Loans and Other Lending Investments, net (Details) (USD $)	3 Months Ended			6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011	Jun. 30, 2012		Jun. 30, 2011	Dec. 31, 2011
Loans and other lending investments
Total gross carrying value of loans	$ 2,848,924,000	[1]		$ 2,848,924,000	[1]		$ 3,491,596,000	[1]
Reserve for loan losses	(563,786,000)		(701,228,000)	(563,786,000)		(701,228,000)
Total carrying value of loans	2,285,138,000			2,285,138,000			2,844,972,000
Other lending investments-securities	15,672,000			15,672,000			15,790,000
Total loans and other lending investments, net	2,300,810,000			2,300,810,000			2,860,762,000
Recorded investment in loans	2,859,344,000			2,859,344,000			3,504,861,000
Accrued interest	10,400,000			10,400,000			13,300,000
Fundings under existing loan commitments				23,877,000		39,772,000
Amount received from principal repayments				322,045,000		798,274,000
Carrying value of loans sold				53,900,000
Gross gain on sale realized				6,400,000
Charge-offs related to loans sold				3,300,000
Changes in the Company's reserve for loan losses
Reserve for loan losses at beginning of period	567,179,000		804,070,000	646,624,000		814,625,000
Provision for loan losses	26,531,000		10,350,000	44,031,000		21,230,000
Charge-offs	(29,924,000)		(113,192,000)	(126,869,000)		(134,627,000)
Reserve for loan losses at end of period	563,786,000		701,228,000	563,786,000		701,228,000
Non-performing Loans
Loans and other lending investments
Mortgage loans gross carrying value	229,000,000			229,000,000
Recorded charge-offs on mortgage loans				43,200,000
Senior mortgages
Loans and other lending investments
Total gross carrying value of loans	2,237,764,000	[1]		2,237,764,000	[1]		2,801,213,000	[1]
Recorded investment in loans	2,243,285,000			2,243,285,000
Subordinate mortgages
Loans and other lending investments
Total gross carrying value of loans	149,735,000	[1]		149,735,000	[1]		211,491,000	[1]
Recorded investment in loans	150,629,000			150,629,000
Corporate/Partnership loans
Loans and other lending investments
Total gross carrying value of loans	461,425,000	[1]		461,425,000	[1]		478,892,000	[1]
Recorded investment in loans	$ 465,430,000			$ 465,430,000

[1] The Company's recorded investment in loans as of June 30, 2012 and December 31, 2011 was $2.86 billion and $3.50 billion, respectively, which consists of total gross carrying value of loans plus accrued interest of $10.4 million and $13.3 million, for the same two periods, respectively.