Annual report pursuant to Section 13 and 15(d)

Derivative Instruments and Hedging Activities Schedule of Interest Rate Swaps Associated with Borrowings (Details)

v3.6.0.2
Derivative Instruments and Hedging Activities Schedule of Interest Rate Swaps Associated with Borrowings (Details)
$ in Thousands
Dec. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Dec. 31, 2014
USD ($)
Derivative [Line Items]      
Derivative, Notional Amount $ 18,802,500 $ 21,998,381 $ 48,115,523
Forward Starting Interest Rate Swap [Member]      
Derivative [Line Items]      
Derivative, Notional Amount $ 777,063    
Derivative, Average Fixed Interest Rate 2.00%    
Interest Rate Swap [Member]      
Derivative [Line Items]      
Derivative, Notional Amount $ 20,371,063 14,268,806 $ 18,584,000
Interest Rate Swap [Member] | Interest Rate Risk Associated with Borrowings [Member]      
Derivative [Line Items]      
Derivative, Notional Amount $ 10,057,063 $ 7,854,806  
Derivative, Average Fixed Interest Rate 1.405% 1.094%  
Derivative, Average Variable Interest Rate 0.927% 0.437%  
Derivative, Average Remaining Period Until Maturity 3.85 3.71  
Interest Rate Swap [Member] | Interest Rate Risk Associated with Borrowings [Member] | Derivative Maturity Within One Year From Balance Sheet Date [Member]      
Derivative [Line Items]      
Derivative, Notional Amount $ 2,375,000 $ 1,700,000  
Derivative, Average Fixed Interest Rate 0.765% 0.462%  
Derivative, Average Variable Interest Rate 0.934% 0.481%  
Derivative, Average Remaining Period Until Maturity 0.59 0.73  
Interest Rate Swap [Member] | Interest Rate Risk Associated with Borrowings [Member] | Derivative Maturity Over One And Within Two Years From Balance Sheet Date [Member]      
Derivative [Line Items]      
Derivative, Notional Amount $ 1,300,000 $ 2,375,000  
Derivative, Average Fixed Interest Rate 1.002% 0.765%  
Derivative, Average Variable Interest Rate 0.86% 0.51%  
Derivative, Average Remaining Period Until Maturity 1.60 1.59  
Interest Rate Swap [Member] | Interest Rate Risk Associated with Borrowings [Member] | Derivative Maturity Over Two And Within Three Years From Balance Sheet Date [Member]      
Derivative [Line Items]      
Derivative, Notional Amount $ 350,000 $ 800,000  
Derivative, Average Fixed Interest Rate 1.283% 0.944%  
Derivative, Average Variable Interest Rate 0.895% 0.384%  
Derivative, Average Remaining Period Until Maturity 2.44 2.14  
Interest Rate Swap [Member] | Interest Rate Risk Associated with Borrowings [Member] | Derivative Maturity Over Three And Within Four Years From Balance Sheet Date [Member]      
Derivative [Line Items]      
Derivative, Notional Amount $ 1,150,000 $ 350,000  
Derivative, Average Fixed Interest Rate 1.463% 1.283%  
Derivative, Average Variable Interest Rate 0.93% 0.34%  
Derivative, Average Remaining Period Until Maturity 3.78 3.44  
Interest Rate Swap [Member] | Interest Rate Risk Associated with Borrowings [Member] | Derivative Maturity Over Four Years From Balance Sheet Date [Member]      
Derivative [Line Items]      
Derivative, Notional Amount $ 4,882,063 $ 2,629,806  
Derivative, Average Fixed Interest Rate 1.897% 1.821%  
Derivative, Average Variable Interest Rate 0.946% 0.371%  
Derivative, Average Remaining Period Until Maturity 6.59 8.04