Investment Securities - Debt Securities, Held-to-Maturity, Allowance for Credit Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Allowance for credit losses:
Beginning balance	$ 146	$ 196
Credit loss (reduction) expense	(1)	1
Securities charged-off	0	0
Recoveries	0	0
Total ending allowance balance	145	197
State and Political Subdivisions
Allowance for credit losses:
Beginning balance	68	80
Credit loss (reduction) expense	(1)	1
Securities charged-off	0	0
Recoveries	0	0
Total ending allowance balance	67	81
Corporate Securities
Allowance for credit losses:
Beginning balance	78	116
Credit loss (reduction) expense	0	0
Securities charged-off	0	0
Recoveries	0	0
Total ending allowance balance	$ 78	$ 116