Annual report pursuant to Section 13 and 15(d)

Available-for-Sale Securities, at Fair Value (Details)

v3.22.0.1
Available-for-Sale Securities, at Fair Value (Details) - USD ($)
$ in Thousands
Dec. 31, 2021
Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]    
Available-for-sale securities, at fair value $ 7,161,703 $ 14,650,922
Available-for-sale securities, at fair value, pledged as collateral for borrowings 7,000,000 14,600,000
Federal National Mortgage Association Certificates and Obligations (FNMA) [Member]    
Debt Securities, Available-for-sale [Line Items]    
Available-for-sale securities, at fair value 5,040,988 11,486,658
Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member]    
Debt Securities, Available-for-sale [Line Items]    
Available-for-sale securities, at fair value 1,922,809 2,837,103
Government National Mortgage Association Certificates and Obligations (GNMA) [Member]    
Debt Securities, Available-for-sale [Line Items]    
Available-for-sale securities, at fair value 185,602 314,130
Mortgage-backed Securities, Issued by Private Enterprises [Member]    
Debt Securities, Available-for-sale [Line Items]    
Available-for-sale securities, at fair value $ 12,304 $ 13,031