Annual report pursuant to Section 13 and 15(d)

Properties, net (Details)

v2.4.0.6
Properties, net (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Properties        
Gross $ 3,859,960 $ 4,038,932 $ 3,948,487 $ 3,452,512
Operating properties, net 2,597,666 2,714,056    
Operating properties, net
       
Properties        
Less: accumulated depreciation (555,975) (559,679)    
Operating properties, net | Land
       
Properties        
Gross 427,766 472,483    
Operating properties, net | Buildings and improvements
       
Properties        
Gross $ 2,725,875 $ 2,801,252