Variable Interest Entities - Schedule of Variable Interest Entities (Details) $ in Thousands	Mar. 31, 2019 USD ($)
VIE tenants-DFLs
Variable Interest Entity [Line Items]
Maximum Loss Exposure and Carrying Amount	$ 249,803
VIE tenants-operating leases
Variable Interest Entity [Line Items]
Maximum Loss Exposure and Carrying Amount	6,909
CCRC OpCo
Variable Interest Entity [Line Items]
Maximum Loss Exposure and Carrying Amount	175,011
Unconsolidated Development JVs
Variable Interest Entity [Line Items]
Maximum Loss Exposure and Carrying Amount	15,206
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	$ 34,397