Herbalife Ltd. Annual report pursuant to Section 13 and 15(d)

Derivative Instruments and Hedging Activities - Effect of Cash Flow Hedging Relationships on Consolidated Statements of Income (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Cost of sales	$ 958.0	$ 919.3	$ 848.6
Selling, general, and administrative expenses	1,940.3	1,955.2	1,758.6
Foreign Exchange Currency Contracts Relating To Inventory Hedges [Member] \| Cost of sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (loss) gain reclassified from accumulated other comprehensive loss to income	(0.2)	3.6	(0.5)
Amount of (loss) gain excluded from assessment of effectiveness recognized in income	(3.3)
Foreign Exchange Currency Contracts Relating To Inventory Hedges [Member] \| Selling, General and Administrative Expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (loss) gain excluded from assessment of effectiveness recognized in income		(2.9)	(1.5)
Foreign Exchange Currency Contracts Relating To Intercompany Management Fee Hedges [Member] \| Selling, General and Administrative Expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (loss) gain reclassified from accumulated other comprehensive loss to income	1.0	(3.8)	(2.2)
Amount of (loss) gain excluded from assessment of effectiveness recognized in income	$ 0.2	$ 0.8	$ 1.4