Information Related to Effect of Derivative Instruments on Our Consolidated Condensed Statements of Income (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Derivative Instruments Gain Loss [Line Items]
Gain (loss) on derivatives	$ (434)	$ (254)	$ 5,516	$ (485)
Other Comprehensive Income (Loss) | Foreign Currency Derivatives
Derivative Instruments Gain Loss [Line Items]
Gain (loss) on derivatives	(430)	99	(777)	160
Other Comprehensive Income (Loss) | Interest Rate Swap
Derivative Instruments Gain Loss [Line Items]
Gain (loss) on derivatives				39
Other Comprehensive Income (Loss) | Commodity derivatives
Derivative Instruments Gain Loss [Line Items]
Gain (loss) on derivatives	(124)		(48)
Revaluation of Derivatives | Foreign Currency Derivatives
Derivative Instruments Gain Loss [Line Items]
Gain (loss) on derivatives	81	(421)	6,278	(159)
Revaluation of Derivatives | Currency Related Swap
Derivative Instruments Gain Loss [Line Items]
Gain (loss) on derivatives	(134)	82	(7,295)	(427)
Revaluation of Derivatives | Interest Rate Swap
Derivative Instruments Gain Loss [Line Items]
Gain (loss) on derivatives		(1)		(1)
Cost of Sales | Foreign Currency Derivatives
Derivative Instruments Gain Loss [Line Items]
Gain (loss) on derivatives	(192)	83	(320)	30
Selling, General and Administrative Expense | Foreign Currency Derivatives
Derivative Instruments Gain Loss [Line Items]
Gain (loss) on derivatives	25	(20)	46	(68)
Foreign Currency (Loss) Gain | Foreign Currency Derivatives
Derivative Instruments Gain Loss [Line Items]
Gain (loss) on derivatives	$ 82	$ 5	$ 289	$ (448)