Quarterly report pursuant to Section 13 or 15(d)

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

v3.20.2
Derivative Instruments and Hedging Activities Interest Rate Sensitive Assets/Liabilities (Details) - USD ($)
$ in Thousands
Sep. 30, 2020
Jun. 30, 2020
Dec. 31, 2019
Sep. 30, 2019
Jun. 30, 2019
Dec. 31, 2018
Derivatives, Fair Value [Line Items]            
Available-for-sale securities, at fair value $ 16,574,321   $ 31,406,328      
Mortgage servicing rights, at fair value 1,257,503 $ 1,279,195 1,909,444 $ 1,651,556 $ 1,800,826 $ 1,993,440
Interest-Only-Strip [Member]            
Derivatives, Fair Value [Line Items]            
Available-for-sale securities, at fair value $ 48,700   $ 122,200