Quarterly report pursuant to Section 13 or 15(d)

Schedule of Available-for-sale Securities Reconciliation (Details)

v3.8.0.1
Schedule of Available-for-sale Securities Reconciliation (Details) - USD ($)
$ in Thousands
Sep. 30, 2017
Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]    
Face Value $ 22,841,317 $ 16,303,556
Unamortized premium 1,038,789 571,749
Designated credit reserve (525,687) (367,437)
Net, unamortized (3,606,045) (3,567,420)
Amortized Cost 19,748,374 12,940,448
Gross unrealized gains 571,418 432,398
Gross unrealized losses (120,698) (243,989)
Available-for-sale securities, at fair value 20,199,094 13,128,857
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Face Value 19,303,065 13,571,417
Unamortized premium 1,038,789 571,749
Designated credit reserve 0 0
Net, unamortized (2,789,785) (2,758,445)
Amortized Cost 17,552,069 11,384,721
Gross unrealized gains 120,236 79,040
Gross unrealized losses (117,934) (237,287)
Available-for-sale securities, at fair value 17,554,371 11,226,474
Mortgage-backed Securities, Issued by Private Enterprises [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Face Value 3,538,252 2,732,139
Unamortized premium 0 0
Designated credit reserve (525,687) (367,437)
Net, unamortized (816,260) (808,975)
Amortized Cost 2,196,305 1,555,727
Gross unrealized gains 451,182 353,358
Gross unrealized losses (2,764) (6,702)
Available-for-sale securities, at fair value $ 2,644,723 $ 1,902,383