Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 399,345	$ 354,950	$ 378,586	$ 354,707
Other comprehensive loss before reclassification			(5,531)
Amounts reclassified from accumulated other comprehensive loss			190
Total other comprehensive income (loss)	(4,233)	4,514	(5,341)	(336)
Ending balance	602,262	359,455	602,262	359,455
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			854
Other comprehensive loss before reclassification			(5,685)
Total other comprehensive income (loss)			(5,685)
Ending balance	(4,831)		(4,831)
Retirement Related Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(3,651)
Other comprehensive loss before reclassification			154
Amounts reclassified from accumulated other comprehensive loss			190
Total other comprehensive income (loss)			344
Ending balance	(3,307)		(3,307)
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(3,905)	(14,378)	(2,797)	(9,528)
Ending balance	$ (8,138)	$ (9,864)	$ (8,138)	$ (9,864)