Reconciliation of Changes in Accrued Warranty Costs (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Balance at beginning of year	$ 4,558	$ 5,221
Warranty claims paid or retired	(1,096)	(1,654)
Expense	2,053	1,339
Adjustment due to currency translation	(72)	(348)
Balance at end of year	$ 5,443	$ 4,558