Benefit Plans - Liability Under Executive Benefit Plans (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	$ 32,007	$ 31,653
Executive Benefit Plans | Supplemental Savings Incentive Plan and Director Deferral Plan
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	10,111	11,132
Noncurrent liabilities	84,664	80,890
Total liability	94,775	92,022
Executive Benefit Plans | Long-Term Retention Plan
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	178	137
Noncurrent liabilities	6,815	4,728
Total liability	6,993	4,865
Executive Benefit Plans | Officer Retention Plan
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	4,036	4,176
Noncurrent liabilities	37,008	38,605
Total liability	41,044	42,781
Executive Benefit Plans | Long-Term Performance Plan
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	8,247	8,515
Noncurrent liabilities	7,675	7,866
Total liability	$ 15,922	$ 16,381