Retirement Plans, Summary of Change in Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Pension Plan [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of year	$ 430,821	$ 395,137
Actual return on plan assets	(72,402)	50,619
Employer contribution	906	479
Gross benefits paid	(12,665)	(11,967)
Settlements	(5,599)	(3,447)
Fair value of plan assets at end of year	341,061	430,821
SERP [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Employer contribution	155	160
Gross benefits paid	(155)	(160)
Settlements	0	0
Fair value of plan assets at end of year	0	0
Other Postretirement Benefits [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Employer contribution	109	168
Gross benefits paid	(109)	(168)
Settlements	0	0
Fair value of plan assets at end of year	$ 0	$ 0