Noncontrolling and Redeemable Noncontrolling Interests - Changes in Noncontrolling Interests (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Noncontrolling Interest [Line Items]
Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest	$ 15,000	$ 1,470	$ 33,537	$ 2,623
Nonredeemable Noncontrolling Interest	513,085		513,085		$ 508,287
Adjustments to Additional Paid in Capital, Changes due to Business Combinations	(1,000)	0	(1,000)	0
Net Income Loss Including Transfer from Non Controlling Interests	9,463	17,345	22,138	21,710
Stagwell Inc. Shareholders' Equity
Noncontrolling Interest [Line Items]
Adjustments to Additional Paid in Capital, Changes due to Business Combinations	(1,000)	0	(1,000)	0
Stagwell Global
Noncontrolling Interest [Line Items]
Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest	980	1,470	1,796	2,623
Nonredeemable Noncontrolling Interest	29,459		29,459		32,914
Stagwell Media
Noncontrolling Interest [Line Items]
Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest	14,020	$ 0	31,741	$ 0
Nonredeemable Noncontrolling Interest	$ 483,626		$ 483,626		$ 475,373