Derivative Financial Instruments - Effects of Derivative Instruments on Financial Statements (Detail) - Derivatives Designated as Hedges [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in other comprehensive income (loss)	$ (10,304)	$ 8,034	$ 10,230	$ (28,656)
Cost of operations [Member]
Derivative Instruments Gain Loss [Line Items]
Income reclassified from AOCI into income (loss): effective portion	14,932	19,572	24,611	39,426
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	$ (344)	$ 2,047	$ (1,549)	$ 3,864