CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Consolidated net income (loss)	$ 52.1	$ (202.0)	$ 576.7
Changes in other comprehensive (loss) income, net of tax:
Currency translation adjustment (1)	2.0	51.6	6.5
Pension and postretirement	1.8	18.9	(1.7)
Change in net unrealized (loss) gain on derivative instruments	(36.8)	(20.1)	3.6
Total other comprehensive (loss) income, net of tax	(33.0)	50.4	8.4
Consolidated comprehensive income (loss)	19.1	(151.6)	585.1
Less: Comprehensive income attributable to noncontrolling interests	7.5	8.9	6.9
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 11.6	$ (160.5)	$ 578.2