Debt - Schedule of Debt Maturities of Company's Revolving Credit Facilities, Mortgages and Notes Payable, Including Balloon Payments (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Scheduled Principal Payments For Borrowings [Line Items]    
Total debt, net $ 4,369,634 $ 3,778,218
Mortgages and Notes Payable [Member]    
Scheduled Principal Payments For Borrowings [Line Items]    
2015 352,924  
2016 319,212  
2017 869,644  
2018 292,601  
2019 497,771  
Thereafter 2,089,068  
Total debt, net 4,421,220  
Mortgages and Notes Payable [Member] | Scheduled Principal [Member]    
Scheduled Principal Payments For Borrowings [Line Items]    
2015 31,552  
2016 30,167  
2017 29,667  
2018 43,750  
2019 45,771  
Thereafter 289,752  
Total debt, net 470,659  
Mortgages and Notes Payable [Member] | Balloon Payment [Member]    
Scheduled Principal Payments For Borrowings [Line Items]    
2015 321,372  
2016 289,045  
2017 839,977  
2018 248,851  
2019 452,000  
Thereafter 1,799,316  
Total debt, net $ 3,950,561