Goodwill and Other Intangible Assets - Other Intangible Assets (Details) - USD ($) $ in Millions	Mar. 31, 2023	Sep. 30, 2022
Other intangible assets
Amortized intangible assets, carrying amount	$ 1,232.4	$ 1,167.9
Amortized intangible assets, accumulated amortization	366.1	309.6
Amortized intangible assets, net	866.3	858.3
Total, carrying amount	1,276.1	1,211.6
Total, net	910.0	902.0
Goodwill and Other Intangible Assets (Textual) [Abstract]
Estimated amortization expense in 2023	115.4
Estimated amortization expense in 2024	113.7
Estimated amortization expense in 2025	110.5
Estimated amortization expense in 2026	109.3
Estimated amortization expense in 2027	102.3
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	101.1	97.6
Amortized intangible assets, accumulated amortization	63.0	57.9
Amortized intangible assets, net	38.1	39.7
Customer relationships
Other intangible assets
Amortized intangible assets, carrying amount	613.8	582.7
Amortized intangible assets, accumulated amortization	126.0	107.2
Amortized intangible assets, net	487.8	475.5
Technology
Other intangible assets
Amortized intangible assets, carrying amount	423.8	410.8
Amortized intangible assets, accumulated amortization	146.4	119.3
Amortized intangible assets, net	277.4	291.5
Trademarks
Other intangible assets
Amortized intangible assets, carrying amount	86.7	70.4
Amortized intangible assets, accumulated amortization	24.5	19.4
Amortized intangible assets, net	62.2	51.0
Other
Other intangible assets
Amortized intangible assets, carrying amount	7.0	6.4
Amortized intangible assets, accumulated amortization	6.2	5.8
Amortized intangible assets, net	$ 0.8	$ 0.6