Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 294.8	$ 269.0	$ 583.1	$ 1,269.7
Other comprehensive (loss) income:
Pension and other postretirement benefit plan adjustments (net of tax benefit (expense) of $22.3, ($142.9), ($49.6), and ($159.6))	(72.9)	426.5	131.4	482.1
Currency translation adjustments	(62.0)	23.0	(91.3)	58.9
Net change in cash flow hedges (net of tax (expense) benefit of ($4.0), ($0.4), ($7.2), and $0.6)	10.3	0.8	19.6	(2.4)
Other comprehensive (loss) income	(124.6)	450.3	59.7	538.6
Comprehensive income	170.2	719.3	642.8	1,808.3
Comprehensive loss attributable to noncontrolling interests	(3.3)	(3.0)	(10.1)	(10.5)
Comprehensive income attributable to Rockwell Automation, Inc.	$ 173.5	$ 722.3	$ 652.9	$ 1,818.8