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v3.19.2

Derivatives and Hedging-Disclosures and Fair Value Measurements - Additional Information (Detail) gal in Millions | 3 Months Ended |  |
--- | --- | --- | ---
Jun. 30, 2019 USD ($) gal | Jun. 30, 2018 gal | Sep. 30, 2018 USD ($) | Aug. 31, 2018 USD ($)
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |  |
Hedging positions and payable amounts secured under credit facility | $ | $ 3,400,000 |  | $ 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 | $ | 1,800,000 |  |  |
Interest rate swap |  |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |  |
Notional Value | $ |  |  |  | $ 50,000,000
Percentage of market risk exposure of long term debt |  |  |  | 50.00%
Fair Value | $ | $ (1,800,000) |  | $ 39,000 |
Call Option |  |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |  |
Derivative activity volume | 3.6 | 3.2 |  |
Call Option | Synthetic calls |  |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |  |
Derivative activity volume | 58.6 | 60.4 |  |
Put Option |  |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |  |
Derivative activity volume | 3.1 | 3.8 |  |
Swap Contracts Bought |  |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |  |
Derivative activity volume | 6.9 | 8.4 |  |
Swap Contracts Bought | Long |  |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |  |
Derivative activity volume | 1.3 | 0.4 |  |
Future Contracts | Long |  |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |  |
Derivative activity volume | 55.4 | 53.6 |  |
Future Contracts | Short |  |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |  |
Derivative activity volume | 71.5 | 64.2 |  |
Hedge its Internal Fuel Usage and Other Related Activities Short Swap Contracts Bought |  |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |  |
Derivative activity volume | 0.7 |  |  |
Hedge its Internal Fuel Usage and Other Related Activities Swap Contracts Bought |  |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |  |
Derivative activity volume | 7.8 | 3.1 |  |

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- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B + Details
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