Stock Incentive Plans - Components of Pre-Tax Stock-Based Compensation Expense Included in Continuing Operations (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Jun. 30, 2022	[1]	Jun. 30, 2021	[2]	Jun. 30, 2022	[1]	Jun. 30, 2021	[2]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 7		$ 4		$ 18		$ 14
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	0		0		0		1
Nonvested Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	4		2		10		8
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 3		$ 2		$ 8		$ 5

[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.