Stock-Based Compensation (Expense and Tax Benefit Information) (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Compensation	$ 144	$ 224	$ 110
Income tax benefits recognized in income statement for compensation arrangements	19	27	18
Unrecognized compensation cost related to non-vested awards granted	$ 153
Unrecognized compensation cost is expected to be recognized, weighted-average period, years	1 year 3 months 18 days
AspenTech [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Compensation	$ 32	0	0
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Compensation	89	203	98
Restricted stock and restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Compensation	23	21	11
Restricted stock and restricted stock units \| AspenTech [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to non-vested awards granted	$ 97
Unrecognized compensation cost is expected to be recognized, weighted-average period, years	1 year 9 months 18 days
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Compensation	$ 0	$ 0	$ 1
Stock Options [Member] \| AspenTech [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to non-vested awards granted	$ 41
Unrecognized compensation cost is expected to be recognized, weighted-average period, years	2 years 1 month 6 days

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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