Commitments and Contingent Liabilities - Narrative (Details) $ in Millions	12 Months Ended
Sep. 30, 2020 USD ($) site	Sep. 30, 2019 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Number of Superfund sites designated potentially responsible party at \| site	13
Accrual for environmental loss contingencies, net of related receivables	$ 59.2	$ 56.3
Asset retirement obligation, net of recoveries	$ 22.8	$ 21.5

The carrying amount of a liability for an asset retirement obligation, net of probable expected recoveries. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

No definition available.

Name:	rok_AssetRetirementObligationNetofRecoveries
Namespace Prefix:	rok_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant