Quarterly report pursuant to Section 13 or 15(d)

Derivative Instruments and Hedging Activities Schedule of Interest Rate Caps (Details)

v3.19.1
Derivative Instruments and Hedging Activities Schedule of Interest Rate Caps (Details) - USD ($)
 3 Months Ended 12 Months Ended
Mar. 31, 2019
Dec. 31, 2018
Mar. 31, 2018
Dec. 31, 2017
Derivative [Line Items]        
Notional $ 58,777,783,000 $ 36,528,169,000 $ 18,429,288,000 $ 31,226,878,000
Interest Rate Cap [Member] | Long [Member]        
Derivative [Line Items]        
Notional $ 2,500,000,000 $ 2,500,000,000    
Derivative, Average Cap Interest Rate 1.28% 1.28%    
Weighted Average Variable Interest Rate 2.677% 2.656%    
Weighted Average Remaining Maturity 24 days 1 year 14 days    
Derivative Maturity Within One Year From Balance Sheet Date [Member] | Interest Rate Cap [Member] | Long [Member]        
Derivative [Line Items]        
Notional $ 800,000,000 $ 800,000,000    
Derivative, Average Cap Interest Rate 1.344% 1.344%    
Weighted Average Variable Interest Rate 2.786% 2.422%    
Weighted Average Remaining Maturity 8 days 16 days    
Derivative Maturity Over One And Within Two Years From Balance Sheet Date [Member] | Interest Rate Cap [Member] | Long [Member]        
Derivative [Line Items]        
Notional $ 1,700,000,000 $ 1,700,000,000    
Derivative, Average Cap Interest Rate 1.25% 1.25%    
Weighted Average Variable Interest Rate 2.626% 2.766%    
Weighted Average Remaining Maturity 1 year 14 days 1 year 3 months 14 days