Real Estate Securities, Available for Sale (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Real estate securities
Fair Value	$ 55,289,000		$ 55,289,000		$ 29,582,000
Unrealized gains (losses) recorded in OCI	1,042,000	(222,000)	1,987,000	224,000
CMBS
Real estate securities
Number	8		8		4
Principal Amount	104,542,000		104,542,000		30,575,000
Amortized Cost	52,844,000		52,844,000		29,124,000
Cumulative Unrealized Gain on Investments	2,838,000		2,838,000		458,000
Cumulative Unrealized (Loss) on Investment	(393,000)		(393,000)
Fair Value	55,289,000		55,289,000		29,582,000
Weighted Average Coupon (as a percent)	4.53%		4.53%		5.39%
Weighted Average, Unleveraged Current Yield (as a percent)	9.11%		9.11%		5.71%
Carrying value of securities served as collateral for the company's financing transactions	17,800,000		17,800,000
Unrealized gains (losses) recorded in OCI	$ 1,000,000	$ (200,000)	$ 2,000,000	$ 200,000
Weighted average contractual maturities of the CRE securities			34 years
Weighted average expected maturity of CRE securities			8 years 1 month 6 days