CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Consolidated net (loss) income	$ (2,004.8)	$ 40.7	$ (1,958.0)	$ 224.5
Foreign currency translation adjustments:
Foreign currency translation gain	182.8	129.7	300.3	113.4
Recognition of previously unrealized foreign currency losses on consolidation of equity investment			29.0
Derivatives:
Deferred loss on cash flow hedges	(23.5)		(45.3)
Reclassification adjustment of net loss on cash flow hedges included in earnings	20.1		30.0
Defined benefit pension and other postretirement benefit plans:
Net actuarial gain arising during period		0.1		0.1
Amortization and settlement recognition of net actuarial loss, included in pension cost	10.1	1.5	19.8	2.8
Amortization and settlement recognition of prior service cost, included in pension cost	1.4	1.5	2.8	2.9
Other comprehensive income, net of tax	190.9	132.8	336.6	119.2
Comprehensive (loss) income	(1,813.9)	173.5	(1,621.4)	343.7
Less: Comprehensive income attributable to noncontrolling interests	(1.8)	(1.1)	(3.6)	(2.6)
Comprehensive (loss) income attributable to common stockholders	$ (1,815.7)	$ 172.4	$ (1,625.0)	$ 341.1