Changes in Accumulated Other Comprehensive Income (Loss) (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Reclassifications out of accumulated other comprehensive loss
Interest expense, net of interest capitalized	$ 79,654	$ 84,977	$ 256,713	$ 266,749
Depreciation and amortization expenses	188,541	182,051	564,089	541,957
Other income (expense)	(78,508)	(84,358)	(256,505)	(273,327)
Fuel	215,686	213,434	689,809	680,389
Net Income	365,701	367,779	466,674	411,090
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss into Income
Reclassifications out of accumulated other comprehensive loss
Net Income	28,888		50,697
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	29,535		52,639
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	(890)		(2,641)
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	(217)		(222)
Depreciation and amortization expenses	(449)		(1,348)
Other income (expense)	19,089		18,612
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	12,002		38,238
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	(438)		(1,315)
Prior service costs	(209)		(627)
Net Income	$ (647)		$ (1,942)