Variable Interest Entities - Schedule of Variable Interest Entities (Details) $ in Thousands	Jun. 30, 2017 USD ($)
VIE tenants-DFLs
Variable Interest Entity [Line Items]
Maximum Loss Exposure and Carrying Amount	$ 599,561
VIE tenants-operating leases
Variable Interest Entity [Line Items]
Maximum Loss Exposure and Carrying Amount	5,952
CCRC OpCo
Variable Interest Entity [Line Items]
Maximum Loss Exposure and Carrying Amount	218,832
RIDEA II
Variable Interest Entity [Line Items]
Maximum Loss Exposure and Carrying Amount	254,137
Development JVs
Variable Interest Entity [Line Items]
Maximum Loss Exposure and Carrying Amount	11,653
Loan-senior secured
Variable Interest Entity [Line Items]
Maximum Loss Exposure and Carrying Amount	137,025
Loan-seller financing
Variable Interest Entity [Line Items]
Maximum Loss Exposure and Carrying Amount	10,000
CMBS and LLC Investment
Variable Interest Entity [Line Items]
Maximum Loss Exposure and Carrying Amount	$ 33,511