Derivative Financial Instruments - Effects of Derivative Instruments on Financial Statements (Detail) - Derivatives Designated as Hedges [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in other comprehensive income (loss)	$ 4,228	$ (28,248)	$ 14,458	$ (56,904)
Cost of operations [Member]
Derivative Instruments Gain Loss [Line Items]
Income reclassified from AOCI into income (loss): effective portion	(679)	27,547	23,932	66,973
Gain (loss) on foreign currency-net [Member]
Derivative Instruments Gain Loss [Line Items]
Gain(loss) recognized in income (loss): ineffective portion and amount excluded from effectiveness testing	$ 1,830	$ (1,329)	$ 281	$ 2,535