| Benefit Plans - Accumulated Benefit Obligation (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 | 
|---|---|---|
| Defined Benefit Pension Plans | United States | ||
| Defined Benefit Plan Disclosure | ||
| Accumulated benefit obligation | $ 288,482 | $ 266,992 | 
| Defined Benefit Plan, Funded (Unfunded) Status of Plan | ||
| Projected benefit obligation | 288,482 | 267,392 | 
| Accumulated benefit obligation | 288,482 | 266,992 | 
| Fair value of plan assets | 263,837 | 231,413 | 
| Defined Benefit Pension Plans | Foreign | ||
| Defined Benefit Plan Disclosure | ||
| Accumulated benefit obligation | 110,605 | 96,891 | 
| Defined Benefit Plan, Funded (Unfunded) Status of Plan | ||
| Projected benefit obligation | 92,679 | 82,662 | 
| Accumulated benefit obligation | 88,394 | 80,021 | 
| Fair value of plan assets | 76,658 | 68,104 | 
| Supplemental Retirement Plans | ||
| Defined Benefit Plan Disclosure | ||
| Accumulated benefit obligation | $ 12,415 | $ 11,652 | 
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- Definition Amount of actuarial present value of benefits attributed to employee service rendered, excluding assumptions about future compensation level. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Amount of accumulated benefit obligation for defined benefit plan with accumulated benefit obligation in excess of plan assets. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Amount of plan asset for defined benefit plan with accumulated benefit obligation in excess of plan assets. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Amount of projected benefit obligation for defined benefit pension plan with accumulated benefit obligation in excess of plan assets. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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