Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Cash flows from operating activities:
Net (loss) income	$ (79.8)	$ (206.1)	$ 10.5
Adjustments to reconcile net (loss) income to net cash flows provided by operating activities:
Depreciation, depletion and amortization	103.2	105.0	98.6
Amortization of deferred financing costs	4.4	2.6	2.6
Loss on extinguishment of debt	7.6	0.0	0.0
Non-cash portion of stock-based compensation	10.2	8.1	20.6
Deferred income taxes	(2.6)	(2.7)	(5.0)
Unrealized (gain) loss on foreign exchange	(1.9)	1.5	2.4
Loss on impairment of long-lived assets, definite and indefinite-lived intangible assets and goodwill	53.7	191.0	0.0
Net gain from remeasurement of contingent consideration	(7.9)	(22.1)	0.0
Gain from remeasurement of equity method investment	0.0	0.0	(10.1)
Other, net	(0.6)	4.0	4.5
Changes in operating assets and liabilities, net of acquisition of businesses:
Receivables	(11.4)	9.0	39.1
Inventories	87.3	(15.9)	(81.0)
Other assets	13.8	0.0	16.7
Accounts payable and accrued expenses and other current liabilities	8.7	(55.3)	17.4
Other liabilities	10.8	(4.7)	(14.8)
Net cash provided by operating activities	197.7	14.4	106.0
Cash flows from investing activities:
Capital expenditures	(69.7)	(114.2)	(154.3)
Proceeds from sale of Fortress assets, net of transaction costs	19.6	0.0	0.0
Acquisition of business, net of cash acquired	0.0	0.0	(18.9)
Loss on disposition of assets	2.2	0.0	4.5
Other, net	0.1	(1.9)	(4.7)
Net cash used in investing activities	(50.0)	(116.1)	(177.9)
Cash flows from financing activities:
Borrowings under revolving credit facility	244.3	422.8	150.0
Repayments under revolving credit facility	(434.4)	(314.2)	(220.0)
Proceeds from issuance of long-term debt	78.3	81.6	239.9
Principal payments on long-term debt	(265.2)	(78.6)	(314.6)
Proceeds from 2030 Notes	650.0	0.0	0.0
Repurchase of 2027 Notes	(350.0)	0.0	0.0
Premium paid to extinguish 2027 Notes	(3.9)	0.0	0.0
Payments for contingent consideration	0.0	(9.1)	0.0
Net proceeds from private placement of common stock	0.0	0.0	240.7
Dividends paid	0.0	(12.6)	(24.9)
Payment of deferred financing costs	(15.9)	(2.1)	(3.9)
Shares withheld to satisfy employee tax obligations	(1.4)	(2.1)	(1.7)
Other, net	(10.1)	(2.6)	(1.5)
Net cash (used in) provided by financing activities	(108.3)	83.1	64.0
Effect of exchange rate changes on cash and cash equivalents	0.1	0.1	0.5
Net change in cash and cash equivalents	39.5	(18.5)	(7.4)
Cash and cash equivalents, beginning of the year	20.2	38.7	46.1
Cash and cash equivalents, end of period	59.7	20.2	38.7
Supplemental cash flow information:
Interest paid, net of amounts capitalized	59.3	66.3	54.5
Income taxes paid, net of refunds	$ 30.4	$ 31.3	$ 12.5