Earnings Per Common Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Numerator
Income from continuing operations									$ 906,845	$ 910,633	$ 801,190
Noncontrolling interests' share in continuing operations									(13,181)	(14,110)	(12,411)
Income from continuing operations applicable to HCP, Inc.									893,664	896,523	788,779
Preferred stock dividends											(17,006)
Participating securities' share in earnings									(2,437)	(1,734)	(3,245)
Income from continuing operations applicable to common shares									891,227	894,789	768,528
Discontinued operations				29,746	59,489	9,824	2,828	2,232	29,746	74,373	45,652
Noncontrolling interests' share in discontinued operations									(1,177)	(59)	(1,891)
Net income applicable to common shares									$ 919,796	$ 969,103	$ 812,289
Denominator
Basic weighted average common shares									458,425,000	455,002,000	427,047,000
Dilutive potential common shares									371,000	700,000	1,269,000
Diluted weighted average common shares									458,796,000	455,702,000	428,316,000
Basic earnings per common share
Income from continuing operations (in dollars per share)									$ 1.94	$ 1.97	$ 1.80
Discontinued operations (in dollars per share)									$ 0.07	$ 0.16	$ 0.10
Net income applicable to common shares (in dollars per share)	$ 0.430	$ 0.540	$ 0.480	$ 0.560	$ 0.64	$ 0.51	$ 0.47	$ 0.51	$ 2.01	$ 2.13	$ 1.90
Diluted earnings per common share
Income from continuing operations (in dollars per share)									$ 1.94	$ 1.97	$ 1.80
Discontinued operations (in dollars per share)									$ 0.06	$ 0.16	$ 0.10
Net income applicable to common shares (in dollars per share)	$ 0.430	$ 0.540	$ 0.480	$ 0.560	$ 0.64	$ 0.51	$ 0.47	$ 0.51	$ 2.00	$ 2.13	$ 1.90
Common Stock Options
Diluted earnings per common share
Shares of anti-dilutive securities excluded from earnings per share calculation									1,000,000	800,000	500,000
Down REIT
Diluted earnings per common share
Shares of anti-dilutive securities excluded from earnings per share calculation									6,000,000	6,000,000	6,000,000
DownREIT LLCs, non-managing member units outstanding									4,000,000	4,000,000	4,000,000