Quarterly report pursuant to Section 13 or 15(d)

Available-for-sale Securities Classified by Rate Type (Details)

v3.20.2
Available-for-sale Securities Classified by Rate Type (Details) - USD ($)
$ in Thousands
Jun. 30, 2020
Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]    
Adjustable Rate $ 33,339 $ 3,358,871
Fixed Rate 17,639,950 28,047,457
Available-for-sale securities, at fair value 17,673,289 31,406,328
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]    
Debt Securities, Available-for-sale [Line Items]    
Adjustable Rate 12,904 14,584
Fixed Rate 17,637,205 27,763,471
Available-for-sale securities, at fair value 17,650,109 27,778,055
Mortgage-backed Securities, Issued by Private Enterprises [Member]    
Debt Securities, Available-for-sale [Line Items]    
Adjustable Rate 20,435 3,344,287
Fixed Rate 2,745 283,986
Available-for-sale securities, at fair value $ 23,180 $ 3,628,273