Dispositions, Assets Held for Sale and Discontinued Operations (Details) (USD $)	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Real property dispositions:
Total dispositions	$ 127,740,000	$ 268,808,000
Net loss (gain) on sales of properties	(13,079,000)	(52,495,000)
Real property held for sale, net of accumulated depreciation	77,436,000		18,502,000
Proceeds from sales of real property	140,819,000	321,303,000
Seniors Housing Facilities Triple Net [Member]
Real property dispositions:
Total dispositions	41,124,000	133,024,000
Net loss (gain) on sales of properties	6,411,000
Real property held for sale, net of accumulated depreciation	18,502,000
Medical facilities [Member]
Real property dispositions:
Total dispositions	$ 86,616,000	$ 135,784,000