Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010
Income Taxes (Textuals) [Abstract]
Income tax benefit (expense)	$ 13,904,000	$ (1,657,000)	$ 23,310,000	$ (2,352,000)
Income tax expense related to the noncontrolling interest share of net income	0	600,000	0	1,600,000
Deferred income taxes	274,852,000		274,852,000		241,333,000
Deferred tax liabilities related to Atria Senior Living transaction			$ 43,889,000