v2.4.0.6
Acquisitions of Real Estate Property (Details) (USD $)
 12 Months Ended 1 Months Ended 8 Months Ended 12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Oct. 31, 2011
ASLG
May 31, 2011
ASLG
property
Dec. 31, 2011
ASLG
Dec. 31, 2011
ASLG
May 12, 2011
ASLG
Business acquisition                
Business acquisition equity interests issued or issuable, number of shares issued         24,958,543      
Value of common stock shares issued related to acquisition               $ 1,380,000,000
Closing price on acquisition date used to value shares issued in the acquisition (in dollars per share)               $ 55.33
Working capital adjustment, shares cancelled       83,441        
Senior housing communities acquired         117      
Number of development land properties acquired         1      
Revenues attributable to the acquired assets           403,200,000    
NOI attributable to the acquired assets           122,100,000    
Fair values of the assets acquired and liabilities assumed at the date of acquisition                
Land and improvements               341,540,000
Buildings and improvements               2,876,717,000
Acquired lease intangibles               160,340,000
Other assets               216,009,000
Total assets acquired               3,594,606,000
Notes payable and other debt               1,629,212,000
Deferred tax liability               44,608,000
Other liabilities               202,167,000
Total liabilities assumed               1,875,987,000
Net assets acquired               1,718,619,000
Cash acquired               77,718,000
Equity issued               1,376,437,000
Total cash used               264,464,000
Goodwill included in other assets               81,000,000
Total acquisition-related cost           53,300,000 53,300,000  
Acquisition-related costs 153,923,000 19,243,000 13,015,000       48,900,000  
Contingent consideration liabilities, Fair Value           $ 44,200,000 $ 44,200,000 $ 44,200,000