Segment Information - Reconciliation of Partnership Adjusted EBITDA (Details) - USD ($) $ in Millions	3 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information
Depreciation and amortization	$ (110.3)	$ (98.1)
Interest expense	(58.2)	(55.4)
Loss on extinguishments of debt	0.0	(33.2)
Income (loss) before income taxes	$ 329.8	$ 378.7
Amerigas Propane \| AmeriGas OLP
Segment Reporting Information
General Partnership interest (percentage)	1.01%	1.01%
Operating Segments \| Amerigas Propane
Segment Reporting Information
Partnership Adjusted EBITDA	$ 194.1	$ 185.1
Depreciation and amortization	(47.4)	(44.6)
Interest expense	(40.6)	(40.0)
Loss on extinguishments of debt	0.0	(33.2)
Noncontrolling interest	1.2	1.4
Income (loss) before income taxes	$ 107.3	$ 68.7

Non-controlling interests representing general partners interest in OLP.

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- Definition

Partnership EBITDA.

+ References

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- Definition

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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-Section 45
-Paragraph 28
-Subparagraph (b)
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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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-Publisher FASB
-Name Accounting Standards Codification
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Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Interest and debt related expenses associated with nonoperating financing activities of the entity.

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Percentage investment held by the managing member or general partner of the limited liability company (LLC) or limited partnership (LP).

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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.

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