Loans Receivable (Details) (USD $)	1 Months Ended										1 Months Ended	9 Months Ended
	Nov. 30, 2011	Oct. 31, 2011	Aug. 31, 2011	Jun. 30, 2011	Apr. 30, 2011	Mar. 31, 2011	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2011 Nationwide Health Properties [Member] Senior unsecured term loan [Member]	May 31, 2011 Senior unsecured term loan [Member]	Jun. 30, 2011 First Mortgage loan maturing in 2016 [Member]	Sep. 30, 2011 Nationwide Health Properties [Member] Property HousingCommunity
Debt Instrument [Line Items]
Interest rate on term loan										5.00%
Aggregate principal amount of senior unsecured term loan									$ 800,000,000	$ 600,000,000
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage loan receivable												270,000,000
Number of senior housing and healthcare properties												53
Other loans												60,000,000
Interest rate on loans issued											9.00%
Loans Receivable (Textuals) [Abstract]
Net loans receivable							302,264,000	149,263,000
Gain Loss on Repayment of Loans Receivable	3,000,000		5,500,000		3,300,000	800,000
Proceeds from final repayment of the loan		6,400,000			112,400,000	19,900,000
Principal amount of first mortgage debt				$ 12,900,000								$ 400,000,000