Debt - Summary of Debt (Details) - USD ($)
$ in Thousands
6 Months Ended
Jun. 30, 2017
Dec. 31, 2016
May 31, 2014
Debt Instrument [Line Items]      
Total debt, gross $ 3,926,442 $ 3,754,633  
Debt discount, net (46,687) (52,894)  
Deferred financing costs, net (33,132) (37,111)  
Total debt, net $ 3,846,623 3,664,628  
Weighted Average      
Debt Instrument [Line Items]      
Weighted average effective interest rates 5.13%    
Weighted average stated rate 4.26%    
Weighted average maturity 4 years 4 months 24 days    
Revolving Credit Facility      
Debt Instrument [Line Items]      
Total debt, gross $ 320,000 86,000  
Revolving Credit Facility | Weighted Average      
Debt Instrument [Line Items]      
Weighted average effective interest rates 4.84%    
Weighted average stated rate 2.41%    
Weighted average maturity 1 year 8 months 12 days    
Term Loan      
Debt Instrument [Line Items]      
Total debt, gross $ 420,000 420,000  
Deferred financing costs, net $ (1,100) (1,500)  
Term Loan | Weighted Average      
Debt Instrument [Line Items]      
Weighted average effective interest rates 2.64%    
Weighted average stated rate 2.57%    
Weighted average maturity 1 year 3 months 18 days    
Senior Unsecured Notes      
Debt Instrument [Line Items]      
Total debt, gross $ 300,000 300,000  
Senior Unsecured Notes | Weighted Average      
Debt Instrument [Line Items]      
Weighted average effective interest rates 4.70%    
Weighted average stated rate 4.45%    
Weighted average maturity 9 years 2 months 12 days    
Master Trust Notes      
Debt Instrument [Line Items]      
Total debt, gross $ 1,662,578 1,672,706  
Debt discount, net (16,679) (18,787)  
Deferred financing costs, net (14,832) (16,376)  
Total debt, net $ 1,631,067 1,637,543  
Master Trust Notes | Weighted Average      
Debt Instrument [Line Items]      
Weighted average effective interest rates 5.58%    
Weighted average stated rate 5.03%    
Weighted average maturity 5 years 8 months 12 days    
CMBS fixed-rate      
Debt Instrument [Line Items]      
Total debt, gross $ 476,364 528,427  
CMBS fixed-rate | Weighted Average      
Debt Instrument [Line Items]      
Weighted average effective interest rates 5.87%    
Weighted average stated rate 5.75%    
Weighted average maturity 3 years 8 months 12 days    
Convertible Notes      
Debt Instrument [Line Items]      
Total debt, gross $ 747,500 747,500  
Deferred financing costs, net $ (9,700) $ (11,400) $ (19,600)
Convertible Notes | Weighted Average      
Debt Instrument [Line Items]      
Weighted average effective interest rates 5.32%    
Weighted average stated rate 3.28%    
Weighted average maturity 2 years 9 months 18 days