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	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	$ 72,462	$ (256,868)	$ 331,838	$ (362,543)
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	55,941	(15,298)	123,063	(9,057)
Amount of Gain (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness testing)	3,346	229	9,458	510
Cross currency swaps | Other income (expense)
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	13,691	(30,911)	38,578	(30,911)
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	13,760	(19,200)	44,720	(19,200)
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)
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(71)	262	191	525
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)	44,307	(157,090)	112,156	(259,399)
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(175)	54	(349)	108
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)	1,661	414	2,689	240
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)	1,685	(185)	6,769	270
Fuel swaps | Fuel
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	14,464	(68,867)	193,479	(72,233)
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	$ 42,427	$ 3,586	$ 78,501	$ 9,510