Supplemental Cash Flow Information $ in Millions	12 Months Ended
	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)
Supplemental Cash Flow Information
Interest Paid, Excluding Capitalized Interest, Operating Activity	$ 1,100	$ 1,100	$ 1,100
ARO project accruals included in AP	57	45	71
Capital Expenditures Incurred but Not yet Paid	1,200	898	559
Lease Obligation Incurred		$ 163
Finance Leased Asset, Measurement Input		179,000,000
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability		$ 56
Lease assets obtained in exchange for lease obligations - finance	$ 28	$ 230	$ 3