Loans Receivable (Details) (USD $)	9 Months Ended							1 Months Ended			1 Months Ended		9 Months Ended				1 Months Ended								1 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Sep. 30, 2012 Real Estate Secured	Dec. 31, 2011 Real Estate Secured	Sep. 30, 2012 Other Secured	Dec. 31, 2011 Other Secured	Jul. 31, 2012 Tandem Health Care Loan	Jul. 31, 2012 Tandem Health Care Loan First Tranche	Jul. 31, 2012 Tandem Health Care Loan Second Tranche	Sep. 30, 2011 Delphis	Dec. 31, 2009 Delphis	Sep. 30, 2012 Delphis	Sep. 30, 2011 Delphis	Oct. 31, 2012 Delphis	Dec. 31, 2011 Delphis	Apr. 30, 2011 HCR ManorCare	Dec. 31, 2007 HCR ManorCare, mezzanine loan	Jan. 31, 2011 HCR ManorCare, participation in first mortgage debt	Aug. 31, 2009 HCR ManorCare, participation in first mortgage debt	Apr. 30, 2011 Genesis HealthCare Loans	Sep. 30, 2010 Genesis Senior Loans	Sep. 30, 2010 Genesis Senior Loans Minimum	Sep. 30, 2010 Genesis Senior Loans Maximum	Oct. 31, 2010 Genesis Mezzanine participation loan
Loans receivable:
Mezzanine	$ 183,253,000		$ 90,148,000			$ 183,253,000	$ 90,148,000
Loan receivable	74,413,000		35,643,000	74,413,000	35,643,000			205,000,000	100,000,000	105,000,000
Unamortized discounts, fees and costs	(3,327,000)		(2,128,000)	(255,000)	(1,040,000)	(3,072,000)	(1,088,000)
Allowance for loan losses	(13,410,000)		(13,410,000)			(13,410,000)	(13,410,000)
Loans receivable, net	240,929,000		110,253,000	74,158,000	34,603,000	166,771,000	75,650,000
Loan receivable subordinated to senior mortgage debt								400,000,000
Loan receivable subordinated to senior mezzanine debt								137,000,000
Loan receivable, interest rate payable at maturity (as a percent)									12.00%	14.00%
Loan receivable term								63 months
Provision for loan loss											15,400,000	4,300,000
Distribution of fund to guarantor													1,500,000
Cash payment received													4,900,000
Legal expenses													500,000
Loans receivable, net reported amount													68,800,000		59,100,000	75,700,000
Proceeds from repayment	4,660,000	303,867,000											6,900,000	2,100,000							330,400,000
Proceeds from sale of collateral asset													9,700,000
Loans receivable purchased, face or par value																			360,000,000	720,000,000		278,000,000			50,000,000
Loan receivable purchased, acquisition cost																		900,000,000
Loans receivable purchased, discount																		100,000,000		130,000,000		28,000,000			10,000,000
Debt instrument, variable rate basis																		one-month London Interbank Offered Rate ("LIBOR")	LIBOR	LIBOR		LIBOR			LIBOR
Debt instrument, variable rate floor (as a percent)																							1.50%	2.50%
Debt instrument, basis spread on variable rate (as a percent)																		4.00%	1.25%	1.25%			4.75%	5.75%	7.50%
Additional interest income as a result of extinguishment of loans																	23,000,000				34,800,000
Termination fee																									$ 2,300,000