Employee Benefit Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Employee Thrift Plan
Defined Benefit Plan Disclosure [Line Items]
Bank's expense related to the thrift plan	$ 1,400	$ 1,200	$ 942
Thrift Plan owns outstanding shares (in shares)	851,388
Percentage of outstanding shares owns with thrift plan	1.90%
Pentegra Plan
Defined Benefit Plan Disclosure [Line Items]
Termination liability	$ 3,400
Withdrawal liability	2,900
Termination expense	$ 460