v3.23.1
Goodwill and intangible assets - Schedule of Finite-Lived Intangible Assets (Details) - USD ($)
$ in Millions
 6 Months Ended
Mar. 31, 2023
Sep. 30, 2022
Finite-Lived Intangible Assets [Line Items]    
Cumulative translation adjustment $ 16.4  
Gross Carrying Amount 780.0 $ 777.3
Trademarks and trade names - indefinite lived 763.4 762.5
Total Other intangible assets, net 1,543.4 1,539.8
Accumulated Amortization (276.1) (244.0)
Net Carrying Amount 503.9 533.3
Total Other intangible assets, net 1,267.3 1,295.8
Trademarks and trade names - indefinite lived    
Finite-Lived Intangible Assets [Line Items]    
Trademarks and trade names - indefinite lived   762.5
Trade names    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 142.4 141.8
Accumulated Amortization (25.5) (21.4)
Net Carrying Amount 116.9 120.4
Customer Relationships    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 394.3 393.5
Accumulated Amortization (126.6) (112.6)
Net Carrying Amount 267.7 280.9
Patents    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 34.0 33.4
Accumulated Amortization (16.9) (15.7)
Net Carrying Amount 17.1 17.7
Proprietary technology    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 172.5 172.5
Accumulated Amortization (91.3) (81.5)
Net Carrying Amount 81.2 91.0
Proprietary Formula    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 29.2 29.2
Accumulated Amortization (8.2) (6.3)
Net Carrying Amount 21.0 22.9
Vendor Relationships    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 7.6 6.9
Accumulated Amortization (7.6) (6.5)
Net Carrying Amount $ 0.0 $ 0.4