Fair Value Measurements and Derivative Instruments (Designated Cash Flow Hedges) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative									$ (41,109)	$ (146,108)
Amount of gain or (loss) reclassified from accumulated other comprehensive loss into income									(79,119)	5,205
Interest expense									(844,238)	(408,513)	$ (333,672)
Depreciation and amortization expenses									(1,279,254)	(1,245,942)	(1,033,697)
Other Income (Expense)									(137,085)	(24,513)	11,107
Fuel									(371,015)	(697,962)	(710,617)
Net Income (loss)	$ (1,366,935)	$ (1,346,756)	$ (1,639,292)	$ (1,444,479)	$ 273,136	$ 883,240	$ 472,830	$ 249,681	(5,797,462)	1,878,887	1,811,042
Interest rate swaps
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative									(112,960)	(72,732)
Interest rate swaps | Interest Income (Expense)
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of gain or (loss) reclassified from accumulated other comprehensive loss into income									(25,267)	(4,289)
Foreign currency forward contracts
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative									130,426	(148,881)
Foreign currency forward contracts | Depreciation and Amortization Expenses
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of gain or (loss) reclassified from accumulated other comprehensive loss into income									(14,679)	(14,063)
Foreign currency forward contracts
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative									0	0
Foreign currency forward contracts | Other income (expense)
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of gain or (loss) reclassified from accumulated other comprehensive loss into income									(7,315)	(5,080)
Foreign currency forward contracts
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative									0	0
Foreign currency forward contracts | Other indirect operating expenses
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of gain or (loss) reclassified from accumulated other comprehensive loss into income									0	0
Foreign currency collar options
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative									0	0
Foreign currency collar options | Depreciation and Amortization Expenses
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of gain or (loss) reclassified from accumulated other comprehensive loss into income									0	0
Fuel swaps
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative									0	0
Fuel swaps | Other income (expense)
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of gain or (loss) reclassified from accumulated other comprehensive loss into income									3,549	(1,292)
Fuel swaps | Fuel
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of gain or (loss) reclassified from accumulated other comprehensive loss into income									(35,407)	29,929
Fuel swaps
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative									(58,575)	75,505
Fuel swaps | Fuel
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of gain or (loss) reclassified from accumulated other comprehensive loss into income									(35,407)	29,929
Cash flow hedge
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative											(297,994)
Cash flow hedge | Interest rate swaps
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative											18,578
Cash flow hedge | Foreign currency forward contracts
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative											(222,645)
Cash flow hedge | Foreign currency forward contracts
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative											0
Cash flow hedge | Foreign currency forward contracts
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative											0
Cash flow hedge | Foreign currency collar options
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative											0
Cash flow hedge | Fuel swaps
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative											0
Cash flow hedge | Fuel swaps
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative											(93,927)
Reclassification out of accumulated other comprehensive income (loss) | Gain (loss) on cash flow derivative hedges:
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Net Income (loss)											(11,133)
Reclassification out of accumulated other comprehensive income (loss) | Gain (loss) on cash flow derivative hedges: | Interest rate swaps
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Interest expense									(25,267)	(4,289)	(10,931)
Reclassification out of accumulated other comprehensive income (loss) | Gain (loss) on cash flow derivative hedges: | Foreign currency forward contracts
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Depreciation and amortization expenses									(14,679)	(14,063)	(12,843)
Other Income (Expense)									(7,315)	(5,080)	12,855
Reclassification out of accumulated other comprehensive income (loss) | Gain (loss) on cash flow derivative hedges: | Foreign currency forward contracts
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Other Income (Expense)											12,855
Reclassification out of accumulated other comprehensive income (loss) | Gain (loss) on cash flow derivative hedges: | Foreign currency forward contracts
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Other indirect operating expenses											0
Reclassification out of accumulated other comprehensive income (loss) | Gain (loss) on cash flow derivative hedges: | Foreign currency collar options
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Depreciation and amortization expenses											0
Reclassification out of accumulated other comprehensive income (loss) | Gain (loss) on cash flow derivative hedges: | Fuel swaps
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Other Income (Expense)									3,549	(1,292)	(1,580)
Fuel									$ (35,407)	$ 29,929	1,366
Reclassification out of accumulated other comprehensive income (loss) | Gain (loss) on cash flow derivative hedges: | Fuel swaps
Effect of derivative instruments involved in fair value hedging on the consolidated financial statements
Fuel											$ 1,366