Investments in and Advances to Unconsolidated Joint Ventures - Income Statement Disclosures (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Total revenues	$ 441,919	$ 456,022	$ 469,551	$ 479,197	$ 443,259	$ 454,023	$ 458,928	$ 492,168	$ 1,846,689	$ 1,848,378	$ 2,129,294
Operating expenses									(705,038)	(666,251)	(738,399)
Income (loss) from discontinued operations									0	0	265,755
Net income (loss)	834,383	$ 102,926	$ 92,928	$ 43,237	(57,924)	$ (5,720)	$ 22,101	$ 464,177	1,073,474	422,634	639,926
Distributions received by HCP									22,467	44,142	26,492
Unconsolidated Joint Ventures
Schedule of Equity Method Investments [Line Items]
Total revenues									642,724	810,216	424,134
Operating expenses									(492,784)	(643,452)	(344,553)
Income (loss) from discontinued operations									0	0	8,810
Net income (loss)									(43,704)	(42,408)	43,015
Fees earned by HCP									125	133	299
Distributions received by HCP									48,939	81,165	54,858
Aggregate unamortized basis difference	$ (69,000)				$ (115,000)				(69,000)	(115,000)
HCP Inc | Unconsolidated Joint Ventures
Schedule of Equity Method Investments [Line Items]
Net income (loss)									$ (2,594)	$ 10,901	$ 11,360