Derivative Instruments - Summary of Amount Recognized as and Reclassified from Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative [Line Items]
Accumulated Other Comprehensive Income (Loss) Beginning of the Year	$ 739	$ 551
Plus Recognized as Comprehensive Income (Loss)	(315)	224
Less Gain Reclassified from Accumulated Other Comprehensive Loss	209	155
Accumulated Other Comprehensive Income (Loss) End of the Period	215	620
Foreign Currency Purchase Contracts [Member]
Derivative [Line Items]
Accumulated Other Comprehensive Income (Loss) Beginning of the Year	239	216
Plus Recognized as Comprehensive Income (Loss)	0	0
Less Gain Reclassified from Accumulated Other Comprehensive Loss	7	7
Accumulated Other Comprehensive Income (Loss) End of the Period	232	209
Futures Contracts - Copper and Aluminum [Member]
Derivative [Line Items]
Accumulated Other Comprehensive Income (Loss) Beginning of the Year	500	335
Plus Recognized as Comprehensive Income (Loss)	(315)	224
Less Gain Reclassified from Accumulated Other Comprehensive Loss	202	148
Accumulated Other Comprehensive Income (Loss) End of the Period	$ (17)	$ 411