Components of Accumulated Other Comprehensive Loss, Net (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period				$ 210,279
Balance at end of period		$ 272,010		272,010
Accumulated Translation Adjustment:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period		(29,930)	$ (30,356)	(27,821)	$ (35,644)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax		124	2,246	(1,985)	7,534
Balance at end of period		(29,806)	(28,110)	(29,806)	(28,110)
Accumulated Deferred Gains (Losses) on Cash Flow Hedges:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period		(263)	11	14	(3)
Amounts reclassified from accumulated other comprehensive loss	[1]			(14)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax		(381)	(4)	(644)	10
Balance at end of period		(644)	7	(644)	7
Accumulated Effect of Retirement Benefit Obligations:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period		(1,483)	(1,321)	(1,518)	(1,352)
Amounts reclassified from accumulated other comprehensive loss	[2]	19	16	54	47
Balance at end of period		(1,464)	(1,305)	(1,464)	(1,305)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at end of period		$ (31,914)	$ (29,408)	$ (31,914)	$ (29,408)

[1] Amount is recorded as interest expense on the unaudited condensed consolidated statements of operations.

[2] Amounts are recorded in selling, general and administrative expense on the unaudited condensed consolidated statements of operations.