Debt and Financing Arrangements - Components of Net Financing Charges (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Debt Disclosure [Abstract]
Interest expense, net of capitalized interest costs	$ 56	$ 53	$ 111	$ 112
Banking fees and bond cost amortization	5	4	10	12
Interest income	(1)	(3)	(3)	(6)
Net foreign exchange results for financing activities	(9)	(10)	(14)	(15)
Net financing charges	$ 51	$ 44	$ 104	$ 103