v2.4.0.6
Income Taxes (Details 3) (USD $)
12 Months Ended
Dec. 31, 2011
Y
Dec. 31, 2010
property
Dec. 31, 2009
Tax effects of temporary differences and carryforwards included in the net deferred tax liabilities      
Property, primarily differences in depreciation and amortization, the tax basis of land assets and the treatment of interests and certain costs $ (332,111,000) $ (287,165,000) $ (293,800,000)
Operating loss and interest deduction carryforwards 343,843,000 103,733,000 86,014,000
Expense accruals and other 11,511,000 3,093,000 (58,000)
Valuation allowance (281,954,000) (60,994,000) (45,821,000)
Net deferred tax liabilities 258,711,000 241,333,000 253,665,000
Deferred Tax Assets, Net 2,000,000    
Increase (decrease) in net deferred tax liability 17,400,000 (12,300,000)  
Number of seniors housing communities noncontrolling interests acquired   58  
Period during which subject built-in gains tax (in years) 10    
NOL carryforward related to TRS entities 240,000,000    
NOL carryforward related to REIT 690,000,000    
NOL carryforward related to Lillibridge, TRS entities 10,400,000    
NOL carryforward related to Lillibridge, REIT entities $ 16,200,000