Business Combinations - Additional Information (Detail) $ in Millions	9 Months Ended
Jun. 30, 2018 USD ($) PartnershipUnit
Business Acquisition [Line Items]
Number of dealers acquired \| PartnershipUnit	3
Heating Oil Dealer and Motor Fuel Dealer
Business Acquisition [Line Items]
Aggregate purchase price partnership acquired	$ 22.8
Cash paid	21.3
Deferred liabilities	1.5
Aggregate purchase price allocation, intangible assets	12.7
Aggregate purchase price allocation, fixed assets	6.9
Aggregate purchase price allocation, working capital	$ 3.2

Business combination, recognized identifiable assets acquired and liabilities assumed, net working capital.

No definition available.

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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.

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- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6578-128477

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- Definition

Amount of liabilities incurred by the acquirer as part of consideration transferred in a business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6405-128476

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- Definition

Amount of intangible assets, excluding goodwill, acquired at the acquisition date.

+ References

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- Definition

The amount of property, plant, and equipment recognized as of the acquisition date.

+ References

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- Definition

The number of businesses acquired by the entity during the period.

+ References

No definition available.

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- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

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