Derivative Instruments - Summary of Change in Fair Value Reclassified or Expected to be Reclassified from Accumulated Other Comprehensive Loss to Earnings (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Foreign Currency Sales Contracts [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Amount released to pre - tax earnings	$ 0
Amount released to pre - tax earnings	(33)	0	197
Foreign Currency Purchase Contracts [Member]
Derivative [Line Items]
Amount released to pre - tax earnings	27
Amount released to pre - tax earnings	27	27	27
Futures Contracts - Copper and Aluminum [Member]
Derivative [Line Items]
Amount released to pre - tax earnings	(290)
Amount released to pre - tax earnings	$ (146)	$ (419)	$ (398)