Fair Value Measurements and Derivative Instruments - Recurring (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands		Mar. 31, 2021	Dec. 31, 2020
Level 1
Assets:
Derivative financial instruments	[1],[2]	$ 0	$ 0
Total Assets	[2]	0	0
Liabilities:
Derivative financial instruments	[2],[3]	0	0
Total Liabilities	[2]	0	0
Level 2
Assets:
Derivative financial instruments	[1],[4]	72,900	108,539
Total Assets	[4]	72,900	108,539
Liabilities:
Derivative financial instruments	[3],[4]	196,293	259,705
Total Liabilities	[4]	196,293	259,705
Level 3
Assets:
Derivative financial instruments	[1],[5]	0	0
Total Assets	[5]	0	0
Liabilities:
Derivative financial instruments	[3],[5]	0	0
Total Liabilities	[5]	0	0
Total
Assets:
Derivative financial instruments	[1]	72,900	108,539
Total Assets		72,900	108,539
Liabilities:
Derivative financial instruments	[3]	196,293	259,705
Total Liabilities		$ 196,293	$ 259,705

[1] Consists of foreign currency forward contracts, interest rate swaps and fuel swaps. Refer to the "Fair Value of Derivative Instruments" table for breakdown by instrument type.(5

[2] Inputs based on quoted prices (unadjusted) in active markets for identical assets or liabilities that we have the ability to access. Valuation of these items does not entail a significant amount of judgment.

[3] Consists of foreign currency forward contracts, interest rate swaps and fuel swaps. Refer to the "Fair Value of Derivative Instruments" table for breakdown by instrument type.

[4] Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. For foreign currency forward contracts, interest rate swaps and fuel swaps, fair value is derived using valuation models that utilize the income valuation approach. These valuation models take into account the contract terms, such as maturity, as well as other inputs, such as foreign exchange rates and curves, fuel types, fuel curves and interest rate yield curves. Derivative instrument fair values take into account the creditworthiness of the counterparty and the Company.

[5] Inputs that are unobservable. No Level 3 inputs were used in fair value measurements of Other financial instruments as of March 31, 2021 and December 31, 2020.