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
	Mar. 31, 2024	Mar. 31, 2023
Pension Benefits
Plan expense for noncontributory benefit pension plan and post-retirement health and life plans
Interest cost	$ 227	$ 249
Expected return on plan assets	(248)	(309)
Recognized actuarial loss (gain)	129	131
Net periodic benefit cost (return)	108	71
Other Benefits
Plan expense for noncontributory benefit pension plan and post-retirement health and life plans
Interest cost	5	6
Expected return on plan assets	0	0
Recognized actuarial loss (gain)	(23)	(15)
Net periodic benefit cost (return)	$ (18)	$ (9)