Earnings Per Common Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Numerator
Income from continuing operations	$ 198,059	$ 174,662	$ 598,142	$ 479,911
Noncontrolling interests' share in continuing operations	(2,935)	(3,276)	(9,070)	(12,660)
Income from continuing operations applicable to HCP, Inc.	195,124	171,386	589,072	467,251
Preferred stock dividends		(5,282)	(17,006)	(15,848)
Participating securities' share in continuing operations	(479)	(546)	(2,154)	(1,893)
Income from continuing operations applicable to common shares	194,645	165,558	569,912	449,510
Discontinued operations	984	809	2,440	3,796
Net income applicable to common shares	$ 195,629	$ 166,367	$ 572,352	$ 453,306
Denominator
Basic weighted-average common shares	429,557,000	407,081,000	420,049,000	395,258,000
Dilutive potential common shares	1,221,000	1,565,000	1,355,000	1,755,000
Diluted weighted-average common shares	430,778,000	408,646,000	421,404,000	397,013,000
Basic earnings per common share
Income from continuing operations (in dollars per share)	$ 0.45	$ 0.41	$ 1.36	$ 1.14
Discontinued operations (in dollars per share)	$ 0.01			$ 0.01
Net income applicable to common shares (in dollars per share)	$ 0.46	$ 0.41	$ 1.36	$ 1.15
Diluted earnings per common share
Income from continuing operations (in dollars per share)	$ 0.45	$ 0.41	$ 1.36	$ 1.13
Discontinued operations (in dollars per share)				$ 0.01
Net income applicable to common shares (in dollars per share)	$ 0.45	$ 0.41	$ 1.36	$ 1.14
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		15,000
Down REIT
Diluted earnings per common share
Shares of anti-dilutive securities excluded from earnings per share calculation	6,400,000	5,900,000
DownREIT LLCs, non-managing member units outstanding	4,400,000	4,200,000