Employee Benefit and Deferred Compensation Plans - Plan Expense for Non-Contributory Benefit Pension Plan and Post-Retirement Health and Life Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Pension Benefits
Plan expense for noncontributory benefit pension plan and post-retirement health and life plans
Interest cost	$ 237	$ 227	$ 711	$ 681
Expected return on plan assets	(267)	(249)	(801)	(745)
Recognized actuarial loss (gain)	121	129	364	387
Net periodic benefit cost (return)	91	107	274	323
Other Benefits
Plan expense for noncontributory benefit pension plan and post-retirement health and life plans
Interest cost	5	5	15	16
Expected return on plan assets	0	0	0	0
Recognized actuarial loss (gain)	(22)	(23)	(66)	(70)
Net periodic benefit cost (return)	$ (17)	$ (18)	$ (51)	$ (54)