Annual report pursuant to Section 13 and 15(d)

Derivative Instruments and Hedging Activities Interest Rate Sensitive Assets/Liabilities (Details)

v3.20.4
Derivative Instruments and Hedging Activities Interest Rate Sensitive Assets/Liabilities (Details) - USD ($)
$ in Thousands
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Derivatives, Fair Value [Line Items]        
Available-for-sale securities, at fair value $ 14,650,922 $ 31,406,328    
Mortgage servicing rights, at fair value 1,596,153 1,909,444 $ 1,993,440 $ 1,086,717
Interest-Only-Strip [Member]        
Derivatives, Fair Value [Line Items]        
Available-for-sale securities, at fair value $ 245,900 $ 122,200