Loans Receivable (Details)	3 Months Ended		9 Months Ended					9 Months Ended		0 Months Ended								0 Months Ended				1 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2013 USD ($)	Sep. 30, 2012 USD ($)	Sep. 30, 2013 USD ($)	Sep. 30, 2012 USD ($)	Dec. 31, 2012 USD ($)	Sep. 30, 2013 Real Estate Secured USD ($)	Dec. 31, 2012 Real Estate Secured USD ($)	Sep. 30, 2013 Other Secured USD ($)	Dec. 31, 2012 Other Secured USD ($)	Sep. 06, 2013 Barchester Loan USD ($)	Sep. 06, 2013 Barchester Loan GBP (£)	Aug. 23, 2013 Barchester Loan USD ($)	Aug. 23, 2013 Barchester Loan GBP (£)	May 02, 2013 Barchester Loan USD ($) item	May 02, 2013 Barchester Loan GBP (£)	Sep. 30, 2013 Tandem Health Care Loan USD ($)	Jul. 31, 2012 Tandem Health Care Loan USD ($)	Jul. 30, 2012 Tandem Health Care Loan Maximum	Jul. 31, 2012 Tandem Health Care Loan Maximum USD ($)	Jul. 31, 2012 Tandem Health Care Loan - First Tranche USD ($)	Jun. 30, 2013 Tandem Health Care Loan - Second Tranche USD ($)	Mar. 31, 2012 Delphis USD ($)	Sep. 30, 2013 Delphis USD ($) item	Dec. 31, 2012 Delphis USD ($) item
Loans receivable:
Mezzanine	$ 245,535,000		$ 245,535,000		$ 145,150,000			$ 245,535,000	$ 145,150,000
Loan receivable, other	161,471,000		161,471,000		147,264,000	161,471,000	147,264,000												205,000,000	100,000,000	102,000,000
Unamortized discounts, fees and costs	(2,793,000)		(2,793,000)		(2,974,000)			(2,793,000)	(2,974,000)
Allowance for loan losses	(13,410,000)		(13,410,000)		(13,410,000)			(13,410,000)	(13,410,000)
Loans receivable, net	390,803,000		390,803,000		276,030,000	161,471,000	147,264,000	229,332,000	128,766,000
Construction loans outstanding related to senior housing development projects								110,000,000	72,000,000
Remaining commitments to fund development projects								37,000,000
Loans receivable purchased, face or par value												14,000,000	9,000,000	188,000,000	121,000,000
Loans receivable purchased, discount												8,000,000	5,000,000	170,000,000	109,000,000
Number of facilities														160	160
Debt instrument, variable rate basis														London Interbank Offered Rate ("LIBOR")	London Interbank Offered Rate ("LIBOR")
Debt instrument, weighted-average basis spread on variable rate (as a percent)														3.14%	3.14%
Loan receivable subordinated to senior mortgage debt																443,000,000	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
Number of partnerships that lease a property owned by the Company																							1
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	30,700,000
Cash payments received from borrower										202,000,000	129,000,000												1,500,000
Additional interest income as a result of extinguishment of loans	$ 42,078,000	$ 10,278,000	$ 68,611,000	$ 12,313,000						$ 24,000,000