Fair Value Measurements (Narratives) (Details) (USD $)	12 Months Ended								3 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Deferred acquisition fees payable	Dec. 31, 2013 Level 3 Nonrecurring	Dec. 31, 2012 Level 3 Nonrecurring	Dec. 31, 2011 Level 3 Nonrecurring	Mar. 31, 2012 CMBS	Mar. 31, 2012 CMBS Level 3 Nonrecurring	Dec. 31, 2013 Equity method investments
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Impairment charges	$ 0	$ 2,019,000	$ (70,000)		$ 3,778,000	$ 2,019,000	$ (70,000)		$ 2,000,000
CMBS portfolio carrying value								$ 0
Fair Value Inputs [Abstract]
Leverage adjusted unsecured spread				3.80%
Illiquidity Adjustment				0.75%
Cash Flows Discount Rate										6.00%
Fair Value Inputs, Discount Rate										6.25%
Fair Value Inputs, Cap Rate										5.75%