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
Income for basic earnings per common share:
Net income available to common shareholders	$ 425	$ 323	$ 932	$ 769
Less allocation of earnings and dividends to participating securities	(2)	0	(3)	(1)
Net income available to common shareholders after participating securities	423	323	929	768
Income for diluted earnings per common share:
Net income available to common shareholders	425	323	932	769
Less allocation of earnings and dividends to participating securities	(2)	0	(3)	(1)
Net income available to common shareholders after participating securities	$ 423	$ 323	$ 929	$ 768
Common shares:
Average common shares in basic computation (in shares)	214.3	207.7	214.5	207.0
Dilutive effect of outstanding stock options and certain restricted stock units (in shares)	4.9	5.3	5.2	5.6
Average common and common equivalent shares used in diluted computation (in shares)	219.2	213.0	219.7	212.6
Earnings per common share:
Basic (in dollars per share)	$ 1.97	$ 1.56	$ 4.33	$ 3.71
Diluted (in dollars per share)	$ 1.93	$ 1.52	$ 4.23	$ 3.61
Stock options and certain RSUs excluded from weighted-average diluted common shares because their effect would be antidilutive (in shares)	1.6	0.0	1.3	0.5