Basis of Presentation and Accounting Policies - Reconciliation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Reconciled Basic and Diluted EPS
Net income attributable to Rockwell Automation, Inc.	$ 952.5	$ 1,387.4	$ 932.2
Less: Allocation to participating securities	(4.3)	(5.9)	(2.9)
Net income available to common shareowners	$ 948.2	$ 1,381.5	$ 929.3
Basic weighted average outstanding shares (in shares)	114.0	114.8	115.9
Effect of dilutive securities
Diluted weighted average outstanding shares (in shares)	114.5	115.6	116.7
Earnings per share:
Basic (in dollars per share)	$ 8.32	$ 12.03	$ 8.02
Diluted (in dollars per share)	$ 8.28	$ 11.95	$ 7.97
Stock options
Effect of dilutive securities
Dilutive securities (in shares)	0.5	0.7	0.7
Performance shares
Effect of dilutive securities
Dilutive securities (in shares)	0.0	0.1	0.1