Effect of Derivative Instruments Qualifying and Designated as Hedging Instruments in Cash Flow Hedges on the Consolidated Financial Statements (Detail) (Cash Flow Hedging, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	$ 70,480	$ (54,877)
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	146,586	68,303
Amount of Gain (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness testing)	6,050	7,986
Cross currency swaps | Other income (expense)
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	(6,013)	13,016
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(15,011)	26,360
Interest rate swaps | Other income (expense)
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	(10,131)
Amount of Gain (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness testing)	(21)
Foreign currency forward contracts | Other income (expense)
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	(12,375)	(21,021)
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(285)	1,051
Foreign currency forward contracts | Depreciation and amortization expenses
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	(22,263)	(83,601)
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(734)	227
Foreign currency forward contracts | Other Income
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness testing)	(1,015)	207
Fuel swaps | Other income (expense)
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness testing)	7,086	7,779
Fuel swaps | Fuel
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	121,262	36,729
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	$ 162,616	$ 40,665