Noncontrolling and Redeemable Noncontrolling Interests - Changes in Noncontrolling Interests (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Noncontrolling Interest [Line Items]
Net Income (Loss) Attributable to Parent	$ 27,269	$ 21,036	$ 56,356
Adjustments to Additional Paid in Capital, Changes due to Business Combinations, Conversion of Class C to Class A Shares	47,911
Change from net income (loss) attributable to Stagwell Inc. and transfers to noncontrolling interests	74,180	(5,502)	$ 56,356
Stagwell Inc. Shareholders' Equity
Noncontrolling Interest [Line Items]
Adjustments to Additional Paid in Capital, Changes due to Business Combinations, Purchase of Redeemable Noncontrolling Interests and Noncontrolling Interests	(1,000)
Purchase of noncontrolling interests	$ 46,911	$ (26,538)