Earnings Per Share - Computation of Basic and Diluted Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Numerator
Numerator for basic and diluted EPS - Income from continuing operations	$ 92	$ 38	$ 134	$ 70
Denominator
Denominator for basic EPS - Weighted-average common shares outstanding	54	56	54	57
Share based awards convertible to common shares	1	1	1	1
Denominator for diluted EPS - Adjusted weighted-average shares and assumed conversions	55	57	55	58
Earnings Per Share from Continuing Operations [Abstract]
Basic	$ 1.71	$ 0.67	$ 2.47	$ 1.22
Diluted	$ 1.68	$ 0.66	$ 2.43	$ 1.20