Employee Benefit Plans - Changes in Projected Benefit Obligation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Change in benefit obligation:
Actuarial (gain) loss	$ (6,400)	$ 15,500
DB Pension Plan
Change in benefit obligation:
Benefit obligation at beginning of year	98,021	90,346
Service cost	0	0	$ 0
Interest cost	1,628	2,371	2,936
Plan participants’ contributions	0	0
Actuarial (gain) loss	(2,834)	10,046
Benefits paid	(3,806)	(4,742)
Benefit obligation at end of year	93,009	98,021	90,346
Change in plan assets:
Fair value of plan assets at beginning of year	89,172	82,352
Actual return on plan assets	11,027	11,562
Plan participants’ contributions	0	0
Employer contributions	0	0
Benefits paid	(3,806)	(4,742)
Fair value of plan assets at end of year	96,393	89,172	82,352
Funded (unfunded) status	3,384	(8,849)
Life and Healthcare Plan
Change in benefit obligation:
Benefit obligation at beginning of year	10,508	9,022
Service cost	186	173	159
Interest cost	180	245	289
Plan participants’ contributions	108	90
Actuarial (gain) loss	(574)	1,340
Benefits paid	(353)	(362)
Benefit obligation at end of year	10,055	10,508	9,022
Change in plan assets:
Fair value of plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Plan participants’ contributions	108	90
Employer contributions	245	272
Benefits paid	(353)	(362)
Fair value of plan assets at end of year	0	0	0
Funded (unfunded) status	(10,055)	(10,508)
SERP Plan
Change in benefit obligation:
Benefit obligation at beginning of year	36,710	32,153
Service cost	231	214	157
Interest cost	692	914	909
Plan participants’ contributions	0	0
Actuarial (gain) loss	(3,002)	4,070
Benefits paid	(598)	(641)
Benefit obligation at end of year	34,033	36,710	32,153
Change in plan assets:
Fair value of plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Plan participants’ contributions	0	0
Employer contributions	598	641
Benefits paid	(598)	(641)
Fair value of plan assets at end of year	0	0	$ 0
Funded (unfunded) status	$ (34,033)	$ (36,710)