Leases - Schedule of Components of Lease Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 29, 2025	Mar. 30, 2024
Operating lease cost:
Fixed lease cost	$ 3,459	$ 3,983
Lease termination benefit		(156)
Variable lease cost	2	14
Total operating lease cost	3,461	3,841
Finance lease cost:
Amortization of leased assets		2
Interest on lease liabilities		0
Total finance lease cost		2
Total lease cost	$ 3,461	$ 3,843

Amount of interest expense on finance lease liability.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 53
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479589/842-20-55-53

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479041/842-20-45-4

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478964/842-20-50-4

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of amortization expense attributable to right-of-use asset from finance lease.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of lease cost recognized by lessee for lease contract.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.

+ References

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Balance Type:	debit
Period Type:	duration

- Definition

Amount of variable lease cost, excluded from lease liability, recognized when obligation for payment is incurred for finance and operating leases.

+ References

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Data Type:	xbrli:monetaryItemType
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- Definition

Finance lease cost.

+ References

No definition available.

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Namespace Prefix:	ww_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Definition

Finance lease costs.

+ References

No definition available.

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- Definition

Fixed lease cost.

+ References

No definition available.

+ Details

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

- Definition

Lease termination cost (benefit).

+ References

No definition available.

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

- Definition

Operating lease cost abstract.

+ References

No definition available.

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