Dispositions (Details)		1 Months Ended	3 Months Ended	12 Months Ended
	Aug. 17, 2015 USD ($) property	Feb. 12, 2016 USD ($) property	Dec. 31, 2015 USD ($) loan	Dec. 31, 2015 USD ($) property loan	Dec. 31, 2014 USD ($) property	Dec. 31, 2013 USD ($) property
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from debt related to CCP Spin-off				$ 1,400,000,000	$ 0	$ 0
Repayment of debt				(1,435,596,000)	(1,151,395,000)	(1,792,492,000)
Cash distribution to common stockholders				(1,003,413,000)	(875,614,000)	(802,123,000)
Impairment of real estate				42,200,000	56,600,000	51,500,000
Impairment of assets to be disposed of				8,900,000	13,200,000	41,600,000
Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Debt instrument, face amount		$ 200,000,000
CCP
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Amount charge for Service Fee				2,500,000
Income related to Service Fee				900,000
Dispositions 2015, Not Including Care Capital Properties Inc.
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net income from discontinued operations				1,000,000	$ 5,100,000	30,300,000
2015 Dispositions
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of real estate properties including termination fees				541,000,000
Lease termination fees				6,000,000.0
Net gain on the sales of assets				46,300,000
Deferred gain on sale of property			$ 27,400,000	$ 27,400,000
2015 Dispositions | Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of real estate properties including termination fees		54,500,000
Net gain on the sales of assets		$ 26,900,000
2015 Dispositions | Medical Office Buildings | Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties sold | property		1
2015 Dispositions | Seniors Housing Communities | Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties sold | property		1
2015 Dispositions | Triple-net leased properties
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties sold | property				39
2015 Dispositions | Triple-net leased properties | Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties sold | property		1
2015 Dispositions | MOB operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties sold | property				4	4
2015 Dispositions | MOB operations | Medical Office Buildings
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties sold | property				26
2014 Dispositions
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of real estate properties including termination fees					$ 118,200,000
Net gain on the sales of assets					1,500,000
Gain from sale of assets					$ 21,300,000
2014 Dispositions | Triple-net leased properties
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties sold | property					16
2014 Dispositions | Senior living operations | Seniors Housing Communities
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties sold | property					2
2014 Dispositions | MOB operations | Medical Office Buildings
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties sold | property					4
2013 Dispositions
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of real estate properties including termination fees						35,100,000
Lease termination fees						300,000
Net gain on the sales of assets						$ 5,000,000
2013 Dispositions | Triple-net leased properties
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties sold | property						19
2013 Dispositions | Senior living operations | Seniors Housing Communities
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties sold | property						1
2013 Dispositions | MOB operations | Medical Office Buildings
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties sold | property						2
Spinoff | CCP
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties sold | property	355				323
Shares received from spinoff	0.25
Proceeds from debt related to CCP Spin-off	$ 1,400,000,000
Dividends received	1,300,000,000
Repayment of debt	(1,100,000,000)
Cash distribution to common stockholders	$ (200,000,000)
Transaction cost due to discontinued operations				$ 42,300,000	$ 200,000
Stock-based compensation				3,500,000
Capital and development project expense			$ 21,800,000		17,200,000	$ 10,200,000
Net income from discontinued operations				10,104,000	94,629,000	109,511,000
Net gain on the sales of assets				$ 0	$ 0	$ 0
Secured Debt
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of loans | loan			1	1
Debt instrument, face amount			$ 78,400,000	$ 78,400,000
Non-mortgaged
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of loans | loan			1	1
Debt instrument, face amount			$ 20,000,000	$ 20,000,000