Quarterly report pursuant to Section 13 or 15(d)

Derivative Instruments and Hedging Activities - Gains (Losses) Relating to Derivative Instruments Recorded to Income (Detail)

v2.4.1.9
Derivative Instruments and Hedging Activities - Gains (Losses) Relating to Derivative Instruments Recorded to Income (Detail) (Selling, general and administrative expenses [Member], USD $)
In Millions, unless otherwise specified
 3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Foreign exchange currency contracts relating to inventory and intercompany management fee hedges [Member] | Derivatives designated as hedging instruments [Member]    
Derivative Instruments, Gain (Loss) [Line Items]    
Amount of Gain (Loss) Recognized in Income $ (0.1)us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet
/ us-gaap_DerivativeInstrumentRiskAxis
= hlf_ForeignExchangeCurrencyContractsRelatingToInventoryHedgesAndIntercompanyManagementFeeHedgesMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
/ us-gaap_IncomeStatementLocationAxis
= us-gaap_SellingGeneralAndAdministrativeExpensesMember 		$ (1.6)us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet
/ us-gaap_DerivativeInstrumentRiskAxis
= hlf_ForeignExchangeCurrencyContractsRelatingToInventoryHedgesAndIntercompanyManagementFeeHedgesMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
/ us-gaap_IncomeStatementLocationAxis
= us-gaap_SellingGeneralAndAdministrativeExpensesMember
Foreign exchange currency contracts [Member] | Derivatives not designated as hedging instruments [Member]    
Derivative Instruments, Gain (Loss) [Line Items]    
Amount of Gain (Loss) Recognized in Income $ (6.0)us-gaap_DerivativeGainLossOnDerivativeNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
/ us-gaap_IncomeStatementLocationAxis
= us-gaap_SellingGeneralAndAdministrativeExpensesMember 		$ (2.9)us-gaap_DerivativeGainLossOnDerivativeNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
/ us-gaap_IncomeStatementLocationAxis
= us-gaap_SellingGeneralAndAdministrativeExpensesMember