v3.25.0.1
Goodwill (Details) - USD ($)
$ in Millions
3 Months Ended
Dec. 31, 2024
Sep. 30, 2024
Goodwill    
Goodwill (gross) $ 5,341.2 $ 5,400.7
Accumulated impairment losses (700.0) (700.0)
Goodwill 4,641.2 4,700.7
Currency translation adjustment (59.5)  
Post Consumer Brands    
Goodwill    
Goodwill (gross) 2,304.0 2,304.3
Accumulated impairment losses (609.1) (609.1)
Goodwill 1,694.9 1,695.2
Currency translation adjustment (0.3)  
Weetabix    
Goodwill    
Goodwill (gross) 878.2 937.4
Accumulated impairment losses 0.0 0.0
Goodwill 878.2 937.4
Currency translation adjustment (59.2)  
Foodservice    
Goodwill    
Goodwill (gross) 1,355.3 1,355.3
Accumulated impairment losses 0.0 0.0
Goodwill 1,355.3 1,355.3
Currency translation adjustment 0.0  
Refrigerated Retail    
Goodwill    
Goodwill (gross) 803.7 803.7
Accumulated impairment losses (90.9) (90.9)
Goodwill 712.8 $ 712.8
Currency translation adjustment $ 0.0