [Member] Effective rate - minimum [Member] Trust Portfolio--MBS Bonds [Member]	Dec. 31, 2012 10% adverse [Member] Effective rate - maximum [Member]	Dec. 31, 2012 10% adverse [Member] Effective rate - maximum [Member] Public housing capital fund trusts [Member]	Dec. 31, 2012 10% adverse [Member] Effective rate - maximum [Member] Trust Portfolio--MBS Bonds [Member]	Dec. 31, 2012 Minimum [Member] Public housing capital fund trusts [Member]
Schedule of Available-for-sale Securities [Line Items]
TOB Financing			$ 17,700,000							$ 16,000,000	$ 16,000,000	$ 6,500,000	$ 49,000,000	$ 49,000,000	$ 25,100,000
Number of Available for Sale Securities, Public Housing Authorities				3	3
Available for Sale Securities, not Including Premiums					65,264,703	65,300,000	31,620,000
Available-for-Sale Securities, Ownership Percentage							100.00%		100.00%
Debt Instrument, Unamortized Premium						653,000	316,000
Effective rate																5.70%	4.60%	3.60%	8.40%	5.90%	5.40%			6.20%	5.10%	4.00%	9.30%	6.50%	5.90%
Adverse change rate	10.00%				10.00%		10.00%
Available-for-sale Securities, Gross Unrealized Losses		$ 4,289,886	$ 5,000,093					$ (413,665)														$ 2,900,000	$ 2,400,000
Unrealized Loss Position for Available-for-sale Securities																														12 months