Changes in Accumulated Other Comprehensive Loss - Reclassifications (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Reclassifications out of accumulated other comprehensive loss
Interest expense, net of interest capitalized	$ (272,514)	$ (92,911)
Depreciation and amortization expenses	(310,166)	(324,330)
Other income (expense)	5,033	(32,859)
Fuel	(41,822)	(194,268)
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income
Reclassifications out of accumulated other comprehensive loss
Total reclassifications for the period	(11,972)	(22,885)
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
Total reclassifications for the period	(11,229)	(22,380)
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	(9,509)	(3,391)
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	(3,781)	(3,337)
Other income (expense)	(1,291)	(1,763)
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 income (expense)	(407)	344
Fuel	3,759	(14,233)
Changes in defined benefit plans | Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income
Reclassifications out of accumulated other comprehensive loss
Payroll and related	(743)	(505)
Total reclassifications for the period	$ (743)	$ (505)