Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Numerator
Net income (loss)	$ 92,928	$ 22,101	$ 136,165	$ 486,278
Noncontrolling interests' share in earnings	(2,986)	(2,718)	(5,991)	(5,750)
Net income (loss) attributable to HCP, Inc.	89,942	19,383	130,174	480,528
Less: Participating securities' share in earnings	(461)	(100)	(852)	(674)
Net income (loss) applicable to common shares	89,481	19,283	129,322	479,854
Numerator - Dilutive
Net income (loss) applicable to common shares	89,481	19,283	129,322	479,854
Add: distributions on dilutive convertible units and other	0	0	0	3,655
Dilutive net income (loss) available to common shares	$ 89,481	$ 19,283	$ 129,322	$ 483,509
Denominator
Basic weighted average common shares	469,769	468,646	469,664	468,474
Diluted weighted average common shares	469,941	468,839	469,799	473,366
Earnings per common share:
Earnings per common share, basic (in dollars per share)	$ 0.19	$ 0.04	$ 0.28	$ 1.02
Earnings per common share, diluted (in dollars per share)	$ 0.19	$ 0.04	$ 0.28	$ 1.02
Equity awards
Denominator
Dilutive potential common shares	172	193	135	195
Down REIT
Denominator
Dilutive potential common shares	0	0	0	4,697
Earnings per common share:
Shares of anti-dilutive securities excluded from earnings per share calculation	7,000	7,000	7,000
DownREIT LLCs, non-managing member units outstanding	4,000	4,000	4,000