Derivative Instruments - Summary of Amount Recognized as and Reclassified from Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Accumulated Other Comprehensive Income (Loss) Beginning of the Year	$ 551	$ 45	$ 85
Fair value of cash flow hedges	804	398	(475)
Less Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss	670	(108)	(435)
Accumulated Other Comprehensive Income (Loss) End of the Year	685	551	45
Foreign Currency Sales Contracts [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Accumulated Other Comprehensive Income (Loss) Beginning of the Year	0	4	0
Fair value of cash flow hedges	0	0	14
Less Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss	0	4	10
Accumulated Other Comprehensive Income (Loss) End of the Year	0	0	4
Foreign Currency Purchase Contracts [Member]
Derivative [Line Items]
Accumulated Other Comprehensive Income (Loss) Beginning of the Year	216	241	258
Fair value of cash flow hedges	0	0	0
Less Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss	31	25	17
Accumulated Other Comprehensive Income (Loss) End of the Year	185	216	241
Futures Contracts - Copper and Aluminum [Member]
Derivative [Line Items]
Accumulated Other Comprehensive Income (Loss) Beginning of the Year	335	(200)	(173)
Fair value of cash flow hedges	804	398	(489)
Less Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss	639	(137)	(462)
Accumulated Other Comprehensive Income (Loss) End of the Year	$ 500	$ 335	$ (200)