Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 749.0	$ 948.0	$ 1,278.0
Other comprehensive income
Pension and other postretirement benefit plan adjustments (net of tax (expense) benefit of ($31), $7, and ($15))	96.0	(23.0)	40.0
Currency translation adjustments	16.0	68.0	100.0
Net change in cash flow hedges (net of tax (expense) benefit of ($2), $11, and $5)	3.0	(27.0)	(12.0)
Other comprehensive income	115.0	18.0	128.0
Comprehensive income	864.0	966.0	1,406.0
Comprehensive loss attributable to noncontrolling interests	(120.0)	(5.0)	(109.0)
Comprehensive income attributable to Rockwell Automation, Inc.	$ 984.0	$ 971.0	$ 1,515.0