Real Estate Property Investments (Details) $ / shares in Units, £ in Millions				1 Months Ended			3 Months Ended		9 Months Ended
	Oct. 07, 2015 property	Oct. 06, 2015 USD ($)	Sep. 30, 2015 USD ($) property item	Oct. 31, 2015 USD ($)	Jun. 30, 2015 USD ($)	Aug. 31, 2014 USD ($)	Sep. 30, 2015 USD ($) property	Sep. 30, 2014 USD ($) $ / shares	Sep. 30, 2015 GBP (£)	Sep. 30, 2015 USD ($) property $ / shares	Sep. 30, 2014 GBP (£) property	Sep. 30, 2014 USD ($) property $ / shares	May. 31, 2015 GBP (£) property	May. 31, 2015 USD ($) property	Dec. 31, 2014 USD ($)
Acquisition
Consideration, Cash Paid										$ 777,081,000		$ 467,147,000
Consideration, Debt and Other Liabilities Assumed			$ 21,076,000				$ 21,076,000	$ 1,734,000		21,076,000		1,734,000
Consideration, Noncontrolling Interest			3,885,000				3,885,000	6,321,000		3,885,000		6,321,000
Assets Acquired, Real Estate			710,396,000				710,396,000	433,858,000		710,396,000		433,858,000
Assets Acquired, Net Intangibles			91,646,000				91,646,000	41,344,000		91,646,000		41,344,000
Net termination fee revenue						$ 38,000,000				1,103,000		38,001,000
Other real estate acquisitions
Loans and Leases Receivable, Gross													£ 27	$ 42,000,000
Consideration to non-managing member limited liability company units								5,000,000				5,000,000
Investment Building and Building Improvements			$ 12,384,413,000				$ 12,384,413,000			12,384,413,000					$ 10,972,973,000
Payments to acquire productive assets										253,929,000		162,717,000
HC-One Facility
Other real estate acquisitions
Consideration, Fair Value of Real Estate Exchanged									£ 174	$ 254,000,000
Number of properties | property			36				36			36
Senior housing
Acquisition
Consideration, Cash Paid												215,381,000
Cash Paid/Debt Settled										$ 221,023,000
Consideration, Debt and Other Liabilities Assumed			$ 8,227,000				$ 8,227,000	1,021,000		8,227,000		1,021,000
Consideration, Noncontrolling Interest			3,885,000				3,885,000	6,321,000		3,885,000		6,321,000
Assets Acquired, Real Estate			209,084,000				209,084,000	205,778,000		209,084,000		205,778,000
Consideration, Amount translated										129,000,000	£ 76
Assets Acquired, Net Intangibles			24,051,000				24,051,000	16,945,000		24,051,000		16,945,000
Total Consideration for Disposition of Real Estate										60,000,000
Other real estate acquisitions
Number of properties | property													2	2
Payments to acquire productive assets										76,640,000		23,876,000
Life science
Acquisition
Consideration, Cash Paid												43,500,000
Consideration, Debt and Other Liabilities Assumed								250,000				250,000
Assets Acquired, Real Estate								41,281,000				41,281,000
Assets Acquired, Net Intangibles								2,469,000				$ 2,469,000
Total Consideration for Disposition of Real Estate										11,000,000
Other real estate acquisitions
Number of Facilities Placed into Service | property											2	2
Payments to acquire productive assets										80,871,000		$ 91,178,000
Life science | Subsequent event
Acquisition
Total Consideration for Disposition of Real Estate		$ 40,000,000
Medical office
Acquisition
Consideration, Cash Paid												208,266,000
Cash Paid/Debt Settled										377,351,000
Consideration, Debt and Other Liabilities Assumed			12,849,000				12,849,000	463,000		12,849,000		463,000
Assets Acquired, Real Estate			349,649,000				349,649,000	186,799,000		349,649,000		186,799,000
Assets Acquired, Net Intangibles			40,551,000				40,551,000	21,930,000		40,551,000		21,930,000
Total Consideration for Disposition of Real Estate										400,000		145,000
Other real estate acquisitions
Payments to acquire productive assets										93,012,000		43,773,000
Hospital
Acquisition
Total Consideration for Disposition of Real Estate												17,000,000
Other real estate acquisitions
Payments to acquire productive assets										37,000		1,357,000
Post-acute/skilled
Acquisition
Cash Paid/Debt Settled										178,707,000
Assets Acquired, Real Estate			151,663,000				151,663,000			151,663,000
Assets Acquired, Net Intangibles			27,044,000				27,044,000			27,044,000
Total Consideration for Disposition of Real Estate												22,000,000
Other real estate acquisitions
Payments to acquire productive assets										3,369,000		2,533,000
Life Science, Medical Office and Post-acute/skilled [Member]
Other real estate acquisitions
Investment Building and Building Improvements															$ 41,000,000
RIDEA III
Acquisition
Cash consideration, net of cash assumed			770,000,000
Consideration, Debt and Other Liabilities Assumed			32,000,000				32,000,000			32,000,000
Consideration, Noncontrolling Interest			29,000,000				29,000,000			29,000,000
Assets Acquired, Real Estate			771,000,000				771,000,000			771,000,000
Assets Acquired, Net Intangibles			53,000,000				53,000,000			53,000,000
Assets Acquired, Working Capital			7,000,000				$ 7,000,000			$ 7,000,000
Net termination fee revenue			$ 8,000,000
Stabilized occupancy rate (as a percent)			80.00%				80.00%			80.00%
Revenue from acquiree since the acquisition date							$ 47,000,000
Income from acquiree since the acquisition date							$ 1,000,000
Business Acquisition, Pro Forma Information [Abstract]
Revenues								644,856,000		$ 1,963,402,000		1,807,405,000
Net income								255,107,000		56,009,000		749,106,000
Net income applicable to HCP, Inc.								$ 251,297,000		$ 46,662,000		$ 736,580,000
Basic earnings per common share (in dollars per share) | $ / shares								$ 0.55		$ 0.10		$ 1.60
Diluted earnings per common share (in dollars per share) | $ / shares								$ 0.55		$ 0.10		$ 1.60
RIDEA III | Brookdale Senior Living
Acquisition
Number of individual leases | property			2
Number of Units Acquired | item			5,025
Noncontrolling interest (as a percent)			10.00%				10.00%			10.00%
Management Agreement Term			7 years
RIDEA III | Senior housing | Brookdale Senior Living
Acquisition
Number of facilities acquired | property			35
HCP Ventures V | Subsequent event
Acquisition
Minority Interest Percentage Of Ownership Sold	49			49
Total Consideration for Disposition of Real Estate				$ 110,000,000
Other real estate acquisitions
Number of properties | property	11
Noncontrolling interest issued (as a percentage)	49			49
HCP Ventures V | Medical office
Acquisition
Cash Paid/Debt Settled					$ 225,000,000