Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Numerator
Net income attributable to Stagwell Inc. common shareholders	$ 12,675	$ 4,365
Net income attributable to Class C shareholders	17,721
Net income available to stockholders, diluted	$ 30,396
Denominator
Basic weighted average number of common shares outstanding (in shares)	122,285
Diluted weighted average number of common shares outstanding (in shares)	297,484
Basic (in dollars per share)	$ 0.10
Diluted (in dollars per share)	$ 0.10
Antidilutive securities excluded from computation of earnings per share (shares)	1,005
Net income attributable to noncontrolling and redeemable noncontrolling interests	$ (20,947)	$ (238)
Stagwell Media
Denominator
Net income attributable to noncontrolling and redeemable noncontrolling interests	(17,721)
Stagwell Global
Denominator
Net income attributable to noncontrolling and redeemable noncontrolling interests	$ (3,226)
Common Class C
Denominator
Weighted average number diluted shares outstanding adjustment	170,372
Stock Appreciation Rights (SARs)
Denominator
Weighted average number diluted shares outstanding adjustment	2,041
Restricted Stock Units (RSUs)
Denominator
Weighted average number diluted shares outstanding adjustment	2,786