Consolidated Securitization Vehicles (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended						6 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 Securitization Vehicles		Dec. 31, 2011 Securitization Vehicles		Jun. 30, 2012 Securitization Vehicles CMBS	Dec. 31, 2011 Securitization Vehicles CMBS	Jun. 30, 2012 Securitization Vehicles CDOs & Other	Dec. 31, 2011 Securitization Vehicles CDOs & Other
Amortized cost basis					$ 179,116				$ 148,978		$ 30,138
Mark-to-market adjustments on securities previously classified as available-for-sale					11				11
Other-than-temporary impairments recognized in accumulated other comprehensive income			160	3,271	(12,497)				(12,497)
Securities held-to-maturity					$ 166,630	[1]	$ 358,972	[1]	$ 136,492	$ 357,037	$ 30,138	$ 1,935

[1] Includes securities with a total face value of $248.9 million and $490.9 million as of June 30, 2012 and December 31, 2011, respectively.