Investment Securities - Allowance for Credit Losses HTM (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Beginning balance	$ 1,279	$ 2,915
Provision for credit loss expense	0	(697)
Securities charged-off	0	600
Recoveries	98
Ending balance	1,377	1,618
State and political subdivisions
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Beginning balance	1,197	2,307
Provision for credit loss expense	0	(1,265)
Securities charged-off	0	0
Recoveries	88
Ending balance	1,285	1,042
Other securities
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Beginning balance	82	608
Provision for credit loss expense	0	568
Securities charged-off	0	600
Recoveries	10
Ending balance	$ 92	$ 576