Loans and Other Lending Investments, net (Details 6) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012 loans	Sep. 30, 2011 loans	Sep. 30, 2012 loans	Sep. 30, 2011 loans
Troubled debt restructurings
Unfunded commitments	$ 6,000,000		$ 6,000,000
Non-performing Loans
Troubled debt restructurings
Trouble debt restructuring time period	1 year
Recorded investment of loans whose maturity was extended	7,900,000
Senior mortgages
Troubled debt restructurings
Number of loans	2	3	7	7
Pre-modification recorded investment	54,192,000	65,107,000	318,227,000	191,158,000
Post-modification recorded investment	54,192,000	65,107,000	272,753,000	190,893,000
Senior mortgages troubled debt restructurings
Troubled debt restructurings
Number of loans	0	1	1	2
Outstanding recorded investment	0	12,257,000	24,604,000	40,262,000
Performing senior mortgages
Troubled debt restructurings
Trouble debt restructuring time period	3 months
Recorded investment of loans whose maturity was extended	46,300,000	49,300,000	62,600,000	129,200,000
Performing First Mortgage - Minimum [Member]
Troubled debt restructurings
Trouble debt restructuring time period		3 months	3 months	3 months
Performing First Mortgage With Rates Reduced [Member]
Troubled debt restructurings
Outstanding recorded investment				59,500,000
Financing Receivable Modifications Weighted Average Rate of Loans after Reduction				4.10%
Weighted average maturity rate of loans before reduction				6.20%
Non-performing senior mortgages
Troubled debt restructurings
Trouble debt restructuring time period				6 months
Recorded investment of loans whose maturity was extended			255,600,000	62,000,000
Financing Receivable Modifications Recorded Investment of Contracts Whose Maturity Extended and Reduced Principal				1.0
Non-Performing First Mortgage with Recorded Chargeoffs and Rate Reductions [Member]
Troubled debt restructurings
Financing Receivable Modification Chargeoffs			45,500,000
Recorded investment of loans whose maturity was extended				46,100,000
Financing Receivable Modifications Recorded Investment of Contracts Whose Maturity Extended and Reduced Principal			$ 181,500,000
Variable rate basis of loans			LIBOR
Basis spread on variable rate of loans after reduction	3.50%		3.50%
Basis spread on variable rate of loans before reduction	7.00%		7.00%
Non-Performing First Mortgage with Recorded Chargeoffs and Rate Reductions - Minimum [Member]
Troubled debt restructurings
Trouble debt restructuring time period			1 month
Non-Performing First Mortgage with Recorded Chargeoffs and Rate Reductions - Maximum [Member]
Troubled debt restructurings
Trouble debt restructuring time period			7 months
Minimum [Member]
Troubled debt restructurings
Trouble debt restructuring time period	6 months		1 year	5 years