XML 48 R36.htm IDEA: XBRL DOCUMENT v3.21.1
Basis of Presentation (Details) - $ / shares
Mar. 31, 2021
Sep. 30, 2020
Oct. 21, 2019
Common Class A      
Common stock, shares issued     39,400,000
Common stock, par value per share $ 0.01    
Voting power of common stock 33.00%    
Common stock, shares outstanding 39,500,000    
Common Class B      
Common stock, par value per share $ 0.01    
Voting power of common stock 67.00%    
Common stock, shares outstanding 1    
BellRing Brands, LLC unit | BellRing Brands, Inc.      
Common unit, issued     39,400,000
Noncontrolling interest, ownership percentage by parent 28.80% 28.80%  
BellRing Brands, LLC unit | Post Holdings, Inc.      
Noncontrolling interest, ownership percentage by noncontrolling owners 71.20% 71.20%  
Common units, outstanding 97,500,000 97,500,000