EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income for basic earnings per common share:
Net income available to common shareholders	$ 497	$ 507
Less allocation of earnings and dividends to participating securities	(1)	(1)
Net income available to common shareholders after participating securities	496	506
Income for diluted earnings per common share:
Net income available to common shareholders	497	507
Less allocation of earnings and dividends to participating securities	(1)	(1)
Net income available to common shareholders after participating securities	$ 496	$ 506
Common shares:
Average common shares in basic computation (in shares)	208.6	214.7
Dilutive effect of outstanding stock options and certain RSUs (in shares)	5.2	5.7
Average common and common equivalent shares used in diluted computation (in shares)	213.8	220.4
Earnings per common share:
Basic (in usd per share)	$ 2.38	$ 2.36
Diluted (in usd per share)	$ 2.32	$ 2.30
Stock options and certain RSUs excluded from weighted-average diluted common shares because their effect would be antidilutive (in shares)	1.2	1.2