Shareholders' Equity Changes in Accumulated Other Comprehensive Income (Loss) Balances (Detail) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance as of December 31, 2019				$ (72,700)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax				1,200
Stockholders' Equity, Other			$ 0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	$ 12,800	$ (12,400)		(1,800)	$ (13,200)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax				(13,400)
Balance as of September 30, 2020	(84,900)			(84,900)
Foreign Currency Items
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance as of December 31, 2019				(63,300)
Balance as of September 30, 2020	(65,100)			(65,100)
Cash Flow Hedging | Foreign Exchange Contract
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance as of December 31, 2019				(6,100)
Reclassification to the statement of income				1,000
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax				(11,600)
Balance as of September 30, 2020	(16,700)			(16,700)
Accumulated Defined Benefit Plans Adjustment Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance as of December 31, 2019				(3,300)
Reclassification to the statement of income				200
Balance as of September 30, 2020	$ (3,100)			$ (3,100)
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Stockholders' Equity, Other			$ 600