Variable Interest Entities (Narrative) (Details) - USD ($)	1 Months Ended		9 Months Ended
	Jul. 31, 2023	May 31, 2023	Jun. 30, 2023	Jun. 30, 2022	Sep. 30, 2022
Variable Interest Entity [Line Items]
Long-term debt proceeds			$ 2,116,300,000	$ 357,000,000.0
Operating lease right-of-use assets, net			970,800,000		$ 694,800,000
Payables and accrued liabilities			3,062,200,000		2,771,600,000
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Maximum guarantor obligations			$ 1,200,000,000
NEOM Green Hydrogen Company | Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Ownership interest (in percent)			33.30%
Agreement cost		$ 6,700,000,000
Financing fees			$ 125,000,000
Operating lease right-of-use assets, net			226,800,000		0
Payables and accrued liabilities			$ 474,700,000		$ 58,100,000
NEOM Green Hydrogen Company | Variable Interest Entity, Primary Beneficiary | Land
Variable Interest Entity [Line Items]
Term of lease agreement			50 years
Operating lease right-of-use assets, net			$ 223,000,000
Payables and accrued liabilities			$ 209,000,000
Term for which additional payments are due			30 years
NEOM Green Hydrogen Company | Variable Interest Entity, Primary Beneficiary | Nonrecourse
Variable Interest Entity [Line Items]
Project financing maximum borrowing capacity		$ 6,100,000,000
Amount of debt funding (in percent)		73.00%
Available financing borrowed and outstanding			$ 0
NEOM Green Hydrogen Company | Variable Interest Entity, Primary Beneficiary | Nonrecourse | Subsequent event
Variable Interest Entity [Line Items]
Long-term debt proceeds	$ 1,300,000,000