Pension and Postretirement Benefits - Fair Value of the Plans' Assets by Asset Class (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Domestic Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	$ 11,878	$ 11,291
Domestic Plans | Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	6,430	5,267
Domestic Plans | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	4,485	5,518
Domestic Plans | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	774	316
Domestic Plans | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	189	190
Foreign Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	10,798	10,013
Foreign Pension Plans | Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	5,450	5,194
Foreign Pension Plans | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	5,153	4,669
Foreign Pension Plans | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	195	150
Quoted Prices in Active Markets (Level 1) | Domestic Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	11,689	11,101
Quoted Prices in Active Markets (Level 1) | Domestic Plans | Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	6,430	5,267
Quoted Prices in Active Markets (Level 1) | Domestic Plans | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	4,485	5,518
Quoted Prices in Active Markets (Level 1) | Domestic Plans | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	774	316
Quoted Prices in Active Markets (Level 1) | Foreign Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	10,798	10,013
Quoted Prices in Active Markets (Level 1) | Foreign Pension Plans | Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	5,450	5,194
Quoted Prices in Active Markets (Level 1) | Foreign Pension Plans | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	5,153	4,669
Quoted Prices in Active Markets (Level 1) | Foreign Pension Plans | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	195	150
Significant Other Observable Inputs (Level 2) | Domestic Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	189	190
Significant Other Observable Inputs (Level 2) | Domestic Plans | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	$ 189	$ 190