Earnings Per Common Share - Schedule of Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Numerator
Net income (loss)	$ (9,980)	$ 92,928	$ 55,010	$ 136,165
Noncontrolling interests' share in earnings	(3,617)	(2,986)	(7,137)	(5,991)
Net income (loss) attributable to HCP, Inc.	(13,597)	89,942	47,873	130,174
Less: Participating securities' share in earnings	(394)	(461)	(837)	(852)
Net income (loss) applicable to common shares	$ (13,991)	$ 89,481	$ 47,036	$ 129,322
Denominator
Basic weighted average shares outstanding (in shares)	478,739	469,769	478,260	469,664
Dilutive potential common shares - equity awards (in shares)	0	172	281	135
Dilutive potential common shares - forward equity agreements (in shares)	0	0	1,344	0
Diluted weighted average common shares (in shares)	478,739	469,941	479,885	469,799
Basic earnings per common share
Earnings per common share, basic (in dollars per share)	$ (0.03)	$ 0.19	$ 0.10	$ 0.28
Earnings per common share, diluted (in dollars per share)	$ (0.03)	$ 0.19	$ 0.10	$ 0.28
Forward sales agreements that have not been settled (in shares)			22,000
Forward equity sales agreements that have not been settled			$ 641,000