Variable Interest Entities and Investment in Unconsolidated Ventures - Investments in Unconsolidated Ventures (Details)	Dec. 31, 2017
CCRC Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	51.00%
BKD-HCN Venture opco and propco
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	20.00%
Blackstone Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	15.00%
HCP 49 Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	10.00%
S-H Twenty-One Venture opco and propco
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	10.00%