Quarterly report pursuant to Section 13 or 15(d)

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

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Derivative Instruments and Hedging Activities Schedule of Interest Rate Swap Payers (Details) - USD ($)
3 Months Ended 12 Months Ended
Mar. 31, 2018
Dec. 31, 2017
Mar. 31, 2017
Dec. 31, 2016
Derivative [Line Items]        
Notional $ 18,429,288,000 $ 31,226,878,000 $ 15,935,535,000 $ 18,802,500,000
Interest Rate Swap [Member] | Long [Member]        
Derivative [Line Items]        
Notional $ 17,422,825,000 $ 22,920,135,000    
Weighted Average Fixed Interest Rate 1.831% 1.694%    
Weighted Average Variable Interest Rate 1.936% 1.493%    
Weighted Average Remaining Maturity 3 years 7 months 25 days 3 years 2 days    
Interest Rate Swap [Member] | Derivative Maturity Within One Year From Balance Sheet Date [Member] | Long [Member]        
Derivative [Line Items]        
Notional $ 2,020,000,000 $ 4,320,000,000    
Weighted Average Fixed Interest Rate 1.289% 1.155%    
Weighted Average Variable Interest Rate 1.885% 1.508%    
Weighted Average Remaining Maturity 7 months 7 days 6 months 1 day    
Interest Rate Swap [Member] | Derivative Maturity Over One And Within Two Years From Balance Sheet Date [Member] | Long [Member]        
Derivative [Line Items]        
Notional $ 4,336,897,000 $ 5,448,135,000    
Weighted Average Fixed Interest Rate 1.769% 1.767%    
Weighted Average Variable Interest Rate 1.802% 1.386%    
Weighted Average Remaining Maturity 1 year 6 months 15 days 1 year 9 months 14 days    
Interest Rate Swap [Member] | Derivative Maturity Over Two And Within Three Years From Balance Sheet Date [Member] | Long [Member]        
Derivative [Line Items]        
Notional $ 2,890,000,000 $ 5,490,000,000    
Weighted Average Fixed Interest Rate 1.785% 1.945%    
Weighted Average Variable Interest Rate 1.952% 1.509%    
Weighted Average Remaining Maturity 2 years 6 months 22 days 2 years 10 months 15 days    
Interest Rate Swap [Member] | Derivative Maturity Over Three And Within Four Years From Balance Sheet Date [Member] | Long [Member]        
Derivative [Line Items]        
Notional $ 2,417,000,000 $ 2,417,000,000    
Weighted Average Fixed Interest Rate 1.788% 1.788%    
Weighted Average Variable Interest Rate 2.198% 1.628%    
Weighted Average Remaining Maturity 3 years 8 months 3 years 11 months    
Interest Rate Swap [Member] | Derivative Maturity Over Four Years From Balance Sheet Date [Member] | Long [Member]        
Derivative [Line Items]        
Notional $ 5,758,928,000 $ 5,245,000,000    
Weighted Average Fixed Interest Rate 2.20% 1.764%    
Weighted Average Variable Interest Rate 1.936% 1.516%    
Weighted Average Remaining Maturity 7 years 10 months 16 days 6 years 5 months 7 days    
Forward Starting Interest Rate Swap [Member]        
Derivative [Line Items]        
Notional $ 1,400,313,000 $ 570,000,000    
Weighted Average Fixed Interest Rate 2.50% 2.10%