Dispositions of Real Estate and Discontinued Operations (Details)		9 Months Ended
	Oct. 06, 2015 USD ($)	Sep. 30, 2015 USD ($) property	Sep. 30, 2014 USD ($) item	Aug. 29, 2014 USD ($) property
Operating income from discontinued operations
Rental and related revenues			$ 1,810,000
Operating expenses			54,000
Other expenses, net			20,000
Income before gain on sales of real estate, net of income taxes			1,736,000
Gain on sales of real estate, net of income taxes			$ 28,010,000
Number of properties included in discontinued operations | item			3
Brookdale Senior Living
Dispositions of Real Estate and Land
Carrying value of properties contributed				$ 92,000,000
Senior housing
Dispositions of Real Estate and Land
Number of properties disposed | property		9
Total consideration for disposition of real estate		$ 60,000,000
Post-acute/skilled
Dispositions of Real Estate and Land
Number of properties disposed | item			2
Total consideration for disposition of real estate			$ 22,000,000
Life science
Dispositions of Real Estate and Land
Total consideration for disposition of real estate		11,000,000
Life science | Subsequent event
Dispositions of Real Estate and Land
Total consideration for disposition of real estate	$ 40,000,000
Hospital
Dispositions of Real Estate and Land
Total consideration for disposition of real estate			17,000,000
Medical office
Dispositions of Real Estate and Land
Total consideration for disposition of real estate		$ 400,000	$ 145,000
CCRC JV | Senior housing
Dispositions of Real Estate and Land
Number of properties contributed to joint venture | property				3
Carrying value of properties contributed				$ 92,000,000