Equity Items - Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Equity [Abstract]
Unrealized translation gain (loss), before tax	$ (86)	$ 23	$ (108)	$ 38
Unrealized translation gain (loss), tax	0	0	1	(1)
Unrealized translation gain (loss), net of tax	(86)	23	(107)	37
Unrealized gain (loss) on commodity hedges, before tax	(4)	0	(3)	0
Unrealized gain (loss) on commodity hedges, tax	1	0	1	0
Unrealized gain (loss) on commodity hedges, net of tax	(3)	0	(2)	0
Total other comprehensive income (loss), before tax	(90)	23	(111)	38
Total other comprehensive income (loss), tax	1	0	2	(1)
Other comprehensive income (loss), net of tax	$ (89)	$ 23	$ (109)	$ 37