Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Cash flows from operating activities:
Net income	$ 105,040	$ 116,626	$ 62,479
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization	32,429	25,300	24,938
Non-cash lease expense	6,767	6,065	6,321
Lease-related impairment charges	738	3,513	6,248
Share-based compensation	46,512	45,074	45,697
Amortization of debt discount and issuance costs	1,147	1,078	769
Allowances for doubtful accounts	942	3,073	421
Deferred income taxes	10,880	2,613	(6,182)
(Gains) losses on sale of property and equipment	132	(101)	(64)
Gain on sale of businesses, excluding transaction costs	0	(4,309)	0
Change in fair value of contingent consideration liabilities	(2,952)	533	490
Change in fair value of preferred stock investment	5,014	0	26,262
Credit-related impairment charge on convertible debt investment	10,382	0	0
Changes in operating assets and liabilities, net of acquisitions and divestiture:
(Increase) decrease in receivables from clients, net	16,904	(30,496)	(15,046)
(Increase) decrease in unbilled services, net	(31,827)	31,123	(49,051)
(Increase) decrease in current income tax receivable / payable, net	(7,797)	5,412	(5,139)
(Increase) decrease in other assets	(12,579)	(8,153)	(6,535)
Increase (decrease) in accounts payable and other liabilities	(6,253)	(12,228)	(6,948)
Increase (decrease) in accrued payroll and related benefits	9,330	16,370	51,022
Increase (decrease) in deferred revenues	2,681	892	560
Net cash provided by operating activities	193,394	201,319	135,262
Cash flows from investing activities:
Purchases of property and equipment	(10,437)	(8,651)	(9,444)
Investments in life insurance policies	(3,241)	(2,594)	(3,074)
Distributions from life insurance policies	0	0	2,956
Purchases of businesses, net of cash acquired	(111,630)	(49,503)	(1,613)
Capitalization of internally developed software costs	(20,647)	(23,932)	(25,742)
Proceeds from note receivable	154	154	154
Proceeds from sale of property and equipment	50	102	111
Proceeds from divestitures of businesses	0	4,675	0
Net cash used in investing activities	(145,751)	(79,749)	(36,652)
Cash flows from financing activities:
Proceeds from exercises of stock options	5,087	1,832	2,524
Shares redeemed for employee tax withholdings	(33,568)	(22,085)	(10,536)
Share repurchases	(166,725)	(123,006)	(122,757)
Proceeds from bank borrowings	1,108,000	743,500	354,000
Repayments of bank borrowings	(954,688)	(709,813)	(320,000)
Payments for debt issuance costs	(3,100)	(1,446)	(58)
Deferred payments on business acquisition	36	617	1,500
Net cash used in financing activities	(45,030)	(111,635)	(98,327)
Effect of exchange rate changes on cash	(16)	(173)	32
Net increase in cash and cash equivalents	2,597	9,762	315
Cash and cash equivalents at end of the period	24,508	21,911	12,149
Cash and cash equivalents at beginning of the period	21,911	12,149	11,834
Non-cash investing and financing activities:
Property and equipment expenditures and capitalized software included in current liabilities	6,417	5,016	5,156
Common stock issued related to purchases of businesses	29,207	20,851	1,646
Contingent consideration accrued related to purchases of businesses	20,251	36	374
Notes Issued	0	2,250	0
Share Repurchases Initiated but not yet Settled	0	636	1,030
Excise tax on net share repurchases incurred but not paid [Abstract]	$ 616	$ 533	$ 947