Variable Interest Entities (JIGPC Joint Venture) (Details) - USD ($) $ in Billions	3 Months Ended
	Dec. 31, 2021	Jun. 30, 2026	Sep. 30, 2025
Jazan Integrated Gasification and Power Company ("JIGPC")
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage		55.00%
Ownership percentage attributable to noncontrolling partner		4.00%
Investment balance		$ 3.1	$ 3.1
Jazan Integrated Gasification and Power Company ("JIGPC") | Aramco
Schedule of Equity Method Investments [Line Items]
Term of project agreement	25 years