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)

v3.6.0.2
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, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Revenue from External Customer [Line Items]                      
Total Net Sales $ 1,045.0 $ 1,122.0 $ 1,201.8 $ 1,119.6 $ 1,098.4 $ 1,102.9 $ 1,162.3 $ 1,105.4 $ 4,488.4 $ 4,469.0 $ 4,958.6
Weight Management [Member]                      
Revenue from External Customer [Line Items]                      
Total Net Sales                 2,864.5 2,862.8 3,177.0
Targeted Nutrition [Member]                      
Revenue from External Customer [Line Items]                      
Total Net Sales                 1,062.8 1,015.4 1,108.5
Energy, Sports & Fitness [Member]                      
Revenue from External Customer [Line Items]                      
Total Net Sales                 268.4 250.9 260.6
Outer Nutrition [Member]                      
Revenue from External Customer [Line Items]                      
Total Net Sales                 110.4 133.0 178.9
Literature, Promotional and Other [Member]                      
Revenue from External Customer [Line Items]                      
Total Net Sales                 $ 182.3 $ 206.9 $ 233.6