Fair Value Measurements and Derivative Instruments - Designated Cash Flow Hedges (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 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	$ (64,814)	$ (57,684)	$ (3,249)	$ 69,932
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income	6,920	11,217	19,642	(3,698)
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 June 30, 2019			1,556
Amount of loss remaining to be amortized in accumulated other comprehensive loss, as of June 30, 2019			(4,518)
Fair value at June 30, 2019	(11,321)		(11,321)
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	(40,132)	8,867	(68,461)	46,058
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	19,394	(193,329)	(70,750)	(97,963)
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 Swap
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	(44,076)	126,778	135,962	121,837
Interest 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	(409)	(2,138)	(800)	(8,976)
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	(3,545)	(3,156)	(6,879)	(6,468)
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	(1,300)	14,601	(2,615)	14,643
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	(1,188)	(133)	(1,444)	192
Fuel | Fuel Swap
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	$ 13,362	$ 2,043	$ 31,380	$ (3,089)