Segment Disclosures - Summary Information for the Reportable Segments (Details) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Jan. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) facility	Sep. 30, 2016 USD ($)	Dec. 31, 2016 facility
Segment reporting information, revenues
Rental revenues		$ 442,249	$ 510,075	$ 1,354,145	$ 1,518,051
HCP share of unconsolidated JV revenues		84,884	53,814	248,379	160,779
Operating expenses		(155,338)	(187,714)	(467,582)	(542,751)
HCP share of unconsolidated JV operating expenses		(65,631)	(43,037)	(191,772)	(126,899)
Segment NOI		306,164	333,138	943,170	1,009,180
Adjustments to NOI		1,335	810	2,806	352
Adjusted NOI		307,499	333,948	945,976	1,009,532
Addback adjustments		(1,335)	(810)	(2,806)	(352)
Interest income		11,774	20,482	50,974	71,298
Interest expense		(71,328)	(117,860)	(235,834)	(361,255)
Depreciation and amortization		(130,588)	(141,407)	(397,893)	(421,181)
General and administrative		(23,523)	(34,781)	(67,287)	(83,011)
Acquisition and pursuit costs		(580)	(2,763)	(2,504)	(6,061)
Recoveries (impairments), net		(25,328)	0	(82,010)	0
Gain (loss) on sales of real estate, net		5,182	(9)	322,852	119,605
Loss on debt extinguishments		(54,227)	0	(54,227)	0
Other income (expense), net		(10,556)	1,432	40,723	5,064
Income tax benefit (expense)		5,481	424	14,630	(1,101)
Less: HCP share of unconsolidated JV NOI		(19,253)	(10,777)	(56,607)	(33,880)
Equity income (loss) from unconsolidated JVs		1,062	(2,053)	4,571	(4,028)
Discontinued operations		0	108,213	0	283,996
Net income (loss)		(5,720)	154,039	480,558	578,626
Corporate and other assets
Segment reporting information, revenues
Rental revenues		0	0	0	0
HCP share of unconsolidated JV revenues		0	0	0	0
Operating expenses		0	0	0	0
HCP share of unconsolidated JV operating expenses		0	0	0	0
Segment NOI		0	0	0	0
Adjustments to NOI		0	0	0	0
Adjusted NOI		0	0	0	0
Addback adjustments		0	0	0	0
Interest income		0	0	0	0
Interest expense		(68,924)	(104,584)	(222,775)	(314,708)
Depreciation and amortization		0	0	0	0
General and administrative		(23,523)	(34,781)	(67,287)	(83,011)
Acquisition and pursuit costs		(580)	(2,763)	(2,504)	(6,061)
Recoveries (impairments), net		0		0
Gain (loss) on sales of real estate, net		0	0	0	0
Loss on debt extinguishments		(54,227)		(54,227)
Other income (expense), net		(10,556)	1,432	40,723	5,064
Income tax benefit (expense)		5,481	424	14,630	(1,101)
Less: HCP share of unconsolidated JV NOI		0	0	0	0
Equity income (loss) from unconsolidated JVs		0	0	0	0
Discontinued operations			108,213		283,996
Net income (loss)		(152,329)	(32,059)	$ (291,440)	(115,821)
Senior housing triple-net
Segment Disclosure
Number of SH NNN facilities transitioned to RIDEA structure | facility				4		17
Senior housing triple-net | Operating segment
Segment reporting information, revenues
Rental revenues		77,220	104,262	$ 255,332	319,989
HCP share of unconsolidated JV revenues		0	0	0	0
Operating expenses		(934)	(1,794)	(2,927)	(5,521)
HCP share of unconsolidated JV operating expenses		0	0	0	0
Segment NOI		76,286	102,468	252,405	314,468
Adjustments to NOI		(600)	(1,003)	(2,844)	(8,464)
Adjusted NOI		75,686	101,465	249,561	306,004
Addback adjustments		600	1,003	2,844	8,464
Interest income		0	0	0	0
Interest expense		(640)	(644)	(1,898)	(8,859)
Depreciation and amortization		(25,547)	(34,030)	(77,478)	(101,737)
General and administrative		0	0	0	0
Acquisition and pursuit costs		0	0	0	0
Recoveries (impairments), net		0		0
Gain (loss) on sales of real estate, net		(6)	0	268,227	23,940
Loss on debt extinguishments		0		0
Other income (expense), net		0	0	0	0
Income tax benefit (expense)		0	0	0	0
Less: HCP share of unconsolidated JV NOI		0	0	0	0
Equity income (loss) from unconsolidated JVs		0	0	0	0
Discontinued operations			0		0
Net income (loss)		50,093	67,794	441,256	227,812
SHOP | Operating segment
Segment reporting information, revenues
Rental revenues		126,040	170,739	391,684	500,704
HCP share of unconsolidated JV revenues		81,936	50,973	239,667	152,424
Operating expenses		(86,821)	(121,502)	(267,226)	(350,949)
HCP share of unconsolidated JV operating expenses		(65,035)	(42,463)	(190,049)	(125,244)
Segment NOI		56,120	57,747	174,076	176,935
Adjustments to NOI		4,551	4,081	12,229	14,648
Adjusted NOI		60,671	61,828	186,305	191,583
Addback adjustments		(4,551)	(4,081)	(12,229)	(14,648)
Interest income		0	0	0	0
Interest expense		(933)	(8,130)	(6,950)	(23,818)
Depreciation and amortization		(24,884)	(26,837)	(75,657)	(78,124)
General and administrative		0	0	0	0
Acquisition and pursuit costs		0	0	0	0
Recoveries (impairments), net		0		0
Gain (loss) on sales of real estate, net		5,180	0	5,313	0
Loss on debt extinguishments		0		0
Other income (expense), net		0	0	0	0
Income tax benefit (expense)		0	0	0	0
Less: HCP share of unconsolidated JV NOI		(16,901)	(8,510)	(49,618)	(27,180)
Equity income (loss) from unconsolidated JVs		(245)	(3,517)	683	(8,477)
Discontinued operations			0		0
Net income (loss)		18,337	10,753	47,847	39,336
Life science
Segment reporting information, revenues
Gain (loss) on sales of real estate, net	$ 45,000
Life science | Operating segment
Segment reporting information, revenues
Rental revenues		90,174	90,847	262,224	269,994
HCP share of unconsolidated JV revenues		2,031	1,929	5,975	5,628
Operating expenses		(19,960)	(18,487)	(56,024)	(53,191)
HCP share of unconsolidated JV operating expenses		(433)	(406)	(1,234)	(1,173)
Segment NOI		71,812	73,883	210,941	221,258
Adjustments to NOI		(751)	(314)	(1,094)	(1,545)
Adjusted NOI		71,061	73,569	209,847	219,713
Addback adjustments		751	314	1,094	1,545
Interest income		0	0	0	0
Interest expense		(87)	(634)	(288)	(1,904)
Depreciation and amortization		(30,851)	(31,967)	(95,648)	(97,640)
General and administrative		0	0	0	0
Acquisition and pursuit costs		0	0	0	0
Recoveries (impairments), net		0		0
Gain (loss) on sales of real estate, net		8	0	45,922	29,428
Loss on debt extinguishments		0		0
Other income (expense), net		0	0	0	0
Income tax benefit (expense)		0	0	0	0
Less: HCP share of unconsolidated JV NOI		(1,598)	(1,523)	(4,741)	(4,455)
Equity income (loss) from unconsolidated JVs		789	778	2,322	2,263
Discontinued operations			0		0
Net income (loss)		40,073	40,537	158,508	148,950
Medical office | Operating segment
Segment reporting information, revenues
Rental revenues		119,847	113,653	357,381	331,881
HCP share of unconsolidated JV revenues		496	502	1,481	1,503
Operating expenses		(46,486)	(44,738)	(137,930)	(129,715)
HCP share of unconsolidated JV operating expenses		(143)	(148)	(431)	(452)
Segment NOI		73,714	69,269	220,501	203,217
Adjustments to NOI		(582)	(814)	(2,321)	(2,361)
Adjusted NOI		73,132	68,455	218,180	200,856
Addback adjustments		582	814	2,321	2,361
Interest income		0	0	0	0
Interest expense		(126)	(1,608)	(382)	(4,899)
Depreciation and amortization		(42,047)	(41,111)	(127,261)	(120,432)
General and administrative		0	0	0	0
Acquisition and pursuit costs		0	0	0	0
Recoveries (impairments), net		0		0
Gain (loss) on sales of real estate, net		0	(9)	(406)	8,333
Loss on debt extinguishments		0		0
Other income (expense), net		0	0	0	0
Income tax benefit (expense)		0	0	0	0
Less: HCP share of unconsolidated JV NOI		(353)	(354)	(1,050)	(1,051)
Equity income (loss) from unconsolidated JVs		274	462	846	1,541
Discontinued operations			0		0
Net income (loss)		31,462	26,649	92,248	86,709
Other non-reportable segments | Operating segment
Segment reporting information, revenues
Rental revenues		28,968	30,574	87,524	95,483
HCP share of unconsolidated JV revenues		421	410	1,256	1,224
Operating expenses		(1,137)	(1,193)	(3,475)	(3,375)
HCP share of unconsolidated JV operating expenses		(20)	(20)	(58)	(30)
Segment NOI		28,232	29,771	85,247	93,302
Adjustments to NOI		(1,283)	(1,140)	(3,164)	(1,926)
Adjusted NOI		26,949	28,631	82,083	91,376
Addback adjustments		1,283	1,140	3,164	1,926
Interest income		11,774	20,482	50,974	71,298
Interest expense		(618)	(2,260)	(3,541)	(7,067)
Depreciation and amortization		(7,259)	(7,462)	(21,849)	(23,248)
General and administrative		0	0	0	0
Acquisition and pursuit costs		0	0	0	0
Recoveries (impairments), net		(25,328)		(82,010)
Gain (loss) on sales of real estate, net		0	0	3,796	57,904
Loss on debt extinguishments		0		0
Other income (expense), net		0	0	0	0
Income tax benefit (expense)		0	0	0	0
Less: HCP share of unconsolidated JV NOI		(401)	(390)	(1,198)	(1,194)
Equity income (loss) from unconsolidated JVs		244	224	720	645
Discontinued operations			0		0
Net income (loss)		$ 6,644	$ 40,365	$ 32,139	$ 191,640