Debt and Financing Arrangements - Narrative (Details) - USD ($)	1 Months Ended			12 Months Ended
	Oct. 31, 2025	Mar. 31, 2025	Feb. 28, 2025	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023	Oct. 01, 2023
Debt Instrument [Line Items]
Deferred finance fee charges				$ 2,000,000		$ 4,000,000
Total interest paid				183,000,000	$ 187,000,000	132,000,000
Proceeds from sale and collection of receivables				185,000,000	170,000,000
Supplier finance program, obligation, current				$ 105,000,000	$ 76,000,000
Supplier Finance Program, Obligation, Current, Statement of Financial Position [Extensible Enumeration]				Accounts payable, Other current liabilities	Accounts payable, Other current liabilities
Accounts Payable
Debt Instrument [Line Items]
Supplier finance program, obligation, current				$ 16,000,000	$ 5,000,000
Supplier Finance Program, Obligation, Current, Statement of Financial Position [Extensible Enumeration]				Accounts payable	Accounts payable
Current liabilities
Debt Instrument [Line Items]
Supplier finance program, obligation, current				$ 89,000,000	$ 71,000,000
Supplier Finance Program, Obligation, Current, Statement of Financial Position [Extensible Enumeration]				Other current liabilities	Other current liabilities
7.000 % Senior Secured Notes Due 2028 | Senior notes
Debt Instrument [Line Items]
Face amount of debt						$ 500,000,000
Interest rate (as percent)						7.00%
8.250% Senior unsecured Notes Due 2031 | Unsecured debt
Debt Instrument [Line Items]
Face amount of debt						$ 500,000,000
Interest rate (as percent)						8.25%
4.875% Notes due in 2026 | Unsecured debt
Debt Instrument [Line Items]
Face amount of debt					$ 795,000,000	$ 795,000,000
Interest rate (as percent)				4.875%
7.50% Notes due in 2033 | Unsecured debt
Debt Instrument [Line Items]
Face amount of debt			$ 795,000,000
Interest rate (as percent)			7.50%	7.50%
Proceeds from debt, net of issuance costs			$ 783,000,000
Minimum
Debt Instrument [Line Items]
Supplier finance program, payment period							45 days
Maximum
Debt Instrument [Line Items]
Supplier finance program, payment period							120 days
Revolving credit facility
Debt Instrument [Line Items]
Maximum borrowing capacity				$ 1,250,000,000
Credit facility expansion (up to)				250,000,000
Remaining borrowing capacity				$ 814,000,000
Revolving credit facility | Subsequent Event
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 1,000,000,000
Revolving credit facility | Minimum
Debt Instrument [Line Items]
Commitment fee on unused portion of commitments (as percent)				0.25%
Basis spread (as percent)				1.50%
Revolving credit facility | Minimum | Subsequent Event
Debt Instrument [Line Items]
Commitment fee on unused portion of commitments (as percent)	0.20%
Basis spread (as percent)	1.25%
Revolving credit facility | Maximum
Debt Instrument [Line Items]
Commitment fee on unused portion of commitments (as percent)				0.375%
Basis spread (as percent)				2.00%
Revolving credit facility | Maximum | Subsequent Event
Debt Instrument [Line Items]
Commitment fee on unused portion of commitments (as percent)	0.25%
Basis spread (as percent)	1.75%
Revolving credit facility | North American
Debt Instrument [Line Items]
Maximum borrowing capacity				$ 950,000,000
Revolving credit facility | North American | Subsequent Event
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 895,000,000
Revolving credit facility | European
Debt Instrument [Line Items]
Maximum borrowing capacity				300,000,000
Revolving credit facility | European | Subsequent Event
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 105,000,000
Credit facility
Debt Instrument [Line Items]
Maximum borrowing capacity				150,000,000
Letter of Credit
Debt Instrument [Line Items]
Remaining borrowing capacity				8,000,000
Term loan | Term Loan B - LIBOR plus 3.25% due in 2028
Debt Instrument [Line Items]
Debt instrument, modification cost				$ 1,000,000	5,000,000
Debt issuance costs, gross					$ 4,000,000
Term loan | Term Loan B - LIBOR plus 3.25% due in 2028
Debt Instrument [Line Items]
Basis spread (as percent)				2.25%	2.75%	3.25%
Face amount of debt				$ 625,000,000
Debt instrument period percentage (as percent)				1.00%
First lien secured net leverage ratio				1.75
Write off of deferred debt issuance cost		$ 2,000,000
Term loan | Incremental term loan
Debt Instrument [Line Items]
Face amount of debt				$ 750,000,000
Term loan | 7.50% Notes due in 2033
Debt Instrument [Line Items]
Debt issuance costs, gross			$ 12,000,000