Pension and Other Postretirement Benefits - Fair Values of Pension Plan Assets by Asset Category (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	$ 281,332	$ 394,026
U.S. equities fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	49,153	77,687
Non-U.S. equities fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	51,227	77,299
Government bond fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	56,318	64,255
Corporate bond fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	67,406	108,729
Fixed income fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	22,680	16,939
Liability driven investment fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	14,629	22,713
Other investments
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	10,531	15,103
Cash & equivalents
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	9,388	11,301
Quoted  Prices in Active Markets for Identical Assets (Level 1)
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	13,019	14,451
Quoted  Prices in Active Markets for Identical Assets (Level 1) | U.S. equities fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	4,384	2,913
Quoted  Prices in Active Markets for Identical Assets (Level 1) | Non-U.S. equities fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	5,393	6,267
Quoted  Prices in Active Markets for Identical Assets (Level 1) | Government bond fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	0	0
Quoted  Prices in Active Markets for Identical Assets (Level 1) | Corporate bond fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	0	0
Quoted  Prices in Active Markets for Identical Assets (Level 1) | Fixed income fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	0	0
Quoted  Prices in Active Markets for Identical Assets (Level 1) | Liability driven investment fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	0	0
Quoted  Prices in Active Markets for Identical Assets (Level 1) | Other investments
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	0	0
Quoted  Prices in Active Markets for Identical Assets (Level 1) | Cash & equivalents
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	3,242	5,271
Significant Observable Inputs (Level 2)
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	9,186	12,238
Significant Observable Inputs (Level 2) | U.S. equities fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	0	0
Significant Observable Inputs (Level 2) | Non-U.S. equities fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	0	0
Significant Observable Inputs (Level 2) | Government bond fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	2,011	731
Significant Observable Inputs (Level 2) | Corporate bond fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	7,175	11,507
Significant Observable Inputs (Level 2) | Fixed income fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	0	0
Significant Observable Inputs (Level 2) | Liability driven investment fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	0	0
Significant Observable Inputs (Level 2) | Other investments
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	0	0
Significant Observable Inputs (Level 2) | Cash & equivalents
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	0	0
Investments Measured at Net Asset Value
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	259,127	359,749
Investments Measured at Net Asset Value | U.S. equities fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	44,769	83,047
Investments Measured at Net Asset Value | Non-U.S. equities fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	45,834	56,028
Investments Measured at Net Asset Value | Government bond fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	54,307	97,646
Investments Measured at Net Asset Value | Corporate bond fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	60,231	70,284
Investments Measured at Net Asset Value | Fixed income fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	22,680	7,320
Investments Measured at Net Asset Value | Liability driven investment fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	14,629	22,713
Investments Measured at Net Asset Value | Other investments
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	10,531	17,367
Investments Measured at Net Asset Value | Cash & equivalents
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	$ 6,146	$ 5,344