UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenue:
Revenues	$ 617,573	$ 663,791	$ 1,872,282	$ 1,979,607
Operating expenses:
Cost of services	384,980	417,134	1,201,309	1,253,765
Office and general expenses	160,021	119,186	481,379	429,121
Depreciation and amortization	38,830	32,207	107,795	95,642
Impairment and other losses	0	25,211	10,562	28,034
Costs and Expenses, Total	583,831	593,738	1,801,045	1,806,562
Operating Income (Loss), Total	33,742	70,053	71,237	173,045
Other income (expense):
Interest expense, net	(25,886)	(19,672)	(67,755)	(56,552)
Foreign exchange, net	(140)	(3,927)	(2,288)	(4,163)
Other, net	(271)	147	(467)	182
Nonoperating Income (Expense), Total	(26,297)	(23,452)	(70,510)	(60,533)
Income before income taxes and equity in earnings of non-consolidated affiliates	7,445	46,601	727	112,512
Income tax expense	4,324	11,540	12,425	20,150
Income (loss) before equity in earnings of non-consolidated affiliates	3,121	35,061	(11,698)	92,362
Equity in income (loss) of non-consolidated affiliates	(4)	213	(447)	1,053
Net income (loss)	3,117	35,274	(12,145)	93,415
Net (income) loss attributable to noncontrolling and redeemable noncontrolling interests	(2,464)	(24,665)	8,548	(59,668)
Net income (loss) attributable to Stagwell Inc. common shareholders	$ 653	$ 10,609	$ (3,597)	$ 33,747
Earnings Per Share [Abstract]
Earnings per share, basic	$ 0.01	$ 0.08	$ (0.03)	$ 0.27
Earnings per share, diluted	$ 0.00	$ 0.08	$ (0.03)	$ 0.26
Weighted Average Number Of Shares Outstanding For Basic and Diluted [Abstract]
Weighted Average Number of Shares Outstanding, Basic	110,787	125,384	118,772	124,710
Weighted Average Number of Shares Outstanding, Diluted	265,006	130,498	118,772	131,550