Income Taxes - Summary of Deferred Income Taxes Assets And Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Noncurrent deferred tax assets:
Amortization and fixed assets	$ 1,899	$ 1,835
Accounts receivable	166	396
Inventories	2,226	2,254
Pension obligations	2,375	2,903
Warranty obligations	827	973
Accrued benefits	382	787
Foreign exchange contracts	(367)
Foreign exchange contracts		89
Restricted stock	106	73
Tax credits carryforwards	3,784	1,611
Net operating loss carryforwards	16,801	24,784
Other temporary differences not currently available for tax purposes	1,814	(411)
Total noncurrent deferred tax assets	30,013	35,294
Valuation allowance	(14,665)	(15,021)
Net noncurrent deferred tax assets	15,348	20,273
Noncurrent deferred tax liabilities:
Amortization and fixed assets	(2,960)	(100)
Net operating loss carryforwards	2,272	0
Other temporary differences not currently available for tax purposes	(106)	60
Total noncurrent tax liabilities	(794)	(40)
Total net deferred tax asset	$ 14,554	$ 20,233