Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash Flows from Operating Activities
Net income	$ 82,612	$ 64,243	$ 71,132
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	1,164	248	10,912
Deferred income taxes and unrecognized income tax benefits	(17,634)	7,428	8,816
Non-cash equity compensation	14,861	13,171	13,230
Depreciation and amortization	60,738	49,917	31,970
Facilities consolidation reserve		(317)	(302)
Amortization of debt issuance costs	1,996	1,305	617
Impairment of long-lived assets	7,666	8,412	7,901
Gain on divestiture of a business	(7,590)
Other adjustments, net	(1,368)	1,283	1,099
Changes in operating assets and liabilities, net of the effect of acquisitions:
Net contract assets and liabilities	(38,422)	(41,634)	3,069
Contract receivables	20,939	19,732	(19,021)
Prepaid expenses and other assets	18,579	(20,737)	4,529
Operating lease assets and liabilities, net	3,544	(1,466)	(5,481)
Accounts payable	(1,489)	30,003	13,479
Accrued salaries and benefits	2,175	(3,337)	(5,616)
Accrued subcontractors and other direct costs	(269)	6,965	(38,575)
Accrued expenses and other current liabilities	(4,757)	24,742	26,697
Income tax receivable and payable	9,277	(1,526)	(12,802)
Other liabilities	361	3,774	(1,449)
Net Cash Provided by Operating Activities	152,383	162,206	110,205
Cash Flows from Investing Activities
Capital expenditures for property and equipment and capitalized software	(22,337)	(24,475)	(19,932)
Payments for business acquisitions, net of cash acquired	(32,664)	(237,280)	(174,549)
Proceeds from working capital adjustments related to prior business acquisition		2,911
Proceeds from divestiture of a business	51,328
Net Cash Used in Investing Activities	(3,673)	(258,844)	(194,481)
Cash Flows from Financing Activities
Advances from working capital facilities	1,245,198	1,583,936	881,037
Payments on working capital facilities	(1,372,474)	(1,446,125)	(773,264)
Proceeds from other short-term borrowings	48,532
Repayments of other short-term borrowings	(41,653)
Receipt of restricted contract funds	7,672	15,721	264,214
Payment of restricted contract funds	(8,084)	(25,959)	(319,990)
Debt issuence costs		(4,907)
Payments of principal portion of finance leases	(2,438)
Proceeds from exercise of options	279	602	2,848
Dividends paid	(10,537)	(10,547)	(10,565)
Net payments for stockholder issuances and buybacks	(19,083)	(21,218)	(20,040)
Payments on business acquisition liabilities		(1,132)	(1,007)
Net Cash (Used in) Provided by Financing Activities	(152,588)	90,371	23,233
Effect of Exchange Rate Changes on Cash, Cash Equivalents, and Restricted Cash	359	(1,198)	(511)
Decrease in Cash, Cash Equivalents, and Restricted Cash	(3,519)	(7,465)	(61,554)
Cash, Cash Equivalents, and Restricted Cash, Beginning of Period	12,968	20,433	81,987
Cash, Cash Equivalents, and Restricted Cash, End of Period	9,449	12,968	20,433
Supplemental disclosure of cash flow information:
Interest	34,093	22,782	10,331
Income taxes	26,190	16,476	34,132
Non-cash investing and financing transactions:
Share repurchases transacted but not settled and paid			$ 552
Tenant improvements funded by lessor	568	20,253
Acquisition of property and equipment through finance lease	$ 337	$ 18,319