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

Derivative Instruments and Hedging Activities - Summary of Foreign Currency Forward Contracts Outstanding (Detail)

Derivative Instruments and Hedging Activities - Summary of Foreign Currency Forward Contracts Outstanding (Detail) $ in Millions	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Buy Brazilian real sell U.S. dollar [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate		3.92
Notional Amount		$ 4.3
Buy British pound sell Euro [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	0.86	0.90
Notional Amount	$ 3.3	$ 8.3
Buy British pound sell U.S. dollar [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	1.30	1.27
Notional Amount	$ 2.7	$ 2.7
Fair Value Gain (Loss)	$ 0.1
Buy Chinese yuan sell Euro [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	7.99	8.14
Notional Amount	$ 58.4	$ 58.6
Fair Value Gain (Loss)	$ 0.4	$ 1.7
Buy Chinese yuan sell U.S. dollar [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	7.16
Notional Amount	$ 73.8
Fair Value Gain (Loss)	$ 1.9
Buy Colombian peso sell U.S. dollar [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	3,323.67	3,313.00
Notional Amount	$ 1.7	$ 1.8
Buy Euro sell Australian dollar [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	1.62	1.61
Notional Amount	$ 1.1	$ 1.1
Buy Euro sell British pound [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	0.86	0.91
Notional Amount	$ 4.9	$ 4.7
Fair Value Gain (Loss)	$ (0.1)
Buy Euro sell Canadian dollar [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate		1.55
Notional Amount		$ 0.2
Buy Euro sell Chinese yuan [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate		7.91
Notional Amount		$ 6.3
Buy Euro sell Ghanaian cedi [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate		5.73
Notional Amount		$ 8.5
Fair Value Gain (Loss)		$ (0.2)
Buy Euro sell Hong Kong dollar [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	8.70	8.90
Notional Amount	$ 4.1	$ 1.1
Buy Euro sell Indonesian rupiah [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	15,632.92	16,780.97
Notional Amount	$ 13.0	$ 7.3
Fair Value Gain (Loss)	$ (0.1)	$ (0.1)
Buy Euro sell Japanese yen [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate		128.00
Notional Amount		$ 0.3
Buy Euro sell Kazakhstani tenge [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate		431.37
Notional Amount		$ 0.7
Buy Euro sell Korean won [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	1,297.40
Notional Amount	$ 1.7
Buy Euro sell Malaysian ringgit [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	4.62	4.79
Notional Amount	$ 2.9	$ 3.7
Buy Euro sell Mexican peso [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	22.41	23.48
Notional Amount	$ 63.3	$ 55.0
Fair Value Gain (Loss)	$ (1.8)	$ (0.9)
Buy Euro sell Peruvian nuevo sol [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	3.73	3.83
Notional Amount	$ 1.1	$ 2.2
Buy Euro sell Philippine peso [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	56.66	60.58
Notional Amount	$ 12.0	$ 3.9
Fair Value Gain (Loss)	$ 0.1
Buy Euro sell Russian ruble [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	70.47	78.87
Notional Amount	$ 1.7	$ 3.3
Buy Euro sell South African rand [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	15.95	16.55
Notional Amount	$ 2.7	$ 4.6
Fair Value Gain (Loss)		$ 0.1
Buy Euro sell Taiwan dollar [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	33.66	34.98
Notional Amount	$ 3.8	$ 1.2
Buy Euro sell Thai baht [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	33.66	37.32
Notional Amount	$ 2.8	$ 0.8
Buy Euro sell U.S. dollar [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	1.12	1.15
Notional Amount	$ 61.5	$ 51.2
Fair Value Gain (Loss)	$ 0.4	$ (0.1)
Buy Euro sell Ukrainian hryvnia [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate		32.28
Notional Amount		$ 2.6
Buy Hong Kong dollar sell Euro [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate		9.00
Notional Amount		$ 3.1
Buy Indian rupee sell U.S. dollar [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate		70.32
Notional Amount		$ 1.5
Buy Euro sell Vietnamese dong [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	26,052.72
Notional Amount	$ 31.7
Fair Value Gain (Loss)	$ (0.1)
Buy Indonesian rupiah sell U.S. dollar [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	14,080.00	14,670.00
Notional Amount	$ 7.2	$ 7.0
Fair Value Gain (Loss)	$ 0.1	$ 0.1
Buy Korean won sell U.S. dollar [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate		1,116.38
Notional Amount		$ 5.0
Fair Value Gain (Loss)		$ 0.1
Buy Mexican peso sell Euro [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate		22.89
Notional Amount		$ 10.9
Fair Value Gain (Loss)		$ 0.1
Buy Mexican peso sell U.S. dollar [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate		19.68
Notional Amount		$ 0.7
Buy Norwegian krone sell U.S. dollar [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	8.96	8.69
Notional Amount	$ 1.1	$ 1.2
Buy Philippine peso sell Euro [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate		60.27
Notional Amount		$ 1.5
Buy Swedish krona sell U.S. dollar [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	9.36	8.90
Notional Amount	$ 0.6	$ 1.1
Buy Taiwan dollar sell U.S. dollar [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	29.89	30.17
Notional Amount	$ 4.1	$ 9.4
Fair Value Gain (Loss)		$ 0.1
Buy U.S. dollar sell Brazilian real [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate		3.85
Notional Amount		$ 4.4
Buy U.S. dollar sell British pound [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate		1.27
Notional Amount		$ 1.4
Buy U.S. dollar sell Colombian peso [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	3,304.37	3,262.80
Notional Amount	$ 1.9	$ 1.4
Buy U.S. dollar sell Euro [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	1.12	1.16
Notional Amount	$ 134.9	$ 97.6
Fair Value Gain (Loss)	$ (0.4)	$ 0.5
Buy U.S. dollar sell Mexican peso [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weighted-Average Contract Rate	22.54	22.02
Notional Amount	$ 3.7	$ 4.9
Fair Value Gain (Loss)	(0.3)	0.2
Foreign exchange forward contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional Amount	501.7	385.5
Fair Value Gain (Loss)	$ 0.2	$ 1.6