Investments in and Advances to Unconsolidated Joint Ventures - Balance Sheet Disclosures (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Real estate, net	$ 11,033,055	$ 10,209,450
Other assets, net	646,491	591,017
Total assets	14,032,891	12,718,553
Mortgage and other debt	6,299,131
Accounts payable and accrued liabilities	456,153	391,583
Partners' capital	6,667,474	6,512,591	$ 5,594,938	$ 5,941,308
Total liabilities and equity	14,032,891	12,718,553
Unconsolidated Joint Ventures
Schedule of Equity Method Investments [Line Items]
Real estate, net	2,278,743	2,128,147
Other assets, net	511,014	479,935
Total assets	2,789,757	2,608,082
Mortgage and other debt	552,824	827,622
Accounts payable and accrued liabilities	591,498	655,177
Total liabilities and equity	2,789,757	2,608,082
HCP Inc | Unconsolidated Joint Ventures
Schedule of Equity Method Investments [Line Items]
Partners' capital	889,076	609,492
Other partners | Unconsolidated Joint Ventures
Schedule of Equity Method Investments [Line Items]
Partners' capital	$ 756,359	$ 515,791