Real Estate Property Investments (Details) (Operating segment, USD $)	9 Months Ended			3 Months Ended			6 Months Ended	9 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended
	Sep. 30, 2012	Sep. 30, 2013 Senior housing	Sep. 30, 2012 Senior housing	Mar. 31, 2013 Blackstone JV Senior housing item	Dec. 31, 2012 Blackstone JV Senior housing item	Sep. 30, 2012 Blackstone JV Senior housing	Mar. 31, 2013 Blackstone JV Senior housing item	Sep. 30, 2012 Blackstone JV Senior housing	Mar. 31, 2013 Blackstone JV Senior housing Emeritus Corporation item	Dec. 31, 2012 Blackstone JV Senior housing Emeritus Corporation Real Estate Secured item	Mar. 31, 2013 Blackstone JV Senior housing Minimum Emeritus Corporation	Mar. 31, 2013 Blackstone JV Senior housing Maximum Emeritus Corporation
Acquisition
Acquisition of facility		$ 18,000,000		$ 38,000,000	$ 1,700,000,000
Consideration, Cash Paid	172,380,000		3,860,000	1,730,000,000
Assets Acquired, Real Estate	184,564,000		3,541,000	1,570,000,000			1,570,000,000
Assets Acquired, Net Intangibles	50,368,000		319,000	174,000,000			174,000,000
Number of senior housing communities				4	129		133			9
Number of individual leases									5
Number of properties operated pursuant to a new triple-net master lease									128
Number of states where acquired senior housing communities are located				29			29
Percentage of assisted living units							61.00%
Percentage of independent living units							25.00%
Percentage of memory care units							13.00%
Percentage of skilled nursing							1.00%
Number of communities that are stabilized				99			99
Number of communities currently lease-up				34			34		34
Number of stages for acquisition to close							2
Liabilities assumed	35,120,000			13,000,000			13,000,000
Consideration, assumed intangible liabilities				4,000,000			4,000,000
Rental and related revenues									105,800,000
Rate of increase in minimum lease revenue per year on average over the initial 5 years of the lease (as a percent)									3.70%
Initial lease term with Emeritus Corporation									5 years
Rate of increase in minimum lease revenue per year for remaining years of lease term (as a percent)									3.00%
Percentage of operating leases basis spread on variable floor rate									103.00%
Percentage of operating leases basis spread on variable cap rate									130.00%
Number of asset pools									3
Initial available term of asset pools											14 years	16 years
Number of extension options with Emeritus Corporation									2
Total initial available term of asset pools											30 years	35 years
Principal amount of secured debt										52,000,000
Term of loan										4 years
Interest rate on debt, initially (as a percent)										6.10%
Interest rate on debt after four year term (as a percent)										6.80%
Unaudited pro forma consolidated results of operations
Revenues						494,516,000		1,450,349,000
Net income						206,448,000		622,797,000
Net income applicable to HCP, Inc.						$ 203,513,000		$ 613,727,000
Basic earnings per common share (in dollars per share)						$ 0.45		$ 1.35
Diluted earnings per common share (in dollars per share)						$ 0.45		$ 1.34