Segment Information (Details 1) $ in Thousands	3 Months Ended
	Mar. 31, 2026 USD ($) reportable_segment	Mar. 31, 2025 USD ($)	Dec. 31, 2025 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | reportable_segment	5
Revenues	$ 704,143	$ 651,740
Adjusted EBITDA	(89,685)	(82,293)
Stock-based compensation	(14,248)	(11,543)
Depreciation and amortization	44,331	42,006
Deferred Acquisition Consideration Expense (Income)	(10,254)	(6,657)
Other items, net	11,210	3,802
Operating income	9,642	18,285
Interest and Debt Expense	(23,266)	(23,356)
Foreign exchange, net	(3,021)	1,220
Other, net	(69)	249
Nonoperating Income (Expense)	(26,356)	(21,887)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	(16,714)	(3,602)
Income tax (benefit) expense	(2,888)	1,722
Income Loss From Continuing Operations Before Equity In Earnings Of Non-consolidated Affiliates	(13,826)	(5,324)
Income (Loss) from Equity Method Investments	(121)	(1)
Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest	(13,947)	(5,325)
Net Income (Loss) Attributable to Noncontrolling Interest	974	2,408
Net Income (Loss) Attributable to Parent	(12,973)	(2,917)
Goodwill	1,596,242		$ 1,595,238
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	273,900		286,600
Non-US
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	69,000		75,000
UNITED STATES
Segment Reporting Information [Line Items]
Revenues	544,547	512,136
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	204,900		$ 211,600
Operating Segments
Segment Reporting Information [Line Items]
Revenues	706,372	653,555
Billable costs	119,519	87,553
Staff related costs	367,734	357,713
General and Administrative Expense	70,230	73,161
Unbillable and other costs	40,391	40,234
Adjusted EBITDA	(108,498)	(94,894)
Operating Segments | Marketing Services
Segment Reporting Information [Line Items]
Revenues	250,778	247,996
Billable costs	33,202	32,822
Staff related costs	132,189	127,889
General and Administrative Expense	22,732	26,654
Unbillable and other costs	17,680	16,404
Adjusted EBITDA	(44,975)	(44,227)
Operating Segments | Digital Transformation [Member]
Segment Reporting Information [Line Items]
Revenues	101,466	90,887
Billable costs	4,957	2,383
Staff related costs	64,567	59,227
General and Administrative Expense	6,388	5,441
Unbillable and other costs	123	762
Adjusted EBITDA	(25,431)	(23,074)
Operating Segments | Media & Commerce
Segment Reporting Information [Line Items]
Revenues	174,511	160,422
Billable costs	25,016	14,234
Staff related costs	97,225	94,948
General and Administrative Expense	23,173	22,413
Unbillable and other costs	13,682	15,495
Adjusted EBITDA	(15,415)	(13,332)
Operating Segments | Communications
Segment Reporting Information [Line Items]
Revenues	153,102	129,088
Billable costs	56,328	38,107
Staff related costs	56,950	58,312
General and Administrative Expense	12,747	12,996
Unbillable and other costs	2,024	2,081
Adjusted EBITDA	(25,053)	(17,592)
Operating Segments | The Marketing Cloud
Segment Reporting Information [Line Items]
Revenues	26,515	25,162
Billable costs	16	7
Staff related costs	16,803	17,337
General and Administrative Expense	5,190	5,657
Unbillable and other costs	6,882	5,492
Adjusted EBITDA	2,376	3,331
Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment
Segment Reporting Information [Line Items]
Revenues	2,229	1,815
Corporate Segment and Other Operating Segment
Segment Reporting Information [Line Items]
Adjusted EBITDA	$ (18,813)	$ (12,601)