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, 2022	Sep. 30, 2021	Sep. 30, 2020
Reconciled Basic and Diluted EPS
Net income attributable to Rockwell Automation, Inc.	$ 932.2	$ 1,358.1	$ 1,023.4
Less: Allocation to participating securities	(2.9)	(2.1)	(1.0)
Net income available to common shareowners	$ 929.3	$ 1,356.0	$ 1,022.4
Basic weighted average outstanding shares (in shares)	115.9	116.0	115.8
Effect of dilutive securities
Diluted weighted average outstanding shares (in shares)	116.7	117.1	116.6
Earnings per share:
Basic (in dollars per share)	$ 8.02	$ 11.69	$ 8.83
Diluted (in dollars per share)	$ 7.97	$ 11.58	$ 8.77
Stock options
Effect of dilutive securities
Stock options (in shares)	0.7	1.0	0.7
Performance shares
Effect of dilutive securities
Stock options (in shares)	0.1	0.1	0.1