Fair Value Measurements and Derivative Instruments - Designated Cash Flow Hedges (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Effect of derivative instruments involved in hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative	$ (268,478)	$ 36,574	$ (271,726)	$ 106,505
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income	(3,253)	(373)	16,389	(4,071)
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net [Abstract]
Net inception fair value at January 1, 2019					$ (8,359)
Amount of gain recognized in income on derivatives for the period ended September 30, 2019			2,790
Amount of loss remaining to be amortized in accumulated other comprehensive loss, as of September 30, 2019			(4,056)
Fair value at September 30, 2019	(9,625)		(9,625)
Interest rate swaps
Effect of derivative instruments involved in hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative	(23,488)	10,166	(91,949)	56,223
Foreign currency forward contracts
Effect of derivative instruments involved in hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative	(131,523)	(35,397)	(202,273)	(133,360)
Foreign currency forward contracts
Effect of derivative instruments involved in hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative	0	0	0	0
Fuel swaps
Effect of derivative instruments involved in hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative	0	0	0	0
Fuel swaps
Effect of derivative instruments involved in hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivative	(113,467)	61,805	22,496	183,642
Interest income (expense), net of interest capitalized | Interest rate swaps
Effect of derivative instruments involved in hedging on the consolidated financial statements
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income	(373)	(1,395)	(1,173)	(10,371)
Depreciation and amortization expenses | Foreign currency forward contracts
Effect of derivative instruments involved in hedging on the consolidated financial statements
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income	(3,592)	(3,157)	(10,471)	(9,625)
Other income (expense) | Foreign currency forward contracts
Effect of derivative instruments involved in hedging on the consolidated financial statements
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income	(1,251)	(835)	(3,866)	13,808
Other income (expense) | Fuel swaps
Effect of derivative instruments involved in hedging on the consolidated financial statements
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income	(472)	466	(1,916)	658
Fuel | Fuel swaps
Effect of derivative instruments involved in hedging on the consolidated financial statements
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income	$ 2,435	$ 4,548	$ 33,815	$ 1,459