Income Taxes - Summary of Deferred Income Taxes Assets And Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Noncurrent deferred tax assets:
Amortization and fixed assets	$ 4,109	$ 5,270
Accounts receivable	815	706
Inventories	2,899	3,959
Pension obligations	4,623	5,268
Warranty obligations	2,519	3,608
Accrued benefits	1,060	1,370
Foreign exchange contracts	460	94
Restricted stock	145	153
Tax credits carryforwards	2,238	2,562
Net operating loss carryforwards	20,130	15,094
Other temporary differences not currently available for tax purposes	2,135	287
Total noncurrent assets	41,133	38,371
Valuation allowance	(12,546)	(13,118)
Net noncurrent deferred tax assets	28,587	25,253
Noncurrent deferred tax liabilities:
Amortization and fixed assets	(764)	(1,158)
Net operating loss carryforwards	2,178	2,121
Other temporary differences not currently available for tax purposes	(1,430)	(796)
Total noncurrent tax liabilities	(16)	167
Valuation allowance	0	(1,286)
Net noncurrent deferred tax liabilities	(16)	(1,119)
Total deferred tax asset	$ 28,571	$ 24,134