Investments In Direct Financing Lease (Narrative) (Details) (USD $)	9 Months Ended		12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Capital Leases, Net Investment in Direct Financing Leases, Initial Direct Costs	$ 1,700,000		$ 1,800,000
Allowance for lease losses	0		0
Proceeds from Sale of Lease Receivables	$ 4,494,000	$ 0
Minimum [Member]
Direct financing expiration date (in years)	20
Maximum [Member]
Direct financing expiration date (in years)	23
Imagine Schools [Member]
Number of public charter school properties (in properties)	26