Derivative Financial Instruments - Effects of Derivative Instruments on Financial Statements (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2014
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Amount of gain (loss) recognized in other comprehensive income (loss)	$ 8,034	$ 441	$ 12,799
Cost of operations [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Income (loss) reclassified from AOCI into income: effective portion	19,572	293	495
Gain (loss) on foreign currency-net [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Gain(loss) recognized in income (loss): ineffective portion and amount excluded from effectiveness testing	$ 2,047	$ 3,381	$ 4,228