Quarterly report pursuant to Section 13 or 15(d)

Schedule of Repurchase Agreements by Maturity (Details)

v3.20.2
Schedule of Repurchase Agreements by Maturity (Details) - USD ($)
$ in Thousands
Sep. 30, 2020
Dec. 31, 2019
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements $ 16,376,696 $ 29,147,463
Weighted average borrowing rate 0.29% 2.14%
US Government Agencies Debt Securities [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements $ 16,322,224 $ 27,302,527
Weighted average borrowing rate 0.28% 2.08%
Mortgage-backed Securities, Issued by Private Enterprises [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements $ 2,371 $ 1,531,607
Weighted average borrowing rate 2.30% 2.90%
Inverse Interest-Only Securities [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements $ 52,101 $ 50,714
Weighted average borrowing rate 1.02% 2.70%
Mortgage Servicing Rights [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements $ 0 $ 262,615
Weighted average borrowing rate 0.00% 3.51%
Maturity up to 30 days [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements $ 3,790,989 $ 5,305,916
Maturity up to 30 days [Member] | US Government Agencies Debt Securities [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 3,754,489 5,112,681
Maturity up to 30 days [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 0 193,235
Maturity up to 30 days [Member] | Inverse Interest-Only Securities [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 36,500 0
Maturity up to 30 days [Member] | Mortgage Servicing Rights [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 0 0
Maturity 30 to 59 Days [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 3,920,358 6,300,372
Maturity 30 to 59 Days [Member] | US Government Agencies Debt Securities [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 3,903,905 6,074,151
Maturity 30 to 59 Days [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 2,371 212,998
Maturity 30 to 59 Days [Member] | Inverse Interest-Only Securities [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 14,082 13,223
Maturity 30 to 59 Days [Member] | Mortgage Servicing Rights [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 0 0
Maturity 60 to 89 Days [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 0 6,687,285
Maturity 60 to 89 Days [Member] | US Government Agencies Debt Securities [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 0 6,355,887
Maturity 60 to 89 Days [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 0 329,493
Maturity 60 to 89 Days [Member] | Inverse Interest-Only Securities [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 0 1,905
Maturity 60 to 89 Days [Member] | Mortgage Servicing Rights [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 0 0
Maturity 90 to 119 Days [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 3,644,581 4,740,217
Maturity 90 to 119 Days [Member] | US Government Agencies Debt Securities [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 3,644,581 4,227,589
Maturity 90 to 119 Days [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 0 489,352
Maturity 90 to 119 Days [Member] | Inverse Interest-Only Securities [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 0 23,276
Maturity 90 to 119 Days [Member] | Mortgage Servicing Rights [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 0 0
Maturity 120 to 364 days [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 5,020,768 6,113,673
Maturity 120 to 364 days [Member] | US Government Agencies Debt Securities [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 5,019,249 5,532,219
Maturity 120 to 364 days [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 0 306,529
Maturity 120 to 364 days [Member] | Inverse Interest-Only Securities [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 1,519 12,310
Maturity 120 to 364 days [Member] | Mortgage Servicing Rights [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements 0 262,615
Maturity Over One Year [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements $ 0 $ 0