Pension and Other Postretirement Plans - Obligations and Funded Status (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Pension Plans
Changes in projected benefit obligations:
Projected benefit obligations at beginning of year	$ 23,927	$ 22,689
Service cost	119	107	$ 96
Interest cost	528	674	839
Plan amendments	0	0
Actuarial (gain) loss	(805)	2,153
Benefits paid	(1,713)	(1,696)
Projected benefit obligations at end of year	22,056	23,927	22,689
Changes in plan assets:
Fair value of plan assets at beginning of year	20,833	18,512
Actual return on plan assets	3,265	2,910
Contributions	856	1,107
Benefits paid	(1,713)	(1,696)
Fair value of plan assets at end of year	23,241	20,833	18,512
Funded status at end of year	1,185	(3,094)
Chairman and President Non-Qualified Defined Benefit Plans
Changes in projected benefit obligations:
Projected benefit obligations at beginning of year	51,571	29,258
Service cost	1,235	1,209	502
Interest cost	1,044	1,350	1,025
Actuarial (gain) loss	(7,420)	21,736
Benefits paid	(1,982)	(1,982)
Projected benefit obligations at end of year	44,448	51,571	29,258
Changes in plan assets:
Fair value of plan assets at beginning of year	0	0
Contributions	1,982	1,982
Benefits paid	(1,982)	(1,982)
Fair value of plan assets at end of year	0	0	0
Funded status at end of year	(44,448)	(51,571)
Defined Benefit Postretirement Healthcare Plans
Changes in projected benefit obligations:
Projected benefit obligations at beginning of year	6,469	5,782
Interest cost	148	165	198
Actuarial (gain) loss	(457)	522
Benefits paid	0	0
Projected benefit obligations at end of year	6,160	6,469	5,782
Changes in plan assets:
Fair value of plan assets at beginning of year	0	0
Contributions	0	0
Benefits paid	0	0
Fair value of plan assets at end of year	0	0	$ 0
Funded status at end of year	$ (6,160)	$ (6,469)