Retirement Plans - Defined Benefit Plan, Projected Benefit Obligation (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
United States [Member] \| Pension Plans [Member]
Projected benefit obligation, Beginning balance		$ 972
Service cost	$ 0		$ 568
Interest cost	0	29	6,491
Actuarial losses (gains)		(32)
Plan settlements		(969)
Projected benefit obligation, Ending balance			972
United States [Member] \| Retiree Healthcare Plan [Member]
Projected benefit obligation, Beginning balance	21,186	17,724
Service cost	665	499	566
Employee contributions	1,149	1,214
Interest cost	711	777	636
Actuarial losses (gains)	2,788	2,081
Benefits paid	(1,130)	(1,109)
Projected benefit obligation, Ending balance	25,369	21,186	17,724
Non-U.S. Pension Plans [Member] \| Pension Plans [Member]
Projected benefit obligation, Beginning balance	103,366	93,722
Service cost	4,519	4,339	5,368
Employee contributions	514	499
Interest cost	1,413	1,735	1,707
Actuarial losses (gains)	2,624	13,385
Benefits paid	(1,474)	(3,281)
Plan settlements	(1,449)	(7,407)
Other plans		1,598
Currency impact	10,077	(1,224)
Projected benefit obligation, Ending balance	$ 119,590	$ 103,366	$ 93,722

Amount of gain (loss) from change in actuarial assumptions which (increases) decreases benefit obligation of defined benefit plan. Assumptions include, but are not limited to, interest, mortality, employee turnover, salary, and temporary deviation from substantive plan.

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- Definition

Amount of actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

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- Definition

Amount of payment to participant of defined benefit plan which decreases benefit obligation. For pension plan, payment includes, but is not limited to, pension benefits and death benefits. For other postretirement plan, payment includes, but is not limited to, prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services.

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Amount of contributions received by defined benefit plan from participant which increase benefit obligation.

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- Definition

Amount of foreign currency translation gain (loss) which (increases) decreases benefit obligation of defined benefit plan.

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- Definition

Amount of cost recognized for passage of time related to defined benefit plan.

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Amount of increase (decrease) in benefit obligation of defined benefit plan from change, classified as other.

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Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

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- Definition

Amount of (increase) decrease to benefit obligation of defined benefit plan from irrevocable action relieving primary responsibility for benefit obligation and eliminating risk for obligation and assets used to effect settlement. Includes, but is not limited to, lump-sum cash payment to participant in exchange for right to receive specified benefits, purchase of nonparticipating annuity contract and change from remeasurement.

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