Dispositions, Assets Held for Sale and Discontinued Operations (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Real property dispositions:
Total dispositions			$ 152,312,000	$ 45,929,000
Add: Gain on sales of real property	30,224,000	3,314,000	56,380,000	10,033,000
Seller financing on sales of real property				(1,470,000)
Proceeds from sales of real property			208,692,000	54,492,000
Revenues:
Rental income	4,486,000	10,030,000	9,403,000	21,139,000
Expenses:
Interest expense	812,000	2,072,000	1,756,000	4,132,000
Property operating expenses	830,000	1,033,000	2,215,000	2,961,000
Provision for depreciation	671,000	3,414,000	2,635,000	6,990,000
Income (loss) from discontinued operations, net	2,173,000	3,511,000	2,797,000	7,056,000
Senior housing triple-net [Member]
Real property dispositions:
Total dispositions			117,074,000	38,361,000
Medical facilities [Member]
Real property dispositions:
Total dispositions			$ 35,238,000	$ 7,568,000