Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 919.1	$ 1,344.3	$ 1,023.2
Other comprehensive income (loss)
Pension and other postretirement benefit plan adjustments (net of tax expense of ($76.0), ($181.0), and ($3.4))	246.5	576.4	9.3
Currency translation adjustments	(185.4)	31.4	25.7
Net change in cash flow hedges (net of tax (expense) benefit of ($14.3), $3.1, and $6.6)	38.2	(11.4)	(18.5)
Other comprehensive income	99.3	596.4	16.5
Comprehensive income	1,018.4	1,940.7	1,039.7
Comprehensive loss attributable to noncontrolling interests	(13.4)	(14.5)	(0.5)
Comprehensive income attributable to Rockwell Automation, Inc.	$ 1,031.8	$ 1,955.2	$ 1,040.2