v3.26.3
Shareholders' Deficit - Summary of Changes in Shareholders' Deficit (Detail) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Beginning balance $ (466.9) $ (654.4) $ (509.4) $ (801.1)
Issuance of common shares from exercise of SARs, restricted stock units, employee stock purchase plan, and other 0.5 0.4 1.4 1.3
Additional capital from share-based compensation 8.7 11.2 29.4 33.2
Repurchases of common shares (0.2) (1.3) (10.2) (8.1)
Net income (loss) 57.1 43.1 91.8 142.7
Foreign currency translation adjustment, net of income taxes (7.7) (0.7) (19.7) 32.2
Unrealized gain (loss) on derivatives, net of income taxes 4.8 (4.3) 3.0 (12.4)
Acquisition   0.0   6.2
Other 0.0   10.0  
Ending balance (403.7) (606.0) (403.7) (606.0)
Common Shares [Member]        
Beginning balance 0.1 0.1 0.1 0.1
Issuance of common shares from exercise of SARs, restricted stock units, employee stock purchase plan, and other 0.0 0.0 0.0 0.0
Repurchases of common shares 0.0 0.0 0.0 0.0
Other 0.0   0.0  
Ending balance 0.1 0.1 0.1 0.1
Paid-in Capital in Excess of par Value [Member]        
Beginning balance 334.8 294.3 316.0 278.2
Issuance of common shares from exercise of SARs, restricted stock units, employee stock purchase plan, and other 0.5 0.4 1.4 1.3
Additional capital from share-based compensation 8.7 11.2 29.4 33.2
Repurchases of common shares (0.2) (1.3) (10.2) (8.1)
Other 0.0   7.2  
Ending balance 343.8 304.6 343.8 304.6
Accumulated Other Comprehensive Loss [Member]        
Beginning balance (265.3) (246.6) (251.5) (271.4)
Foreign currency translation adjustment, net of income taxes (7.7) (0.7) (19.7) 32.2
Unrealized gain (loss) on derivatives, net of income taxes 4.8 (4.3) 3.0 (12.4)
Ending balance (268.2) (251.6) (268.2) (251.6)
Accumulated Deficit [Member]        
Beginning balance (544.1) (708.3) (579.7) (808.0)
Repurchases of common shares 0.0 0.0 0.0 0.0
Net income (loss) 58.8 43.2 94.4 142.9
Ending balance (485.3) (665.1) (485.3) (665.1)
Total Herbalife Shareholders' Deficit [Member]        
Beginning balance (474.5) (660.5) (515.1) (801.1)
Issuance of common shares from exercise of SARs, restricted stock units, employee stock purchase plan, and other 0.5 0.4 1.4 1.3
Additional capital from share-based compensation 8.7 11.2 29.4 33.2
Repurchases of common shares (0.2) (1.3) (10.2) (8.1)
Net income (loss) 58.8 43.2 94.4 142.9
Foreign currency translation adjustment, net of income taxes (7.7) (0.7) (19.7) 32.2
Unrealized gain (loss) on derivatives, net of income taxes 4.8 (4.3) 3.0 (12.4)
Acquisition   0.0   0.0
Other 0.0   7.2  
Ending balance (409.6) (612.0) (409.6) (612.0)
Noncontrolling Interest [Member]        
Beginning balance 7.6 6.1 5.7 0.0
Net income (loss) (1.7) (0.1) (2.6) (0.2)
Acquisition   0.0   6.2
Other 0.0   2.8  
Ending balance $ 5.9 $ 6.0 $ 5.9 $ 6.0