Annual report pursuant to Section 13 and 15(d)

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

v3.20.4
Segment Information - Schedule of Entity-Wide Information, Revenue from External Customers by Products and Services (Detail) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2020
 [1]
Sep. 30, 2020
Jun. 30, 2020
Mar. 31, 2020
Dec. 31, 2019
 [1]
Sep. 30, 2019
Jun. 30, 2019
Mar. 31, 2019
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Revenue from External Customer [Line Items]                      
Total net sales $ 1,410.7 $ 1,521.8 $ 1,346.9 $ 1,262.4 $ 1,220.3 $ 1,244.5 $ 1,240.1 $ 1,172.2 $ 5,541.8 $ 4,877.1 $ 4,891.8
Weight Management [Member]                      
Revenue from External Customer [Line Items]                      
Total net sales                 3,312.8 3,012.5 3,105.8
Targeted Nutrition [Member]                      
Revenue from External Customer [Line Items]                      
Total net sales                 1,527.4 1,278.5 1,243.5
Outer Nutrition [Member]                      
Revenue from External Customer [Line Items]                      
Total net sales                 111.3 97.3 91.9
Literature, Promotional and Other [Member]                      
Revenue from External Customer [Line Items]                      
Total net sales                 152.9 136.8 142.2
Energy, Sports, and Fitness [Member]                      
Revenue from External Customer [Line Items]                      
Total net sales                 $ 437.4 $ 352.0 $ 308.4
[1] The fourth quarter of 2019 includes a net favorable adjustment to our unrecognized tax benefit liability of $11.4 million primarily attributable to transfer pricing matters in various foreign jurisdictions, and a legal accrual of $40 million relating to the SEC and DOJ investigations relating to the FCPA matter in China as described further in Note 7, Contingencies.