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v3.22.2.2

Derivatives and Hedging-Disclosures and Fair Value Measurements - Additional Information (Detail) gal in Millions | 12 Months Ended
--- | ---
Sep. 30, 2022 USD ($) gal | Sep. 30, 2021 USD ($) gal
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |
Hedging positions and payable amounts secured under credit facility | $ 0 |
Prepaid expense and other current assets |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |
Aggregated cash posted as collateral in normal course of business | 1,300,000 |
Interest rate swap |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |
Notional Value | 54,000,000.0 | $ 59,000,000.0
Fair Value | $ 2,000,000.0 | $ (1,600,000)
Percentage of market risk exposure of long term debt | 33.00% |
Call Option |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |
Derivative activity volume | gal | 36.3 | 7.8
Notional Value | $ 101,400,000 | $ 18,900,000
Fair Value | $ 19,200,000 | $ 1,200,000
Call Option | Synthetic calls |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |
Derivative activity volume | gal | 38.6 | 74.2
Notional Value | $ 126,700,000 | $ 143,200,000
Fair Value | $ (1,800,000) | $ 23,700,000
Put Option |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |
Derivative activity volume | gal | 3.2 | 4.4
Notional Value | $ 7,600,000 | $ 5,800,000
Fair Value | $ 500,000 | $ 100,000
Swap Contracts Bought |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |
Derivative activity volume | gal | 7.5 | 11.8
Notional Value | $ 20,600,000 | $ 22,900,000
Fair Value | $ (300,000) | $ 1,400
Future Contracts | Short |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |
Derivative activity volume | gal | 6.7 | 21.0
Notional Value | $ 22,100,000 | $ 42,100,000
Fair Value | $ 1,000,000.0 | $ (6,800,000)
Future Contracts | Long |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |
Derivative activity volume | gal |  | 3.8
Notional Value |  | $ 5,400,000
Fair Value |  | $ 3,400,000
Hedge its Internal Fuel Usage and Other Related Activities Call Options and Swap Contracts Bought |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |
Derivative activity volume | gal | 5.2 | 6.8
Notional Value | $ 15,100,000 | $ 13,800,000
Fair Value | $ (1,100,000) | $ 1,500,000
Swap Contracts |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |
Derivative activity volume | gal | 14.7 |
Notional Value | $ 55,200,000 |
Fair Value | $ 2,000,000.0 |

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