Income Taxes - Schedule of Differences between U.S. Federal Statutory Income Tax Rate and Income Taxes Provided (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Income Tax Disclosure [Abstract]
U.S. federal corporate statutory tax rate	21.00%	21.00%	21.00%
Taxes on income at the U.S. federal statutory rate	$ 126	$ 128	$ 155
U.S. state and local taxes	1	12	15
Foreign income taxed at different rates, including withholding taxes	29	33	29
Valuation allowance	0	(5)	(6)
Change in tax rates	3	0	1
GILTI and FDII	(3)	(4)	(6)
Federal research and development credits	(3)	(8)	0
Uncertain tax positions	(3)	7	(3)
Non-deductible compensation	11	8	6
Wind down of O&O media properties	(17)	0	0
Return to provision adjustments	(15)	4	(4)
Nontaxable income from partnerships	(9)	(1)	(1)
Other	3	(4)	(1)
Income tax expense	$ 123	$ 170	$ 185