Retirement Plans - Components of Defined Benefit Pension and Post-retirement Benefit Plans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Change in plan assets
Company contributions	$ 0	$ 0	$ 0
Pensions
Change in projected benefit obligation
Beginning balance	45,000,000.0	36,500,000
Service cost	1,700,000	1,600,000	1,200,000
Interest cost	1,100,000	1,200,000	1,200,000
Actuarial loss (gain)	(2,100,000)	6,100,000
Plan amendments	300,000	300,000
Benefit payments	(1,000,000.0)	(700,000)
Ending balance	45,000,000.0	45,000,000.0	36,500,000
Change in plan assets
Beginning balance, fair value of plan asset	31,200,000	26,800,000
Actual return on plan assets	1,400,000	5,000,000.0
Company contributions	200,000	100,000
Benefit payments	(1,000,000.0)	(700,000)
Ending balance, fair value of plan asset	31,800,000	31,200,000	26,800,000
Net Funded Status of the Plan (Liability)	(13,200,000)	(13,800,000)
Pension and other postretirement benefit asset	0	0
Pension and other postretirement benefit (liability)	(13,200,000)	(13,800,000)
Other Benefits
Change in projected benefit obligation
Beginning balance	1,000,000.0	900,000
Service cost	0	0	0
Interest cost	0	0	0
Actuarial loss (gain)	(100,000)	100,000
Plan amendments	0	0
Benefit payments	0	0
Ending balance	900,000	1,000,000.0	900,000
Change in plan assets
Beginning balance, fair value of plan asset	0	0
Actual return on plan assets	0	0
Company contributions	0	0
Benefit payments	0	0
Ending balance, fair value of plan asset	0	0	$ 0
Net Funded Status of the Plan (Liability)	(900,000)	(1,000,000.0)
Pension and other postretirement benefit asset	0	0
Pension and other postretirement benefit (liability)	$ (900,000)	$ (1,000,000.0)
Qualified Plan | Pensions
Defined Benefit Plan Disclosure
Discount rate	2.75%	2.45%
Qualified Plan | Other Benefits
Defined Benefit Plan Disclosure
Discount rate	0.00%	0.00%
Nonqualified Plan | Pensions
Defined Benefit Plan Disclosure
Discount rate	2.65%	2.30%
Nonqualified Plan | Other Benefits
Defined Benefit Plan Disclosure
Discount rate	2.60%	2.20%