Schedule of Deferred Tax Expiration $ in Thousands	Dec. 31, 2025 USD ($)
Income Tax [Line Items]
Deferred Tax Assets, Tax Credit Carryforwards, Foreign	$ 4,236
Deferred Tax Assets, Tax Credit Carryforwards, Other	967
Deferred Tax Assets, Operating Loss Carryforwards	71,125
Operating losses expiring between 2033-2037
Income Tax [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Domestic	2,552
Deferred Tax Assets, Operating Loss Carryforwards, State and Local	500
Deferred Tax Assets, Operating Loss Carryforwards, Foreign	12,922
Indefinite Operating Loss
Income Tax [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Domestic	20,190
Deferred Tax Assets, Operating Loss Carryforwards, State and Local	7,168
Deferred Tax Assets, Operating Loss Carryforwards, Foreign	21,388
Capital Loss Carryforward
Income Tax [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Domestic	1,202
Consolidated Corporate Subsidiaries
Income Tax [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards	47,767
Consolidated Corporate Subsidiaries \| Operating losses expiring between 2033-2037
Income Tax [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Domestic	2,552
Deferred Tax Assets, Operating Loss Carryforwards, State and Local	468
Deferred Tax Assets, Operating Loss Carryforwards, Foreign	12,922
Consolidated Corporate Subsidiaries \| Indefinite Operating Loss
Income Tax [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Domestic	8,637
Deferred Tax Assets, Operating Loss Carryforwards, State and Local	1,800
Deferred Tax Assets, Operating Loss Carryforwards, Foreign	21,388
Stagwell Inc.
Income Tax [Line Items]
Deferred Tax Assets, Tax Credit Carryforwards, Foreign	4,236
Deferred Tax Assets, Tax Credit Carryforwards, Other	967
Deferred Tax Assets, Operating Loss Carryforwards	23,358
Stagwell Inc. \| Operating losses expiring between 2033-2037
Income Tax [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, State and Local	32
Stagwell Inc. \| Indefinite Operating Loss
Income Tax [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Domestic	11,553
Deferred Tax Assets, Operating Loss Carryforwards, State and Local	5,368
Stagwell Inc. \| Capital Loss Carryforward
Income Tax [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Domestic	$ 1,202

Deferred Tax Assets, Operating Loss Carryforward and Tax Credits

No definition available.

Name:	stgw_DeferredTaxAssetsOperatingLossCarryforwardAndTaxCredits
Namespace Prefix:	stgw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Income Tax [Line Items]

+ References

No definition available.

+ Details

Name:	stgw_IncomeTaxLineItems
Namespace Prefix:	stgw_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible domestic operating loss carryforwards. Excludes state and local operating loss carryforwards.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-6

+ Details

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

- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible foreign operating loss carryforwards.

+ References

+ Details

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

- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible state and local operating loss carryforwards.

+ References

+ Details

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

- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible foreign tax credit carryforwards.

+ References

+ Details

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

- Definition

Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible tax credit carryforwards, classified as other.

+ References

+ Details

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

- Details

Name:	us-gaap_TaxCreditCarryforwardAxis=stgw_ExpiringOperatingLossesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TaxCreditCarryforwardAxis=stgw_IndefiniteOperatingLossMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TaxCreditCarryforwardAxis=us-gaap_CapitalLossCarryforwardMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidatedEntitiesAxis=stgw_ConsolidatedCorporateSubsidiariesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidatedEntitiesAxis=stgw_StagwellInc.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: