Basis of Presentation and Recent Developments (Details) - USD ($) $ in Thousands	May 01, 2025	Apr. 23, 2025	Apr. 02, 2025	Jan. 01, 2025	Mar. 31, 2025	Dec. 31, 2024
Business Acquisition [Line Items]
Deferred acquisition consideration					$ 28,100
Subsequent Event [Line Items]
Nonredeemable Noncontrolling Interest					445,493	$ 445,174
Line of Credit Facility, Current Borrowing Capacity					640,000
Stagwell Media
Subsequent Event [Line Items]
Nonredeemable Noncontrolling Interest					$ 423,996	$ 423,428
Subsequent event
Subsequent Event [Line Items]
Conversion of Stock, Shares Converted		151,648,741
Line of Credit Facility, Current Borrowing Capacity		$ 750,000
Line of Credit Facility, Increase (Decrease), Net		$ 110,000
ADK Group
Business Acquisition [Line Items]
Aggregate purchase price				$ 24,000
Create Group Holding Limited | Subsequent event
Business Acquisition [Line Items]
Aggregate purchase price			$ 15,500
Payments to Acquire Businesses, Gross			$ 11,500
Shares issued by the Company (shares)			653,663
Deferred acquisition consideration			$ 24,000
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned			$ 4,000
JetFuel | Subsequent event
Business Acquisition [Line Items]
Aggregate purchase price	$ 21,600
Payments to Acquire Businesses, Gross	$ 10,300
Shares issued by the Company (shares)	2,017,857
Deferred acquisition consideration	$ 59,500
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned	$ 11,300