Herbalife Ltd. Quarterly report pursuant to Section 13 or 15(d)

Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt - Additional Information (Detail)

Long-Term Debt - Additional Information (Detail)						1 Months Ended			3 Months Ended			9 Months Ended		12 Months Ended
Long-Term Debt - Additional Information (Detail)	Aug. 15, 2019 USD ($)	Aug. 16, 2018 USD ($)	Feb. 15, 2017 USD ($)	Mar. 09, 2016 USD ($)	May 04, 2015	Aug. 31, 2018 USD ($)	Mar. 31, 2018 USD ($) $ / shares	Feb. 28, 2014 USD ($) $ / shares	Sep. 30, 2019 USD ($) $ / shares	Sep. 30, 2018 USD ($)	Mar. 31, 2014 USD ($)	Sep. 30, 2019 USD ($) d $ / shares	Sep. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)	Mar. 09, 2011 USD ($)
Debt Instrument [Line Items]
Outstanding principal amount									$ 1,936,800,000			$ 1,936,800,000
Loss on extinguishment of debt													$ 48,500,000
Borrowings under the senior secured credit facility									969,900,000			969,900,000		$ 983,600,000
Interest expense									36,700,000	$ 44,000,000.0		121,500,000	137,700,000
Paid-in-capital in excess of par value									363,700,000			363,700,000		341,500,000
Long-term debt									1,803,800,000			1,803,800,000		2,453,800,000
Convertible notes paid												675,000,000.0	582,500,000
Letters of credit issued but undrawn									56,100,000			56,100,000
Capped call transactions [Member]
Debt Instrument [Line Items]
Capped call transactions with financial institutions								$ 123,800,000
Prepaid forward share repurchase transactions [Member]
Debt Instrument [Line Items]
Forward share repurchase transactions amount								685,800,000			$ 685,800,000
Convertible Senior Notes Due 2019 [Member]
Debt Instrument [Line Items]
Outstanding principal amount								1,150,000,000						675,000,000.0
Deferred financing costs											26,600,000
Aggregate principal amount of convertible senior notes issued								1,000,000,000
Interest expense									5,400,000	10,500,000		27,000,000.0	37,900,000
Non-cash interest expense									3,500,000	6,500,000		17,000,000.0	23,300,000
Amortization of deferred financing costs									$ 400,000	700,000		$ 1,700,000	2,300,000
Additional principal amount of convertible notes								$ 150,000,000
Convertible notes, interest rate								2.00%	2.00%			2.00%
Convertible notes maturity								Aug. 15, 2019				Aug. 15, 2019
Principal amount of convertible notes								$ 1,000
Convertible notes conversion rate								23.1816
Convertible notes conversion price \| $ / shares								$ 43.14
Paid-in-capital in excess of par value								$ 219,100,000			5,100,000
Long-term debt								$ 930,900,000
Effective interest rate on convertible notes								6.20%
Convertible notes paid	$ 675,000,000.0						$ 583,500,000
Accrued interest	$ 6,700,000						1,000,000.0
Fair value of liability to convertible notes														662,100,000
Unamortized debt discount and debt issuance costs														18,600,000
Convertible senior notes, carrying value of liability component									$ 0			$ 0		656,400,000
Convertible Senior Notes Due 2019 [Member] \| Repurchase of 2019 Convertible Notes [Member]
Debt Instrument [Line Items]
Loss on extinguishment of debt							13,100,000						13,100,000
Repurchase of convertible notes							475,000,000.0						475,000,000.0
Fair value of liability to convertible notes							459,400,000
Fair value of equity component to convertible notes							123,000,000.0
Reduction to long-term debt representing liability component of convertible notes							446,400,000
Reduction to additional paid-in capital representing equity component							123,000,000.0
Convertible Senior Notes Due 2019 [Member] \| Debt Issuance Costs [Member]
Debt Instrument [Line Items]
Deferred financing costs											$ 21,500,000
Convertible Senior Notes due 2024 [Member]
Debt Instrument [Line Items]
Outstanding principal amount									550,000,000.0			550,000,000.0		550,000,000.0
Deferred financing costs							12,900,000
Aggregate principal amount of convertible senior notes issued							$ 550,000,000
Interest expense									9,000,000.0	8,600,000		26,700,000	17,900,000
Non-cash interest expense									5,100,000	4,700,000		14,900,000	9,700,000
Amortization of deferred financing costs									$ 300,000	400,000		$ 1,000,000.0	700,000
Convertible notes, interest rate							2.625%		2.625%			2.625%
Convertible notes maturity							Mar. 15, 2024					Mar. 15, 2024
Principal amount of convertible notes							$ 1,000					$ 1,000
Convertible notes conversion rate							16.0056					16.0352
Convertible notes conversion price \| $ / shares							$ 62.48		$ 62.36			$ 62.36
Paid-in-capital in excess of par value							$ 139,900,000
Long-term debt							$ 410,100,000
Effective interest rate on convertible notes							8.40%
Fair value of liability to convertible notes									$ 478,100,000			$ 478,100,000		448,100,000
Unamortized debt discount and debt issuance costs									118,200,000			118,200,000		134,000,000.0
Convertible senior notes, carrying value of liability component									431,800,000			$ 431,800,000		416,000,000.0
Convertible notes, conversion feature												Holders of the 2024 Convertible Notes may convert their notes at their option under the following circumstances: (i) during any calendar quarter commencing after the calendar quarter ending June 30, 2018, if the last reported sale price of the Company’s common shares for at least 20 trading days (whether or not consecutive) in a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter exceeds 130% of the conversion price for the 2024 Convertible Notes on each applicable trading day; (ii) during the five business-day period immediately after any five consecutive trading day period, or the measurement period, in which the trading price per $1,000 principal amount of 2024 Convertible Notes for each trading day of that measurement period was less than 98% of the product of the last reported sale price of the Company’s common shares and the conversion rate for the 2024 Convertible Notes for each such day; (iii) if the Company calls the 2024 Convertible Notes for redemption; or (iv) upon the occurrence of specified corporate events. On and after December 15, 2023, holders may convert their 2024 Convertible Notes at any time, regardless of the foregoing circumstances.
Convertible notes, number of trading days of threshold limit (whether or not consecutive) \| d												20
Convertible notes, number of trading days of threshold limit in consecutive days \| d												30
Minimum percentage of common share price over conversion price for conversion							130.00%
Minimum percentage of the product of common share price and conversion rate for convertible notes							98.00%
Deferred financing costs recorded as additional paid-in-capital in excess of par value							$ 3,300,000
Convertible Senior Notes due 2024 [Member] \| Debt Issuance Costs [Member]
Debt Instrument [Line Items]
Deferred financing costs							$ 9,600,000
Senior Notes Due 2026 [Member]
Debt Instrument [Line Items]
Outstanding principal amount									400,000,000.0			$ 400,000,000.0		400,000,000.0
Deferred financing costs									4,800,000	5,400,000		4,800,000	5,400,000	5,200,000
Aggregate principal amount of convertible senior notes issued						$ 400,000,000
Interest expense									7,300,000	3,700,000		22,100,000	3,700,000
Amortization of deferred financing costs									$ 100,000	100,000		$ 400,000	100,000
Convertible notes, interest rate						7.25%			7.25%			7.25%
Convertible notes maturity						Aug. 15, 2026						Aug. 15, 2026
Senior notes, redemption price, percentage						100.00%
Senior notes, redemption price percentage with equity offerings						107.25%
Carrying amount									$ 395,200,000			$ 395,200,000		394,800,000
Fair value of notes									$ 407,900,000			$ 407,900,000		394,600,000
Senior Notes Due 2026 [Member] \| Debt Issuance Costs [Member]
Debt Instrument [Line Items]
Deferred financing costs										5,400,000			5,400,000
Maximum [Member] \| Senior Notes Due 2026 [Member]
Debt Instrument [Line Items]
Percentage of aggregate pricipal amount of senior notes being redeemed						40.00%
2011 Credit Facility [Member] \| 2011 Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility, maximum amount															$ 700,000,000.0
Credit facility amendment date												May 04, 2015
Line of credit facility extended maturity period												1 year
Amended maturity date of credit facility												Mar. 09, 2017
Repayment of prior senior secured credit facility			$ 410,000,000.0
Revolving credit facility termination date												Feb. 15, 2017
2011 Credit Facility [Member] \| 2011 Revolving Credit Facility [Member] \| LIBOR [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate					4.00%
2011 Credit Facility [Member] \| 2011 Revolving Credit Facility [Member] \| LIBOR [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate					5.00%
2011 Credit Facility [Member] \| 2011 Revolving Credit Facility [Member] \| Base Rate [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate					3.00%
2011 Credit Facility [Member] \| 2011 Revolving Credit Facility [Member] \| Base Rate [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate					4.00%
2011 Credit Facility [Member] \| 2011 Term Loan [Member]
Debt Instrument [Line Items]
Credit facility, maximum amount															$ 500,000,000.0
Credit facility amendment date												Jul. 26, 2012
Credit facility, maturity date												Mar. 09, 2016
Repayment of prior senior secured credit facility				$ 229,700,000
2011 Credit Facility [Member] \| 2011 Term Loan [Member] \| LIBOR [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate					2.00%
2011 Credit Facility [Member] \| 2011 Term Loan [Member] \| LIBOR [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate					3.00%
2011 Credit Facility [Member] \| 2011 Term Loan [Member] \| Base Rate [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate					1.00%
2011 Credit Facility [Member] \| 2011 Term Loan [Member] \| Base Rate [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate					2.00%
2017 Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility, maximum amount			1,450,000,000.0
Credit Facility amended, effective date												Mar. 16, 2018
Deferred financing costs			$ 22,600,000
Credit facility, amount repaid		$ 1,178,100,000										$ 1,226,900,000
2017 Credit Facility [Member] \| Other Expense (Income), Net [Member]
Debt Instrument [Line Items]
Loss on extinguishment of debt										35,400,000			35,400,000	$ 35,400,000
2017 Credit Facility [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate			1.00%
2017 Credit Facility [Member] \| Base Rate [Member]
Debt Instrument [Line Items]
Base rate interest rate floor			1.75%
2017 Credit Facility [Member] \| Federal Funds Rate [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate			0.50%
2017 Credit Facility [Member] \| 2017 Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility, maximum amount			$ 150,000,000.0
Credit facility, maturity date												Feb. 15, 2022
Repayment of prior senior secured credit facility		1,178,100,000
Credit facility LIBOR minimum floor rate interest			0.75%
2017 Credit Facility [Member] \| 2017 Revolving Credit Facility [Member] \| Base Rate [Member] \| Scenario Leverage Ratio One [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate			3.50%
2017 Credit Facility [Member] \| 2017 Revolving Credit Facility [Member] \| Base Rate [Member] \| Scenario Leverage Ratio Two [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate			3.75%
2017 Credit Facility [Member] \| 2017 Revolving Credit Facility [Member] \| Eurodollar [Member] \| Scenario Leverage Ratio One [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate			4.50%
2017 Credit Facility [Member] \| 2017 Revolving Credit Facility [Member] \| Eurodollar [Member] \| Scenario Leverage Ratio Two [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate			4.75%
2017 Credit Facility [Member] \| 2017 Term Loan B [Member]
Debt Instrument [Line Items]
Credit facility, maturity date												Feb. 15, 2023
Outstanding principal amount			$ 1,300,000,000.0
Senior secured credit facility, discount percentage			2.00%
Senior secured credit facility, discount amount			$ 26,000,000.0
2017 Credit Facility [Member] \| 2017 Term Loan B [Member] \| Base Rate [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate			4.50%
2017 Credit Facility [Member] \| 2017 Term Loan B [Member] \| Eurodollar [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate			5.50%
2017 Credit Facility [Member] \| 2017 Term Loan B [Member] \| 2017 Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Revolving credit facility termination date												Aug. 16, 2018
2018 Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility, maximum amount		1,250,000,000
Deferred financing costs		11,700,000
Credit facility, amount repaid												$ 15,000,000.0
Line of credit facility, frequency of interest payments												quarterly
Long-term debt, weighted average interest rate									5.67%			5.67%		6.80%
Borrowings under the senior secured credit facility									$ 980,000,000.0			$ 980,000,000.0		$ 995,000,000.0
Foreign currency borrowings, outstanding									0			0		0
2018 Credit Facility [Member] \| Minimum [Member] \| 2024 Convertible Notes Exceeds 350 Million [Member]
Debt Instrument [Line Items]
Outstanding principal amount		$ 350,000,000.0
2018 Credit Facility [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate		1.00%
2018 Credit Facility [Member] \| Base Rate [Member]
Debt Instrument [Line Items]
Base rate interest rate floor		1.00%
2018 Credit Facility [Member] \| Federal Funds Rate [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate		0.50%
2018 Credit Facility [Member] \| 2018 Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility, maximum amount		$ 250,000,000.0
Credit facility, maturity date		Aug. 16, 2023
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage		0.50%
Borrowings under the senior secured credit facility									0			0		0
2018 Credit Facility [Member] \| 2018 Revolving Credit Facility [Member] \| Base Rate [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate		2.00%
2018 Credit Facility [Member] \| 2018 Revolving Credit Facility [Member] \| Eurodollar [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate		2.00%
2018 Credit Facility [Member] \| 2018 Term Loan A [Member]
Debt Instrument [Line Items]
Credit facility, maturity date		Aug. 16, 2023
Outstanding principal amount		$ 250,000,000.0
Borrowings under the senior secured credit facility									237,500,000			237,500,000		246,900,000
2018 Credit Facility [Member] \| 2018 Term Loan A [Member] \| Level 2 [Member]
Debt Instrument [Line Items]
Outstanding principal amount									236,300,000			236,300,000		245,400,000
Debt instrument, fair value									238,700,000			238,700,000		240,700,000
2018 Credit Facility [Member] \| 2018 Term Loan A [Member] \| Base Rate [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate		3.00%
2018 Credit Facility [Member] \| 2018 Term Loan A [Member] \| Eurodollar [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate		3.00%
2018 Credit Facility [Member] \| 2018 Term Loan B [Member]
Debt Instrument [Line Items]
Credit facility, maturity date		Aug. 18, 2025
Outstanding principal amount		$ 750,000,000.0
Senior secured credit facility, discount percentage		0.25%
Senior secured credit facility, discount amount		$ 1,900,000
Borrowings under the senior secured credit facility									742,500,000			742,500,000		748,100,000
2018 Credit Facility [Member] \| 2018 Term Loan B [Member] \| Level 2 [Member]
Debt Instrument [Line Items]
Outstanding principal amount									733,600,000			733,600,000		738,200,000
Debt instrument, fair value									746,200,000			746,200,000		$ 729,300,000
2018 Credit Facility [Member] \| 2018 Term Loan B [Member] \| 2024 Convertible Notes Exceeds 350 Million [Member]
Debt Instrument [Line Items]
Credit facility, maturity date		Dec. 15, 2023
2018 Credit Facility [Member] \| 2018 Term Loan B [Member] \| Base Rate [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate		2.25%
2018 Credit Facility [Member] \| 2018 Term Loan B [Member] \| Eurodollar [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate		3.25%
Senior Unsecured Notes [Member]
Debt Instrument [Line Items]
Aggregate principal amount of convertible senior notes issued		$ 400,000,000
2018 and 2017 Credit Facility [Member]
Debt Instrument [Line Items]
Interest expense									14,600,000	19,600,000		44,500,000	68,700,000
Non-cash interest expense									100,000	600,000		200,000	2,900,000
Amortization of deferred financing costs									$ 500,000	$ 700,000		$ 1,300,000	$ 2,800,000