Loans and Other Lending Investments, net (Details 5) (USD $)	3 Months Ended			6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011	Jun. 30, 2012		Jun. 30, 2011	Dec. 31, 2011
Investment in impaired loans
Recorded Investment	$ 1,335,766,000	[1]		$ 1,335,766,000	[1]		$ 1,583,631,000	[1]
Unpaid Principal Balance	1,330,924,000	[1]		1,330,924,000	[1]		1,577,370,000	[1]
Related Allowance	(506,986,000)	[1]		(506,986,000)	[1]		(573,124,000)	[1]
Loans modified through troubled debt restructurings	205,500,000			205,500,000			255,300,000
Average Recorded Investment	1,359,375,000		2,125,468,000	1,434,127,000		2,188,126,000
Interest Income Recognized	3,069,000		31,023,000	4,796,000		34,196,000
Senior mortgages
Investment in impaired loans
Recorded Investment	1,211,963,000	[1]		1,211,963,000	[1]		1,488,450,000	[1]
Unpaid Principal Balance	1,207,079,000	[1]		1,207,079,000	[1]		1,481,807,000	[1]
Related Allowance	(470,617,000)	[1]		(470,617,000)	[1]		(540,670,000)	[1]
Average Recorded Investment	1,221,650,000		2,020,471,000	1,310,583,000		2,093,270,000
Interest Income Recognized	2,993,000		30,737,000	4,640,000		33,707,000
Subordinate mortgages
Investment in impaired loans
Recorded Investment	53,109,000	[1]		53,109,000	[1]		22,480,000	[1]
Unpaid Principal Balance	52,881,000	[1]		52,881,000	[1]		22,558,000	[1]
Related Allowance	(27,309,000)	[1]		(27,309,000)	[1]		(22,480,000)	[1]
Average Recorded Investment	65,659,000		25,624,000	51,266,000		17,083,000
Interest Income Recognized	0		0	0		0
Corporate/Partnership loans
Investment in impaired loans
Recorded Investment	70,694,000	[1]		70,694,000	[1]		72,701,000	[1]
Unpaid Principal Balance	70,964,000	[1]		70,964,000	[1]		73,005,000	[1]
Related Allowance	(9,060,000)	[1]		(9,060,000)	[1]		(9,974,000)	[1]
Average Recorded Investment	72,066,000		79,373,000	72,278,000		77,773,000
Interest Income Recognized	76,000		286,000	156,000		489,000
With no related allowance recorded
Investment in impaired loans
Recorded Investment	164,066,000	[1]		164,066,000	[1]		229,598,000	[1]
Unpaid Principal Balance	163,725,000	[1]		163,725,000	[1]		228,772,000	[1]
Related Allowance	0	[1]		0	[1]		0	[1]
Average Recorded Investment	190,147,000		362,208,000	203,297,000		379,796,000
Interest Income Recognized	1,799,000		28,820,000	2,206,000		29,906,000
With no related allowance recorded | Senior mortgages
Investment in impaired loans
Recorded Investment	153,956,000	[1]		153,956,000	[1]		219,488,000	[1]
Unpaid Principal Balance	153,565,000	[1]		153,565,000	[1]		218,612,000	[1]
Related Allowance	0	[1]		0	[1]		0	[1]
Average Recorded Investment	180,037,000		352,098,000	193,187,000		369,686,000
Interest Income Recognized	1,799,000		28,620,000	2,206,000		29,586,000
With no related allowance recorded | Corporate/Partnership loans
Investment in impaired loans
Recorded Investment	10,110,000	[1]		10,110,000	[1]		10,110,000	[1]
Unpaid Principal Balance	10,160,000	[1]		10,160,000	[1]		10,160,000	[1]
Related Allowance	0	[1]		0	[1]		0	[1]
Average Recorded Investment	10,110,000		10,110,000	10,110,000		10,110,000
Interest Income Recognized	0		200,000	0		320,000
With an allowance recorded
Investment in impaired loans
Recorded Investment	1,171,700,000	[1]		1,171,700,000	[1]		1,354,033,000	[1]
Unpaid Principal Balance	1,167,199,000	[1]		1,167,199,000	[1]		1,348,598,000	[1]
Related Allowance	(506,986,000)	[1]		(506,986,000)	[1]		(573,124,000)	[1]
Average Recorded Investment	1,169,228,000		1,763,260,000	1,230,830,000		1,808,330,000
Interest Income Recognized	1,270,000		2,203,000	2,590,000		4,290,000
With an allowance recorded | Senior mortgages
Investment in impaired loans
Recorded Investment	1,058,007,000	[1]		1,058,007,000	[1]		1,268,962,000	[1]
Unpaid Principal Balance	1,053,514,000	[1]		1,053,514,000	[1]		1,263,195,000	[1]
Related Allowance	(470,617,000)	[1]		(470,617,000)	[1]		(540,670,000)	[1]
Average Recorded Investment	1,041,613,000		1,668,373,000	1,117,396,000		1,723,584,000
Interest Income Recognized	1,194,000		2,117,000	2,434,000		4,121,000
With an allowance recorded | Subordinate mortgages
Investment in impaired loans
Recorded Investment	53,109,000	[1]		53,109,000	[1]		22,480,000	[1]
Unpaid Principal Balance	52,881,000	[1]		52,881,000	[1]		22,558,000	[1]
Related Allowance	(27,309,000)	[1]		(27,309,000)	[1]		(22,480,000)	[1]
Average Recorded Investment	65,659,000		25,624,000	51,266,000		17,083,000
Interest Income Recognized	0		0	0		0
With an allowance recorded | Corporate/Partnership loans
Investment in impaired loans
Recorded Investment	60,584,000	[1]		60,584,000	[1]		62,591,000	[1]
Unpaid Principal Balance	60,804,000	[1]		60,804,000	[1]		62,845,000	[1]
Related Allowance	(9,060,000)	[1]		(9,060,000)	[1]		(9,974,000)	[1]
Average Recorded Investment	61,956,000		69,263,000	62,168,000		67,663,000
Interest Income Recognized	$ 76,000		$ 86,000	$ 156,000		$ 169,000

[1] All of the Company's non-accrual loans are considered impaired and included in the table above. In addition, as of June 30, 2012 and December 31, 2011, certain loans modified through troubled debt restructurings with a recorded investment of $205.5 million and $255.3 million, respectively, are also included as impaired loans in accordance with GAAP although they are performing and on accrual status.