Stock Incentive Plans - Components of Pre-Tax Stock-Based Compensation Expense Included in Continuing Operations (Parenthetical) (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Jun. 30, 2022		Jun. 30, 2021		Jun. 30, 2022		Jun. 30, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 7	[1]	$ 4	[2]	$ 18	[1]	$ 14	[2]
Cash-settled Nonvested Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	1		$ 0		3		$ 2
Cash-settled Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 1				$ 1

[1] Included $1 million and $3 million of expense related to cash-settled nonvested restricted stock awards during the three and nine months ended June 30, 2022, and $1 million each of expense related to cash-settled performance units during the three and nine months ended June 30, 2022.

[2] Included zero and $2 million of expense related to cash-settled nonvested restricted stock awards during the three and nine months ended June 30, 2021.