Direct Financing Lease Receivables (Details 1) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Financing Receivable, Recorded Investment [Line Items]
Credit risk profile by creditworthiness category of direct financing lease receivables, Total	$ 429,371	$ 379,952
Very low risk to low risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit risk profile by creditworthiness category of direct financing lease receivables, Total	184,214	121,836
Moderate risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit risk profile by creditworthiness category of direct financing lease receivables, Total	185,102	190,070
Moderately high to High risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit risk profile by creditworthiness category of direct financing lease receivables, Total	$ 60,055	$ 68,046