Variable Interest Entities (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012
Unconsolidated Variable Interest Entities
Company's involvement with VIEs:
Number of senior housing facilities leased	48
Number of VIE tenants	7
Variable Interest Entity, Not Primary Beneficiary | VIE tenants-operating leases
Company's involvement with VIEs:
Maximum Loss Exposure	$ 319,995
Assets/liability type	Lease intangibles, net and straight-line rent receivables
Carrying amount	15,136
Variable Interest Entity, Not Primary Beneficiary | VIE tenants-DFLs
Company's involvement with VIEs:
Maximum Loss Exposure	1,141,858
Assets/liability type	Net investment in DFLs
Carrying amount	595,644
Variable Interest Entity, Not Primary Beneficiary | Loan-senior secured
Company's involvement with VIEs:
Maximum Loss Exposure	68,784
Assets/liability type	Loans receivable, net
Carrying amount	$ 68,784