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Retirement Plans - Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Total recognized in other comprehensive income (loss)	$ 5,397	$ 7,381	$ (42,070)
United States [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net (loss) gain arising during the year		32	(10,616)
Net loss		27	48,239
Total recognized in other comprehensive income (loss)	0	59	37,623
United States [Member] | Retiree Healthcare Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service cost			130
Net (loss) gain arising during the year	(1,692)	(648)	(670)
Prior service credit	(19)	(19)	(19)
Total recognized in other comprehensive income (loss)	(1,711)	(667)	(559)
Non-U.S. Pension Plans [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service cost			44
Net (loss) gain arising during the year	(3,104)	(8,940)	4,088
Prior service credit	(163)	(108)	(35)
Net loss	1,806	2,079	680
Other Plans		18	(354)
Currency impact	(2,225)	178	583
Total recognized in other comprehensive income (loss)	$ (3,686)	$ (6,773)	$ 5,006

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Amount, before tax, of cost (credit) of benefit change attributable to participants' prior service from plan amendment or plan initiation of defined benefit plan, that has not been recognized in net periodic benefit cost (credit).

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