Subsequent Event Information Table on Public Housing Capital Fund Trusts (Details) (Public housing capital fund trusts [Member], USD $)	6 Months Ended
	Jun. 30, 2012
Schedule of Available-for-sale Securities [Line Items]
Available for Sale Securities, not Including Premiums	65,264,703
Public Housing Capital Fund Trust I [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt, Weighted Average Interest Rate	5.33%
Available for Sale Securities, not Including Premiums	26,406,558
Public Housing Capital Fund Trust II [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt, Weighted Average Interest Rate	4.24%
Available for Sale Securities, not Including Premiums	17,959,713
Public Housing Capital Fund Trust III [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt, Weighted Average Interest Rate	5.41%
Available for Sale Securities, not Including Premiums	20,898,432
Standard & Poor's, AA- Rating [Member] | Public Housing Capital Fund Trust I [Member]
Schedule of Available-for-sale Securities [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	12 years 9 months 0 days
Standard & Poor's, AA- Rating [Member] | Public Housing Capital Fund Trust II [Member]
Schedule of Available-for-sale Securities [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	12 years 3 months 18 days
Standard & Poor's, BBB Rating [Member] | Public Housing Capital Fund Trust III [Member]
Schedule of Available-for-sale Securities [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	13 years 3 months 18 days