OTHER FINANCIAL INFORMATION - Schedule of Other Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2025	Sep. 30, 2025
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 15,843	$ 15,832
Less: Accumulated amortization	6,638	6,374
Net carrying amount	9,205	9,458
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Net carrying amount	5,657	5,801
Intellectual Property
Finite-Lived Intangible Assets [Line Items]
Net carrying amount	$ 3,292	$ 3,411