CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Statement of Comprehensive Income [Abstract]
Consolidated net (loss) income	$ (22.7)	$ 46.8
Foreign currency translation adjustments:
Foreign currency translation gain	158.8	117.5
Reclassification of previously unrealized net foreign currency loss upon consolidation of equity investment		29.0
Derivatives:
Deferred loss on cash flow hedges	(11.6)	(21.8)
Reclassification adjustment of net loss on cash flow hedges included in earnings	3.9	9.9
Defined benefit pension and other postretirement benefit plans:
Amortization and settlement recognition of net actuarial loss, included in pension and postretirement cost	4.9	9.7
Amortization and curtailment recognition of prior service cost, included in pension and postretirement cost	1.1	1.4
Other comprehensive income, net of tax	157.1	145.7
Comprehensive income	134.4	192.5
Less: Comprehensive loss (income) attributable to noncontrolling interests	0.3	(1.8)
Comprehensive income attributable to common stockholders	$ 134.7	$ 190.7