Debt - Summary of Debt (Details) - USD ($)
$ in Thousands
9 Months Ended
Sep. 30, 2019
Dec. 31, 2018
May 31, 2014
Debt Instrument [Line Items]      
Total debt, gross $ 2,106,741 $ 2,084,302  
Debt discount, net (10,664) (14,733)  
Deferred financing costs, net (18,569) (14,932)  
Total debt, net $ 2,077,508 2,054,637  
Weighted Average      
Debt Instrument [Line Items]      
Effective Interest Rates 4.56%    
Stated Interest Rate 3.93%    
Remaining Term to Maturity 7 years 1 month 6 days    
Revolving credit facilities      
Debt Instrument [Line Items]      
Total debt, gross   146,300  
Revolving credit facilities | Weighted Average      
Debt Instrument [Line Items]      
Effective Interest Rates 6.40%    
Remaining Term to Maturity 3 years 6 months    
Term loans      
Debt Instrument [Line Items]      
Total debt, gross   420,000  
Term loans | Weighted Average      
Debt Instrument [Line Items]      
Effective Interest Rates 3.87%    
Senior Unsecured Notes      
Debt Instrument [Line Items]      
Total debt, gross $ 1,500,000 300,000  
Deferred financing costs, net $ (13,400) (2,700)  
Senior Unsecured Notes | Weighted Average      
Debt Instrument [Line Items]      
Effective Interest Rates 3.74%    
Stated Interest Rate 3.73%    
Remaining Term to Maturity 8 years 10 months 24 days    
Master Trust Notes      
Debt Instrument [Line Items]      
Total debt, gross   167,854  
Master Trust Notes | Weighted Average      
Debt Instrument [Line Items]      
Effective Interest Rates 5.53%    
CMBS      
Debt Instrument [Line Items]      
Total debt, gross $ 261,741 274,758  
Deferred financing costs, net $ (2,700) (3,200)  
CMBS | Weighted Average      
Debt Instrument [Line Items]      
Effective Interest Rates 5.73%    
Stated Interest Rate 5.35%    
Remaining Term to Maturity 3 years 10 months 24 days    
CMBS | Minimum      
Debt Instrument [Line Items]      
Stated Interest Rate 4.67%    
CMBS | Maximum      
Debt Instrument [Line Items]      
Stated Interest Rate 6.00%    
Related party notes payable | Affiliated Entity | Mortgage loans payable      
Debt Instrument [Line Items]      
Total debt, gross   $ 27,890  
Related party notes payable | Weighted Average | Affiliated Entity | Mortgage loans payable      
Debt Instrument [Line Items]      
Effective Interest Rates 0.96% 1.00%  
Convertible Notes      
Debt Instrument [Line Items]      
Total debt, gross $ 345,000 $ 747,500  
Deferred financing costs, net $ (2,400) $ (4,300) $ (19,600)
Convertible Notes | Weighted Average      
Debt Instrument [Line Items]      
Effective Interest Rates 5.18%    
Stated Interest Rate 3.75%    
Remaining Term to Maturity 1 year 7 months 6 days