UNAUDITED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Current Assets
Cash and cash equivalents	$ 132,238	$ 131,339
Accounts receivable, net	777,947	716,415
Expenditures billable to clients	150,255	173,194
Other current assets	170,011	114,200
Total Current Assets	1,230,451	1,135,148
Fixed assets, net	64,895	72,706
Operating Lease, Right-of-Use Asset	217,398	219,400
Goodwill	1,597,312	1,554,146
Other intangible assets, net	851,487	836,783
Deferred Tax Assets, Tax Deferred Expense	250,360	46,926
Other assets	49,992	43,112
Total Assets	4,261,895	3,908,221
Current Liabilities
Accounts payable	408,149	449,347
Accrued media	206,753	245,883
Accruals and other liabilities	275,227	265,356
Advance billings	375,768	294,609
Current portion of lease liabilities - operating leases	56,774	60,195
Current portion of deferred acquisition consideration	53,569	51,906
Total Current Liabilities	1,376,240	1,367,296
Long-term debt	1,526,291	1,353,624
Long-term portion of deferred acquisition consideration	23,478	50,209
Long-term lease liabilities - operating leases	227,540	245,397
Deferred Tax Liabilities, Tax Deferred Income	53,497	47,239
Long-term tax receivable agreement liability	223,600	25,493
Other liabilities	52,179	33,646
Total Liabilities	3,482,825	3,122,904
Redeemable Noncontrolling Interests	8,589	8,412
Commitments and Contingencies
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Paid-in capital	741,702	343,647
Retained earnings	29,542	11,740
Accumulated other comprehensive loss	(22,451)	(23,773)
Stagwell Inc. Shareholders’ Equity	749,047	331,731
Noncontrolling interests	21,434	445,174
Total Shareholders’ Equity	770,481	776,905
Liabilities and Equity, Total	4,261,895	3,908,221
Common Class A and Common Class B
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Common shares	254	115
Common Class C
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Common shares	$ 0	$ 2