Goodwill and Other Intangible Assets - Other Intangible Assets (Details) - USD ($) $ in Millions	Jun. 30, 2022	Sep. 30, 2021
Other intangible assets
Amortized intangible assets, carrying amount	$ 1,183.7	$ 1,188.0
Amortized intangible assets, accumulated amortization	291.1	209.9
Amortized intangible assets, net	892.6	978.1
Total, carrying amount	1,227.4	1,231.7
Total, net	936.3	1,021.8
Goodwill and Other Intangible Assets (Textual) [Abstract]
Estimated amortization expense in 2022	112.5
Estimated amortization expense in 2023	111.3
Estimated amortization expense in 2024	108.3
Estimated amortization expense in 2025	105.9
Estimated amortization expense in 2026	104.2
Trademarks
Other intangible assets
Allen-Bradley trademark not subject to amortization	43.7	43.7
Software products
Other intangible assets
Amortized intangible assets, carrying amount	96.9	90.4
Amortized intangible assets, accumulated amortization	55.6	43.2
Amortized intangible assets, net	41.3	47.2
Customer relationships
Other intangible assets
Amortized intangible assets, carrying amount	593.3	595.9
Amortized intangible assets, accumulated amortization	104.4	75.4
Amortized intangible assets, net	488.9	520.5
Technology
Other intangible assets
Amortized intangible assets, carrying amount	412.0	420.8
Amortized intangible assets, accumulated amortization	104.0	71.7
Amortized intangible assets, net	308.0	349.1
Trademarks
Other intangible assets
Amortized intangible assets, carrying amount	74.7	73.8
Amortized intangible assets, accumulated amortization	20.9	13.3
Amortized intangible assets, net	53.8	60.5
Other
Other intangible assets
Amortized intangible assets, carrying amount	6.8	7.1
Amortized intangible assets, accumulated amortization	6.2	6.3
Amortized intangible assets, net	$ 0.6	$ 0.8