Income Taxes - Reconciliation of Total Amounts of Uncertain Tax Positions (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Uncertain tax positions, balance at the beginning	$ 11,894	$ 13,330	$ 14,969
Additions based on tax positions related to the current year	(366)	942	1,789
Additions (reductions) for tax positions of prior years	(8,923)	317
Lapse of statute of limitations	(2,218)	(2,380)	(2,142)
Translation adjustments	675	(315)	(1,287)
Uncertain tax positions, balance at the ending	$ 1,062	$ 11,894	$ 13,330