Variable Interest Entities (Details) (USD $) In Thousands, unless otherwise specified		3 Months Ended			1 Months Ended
	Mar. 31, 2013 Unconsolidated Variable Interest Entities item	Mar. 31, 2013 Unconsolidated Variable Interest Entities VIE tenants-operating leases	Mar. 31, 2013 Unconsolidated Variable Interest Entities VIE tenants-DFLs	Mar. 31, 2013 Unconsolidated Variable Interest Entities Loan-senior secured	Sep. 30, 2011 Consolidated Variable Interest Entities item
Company's involvement with VIEs:
Number of senior housing facilities leased	48				21
Number of VIE tenants	7
Maximum Loss Exposure		$ 1,397,774	$ 911,051	$ 30,652
Assets/liability type		Lease intangibles, net and straight-line rent receivables	Net investment in DFLs	Loans receivable, net
Carrying amount		$ 615,655	$ 911,051	$ 30,652
Percentage of partnership interest					90.00%