Effect of Derivative Instruments Qualifying and Designated as Hedging Instruments in Cash Flow Hedges on Consolidated Financial Statements (Detail) (Cash Flow Hedging, USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	$ 179,942	$ 259,376
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	32,472	67,122
Amount of Gain (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness testing)	537	6,112
Cross currency swaps | Other income (expense)
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	(3,587)	24,887
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(2,921)	30,960
Interest rate swaps | Other income (expense)
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	4,554
Amount of Gain (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness testing)	1
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)	(238)	262
Amount of Gain (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness testing)	7	1,028
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)	17,708	67,849
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(196)	(174)
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)	529	5,084
Fuel swaps | Fuel
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	161,267	179,015
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	$ 35,827	$ 36,074