Financial Instruments - Narrative (Details) Bcf in Billions	12 Months Ended	36 Months Ended
	Sep. 30, 2023 USD ($) counterparty Bcf	Dec. 31, 2025 USD ($) payment	Sep. 30, 2022 USD ($)		Jun. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)
Derivative Instruments, Gain (Loss) [Line Items]
Foreign currency forward contracts duration maximum	7 years
After tax net hedging gains in accumulated other comprehensive income (loss)	$ 4,600,000
After tax net hedging gains reclassified within twelve months	11,500,000
Fair market value of derivative liability with a credit-risk related contingency	7,700,000
Hedging collateral deposits	0		$ 91,670,000	[1]		$ 88,610,000	$ 0
Foreign Currency Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Hedging notional amount of forecasted transportation costs	$ 56,900,000
Over the Counter Swaps, No Cost Collars and Foreign Currency Forward Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Number of counterparties in which the company holds over-the-counter swap positions | counterparty	19
Number of counterparties in net gain position | counterparty	11
Credit risk exposure per counterparty	$ 3,900,000
Maximum credit risk exposure per counterparty	16,100,000
Collateral received by company	$ 0
Number of counterparties with a common credit-risk related contingency | counterparty	16
Hedging collateral deposits	$ 0
California Asset Sale | Forecast
Derivative Instruments, Gain (Loss) [Line Items]
Maximum annual contingent payment		$ 10,000,000
Amount of each incremental contingency payment		1,000,000
Incremental price, exceeding ICE Brent Average Price (in dollars per barrel)		1
California Asset Sale | Present Value of Contingent Consideration
Derivative Instruments, Gain (Loss) [Line Items]
Value of contingent consideration received from sale of assets	7,300,000		$ 8,200,000		$ 12,600,000
California Asset Sale | Mark to Market of Contingent Consideration
Derivative Instruments, Gain (Loss) [Line Items]
Mark-to-market adjustment for contingent consideration	$ 900,000
California Asset Sale | Minimum | Forecast
Derivative Instruments, Gain (Loss) [Line Items]
ICE Brent Average (in dollars per barrel)		$ 95
California Asset Sale | Maximum | Forecast
Derivative Instruments, Gain (Loss) [Line Items]
Number of annual contingent payments | payment		3
ICE Brent Average (in dollars per barrel)		$ 105
Cash Flow Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Hedge duration	5 years
Cash Flow Hedges | Natural Gas Bcf
Derivative Instruments, Gain (Loss) [Line Items]
Nonmonetary notional amount of price risk cash flow hedge derivatives, natural gas (in Bcf) | Bcf	411.3

[1] Netting Adjustments represent the impact of legally-enforceable master netting arrangements that allow the Company to net gain and loss positions held with the same counterparties. The net asset or net liability for each counterparty is recorded as an asset or liability on the Company’s balance sheet.