Loans Receivable (Details)							0 Months Ended						0 Months Ended		3 Months Ended		6 Months Ended	12 Months Ended
	Jun. 30, 2013 USD ($)	Dec. 31, 2012 USD ($)	Jun. 30, 2013 Real Estate Secured USD ($)	Dec. 31, 2012 Real Estate Secured USD ($)	Jun. 30, 2013 Other Secured USD ($)	Dec. 31, 2012 Other Secured USD ($)	May 02, 2013 Barchester Loan GBP (£) item	Jun. 30, 2013 Barchester Loan USD ($)	Jun. 30, 2013 Tandem Health Care Loan USD ($)	Jul. 31, 2012 Tandem Health Care Loan USD ($)	Jul. 31, 2012 Tandem Health Care Loan First Tranche USD ($)	Jun. 30, 2013 Tandem Health Care Loan Second Tranche USD ($)	Jul. 30, 2012 Tandem Health Care Loan Maximum	Jul. 31, 2012 Tandem Health Care Loan Maximum USD ($)	Jun. 30, 2013 Delphis USD ($)	Mar. 31, 2012 Delphis USD ($)	Jun. 30, 2013 Delphis USD ($)	Dec. 31, 2012 Delphis USD ($) item
Loans receivable:
Mezzanine	$ 428,723,000	$ 145,150,000			$ 428,723,000	$ 145,150,000
Loan receivable, other	161,957,000	147,264,000	161,957,000	147,264,000							100,000,000	102,000,000		205,000,000
Unamortized discounts, fees and costs	(21,479,000)	(2,974,000)			(21,479,000)	(2,974,000)
Allowance for loan losses	(13,410,000)	(13,410,000)			(13,410,000)	(13,410,000)
Loans receivable, net	555,791,000	276,030,000	161,957,000	147,264,000	393,834,000	128,766,000		165,000,000
Loans receivable purchased, face or par value							121,000,000
Loans receivable purchased, discount							109,000,000
Number of facilities							160
Debt instrument, variable rate basis							London Interbank Offered Rate ("LIBOR")
Debt instrument, weighted-average basis spread on variable rate (as a percent)							3.14%
Loan receivable subordinated to senior mortgage debt									444,000,000	400,000,000
Loan receivable subordinated to senior mezzanine debt										137,000,000
Loan receivable, interest rate payable (as a percent)											12.00%	14.00%
Loan receivable term													63 months
Distribution of fund to guarantor																1,500,000
Cash payment received																4,800,000
Legal expenses																500,000
Other consideration received																2,100,000
Proceeds from guarantor																6,900,000
Proceeds from sale of collateral asset																		38,100,000
Number of collateral primary assets sold																		2
Loans receivable, net reported amount															29,200,000		29,200,000	30,700,000
Cash payments received from borrower															$ 1,500,000		$ 1,500,000