v3.20.4
Segments (Details) - USD ($)
$ in Millions
 3 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Sep. 30, 2020
Segment Reporting Information      
Net Sales $ 1,458.0 $ 1,456.8  
Interest expense, net 96.6 102.9  
Loss on extinguishment of debt, net 0.0 12.9  
Income on swaps, net (41.6) (61.4)  
Earnings before income taxes and equity method loss 122.1 144.8  
Depreciation and amortization 94.1 90.3  
Assets 12,140.3   $ 12,146.7
Corporate      
Segment Reporting Information      
General corporate expenses and other 13.8 27.4  
Depreciation and amortization 1.0 0.9  
Assets 1,256.0   1,315.0
Operating Segments      
Segment Reporting Information      
Net Sales 1,458.0 1,456.8  
Segment Profit (Loss) 190.9 226.6  
Depreciation and amortization 93.1 89.4  
Operating Segments | Post Consumer Brands      
Segment Reporting Information      
Net Sales 445.0 441.2  
Segment Profit (Loss) 70.5 80.6  
Depreciation and amortization 28.2 27.9  
Assets 3,260.5   3,291.7
Operating Segments | Weetabix      
Segment Reporting Information      
Net Sales 113.5 101.5  
Segment Profit (Loss) 28.1 23.7  
Depreciation and amortization 9.4 8.7  
Assets 1,971.3   1,864.5
Operating Segments | Foodservice      
Segment Reporting Information      
Net Sales 354.5 420.6  
Segment Profit (Loss) 10.8 47.0  
Depreciation and amortization 30.7 29.0  
Operating Segments | Refrigerated Retail      
Segment Reporting Information      
Net Sales 263.1 249.9  
Segment Profit (Loss) 33.7 26.0  
Depreciation and amortization 18.1 17.4  
Operating Segments | Foodservice and Refrigerated Retail      
Segment Reporting Information      
Assets 4,971.8   5,022.0
Operating Segments | BellRing Brands      
Segment Reporting Information      
Net Sales 282.4 244.0  
Segment Profit (Loss) 47.8 49.3  
Depreciation and amortization 6.7 6.4  
Assets 680.7   $ 653.5
Eliminations | Segment Eliminations      
Segment Reporting Information      
Net Sales (0.5) (0.4)  
Cereal and granola | Operating Segments      
Segment Reporting Information      
Net Sales 558.3 542.5  
Eggs and egg products | Operating Segments      
Segment Reporting Information      
Net Sales 338.1 395.3  
Side dishes (including potato products) | Operating Segments      
Segment Reporting Information      
Net Sales 155.5 148.5  
Cheese and dairy | Operating Segments      
Segment Reporting Information      
Net Sales 62.7 67.6  
Sausage | Operating Segments      
Segment Reporting Information      
Net Sales 44.3 45.9  
Protein-based products and supplements | Operating Segments      
Segment Reporting Information      
Net Sales 282.5 244.1  
Other | Operating Segments      
Segment Reporting Information      
Net Sales 17.0 13.2  
Product Eliminations | Eliminations      
Segment Reporting Information      
Net Sales $ (0.4) $ (0.3)