Acquisitions and Dispositions - Narrative (Details) $ / shares in Units, £ in Thousands, shares in Thousands	May 31, 2022 USD ($)	Apr. 19, 2022 USD ($)	Apr. 01, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2021 GBP (£)	Dec. 01, 2021 USD ($)	Oct. 01, 2021 USD ($)	Aug. 02, 2021 USD ($) $ / shares shares	Jul. 31, 2023	Jun. 30, 2022 USD ($)	Dec. 31, 2021 GBP (£)
Business Acquisition [Line Items]
Goodwill				$ 1,652,723,000						$ 1,668,892,000
Payments for Acquire Businesses, Working Capital Payments | £					£ 9
Stagwell Media
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash								$ 1.80
MDC
Business Acquisition [Line Items]
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable								$ 80,000,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life								13 years
Goodwill								$ 1,298,370,000
Business Acquisition, Share Price | $ / shares								$ 5.42
MDC | Previously Reported Goodwill
Business Acquisition [Line Items]
Goodwill								$ 1,300,360,000
MDC | Common Class C | Stagwell Media
Business Acquisition [Line Items]
Stock Issued During Period, Shares, Acquisitions | shares								179,970
MDC | Common Units | Stagwell OpCo
Business Acquisition [Line Items]
Remaining ownership interest acquired (percent)								69.55%
MDC | Integrated Agencies Network
Business Acquisition [Line Items]
Goodwill								$ 1,058,365,000
MDC | Media Network
Business Acquisition [Line Items]
Goodwill								173,633,000
MDC | Communications Network
Business Acquisition [Line Items]
Goodwill								66,372,000
Goodstuff Holdings Limited
Business Acquisition [Line Items]
Closing cash payment | £					21
Goodwill				$ 4,275,000
Payment for contingent consideration | £					8
Payments to Acquire Businesses, Deferred Payments | £					4
Payment for contingent consideration | £					8
Payments to Acquire Businesses, Deferred Payments | £					£ 4
Goodstuff Holdings Limited | Maximum
Business Acquisition [Line Items]
Deferred acquisition consideration | £											£ 22
Targeted Victory
Business Acquisition [Line Items]
Remaining ownership interest acquired (percent)							27.00%
Aggregate purchase price							$ 73,898,000
Deferred acquisition consideration							$ 46,618,000
Business Acquisition, Percentage of Voting Interests Acquired, Step One							13.30%
Business Combination, Consideration Transferred, Redeemable Noncontrolling Interest							$ 27,280,000
Business Acquisition, Percentage of Voting Interests Acquired, Step One							13.30%
Business Combination, Consideration Transferred, Redeemable Noncontrolling Interest							$ 27,280,000
Targeted Victory | Forecast
Business Acquisition [Line Items]
Business Acquisitions, Percentage of Voting Interests Acquired, Step Two									13.30%
Business Acquisitions, Percentage of Voting Interests Acquired, Step Two									13.30%
Targeted Victory | Common Class A
Business Acquisition [Line Items]
Business Combination, Contingent Consideration Arrangements, Purchase Price Option Sacrificed in Shares, Percentage							50.00%
Business Combination, Contingent Consideration Arrangements, Change in Range of Outcomes, Contingent Consideration, Liability, Value, High							$ 135,000
Business Combination, Contingent Consideration Arrangements, Purchase Price Option Sacrificed in Shares, Percentage							50.00%
Business Combination, Contingent Consideration Arrangements, Change in Range of Outcomes, Contingent Consideration, Liability, Value, High							$ 135,000
Concentric
Business Acquisition [Line Items]
Remaining ownership interest acquired (percent)						27.00%
Aggregate purchase price						$ 8,058,000
Closing cash payment						1,581,000
Deferred acquisition consideration						$ 6,477,000
Instrument Holdings Inc.
Business Acquisition [Line Items]
Remaining ownership interest acquired (percent)				49.00%							49.00%
Aggregate purchase price				$ 157,072,000
Closing cash payment				37,500,000
Business Combination, Consideration Transferred, Deferred Acquisition Payment				82,072,000
Business Combination, Consideration Transferred, Deferred Acquisition Payment				82,072,000
Instrument Holdings Inc. | Common Class A
Business Acquisition [Line Items]
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable				$ 37,500,000
Hello Design
Business Acquisition [Line Items]
Aggregate purchase price			$ 4,600,000
Closing cash payment			3,600,000
Deferred acquisition consideration			$ 1,000,000
BNG
Business Acquisition [Line Items]
Aggregate purchase price		$ 20,695,000
Goodwill								$ 25,552,000
Estimated contingent consideration		$ 50,000,000
Contingent consideration payable in cash (percent)		67.00%
Contingent consideration payable in equity (percent)		33.00%
TMA Direct
Business Acquisition [Line Items]
Remaining ownership interest acquired (percent)	87.00%
Aggregate purchase price	$ 19,431,000
Deferred acquisition consideration	482,000
Goodwill	$ 10,503,000
Business Acquisition, Percentage of Voting Interests Acquired, Step One	13.00%
Business Combination, Contingent Consideration Arrangements, Change in Range of Outcomes, Contingent Consideration, Liability, Value, High	$ 13,330,000
Business Acquisition, Percentage of Voting Interests Acquired, Step One	13.00%
Business Combination, Contingent Consideration Arrangements, Change in Range of Outcomes, Contingent Consideration, Liability, Value, High	$ 13,330,000