Public Housing Capital Fund Trusts Information Table on Public Housing Capital Fund Trusts (Details) (Public housing capital fund trusts [Member], USD $)						9 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Sep. 30, 2012 Public Housing Capital Fund Trust I [Member]	Sep. 30, 2012 Public Housing Capital Fund Trust II [Member]	Sep. 30, 2012 Public Housing Capital Fund Trust III [Member]	Sep. 30, 2012 Standard & Poor's, AA- Rating [Member] Public Housing Capital Fund Trust I [Member]	Sep. 30, 2012 Standard & Poor's, AA- Rating [Member] Public Housing Capital Fund Trust II [Member]	Sep. 30, 2012 Standard & Poor's, BBB Rating [Member] Public Housing Capital Fund Trust III [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Lives (Years)						12 years 9 months 0 days	12 years 3 months 18 days	13 years 3 months 18 days
Investment Rating						AA-	AA-	BBB
Weighted Average Interest Rate over Life			5.33%	4.24%	5.41%
Principal Outstanding September 30, 2012	$ 65,264,703	$ 65,300,000	$ 26,406,558	$ 17,959,713	$ 20,898,432