Fair Value Measurements and Derivative Instruments - Derivatives Not Designated as Hedging Instruments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Derivative Instruments
Amount of Gain (Loss) Recognized in Income on Derivatives	$ (4,658)	$ (8,205)	$ 10,004	$ (124,736)
Foreign currency forward contracts | Other income (expense)
Derivative Instruments
Amount of Gain (Loss) Recognized in Income on Derivatives	(12,880)	4,907	(25,854)	(35,265)
Fuel swaps | Other income (expense)
Derivative Instruments
Amount of Gain (Loss) Recognized in Income on Derivatives	$ 8,222	$ (13,112)	$ 35,858	$ (89,471)