Segment Disclosures (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012
Segment Disclosure
Assets held for sale, net	$ 9,819,000		$ 56,659,000
Total assets	20,075,870,000	[1]	19,915,555,000	[1]
Goodwill	50,346,000		50,346,000
Impairment related to goodwill	0
Operating segment
Segment Disclosure
Gross assets	21,381,636,000		20,956,283,000
Accumulated depreciation and amortization	(2,257,188,000)		(1,933,311,000)
Total assets	19,124,448,000		19,022,972,000
Operating segment | Senior housing
Segment Disclosure
Gross assets	7,803,085,000		7,638,316,000
Goodwill	31,000,000
Operating segment | Post-acute/skilled nursing
Segment Disclosure
Gross assets	6,266,938,000		6,039,575,000
Goodwill	3,000,000
Operating segment | Life science
Segment Disclosure
Gross assets	3,986,187,000		3,932,397,000
Operating segment | Medical office
Segment Disclosure
Gross assets	2,686,069,000		2,643,893,000
Goodwill	11,000,000
Operating segment | Hospital
Segment Disclosure
Gross assets	639,357,000		702,102,000
Goodwill	5,000,000
Other non-segment
Segment Disclosure
Total assets	$ 941,603,000		$ 835,924,000

[1] The Company's consolidated total assets at December 31, 2013 and 2012 include assets of certain variable interest entities (VIEs) that can only be used to settle the liabilities of those VIEs. At December 31, 2013: other assets, net, $1 million. At December 31, 2012: accounts receivable, net, $2 million; cash and cash equivalents, $10 million; and other assets, net, $2 million. See Note 21 for additional details.