Quarterly report pursuant to Section 13 or 15(d)

Properties, net (Details)

v2.4.0.6
Properties, net (Details) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2013
Dec. 31, 2012
Properties    
Operating properties, net $ 2,705,335 $ 2,597,666
Operating properties, net
   
Properties    
Less: accumulated depreciation (576,299) (555,975)
Operating properties, net | Land
   
Properties    
Gross 431,152 427,766
Operating properties, net | Buildings and improvements
   
Properties    
Gross $ 2,850,482 $ 2,725,875