Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Numerator
Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest	$ 3,117	$ 35,274	$ (12,145)	$ 93,415
Net Income (Loss) Attributable to Noncontrolling Interest	(2,464)	(24,665)	8,548	(59,668)
Net Income (Loss) Attributable to Parent	653	$ 10,609	$ (3,597)	$ 33,747
Net income available to stockholders, diluted	$ 686
Denominator
Basic weighted average number of common shares outstanding (in shares)	110,787	125,384	118,772	124,710
Diluted weighted average number of common shares outstanding (in shares)	265,006	130,498	118,772	131,550
Class of Stock [Line Items]
Basic (in dollars per share)	$ 0.01	$ 0.08	$ (0.03)	$ 0.27
Diluted (in dollars per share)	$ 0.00	$ 0.08	$ (0.03)	$ 0.26
Antidilutive securities excluded from computation of earnings per share (shares)			3,700	2,300
Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest	$ 3,117	$ 35,274	$ (12,145)	$ 93,415
Income attributable to noncontrolling interests	2,464	24,665	(8,548)	59,668
Net Income (Loss) Attributable to Parent	$ 653	$ 10,609	$ (3,597)	$ 33,747
Weighted Average Number of Shares Outstanding, Basic	110,787	125,384	118,772	124,710
Net income available to stockholders, diluted	$ 686
Diluted weighted average number of common shares outstanding (in shares)	265,006	130,498	118,772	131,550
Stagwell Media
Numerator
Net Income (Loss) Attributable to Noncontrolling Interest	$ 33	$ (19,286)	$ (7,684)	$ (51,027)
Class of Stock [Line Items]
Income attributable to noncontrolling interests	(33)	19,286	7,684	51,027
Stagwell Global
Numerator
Net Income (Loss) Attributable to Noncontrolling Interest	2,431	(5,379)	(864)	(8,641)
Class of Stock [Line Items]
Income attributable to noncontrolling interests	$ (2,431)	$ 5,379	$ 864	$ 8,641
Common Class C
Class of Stock [Line Items]
Weighted average number diluted shares outstanding adjustment	151,649
Antidilutive securities excluded from computation of earnings per share (shares)			151,649
Stock Appreciation Rights (SARs)
Class of Stock [Line Items]
Weighted average number diluted shares outstanding adjustment	407	1,837		1,885
Restricted Stock Units (RSUs)
Class of Stock [Line Items]
Weighted average number diluted shares outstanding adjustment	2,139	3,277		4,955
Common Class A
Class of Stock [Line Items]
Weighted average number diluted shares outstanding adjustment	113,357	130,498		131,550
Employee Stock
Class of Stock [Line Items]
Weighted average number diluted shares outstanding adjustment	24
Antidilutive securities excluded from computation of earnings per share (shares)			72
Class A Shares for Instruments with Share Settlement
Class of Stock [Line Items]
Antidilutive securities excluded from computation of earnings per share (shares)	7,480		6,843
Stock Appreciation Rights and Restricted Awards
Class of Stock [Line Items]
Antidilutive securities excluded from computation of earnings per share (shares)			5,532