Effects of Derivative Instruments on Financial Statements (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of loss recognized in other comprehensive income (loss)	$ 24,743	$ 19,324	$ (46,270)	$ (4,880)
Cost of operations
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Income reclassified from AOCI into income: effective portion	(270)	2,867	(1,101)	4,837
Gain (loss) on foreign currency - net
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (loss) recognized in income ineffective portion and amount excluded from effectiveness testing	$ 3,136	$ 3,546	$ 7,578	$ 15,011