Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 1,278.0	$ 919.1	$ 1,344.3
Other comprehensive income (loss)
Pension and other postretirement benefit plan adjustments (net of tax expense of ($15.4), ($76.0), and ($181.0))	41.5	246.5	576.4
Currency translation adjustments	99.4	(185.4)	31.4
Net change in cash flow hedges (net of tax benefit (expense) of $5.3, $(14.3), and $3.1)	(13.4)	38.2	(11.4)
Other comprehensive income	127.5	99.3	596.4
Comprehensive income	1,405.5	1,018.4	1,940.7
Comprehensive loss attributable to noncontrolling interests	(109.3)	(13.4)	(14.5)
Comprehensive income attributable to Rockwell Automation, Inc.	$ 1,514.8	$ 1,031.8	$ 1,955.2