Earnings Per Common Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Numerator
Income from continuing operations	$ 233,784	$ 194,193
Noncontrolling interests' share in continuing operations	(3,199)	(3,184)
Income from continuing operations applicable to HCP, Inc.	230,585	191,009
Preferred stock dividends		(17,006)
Participating securities' share in continuing operations	(478)	(1,117)
Income from continuing operations applicable to common shares	230,107	172,886
Discontinued operations		2,371
Net income applicable to common shares	$ 230,107	$ 175,257
Denominator
Basic weighted-average common shares	453,651,000	410,018,000
Dilutive potential common shares	962,000	1,643,000
Diluted weighted-average common shares	454,613,000	411,661,000
Basic earnings per common share
Income from continuing operations (in dollars per share)	$ 0.51	$ 0.42
Discontinued operations (in dollars per share)		$ 0.01
Net income applicable to common shares (in dollars per share)	$ 0.51	$ 0.43
Diluted earnings per common share
Income from continuing operations (in dollars per share)	$ 0.51	$ 0.42
Discontinued operations (in dollars per share)		$ 0.01
Net income applicable to common shares (in dollars per share)	$ 0.51	$ 0.43
Common stock options
Diluted earnings per common share
Shares of anti-dilutive securities excluded from earnings per share calculation	500,000	1,100,000
Restricted Stock and Performance Restricted Stock Units
Diluted earnings per common share
Shares of anti-dilutive securities excluded from earnings per share calculation	400,000	500,000
Down REIT
Diluted earnings per common share
Shares of anti-dilutive securities excluded from earnings per share calculation	6,000,000	5,900,000
DownREIT LLCs, non-managing member units outstanding	4,000,000	4,200,000