Leases - Summary of Supplemental Cash Flow Information Related to Leases (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 30, 2024	Apr. 01, 2023
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	$ 3,964	$ 7,208
Operating cash flows from finance leases	0	0
Financing cash flows from finance leases	2	26
Lease assets obtained (modified) in exchange for new (modified) operating lease liabilities	766	$ (1,052)
Lease assets (modified) obtained in exchange for (modified) new finance lease liabilities	$ (1)

Amount of interest paid on finance lease liability.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (g)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147478964/842-20-50-4

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479041/842-20-45-5

+ Details

Name:	us-gaap_FinanceLeaseInterestPaymentOnLiability
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of cash outflow for principal payment on finance lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (g)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147478964/842-20-50-4

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 5
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479041/842-20-45-5

+ Details

Name:	us-gaap_FinanceLeasePrincipalPayments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 5
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479041/842-20-45-5

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (g)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147478964/842-20-50-4

+ Details

Name:	us-gaap_OperatingLeasePayments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Cash paid for amounts included in measurement of lease liabilities.

+ References

No definition available.

+ Details

Name:	ww_CashPaidForAmountsIncludedInMeasurementOfLeaseLiabilitiesAbstract
Namespace Prefix:	ww_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Right of use asset modified obtained in exchange for finance lease liability.

+ References

No definition available.

+ Details

Name:	ww_RightOfUseAssetModifiedObtainedInExchangeForFinanceLeaseLiability
Namespace Prefix:	ww_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Right of use asset modified obtained in exchange for operating lease liability.

+ References

No definition available.

+ Details

Name:	ww_RightOfUseAssetModifiedObtainedInExchangeForOperatingLeaseLiability
Namespace Prefix:	ww_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration