Annual report pursuant to Section 13 and 15(d)

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

v3.8.0.1
Derivative Instruments and Hedging Activities Schedule of Interest Rate Swap Receivers (Details) - USD ($)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Derivative [Line Items]      
Notional $ 31,226,878,000 $ 18,802,500,000 $ 21,998,381,000
Interest Rate Swap [Member] | Short [Member]      
Derivative [Line Items]      
Notional $ 5,561,990,000 $ 5,064,000,000  
Weighted Average Variable Interest Rate 1.462% 0.941%  
Weighted Average Fixed Interest Rate 2.211% 1.894%  
Weighted Average Remaining Maturity 7 years 7 months 28 days 4 years 6 months 27 days  
Interest Rate Swap [Member] | Derivative Maturity Over One And Within Two Years From Balance Sheet Date [Member] | Short [Member]      
Derivative [Line Items]      
Notional   $ 575,000,000  
Weighted Average Variable Interest Rate   0.911%  
Weighted Average Fixed Interest Rate   1.44%  
Weighted Average Remaining Maturity   1 year 10 months 21 days  
Interest Rate Swap [Member] | Derivative Maturity Over Two And Within Three Years From Balance Sheet Date [Member] | Short [Member]      
Derivative [Line Items]      
Notional $ 200,000,000 $ 500,000,000  
Weighted Average Variable Interest Rate 1.391% 0.882%  
Weighted Average Fixed Interest Rate 1.642% 1.042%  
Weighted Average Remaining Maturity 2 years 7 months 5 days 2 years 22 days  
Interest Rate Swap [Member] | Derivative Maturity Over Three And Within Four Years From Balance Sheet Date [Member] | Short [Member]      
Derivative [Line Items]      
Notional $ 500,000,000 $ 510,000,000  
Weighted Average Variable Interest Rate 1.357% 0.881%  
Weighted Average Fixed Interest Rate 1.327% 1.58%  
Weighted Average Remaining Maturity 3 years 19 days 3 years 7 months 4 days  
Interest Rate Swap [Member] | Derivative Maturity Over Four Years From Balance Sheet Date [Member] | Short [Member]      
Derivative [Line Items]      
Notional $ 4,861,990,000 $ 3,479,000,000  
Weighted Average Variable Interest Rate 1.475% 0.963%  
Weighted Average Fixed Interest Rate 2.325% 2.137%  
Weighted Average Remaining Maturity 8 years 4 months 4 days 5 years 6 months 8 days