Selected Quarterly Financial Data (Unaudited) (Details) $ / shares in Units, £ in Millions		3 Months Ended									12 Months Ended
	May 01, 2017 USD ($)	Dec. 31, 2017 USD ($) $ / shares	Sep. 30, 2017 USD ($) $ / shares	Jun. 30, 2017 USD ($) $ / shares	Mar. 31, 2017 USD ($) facility $ / shares	Mar. 31, 2017 GBP (£) facility	Dec. 31, 2016 USD ($) $ / shares	Sep. 30, 2016 USD ($) $ / shares	Jun. 30, 2016 USD ($) $ / shares	Mar. 31, 2016 USD ($) $ / shares	Dec. 31, 2017 USD ($) $ / shares	Dec. 31, 2016 USD ($) $ / shares	Dec. 31, 2015 USD ($) $ / shares
Total revenues		$ 443,259,000	$ 454,023,000	$ 458,928,000	$ 492,168,000		$ 539,950,000	$ 530,555,000	$ 538,332,000	$ 520,457,000	$ 1,848,378,000	$ 2,129,294,000	$ 1,940,489,000
Total discontinued operations							(18,246,000)	108,215,000	107,378,000	68,408,000	0	265,755,000	(699,086,000)
Income (loss) before income taxes and equity income from investments in unconsolidated joint ventures		(50,957,000)	(12,263,000)	18,874,000	454,746,000		67,530,000	47,453,000	196,352,000	55,949,000	410,400,000	367,284,000	136,271,000
Net income (loss)		(57,924,000)	(5,720,000)	22,101,000	464,177,000		61,300,000	154,039,000	304,842,000	119,745,000	422,634,000	639,926,000	(546,418,000)
Net income (loss) applicable to HCP, Inc.		$ (58,702,000)	$ (7,657,000)	$ 19,383,000	$ 461,145,000		$ 58,661,000	$ 151,250,000	$ 301,717,000	$ 116,119,000	$ 414,169,000	$ 627,747,000	$ (559,235,000)
Dividends paid per common share (in dollars per share) | $ / shares		$ 0.37	$ 0.37	$ 0.37	$ 0.37		$ 0.37	$ 0.58	$ 0.58	$ 0.58	$ 1.480	$ 2.095	$ 2.260
Basic earnings per common share (in dollars per share) | $ / shares		(0.13)	(0.02)	0.04	0.98		0.12	0.32	0.65	0.25	0.88	1.34	(1.21)
Diluted earnings per common share (in dollars per share) | $ / shares		$ (0.13)	$ (0.02)	$ 0.04	$ 0.97		$ 0.12	$ 0.32	$ 0.64	$ 0.25	$ 0.88	$ 1.34	$ (1.21)
Reduction in rental and related revenues											$ 1,071,153,000	$ 1,159,791,000	$ 1,116,830,000
Operating expenses											666,251,000	738,399,000	610,679,000
Tax expense recorded from Tax Cuts and Jobs Act		$ 17,000,000
Loss on extinguishment of debt							$ 46,000,000				54,227,000	46,020,000	0
Gain (loss) on sales of real estate, net											356,641,000	164,698,000	6,377,000
Transaction costs											0	86,765,000	0
Gain on sales of real estate									$ 120,000,000
Income tax expense										$ 53,000,000	0	48,181,000	$ 796,000
HCRMC
Income tax expense										$ 49,000,000
Four Seasons
Payments to Acquire Loans Receivable					$ 51,000,000	£ 42
Tandem Health Care Loan
Write down of loans receivable		84,000,000	$ 3,000,000	$ 57,000,000							144,000,000
Unsecured Note 5.625 Percent
Repayment of senior unsecured notes	$ 250,000,000		$ 500,000,000
Interest rate (as a percent)	5.625%		5.375%
Loss on extinguishment of debt			$ 54,000,000								$ 54,000,000	$ 46,000,000
Spinoff
Transaction costs							$ 58,000,000
Senior housing triple-net | Held-for-sale
Number of properties disposed | facility					64	64
Gain (loss) on sales of real estate, net					$ 170,000,000
Assets Leased to Others | Senior housing triple-net
Reduction in rental and related revenues		(20,000,000)
Assets Under Management Agreements | SHOP
Operating expenses		$ 35,000,000