Defined Benefit Pension Plans - Fair Values of Plan Investments by Asset Category (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	$ 9,609	$ 10,206	$ 12,665
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	1,075	1,050
Insurance Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	8,534	9,156
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	1,075	1,050
Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	1,075	1,050
Fair Value, Inputs, Level 1 [Member] | Insurance Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	0	0
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	8,534	9,156	11,739
Fair Value, Inputs, Level 3 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	0	0
Fair Value, Inputs, Level 3 [Member] | Insurance Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	$ 8,534	9,156	8,133
Fair Value, Inputs, Level 3 [Member] | Securities (Assets) [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets		$ 0	$ 3,606