CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Cash flows from operating activities:
Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest	$ (13,947)	$ (5,325)
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Stock-based compensation	14,248	11,543
Depreciation and amortization	44,331	42,006
Operating Lease, Right-of-Use Asset, Amortization Expense	16,102	17,118
Impairment and other losses	0	(3,529)
Deferred income taxes	(635)	(747)
Adjustment To Deferred Acquisition Consideration	10,254	6,657
Other, net	1,308	(2,060)
Changes in working capital:
Accounts receivable	(1,993)	(44,701)
Expenditures billable to clients	(5,925)	11,095
Other current assets	(62,850)	(32,778)
Accounts payable	(18,006)	(35,287)
Accrued expenses and other liabilities	(55,613)	(19,075)
Advance billings	63,071	15,628
Increase (Decrease) in Operating Lease Liability	(16,831)	(20,558)
Net Cash Provided by (Used in) Operating Activities, Total	(26,486)	(60,013)
Cash flows from investing activities:
Capitalized software	(22,402)	(11,966)
Capital expenditures	(10,665)	(5,774)
Acquisitions, net of cash acquired	355	(1,090)
Other	(325)	(1,529)
Net Cash Provided by (Used in) Investing Activities, Total	(33,037)	(20,359)
Cash flows from financing activities:
Repayment of borrowings under revolving credit facility	(469,000)	(432,000)
Proceeds from borrowings under revolving credit facility	582,000	543,000
Shares repurchased and cancelled	(40,728)	(11,068)
Distributions to noncontrolling interests	(366)	(581)
Payment of deferred consideration	0	(16,103)
Tax Receivables Agreement payment	(2,554)	0
Net Cash Provided by (Used in) Financing Activities, Total	69,352	83,248
Effect of exchange rate changes on cash and cash equivalents	569	3,438
Net increase in cash and cash equivalents	10,398	6,314
Cash and cash equivalents at beginning of period	104,537	131,339
Cash and cash equivalents at end of period	114,935	137,653
Supplemental Cash Flow Information:
Cash income taxes paid	7,667	7,908
Cash interest paid	36,753	37,738
Non-cash investing and financing activities:
Shares issued for business acquisitions	5,625	0
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 2,923	$ 1,520