CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Revenue:
Revenues	$ 2,909,000	$ 2,841,216	$ 2,527,177
Operating expenses:
Cost of services	1,845,958	1,842,978	1,621,174
Office and general expenses	732,326	711,803	661,250
Depreciation and amortization	171,249	151,652	142,831
Impairment and other losses	466	1,715	11,395
Costs and Expenses, Total	2,749,999	2,708,148	2,436,650
Operating Income (Loss), Total	159,001	133,068	90,527
Other income (expense):
Interest expense, net	(96,438)	(92,317)	(90,644)
Foreign exchange, net	(1,640)	(1,656)	(2,960)
Other, net	171	(1,372)	(359)
Nonoperating Income (Expense), Total	(90,215)	(95,345)	542
Income before income taxes and equity in earnings of non-consolidated affiliates	68,786	37,723	91,069
Income tax expense	38,271	13,182	40,557
Income before equity in earnings of non-consolidated affiliates	30,515	24,541	50,512
Equity in income (loss) of non-consolidated affiliates	111	503	(8,870)
Net income	30,626	25,044	41,642
Net income attributable to noncontrolling and redeemable noncontrolling interests	(1,525)	(22,785)	(41,508)
Net income attributable to Stagwell Inc. common shareholders	$ 29,101	$ 2,259	$ 134
Earnings Per Share [Abstract]
Earnings per share, basic	$ 0.13	$ 0.02	$ 0
Earnings per share, diluted	$ 0.08	$ 0.02	$ 0
Weighted Average Number Of Shares Outstanding For Basic and Diluted [Abstract]
Weighted Average Number of Shares Outstanding, Basic	220,608	110,890	117,259
Weighted Average Number of Shares Outstanding, Diluted	264,523	115,752	122,170
Gain (loss) on disposition of business	$ (2,245)	$ 0	$ 94,505
Business Combination, Bargain Purchase, Gain Recognized, Amount	$ 9,937