Changes in Accumulated Other Comprehensive Income (Loss) - Reclassifications (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Reclassifications out of accumulated other comprehensive loss
Interest expense, net of interest capitalized	$ (68,571)	$ (90,182)
Depreciation and amortization expenses	(193,735)	(189,364)
Other income (expense)	(71,009)	(89,406)
Fuel	(244,459)	(241,652)
Net income	26,457	76,226
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss into Income
Reclassifications out of accumulated other comprehensive loss
Net income	(4,868)	15,270
Gain (loss) on cash flow derivative hedges: | Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss into Income
Reclassifications out of accumulated other comprehensive loss
Net income	(4,437)	15,270
Gain (loss) on cash flow derivative hedges: | Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss into Income | Cross currency swaps
Reclassifications out of accumulated other comprehensive loss
Interest expense, net of interest capitalized	(261)	(871)
Gain (loss) on cash flow derivative hedges: | Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss into Income | Foreign currency forward contracts
Reclassifications out of accumulated other comprehensive loss
Interest expense, net of interest capitalized	(57)	0
Depreciation and amortization expenses	(449)	(449)
Other income (expense)	(3,576)	(238)
Gain (loss) on cash flow derivative hedges: | Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss into Income | Fuel swaps
Reclassifications out of accumulated other comprehensive loss
Fuel	(94)	16,828
Amortization of defined benefit plans: | Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss into Income
Reclassifications out of accumulated other comprehensive loss
Actuarial loss	(222)	0
Prior service costs	(209)	0
Net income	$ (431)	$ 0