Investment Securities - Schedule of Held-to-maturity, Allowance for Credit Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Allowance for credit losses:
Beginning balance	$ 6
Ending balance	4	$ 6
State and political subdivisions
Allowance for credit losses:
Beginning balance	6	0
Provision for credit losses	(2)	(2)
Charge-offs, net	0	0
Ending balance	4	6
State and political subdivisions | Impact of adoption ASC 326
Allowance for credit losses:
Beginning balance	$ 0	8
Ending balance		$ 0