Information Related to Effect of Derivative Instruments on Our Consolidated Condensed Statements of Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Derivative Instruments Gain Loss [Line Items]
Gain (loss) on derivatives	$ (3,884)	$ (758)	$ 1,632	$ (1,243)
Other Comprehensive Income (Loss) | Foreign Currency Derivatives
Derivative Instruments Gain Loss [Line Items]
Gain (loss) on derivatives	(460)	(571)	(1,237)	(411)
Other Comprehensive Income (Loss) | Interest Rate Swap
Derivative Instruments Gain Loss [Line Items]
Gain (loss) on derivatives		42		81
Other Comprehensive Income (Loss) | Commodity Derivatives
Derivative Instruments Gain Loss [Line Items]
Gain (loss) on derivatives	(373)		(421)
Revaluation of Derivatives | Foreign Currency Derivatives
Derivative Instruments Gain Loss [Line Items]
Gain (loss) on derivatives	(2,526)	557	3,752	398
Revaluation of Derivatives | Currency Related Swap
Derivative Instruments Gain Loss [Line Items]
Gain (loss) on derivatives	2,392	(263)	(4,903)	(690)
Revaluation of Derivatives | Interest Rate Swap
Derivative Instruments Gain Loss [Line Items]
Gain (loss) on derivatives				(1)
Product Revenues | Foreign Currency Derivatives
Derivative Instruments Gain Loss [Line Items]
Gain (loss) on derivatives		(129)		(129)
Cost of Sales | Foreign Currency Derivatives
Derivative Instruments Gain Loss [Line Items]
Gain (loss) on derivatives	(694)	64	(1,014)	94
Selling, General and Administrative Expense | Foreign Currency Derivatives
Derivative Instruments Gain Loss [Line Items]
Gain (loss) on derivatives	(235)	(73)	(189)	(141)
Foreign Currency (Loss) Gain | Foreign Currency Derivatives
Derivative Instruments Gain Loss [Line Items]
Gain (loss) on derivatives	$ 31	$ (606)	$ 320	$ (1,054)