Earnings Per Common Share (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Numerator - Basic
Income from continuing operations	$ 175,471,000	$ 21,428,000	$ 483,707,000	$ 192,162,000
Noncontrolling interests' share in continuing operations	(3,276,000)	(3,518,000)	(12,660,000)	(10,077,000)
Income from continuing operations applicable to HCP, Inc.	172,195,000	17,910,000	471,047,000	182,085,000
Preferred stock dividends	(5,282,000)	(5,282,000)	(15,848,000)	(15,848,000)
Participating securities' share in continuing operations	(546,000)	(378,000)	(1,893,000)	(1,648,000)
Income from continuing operations applicable to common shares	166,367,000	12,250,000	453,306,000	164,589,000
Discontinued operations		4,745,000		6,707,000
Net income applicable to common shares	166,367,000	16,995,000	453,306,000	171,296,000
Denominator
Basic weighted-average common shares	407,081,000	309,448,000	395,258,000	299,243,000
Dilutive potential common shares	1,565,000	1,644,000	1,755,000	1,225,000
Diluted weighted-average common shares	408,646,000	311,092,000	397,013,000	300,468,000
Basic earnings per common share
Income from continuing operations (in dollars per share)	$ 0.41	$ 0.04	$ 1.15	$ 0.55
Discontinued operations (in dollars per share)		$ 0.01		$ 0.02
Net income applicable to common shares (in dollars per share)	$ 0.41	$ 0.05	$ 1.15	$ 0.57
Diluted earnings per common share
Income from continuing operations (in dollars per share)	$ 0.41	$ 0.04	$ 1.14	$ 0.55
Discontinued operations (in dollars per share)		$ 0.01		$ 0.02
Net income applicable to common shares (in dollars per share)	$ 0.41	$ 0.05	$ 1.14	$ 0.57
Common stock options
Diluted earnings per common share
Shares of anti-dilutive securities excluded from earnings per share calculation	1,100,000	400,000
Restricted stock
Diluted earnings per common share
Earnings representing nonforfeitable dividends	$ 500,000	$ 400,000	$ 1,900,000	$ 1,600,000
Restricted Stock and Performance Restricted Stock Units
Diluted earnings per common share
Shares of anti-dilutive securities excluded from earnings per share calculation	15,000	30,000
DownREIT
Diluted earnings per common share
Shares of anti-dilutive securities excluded from earnings per share calculation	5,900,000	6,000,000
DownREIT LLCs, non-managing member units outstanding (in units)	4,200,000	4,300,000	4,200,000	4,300,000