Business Combinations - Additional Information (Detail) $ in Thousands	3 Months Ended
Dec. 31, 2015 USD ($) PartnershipUnit	Sep. 30, 2015 USD ($)
Business Acquisition [Line Items]
Number of dealers acquired \| PartnershipUnit	2
Goodwill	$ 212,676	$ 211,045
Motor Fuel Dealer and Propane Dealer
Business Acquisition [Line Items]
Aggregate purchase price partnership acquired	7,600
Gross purchase price allocation, intangible assets	3,800
Goodwill	1,600
Gross purchase price allocation, fixed assets	2,100
Gross purchase price reduced by working capital credits	$ 100

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

+ References

+ Details

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- Definition

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

+ References

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-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
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- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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-Name Accounting Standards Codification
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- Definition

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

+ References

No definition available.

+ Details

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