v3.26.3
Derivative Instruments - Pre-tax Amount of Gains (Losses) on Forward Exchange Contracts Not Designated as Hedging Instruments (Details) - Not Designated as Hedging Instrument - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2024
Derivative Instruments, Gain (Loss) [Line Items]      
Pre-tax amount of gains (losses) from forward exchange contracts not designated as hedging instruments recognized in the Consolidated Statement of Operations $ (6) $ (1) $ (4)
Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServicesSold      
Derivative Instruments, Gain (Loss) [Line Items]      
Pre-tax amount of gains (losses) from forward exchange contracts not designated as hedging instruments recognized in the Consolidated Statement of Operations (1) (10) 3
Location, Statement of Income, Balance [Axis]: rok:OtherIncomeExpense      
Derivative Instruments, Gain (Loss) [Line Items]      
Pre-tax amount of gains (losses) from forward exchange contracts not designated as hedging instruments recognized in the Consolidated Statement of Operations $ (5) $ 9 $ (7)