Segment Disclosures (Details 3) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Segment Disclosure
Assets held-for-sale, net	$ 130,765		$ 145,621
Total assets	19,889,509	[1]	19,915,555	[1]
Goodwill	50,346		50,346
Operating segment
Segment Disclosure
Gross assets	21,278,720		20,834,231
Accumulated depreciation and amortization	(2,192,342)		(1,900,221)
Assets held-for-sale, net	130,765		145,621
Total assets	19,086,378		18,934,010
Operating segment | Senior housing
Segment Disclosure
Gross assets	7,811,003		7,654,221
Goodwill	31,000
Operating segment | Post-acute/skilled nursing
Segment Disclosure
Gross assets	6,269,566		6,080,826
Goodwill	3,000
Operating segment | Life science
Segment Disclosure
Gross assets	3,969,723		3,932,397
Operating segment | Medical office
Segment Disclosure
Gross assets	2,686,241		2,661,394
Goodwill	11,000
Operating segment | Hospital
Segment Disclosure
Gross assets	542,187		505,393
Assets held-for-sale, net	131,000		146,000
Goodwill	5,000
Other non-segment
Segment Disclosure
Total assets	$ 672,366		$ 835,924

[1] The Company's consolidated total assets at September 30, 2013 and December 31, 2012, include assets of certain variable interest entities ("VIEs") that can only be used to settle the liabilities of those VIEs. At September 30, 2013: $1.5 million, other assets, net. At December 31, 2012: accounts receivable, net, $2 million; cash and cash equivalents, $10 million; and other assets, net, $2 million, respectively. See Note 16 to the Condensed Consolidated Financial Statements for additional information.