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Retirement Plans - Defined Benefit Plan, Fair Value Measurement of Plan Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Significant Unobservable Inputs (Level 3) | Bank and Insurance Investment Contracts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	$ 69,120	$ 60,119	$ 56,718
UNITED STATES | Retiree Healthcare Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	16,168	13,773	11,080
Non-U.S. Pension Plans [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	93,890	83,011	$ 81,587
Retirement Plans [Member] | Portion at Fair Value Measurement [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	110,058	96,784
Retirement Plans [Member] | Quoted Prices in Active Market for Identical Assets (Level 1) | Portion at Fair Value Measurement [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	40,938	36,665
Retirement Plans [Member] | Significant Other Observable Inputs (Level 2) | Portion at Fair Value Measurement [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	0
Retirement Plans [Member] | Significant Unobservable Inputs (Level 3) | Portion at Fair Value Measurement [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	69,120	60,119
Retirement Plans [Member] | UNITED STATES | Retiree Healthcare Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	16,168	13,773
Retirement Plans [Member] | UNITED STATES | Retiree Healthcare Plan [Member] | Mutual Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	16,168	13,773
Retirement Plans [Member] | UNITED STATES | Quoted Prices in Active Market for Identical Assets (Level 1) | Retiree Healthcare Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	16,168	13,773
Retirement Plans [Member] | UNITED STATES | Quoted Prices in Active Market for Identical Assets (Level 1) | Retiree Healthcare Plan [Member] | Mutual Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	16,168	13,773
Retirement Plans [Member] | UNITED STATES | Significant Other Observable Inputs (Level 2) | Retiree Healthcare Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	0
Retirement Plans [Member] | UNITED STATES | Significant Other Observable Inputs (Level 2) | Retiree Healthcare Plan [Member] | Mutual Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	0
Retirement Plans [Member] | Non-U.S. Pension Plans [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	93,890	83,011
Retirement Plans [Member] | Non-U.S. Pension Plans [Member] | Pension Plans [Member] | Mutual Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	23,582	22,202
Retirement Plans [Member] | Non-U.S. Pension Plans [Member] | Pension Plans [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	1,188	690
Retirement Plans [Member] | Non-U.S. Pension Plans [Member] | Pension Plans [Member] | Bank and Insurance Investment Contracts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	69,120	60,119
Retirement Plans [Member] | Non-U.S. Pension Plans [Member] | Quoted Prices in Active Market for Identical Assets (Level 1) | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	24,770	22,892
Retirement Plans [Member] | Non-U.S. Pension Plans [Member] | Quoted Prices in Active Market for Identical Assets (Level 1) | Pension Plans [Member] | Mutual Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	23,582	22,202
Retirement Plans [Member] | Non-U.S. Pension Plans [Member] | Quoted Prices in Active Market for Identical Assets (Level 1) | Pension Plans [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	1,188	690
Retirement Plans [Member] | Non-U.S. Pension Plans [Member] | Significant Other Observable Inputs (Level 2) | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	0
Retirement Plans [Member] | Non-U.S. Pension Plans [Member] | Significant Other Observable Inputs (Level 2) | Pension Plans [Member] | Mutual Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	0
Retirement Plans [Member] | Non-U.S. Pension Plans [Member] | Significant Other Observable Inputs (Level 2) | Pension Plans [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	0
Retirement Plans [Member] | Non-U.S. Pension Plans [Member] | Significant Other Observable Inputs (Level 2) | Pension Plans [Member] | Bank and Insurance Investment Contracts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	0
Retirement Plans [Member] | Non-U.S. Pension Plans [Member] | Significant Unobservable Inputs (Level 3) | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	69,120	60,119
Retirement Plans [Member] | Non-U.S. Pension Plans [Member] | Significant Unobservable Inputs (Level 3) | Pension Plans [Member] | Bank and Insurance Investment Contracts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit plan assets	$ 69,120	$ 60,119

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+ References

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