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Inventories - Additional Information (Detail) - gal gal in Millions | 12 Months Ended
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Sep. 30, 2018 | Sep. 30, 2017
Inventory [Line Items] |  |
Heating oil and other fuel inventories | 16.3 | 24.2
Maximum product supply by other supplier | 8.00% | 8.00%
Global Companies LLC |  |
Inventory [Line Items] |  |
Product purchases | 8.00% | 13.00%
Nic Holding Corp |  |
Inventory [Line Items] |  |
Product purchases |  | 8.00%
Home heating oil and Propane |  |
Inventory [Line Items] |  |
Market price based product supply contracts for next twelve months | 287.0 |
Diesel and gasoline |  |
Inventory [Line Items] |  |
Market price based product supply contracts for next twelve months | 44.8 |

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- Definition Heating Oil And Other Fuel Inventories + References No definition available. + Details
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- Definition Market Price Based Product Supply Contracts + References No definition available. + Details
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- Definition Maximum Percentage Of Product Purchases + References No definition available. + Details
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- Definition Percentage Of Product Purchases + References No definition available. + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Details
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- Details
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- Details
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Namespace Prefix: |
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- Details
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Namespace Prefix: |
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Balance Type: |
Period Type: |