Quarterly report pursuant to Section 13 or 15(d)

Fair Value of Financial Instruments (Details)

v3.7.0.1
Fair Value of Financial Instruments (Details) - USD ($)
$ in Thousands
Jun. 30, 2017
Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Repurchase agreements $ 13,316,881 $ 9,316,351
Long-term Federal Home Loan Bank Advances 3,238,762  
Maturity Over One Year [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Repurchase agreements $ 547,366 $ 185,634