Earnings Per Common Share (Details) $ / shares in Units, shares in Thousands, $ in Thousands, item in Millions	3 Months Ended
	Mar. 31, 2016 USD ($) item $ / shares shares	Mar. 31, 2015 USD ($) $ / shares shares
Numerator
Net income (loss) | $	$ 119,745	$ (237,503)
Noncontrolling interests’ share in earnings | $	(3,626)	(3,111)
Net income (loss) attributable to HCP, Inc. | $	116,119	(240,614)
Participating securities' share in earnings | $	(357)	(335)
Net income (loss) applicable to common shares | $	$ 115,762	$ (240,949)
Denominator
Basic weighted average common shares	466,074	460,880
Dilutive potential common shares	188
Diluted weighted average common shares	466,262	460,880
Earnings per common share:
Basic (in dollars per share) | $ / shares	$ 0.25	$ (0.52)
Diluted (in dollars per share) | $ / shares	$ 0.25	$ (0.52)
Common Stock Options
Earnings per common share:
Shares of anti-dilutive securities excluded from earnings per share calculation	1,400
Down REIT
Earnings per common share:
Shares of anti-dilutive securities excluded from earnings per share calculation	6,000
DownREIT LLCs, non-managing member units outstanding | item	4
Restricted Stock and Performance Restricted Stock Units
Earnings per common share:
Shares of anti-dilutive securities excluded from earnings per share calculation	700