Retirement Plans, Schedule of Change in Benefit Obligation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pension Plan [Member]
Change in benefit obligation [Roll Forward]
Benefit obligation at beginning of year	$ 495,272	$ 508,694
Service cost	6,538	7,961	$ 7,671
Interest cost	14,779	14,239	15,630
Actuarial (gain) loss	158,816	(20,208)
Gross benefits paid	(12,665)	(11,967)
Settlements	5,599	(3,447)
Benefit obligation at end of year	339,509	495,272	508,694
Accumulated benefit obligation at end of year	325,274	469,508
SERP [Member]
Change in benefit obligation [Roll Forward]
Benefit obligation at beginning of year	1,033	1,174
Service cost	0	0	0
Interest cost	29	31	40
Actuarial (gain) loss	(74)	(12)
Gross benefits paid	(155)	(160)
Settlements	0	0
Benefit obligation at end of year	833	1,033	1,174
Accumulated benefit obligation at end of year	833	1,033
Other Postretirement Benefits [Member]
Change in benefit obligation [Roll Forward]
Benefit obligation at beginning of year	582	629
Service cost	0	0
Interest cost	17	17	22
Actuarial (gain) loss	(58)	104
Gross benefits paid	(109)	(168)
Settlements	0	0
Benefit obligation at end of year	432	582	$ 629
Accumulated benefit obligation at end of year	$ 432	$ 582