Annual report [Section 13 and 15(d), not S-K Item 405]

Segment Information - Schedule of Entity-Wide Information, Revenue from External Customers by Products and Services (Detail)

v3.25.4
Segment Information - Schedule of Entity-Wide Information, Revenue from External Customers by Products and Services (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Revenue from External Customer [Line Items]      
Total net sales $ 5,037.5 $ 4,993.1 $ 5,062.4
Weight Management [Member]      
Revenue from External Customer [Line Items]      
Total net sales 2,746.7 2,768.1 2,851.7
Targeted Nutrition [Member]      
Revenue from External Customer [Line Items]      
Total net sales 1,509.6 1,484.3 1,480.0
Energy, Sports, and Fitness [Member]      
Revenue from External Customer [Line Items]      
Total net sales 617.1 572.2 560.3
Outer Nutrition [Member]      
Revenue from External Customer [Line Items]      
Total net sales 85.0 83.6 82.5
Literature, Promotional and Other [Member]      
Revenue from External Customer [Line Items]      
Total net sales $ 79.1 $ 84.9 $ 87.9