Changes in Accumulated Other Comprehensive (Loss) Income - Reclassifications (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Reclassifications out of accumulated other comprehensive loss
Interest expense, net of interest capitalized	$ (65,446)	$ (70,159)
Depreciation and amortization expenses	(210,764)	(200,468)
Other (expense) income	63,987	60,452
Fuel	(175,862)	(205,276)
Net income	99,140	45,230
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income
Reclassifications out of accumulated other comprehensive loss
Net income	(102,681)	(61,997)
Loss on cash flow derivative hedges: | Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income
Reclassifications out of accumulated other comprehensive loss
Net income	(102,396)	(61,434)
Loss on cash flow derivative hedges: | Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income | Interest rate swaps
Reclassifications out of accumulated other comprehensive loss
Interest expense, net of interest capitalized	(9,128)	(6,786)
Loss on cash flow derivative hedges: | Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income | Foreign currency forward contracts
Reclassifications out of accumulated other comprehensive loss
Depreciation and amortization expenses	(718)	(718)
Other (expense) income	6,087	(238)
Loss on cash flow derivative hedges: | Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income | Foreign currency collar options
Reclassifications out of accumulated other comprehensive loss
Depreciation and amortization expenses	(602)	0
Loss on cash flow derivative hedges: | Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income | Fuel swaps
Reclassifications out of accumulated other comprehensive loss
Other (expense) income	(7,335)	0
Fuel	(90,700)	(53,692)
Amortization of defined benefit plans: | Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income
Reclassifications out of accumulated other comprehensive loss
Actuarial loss	(285)	(354)
Prior service costs	0	(209)
Net income	$ (285)	$ (563)