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v3.21.1

Fair Value Measurements - Quantitative Information about Level 3 Fair Value (Details) - Significant unobservable inputs (Level 3) - Fuel derivatives - Measurement Input, Option Volatility | Mar. 31, 2021
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Minimum | Second quarter 2021 |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Derivative Asset, Measurement Input | 0.22 |
Minimum | Third quarter 2021 |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Derivative Asset, Measurement Input | 0.30 |
Minimum | Fourth quarter 2021 |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Derivative Asset, Measurement Input | 0.29 |
Minimum | 2022 |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Derivative Asset, Measurement Input | 0.25 |
Minimum | 2023 |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Derivative Asset, Measurement Input | 0.23 |
Minimum | Beyond 2023 |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Derivative Asset, Measurement Input | 0.23 |
Weighted Average | Second quarter 2021 |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Derivative Asset, Measurement Input | 0.32 |
Weighted Average | Third quarter 2021 |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Derivative Asset, Measurement Input | 0.33 | [1]
Weighted Average | Fourth quarter 2021 |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Derivative Asset, Measurement Input | 0.31 | [1]
Weighted Average | 2022 |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Derivative Asset, Measurement Input | 0.29 | [1]
Weighted Average | 2023 |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Derivative Asset, Measurement Input | 0.25 | [1]
Weighted Average | Beyond 2023 |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Derivative Asset, Measurement Input | 0.24 | [1]
Maximum | Second quarter 2021 |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Derivative Asset, Measurement Input | 0.46 |
Maximum | Third quarter 2021 |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Derivative Asset, Measurement Input | 0.40 |
Maximum | Fourth quarter 2021 |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Derivative Asset, Measurement Input | 0.36 |
Maximum | 2022 |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Derivative Asset, Measurement Input | 0.34 |
Maximum | 2023 |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Derivative Asset, Measurement Input | 0.26 |
Maximum | Beyond 2023 |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Derivative Asset, Measurement Input | 0.25 |
[1] | Implied volatility weighted by the notional amount (barrels of fuel) that will settle in respective period.

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