Fair Value Measurements Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 28, 2025	Dec. 29, 2024
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Other investments in equity securities	$ 0	$ 1,718
Series 2022-1 Class A-2-I Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	4.236%	4.236%
Series 2022-1 Class A-2-II Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	4.535%	4.535%
Series 2021-1 Class A-2-I Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	2.37%	2.37%
Series 2021-1 Class A-2-II Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	2.775%	2.775%
Series 2019-1 Class A-2-I Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	3.783%	3.783%
Series 2019-1 Class A-2-II Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	4.08%	4.08%
Series 2018-1 Class A-2-II Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	3.884%	3.884%
7% debentures
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	7.00%	7.00%
Reported Value Measurement
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Cash equivalents	$ 146,711	$ 319,212
Other investments in equity securities	0	1,718
Reported Value Measurement \| Series 2022-1 Class A-2-I Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt instrument	96,750	97,500
Reported Value Measurement \| Series 2022-1 Class A-2-II Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt instrument	383,134	386,134
Reported Value Measurement \| Series 2021-1 Class A-2-I Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt instrument	415,394	418,769
Reported Value Measurement \| Series 2021-1 Class A-2-II Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt instrument	622,155	627,030
Reported Value Measurement \| Series 2019-1 Class A-2-I Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt instrument	350,673	353,673
Reported Value Measurement \| Series 2019-1 Class A-2-II Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt instrument	395,248	398,623
Reported Value Measurement \| Series 2018-1 Class A-2-II Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt instrument	432,787	436,349
Reported Value Measurement \| U.S. advertising fund revolving line of credit
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt instrument	15,000	0
Reported Value Measurement \| 7% debentures
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt instrument	49,413	48,913
Estimate of Fair Value Measurement \| Fair Value, Inputs, Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Cash equivalents	146,711	319,212
Estimate of Fair Value Measurement \| Fair Value, Inputs, Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Other investments in equity securities	0	1,718
Estimate of Fair Value Measurement \| Series 2022-1 Class A-2-I Notes \| Fair Value, Inputs, Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt instrument	94,892	93,744
Estimate of Fair Value Measurement \| Series 2022-1 Class A-2-II Notes \| Fair Value, Inputs, Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt instrument	372,866	371,855
Estimate of Fair Value Measurement \| Series 2021-1 Class A-2-I Notes \| Fair Value, Inputs, Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt instrument	384,572	376,256
Estimate of Fair Value Measurement \| Series 2021-1 Class A-2-II Notes \| Fair Value, Inputs, Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt instrument	557,700	551,981
Estimate of Fair Value Measurement \| Series 2019-1 Class A-2-I Notes \| Fair Value, Inputs, Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt instrument	346,465	345,093
Estimate of Fair Value Measurement \| Series 2019-1 Class A-2-II Notes \| Fair Value, Inputs, Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt instrument	378,608	387,039
Estimate of Fair Value Measurement \| Series 2018-1 Class A-2-II Notes \| Fair Value, Inputs, Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt instrument	426,512	418,027
Estimate of Fair Value Measurement \| U.S. advertising fund revolving line of credit \| Fair Value, Inputs, Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt instrument	15,000	0
Estimate of Fair Value Measurement \| 7% debentures \| Fair Value, Inputs, Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt instrument	$ 50,077	$ 50,034

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-11

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-11

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-10

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

+ Details

Name:	us-gaap_CashAndCashEquivalentsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-28

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-11

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-11

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-10

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2E
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2E

Reference 10: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481568/470-20-55-69B

Reference 11: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69C
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481568/470-20-55-69C

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1D
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1D

+ Details

Name:	us-gaap_DebtInstrumentFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22)(a)(1))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of investment in equity security without readily determinable fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 321
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479536/321-10-50-3

+ Details

Name:	us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-SubTopic 10
-Topic 825
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482881/825-10-55-10

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-11

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-11

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-10

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-13

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482881/825-10-55-12

+ Details

Name:	us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_DebtInstrumentAxis=wen_Series20221ClassA2INotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=wen_Series20221ClassA2IINotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=wen_Series20211ClassA2INotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=wen_Series20211ClassA2IINotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=wen_Series20191ClassA2INotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=wen_Series20191ClassA2IINotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=wen_Series20181ClassA2IINotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=wen_A7DebenturesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByMeasurementBasisAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=wen_U.S.AdvertisingFundRevolvingLineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByMeasurementBasisAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: