Quarterly report pursuant to Section 13 or 15(d)

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

v3.20.1
Derivative Instruments and Hedging Activities Interest Rate Sensitive Assets/Liabilities (Details) - USD ($)
$ in Thousands
Mar. 31, 2020
Dec. 31, 2019
Mar. 31, 2019
Dec. 31, 2018
Derivatives, Fair Value [Line Items]        
Available-for-sale securities, at fair value $ 17,733,059 $ 31,406,328    
Mortgage servicing rights, at fair value 1,505,163 1,909,444 $ 2,014,370 $ 1,993,440
Interest-Only-Strip [Member]        
Derivatives, Fair Value [Line Items]        
Available-for-sale securities, at fair value $ 65,100 $ 122,200