Loans and Other Lending Investments, net (Details 4) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012		Dec. 31, 2011
Recorded investment in loans, aged by payment status and presented by class
Current	$ 1,828,846
Less Than and Equal to 90 Days	124,371	[1]
Greater Than 90 Days	906,127	[1]
Total Past Due	1,030,498
Total	2,859,344		3,504,861
Senior mortgages
Recorded investment in loans, aged by payment status and presented by class
Current	1,276,006
Less Than and Equal to 90 Days	124,371	[1]
Greater Than 90 Days	842,908	[1]
Total Past Due	967,279
Total	2,243,285
Subordinate mortgages
Recorded investment in loans, aged by payment status and presented by class
Current	97,520
Less Than and Equal to 90 Days	0	[1]
Greater Than 90 Days	53,109	[1]
Total Past Due	53,109
Total	150,629
Corporate/Partnership loans
Recorded investment in loans, aged by payment status and presented by class
Current	455,320
Less Than and Equal to 90 Days	0	[1]
Greater Than 90 Days	10,110	[1]
Total Past Due	10,110
Total	$ 465,430

[1] As of June 30, 2012, all loans that are not current are classified as non-performing and are on non-accrual status.