Equity - Common Stock Share Activity (Details) - shares	12 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Common Stock Share Activity
Beginning balance - shares Outstanding (in shares)	0	0	0
Issued:
Ending balance - shares Outstanding (in shares)		0	0
Common Stock
Common Stock Share Activity
Beginning balance - shares Issued/Treasury (in shares)	209,843,296	209,514,044	209,304,129	174,142,997
Beginning balance - shares Outstanding (in shares)	208,354,438	209,004,789	173,748,975
Issued:
Employee and director plans - shares Issued/Treasury (in shares)	329,252	209,915	548,285
Employee and director plans - shares Outstanding (in shares)	883,567	389,965	979,132
AmeriGas Merger -Issued (in shares)			34,612,847
AmeriGas Merger - Outstanding (in shares)			34,612,847
Sale of reacquired common stock - Outstanding (in shares)			15,759
Reacquired common stock, employee and director plans - Outstanding (in shares)	(21,870)	(90,316)	(51,924)
Ending balance - shares Issued/Treasury (in shares)	209,843,296	209,514,044	209,304,129	174,142,997
Ending balance - shares Outstanding (in shares)	209,216,135	208,354,438	209,004,789
Common Stock \| Treasury stock
Common Stock Share Activity
Beginning balance - shares Issued/Treasury (in shares)	627,161	1,159,606	299,340	394,022
Issued:
Employee and director plans - shares Issued/Treasury (in shares)	554,315	180,050	430,847
AmeriGas Merger -Issued (in shares)			0
Sale of reacquired common stock - Treasury (in shares)			15,759
Treasury stock acquired (in shares)	0	950,000	300,000
Reacquired common stock, employee and director plans - Treasury (in shares)	(21,870)	(90,316)	(51,924)
Ending balance - shares Issued/Treasury (in shares)	627,161	1,159,606	299,340	394,022
Preferred stock, without par value
Common Stock Share Activity
Beginning balance - shares Issued/Treasury (in shares)	220,000	0	0	0
Issued:
Ending balance - shares Issued/Treasury (in shares)	220,000	0	0	0
Ending balance - shares Outstanding (in shares)	220,000
Stock Issued During Period, Shares, New Issues	220,000

Common Stock Issued

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Common Stock Share Activity [Roll Forward]

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Stock Issued And Outstanding During Period, Shares, Acquisitions

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Stock Issued And Outstanding During Period, Shares, Dividend Reinvestment Plan

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Stock Issued And Outstanding During Period, Shares, Share-based Compensation, Gross

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Stock Reacquired And Outstanding During Period, Shares, Share-based Compensation

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Stock Reacquired During Period, Shares, Share-based Compensation

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Number of shares of stock issued as of the balance sheet date, including shares that had been issued and were previously outstanding but which are now held in the treasury.

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Number of shares issued which are neither cancelled nor held in the treasury.

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Number of shares of stock issued during the period pursuant to acquisitions.

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Number of shares issued during the period from a dividend reinvestment plan (DRIP). A dividend reinvestment plan allows the shareholders to reinvest dividends paid to them by the entity on new issues of stock by the entity.

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Number of new stock issued during the period.

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Number, before forfeiture, of shares issued under share-based payment arrangement. Excludes employee stock ownership plan (ESOP).

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Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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