Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Numerator
Net Income (Loss) Attributable to Parent	$ 10,609	$ (2,071)	$ 33,747	$ 20,199
Net income available to stockholders, diluted		$ (4,545)		$ (4,545)
Denominator
Basic weighted average number of common shares outstanding (in shares)	125,384	76,106	124,710	76,106
Diluted weighted average number of common shares outstanding (in shares)	130,498	76,106	131,550	76,106
Basic (in dollars per share)	$ 0.08	$ (0.06)	$ 0.27	$ (0.06)
Diluted (in dollars per share)	$ 0.08	$ (0.06)	$ 0.26	$ (0.06)
Antidilutive securities excluded from computation of earnings per share (shares)			2,340
Net Income (Loss) Attributable to Noncontrolling Interest	$ (24,665)	$ (9,994)	$ (59,668)	$ (10,987)
Net income	35,274	7,923	93,415	31,186
Net loss attributable to Stagwell Inc. common shareholders		$ (4,545)		$ (4,545)
Stagwell Media
Denominator
Net Income (Loss) Attributable to Noncontrolling Interest	(19,286)		(51,027)
Stagwell Global
Denominator
Net Income (Loss) Attributable to Noncontrolling Interest	$ (5,379)		$ (8,641)
Common Class C
Denominator
Antidilutive securities excluded from computation of earnings per share (shares)		179,970		179,970
Stock Appreciation Rights and Restricted Awards
Denominator
Antidilutive securities excluded from computation of earnings per share (shares)		6,596		6,596
Stock Appreciation Rights (SARs)
Denominator
Weighted average number diluted shares outstanding adjustment	1,837		1,885
Restricted Stock Units (RSUs)
Denominator
Weighted average number diluted shares outstanding adjustment	3,277		4,955