ICF International (ICFI) 10-K 28 Feb 24 2023 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Feb. 23, 2024	Jun. 30, 2023
Cover [Abstract]
Entity Registrant Name	ICF INTERNATIONAL, INC.
Entity Central Index Key	0001362004
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Document Annual Report	true
Document Transition Report	false
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Entity Well-known Seasoned Issuer	No
Entity Common Stock, Shares Outstanding (in shares)		18,715,376
Entity Public Float			$ 2,309
Document Type	10-K
Document Period End Date	Dec. 31, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity File Number	001-33045
Entity Tax Identification Number	22-3661438
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	false
Entity Incorporation State Country Code	DE
Entity Address, Address Line One	1902 Reston Metro Plaza
Entity Address, City or Town	Reston
Entity Address, State or Province	VA
Entity Address, Postal Zip Code	20190
City Area Code	703
Local Phone Number	934-3000
Auditor Firm ID	248
Auditor Name	Grant Thornton LLP
Auditor Location	Arlington, Virginia
Title of each class	Common Stock, $0.001 par value
Trading Symbol	ICFI
Security Exchange Name	NASDAQ
Documents Incorporated by Reference	List hereunder the following documents if incorporated by reference and the Part of the Form 10-K (e.g., Part I, Part II, etc.) into which the document is incorporated: (1) Any annual report to security holders; (2) Any proxy or information statement; and (3) Any prospectus filed pursuant to Rule 424(b) or (c) under the Securities Act of 1933. The listed documents should be clearly described for identification purposes (e.g., annual report to security holders for fiscal year ended December 24, 1980). Part III incorporates information by reference from the Proxy Statement for the 2024 Annual Meeting of Stockholders expected to be held in June 2024 .

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 6,361	$ 11,257
Restricted cash	3,088	1,711
Contract receivables, net	205,484	232,337
Contract assets	201,832	169,088
Prepaid expenses and other assets	28,055	40,709
Income tax receivable	2,337	11,616
Total Current Assets	447,157	466,718
Property and Equipment, net	75,948	85,402
Other Assets:
Goodwill	1,219,476	1,212,898
Other intangible assets, net	94,904	126,537
Operating lease - right-of-use assets	132,807	149,066
Other assets	41,480	51,637
Total Assets	2,011,772	2,092,258
Current Liabilities:
Current portion of long-term debt	26,000	23,250
Accounts payable	134,503	135,778
Contract liabilities	21,997	25,773
Operating lease liabilities	20,409	19,305
Finance lease liabilities	2,522	2,381
Accrued salaries and benefits	88,021	85,991
Accrued subcontractors and other direct costs	45,645	45,478
Accrued expenses and other current liabilities	79,129	78,036
Total Current Liabilities	418,226	415,992
Long-term Liabilities:
Long-term debt	404,407	533,084
Operating lease liabilities - non-current	175,460	182,251
Finance lease liabilities - non-current	13,874	16,116
Deferred income taxes	26,175	68,038
Other long-term liabilities	56,045	23,566
Total Liabilities	1,094,187	1,239,047
Commitments and Contingencies (Note 20)
Stockholders’ Equity:
Preferred stock, par value $.001 per share; 5,000,000 shares authorized; none issued
Common stock, $.001 par value; 70,000,000 shares authorized; 23,982,132 and 23,771,596 shares issued; and 18,845,521 and 18,883,050 shares outstanding at December 31, 2023 and 2022, respectively	24	23
Additional paid-in capital	421,502	401,957
Retained earnings	775,099	703,030
Treasury stock, 5,136,611 and 4,906,209 shares at December 31, 2023 and 2022, respectively	(267,155)	(243,666)
Accumulated other comprehensive loss	(11,885)	(8,133)
Total Stockholders’ Equity	917,585	853,211
Total Liabilities and Stockholders’ Equity	$ 2,011,772	$ 2,092,258

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized (in shares)	70,000,000	70,000,000
Common stock, issued (in shares)	23,982,132	23,771,596
Common stock, outstanding (in shares)	18,845,521	18,883,050
Treasury stock, shares (in shares)	5,136,611	4,906,209

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Revenue	$ 1,963,238	$ 1,779,964	$ 1,553,048
Direct costs	1,265,018	1,134,422	979,570
Operating costs and expenses:
Indirect and selling expenses	505,162	486,863	430,572
Depreciation and amortization	25,277	21,482	19,478
Amortization of intangible assets	35,461	28,435	12,492
Total operating costs and expenses	565,900	536,780	462,542
Operating income	132,320	108,762	110,936
Interest, net	(39,681)	(23,281)	(9,984)
Other income (expense)	3,908	(1,501)	(862)
Income before income taxes	96,547	83,980	100,090
Provision for income taxes	13,935	19,737	28,958
Net income	$ 82,612	$ 64,243	$ 71,132
Earnings per share:
Basic	$ 4.39	$ 3.41	$ 3.77
Diluted	$ 4.35	$ 3.38	$ 3.72
Weighted-average common shares outstanding:
Basic	18,802	18,818	18,868
Diluted	18,994	19,033	19,124
Cash dividends declared per common share	$ 0.56	$ 0.56	$ 0.56
Other comprehensive (loss) income, net of tax	$ (3,752)	$ 2,902	$ 3,071
Comprehensive income, net of tax	$ 78,860	$ 67,145	$ 74,203

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Loss
Balance at Dec. 31, 2020	$ 746,961	$ 23	$ 369,058	$ 588,731	$ (196,745)	$ (14,106)
Balance (in shares) at Dec. 31, 2020		18,910			4,395
Net Income	71,132			71,132
Other comprehensive income (loss)	3,071					3,071
Equity compensation	13,230		13,230
Exercise of stock options	233		233
Exercise of stock options (in shares)		8
Issuance of shares pursuant to employee stock purchase plan and vesting of restricted stock units	2,463		2,463
Issuance of shares pursuant to employee stock purchase plan and vesting of restricted stock units (in shares)		222
Net payments for stock buybacks	(23,055)				$ (23,055)
Net payments for stock buybacks (in shares)		(264)			264
Balance at Dec. 31, 2021	803,470	$ 23	384,984	649,298	$ (219,800)	(11,035)
Dividends declared	(10,565)			(10,565)
Balance (in shares) at Dec. 31, 2021		18,876			4,659
Net Income	64,243			64,243
Other comprehensive income (loss)	2,902					2,902
Equity compensation	13,171		13,171
Exercise of stock options	602		602
Exercise of stock options (in shares)		19
Issuance of shares pursuant to employee stock purchase plan and vesting of restricted stock units	3,200		3,200
Issuance of shares pursuant to employee stock purchase plan and vesting of restricted stock units (in shares)		235
Net payments for stock buybacks	(23,866)				$ (23,866)
Net payments for stock buybacks (in shares)		(247)			247
Balance at Dec. 31, 2022	853,211	$ 23	401,957	703,030	$ (243,666)	(8,133)
Dividends declared	(10,511)			(10,511)
Balance (in shares) at Dec. 31, 2022		18,883			4,906
Net Income	82,612			82,612
Other comprehensive income (loss)	(3,752)					(3,752)
Equity compensation	14,861		14,861
Exercise of stock options	279		279
Exercise of stock options (in shares)		8
Issuance of shares pursuant to employee stock purchase plan and vesting of restricted stock units		$ 1	4,405
Issuance of shares pursuant to employee stock purchase plan and vesting of restricted stock units (in shares)		185
Net payments for stock buybacks	(23,489)				$ (23,489)
Net payments for stock buybacks (in shares)		(230)			230
Balance at Dec. 31, 2023	917,585	$ 24	$ 421,502	775,099	$ (267,155)	$ (11,885)
Dividends declared	$ (10,543)			$ (10,543)
Balance (in shares) at Dec. 31, 2023		18,846			5,136

Consolidated Statements of Cash

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

Basis of Presentation and Natur

Basis of Presentation and Nature of Operations	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Nature of Operations	NOTE 1 - BASIS OF PRESENTATION AND NATURE OF OPERATIONS Basis of Presentation The accompanying consolidated financial statements include the accounts of ICF International, Inc. (“ICFI”) and its principal subsidiary, ICF Consulting Group, Inc. (“Consulting,” and together with ICFI, the “Company”), and have been prepared in accordance with United States (“U.S.”) generally accepted accounting principles (“U.S. GAAP”). Consulting is a wholly owned subsidiary of ICFI. ICFI is a holding company with no operations or assets other than its investment in the common stock of Consulting. All other subsidiaries of the Company are wholly owned by Consulting. Intercompany transactions and balances have been eliminated. Nature of Operations The Company provides professional services and technology-based solutions, including management, technology, and policy consulting and implementation services, in the areas of energy, environment, infrastructure, and disaster recovery; health and social programs; security and other civilian & commercial. The Company offers a full range of services to clients throughout the entire life cycle of a policy, program, project, or initiative, from research and analysis, assessment and advice, to design and implementation of programs and technology-based solutions, and the provision of engagement services and programs. The Company’s major customers are U.S. federal government departments and agencies. The Company also serves U.S. state (including territories) and local government departments and agencies, international governments, and commercial clients worldwide. Commercial clients primarily include airlines, airports, electric and gas utilities, health care companies, banks and other financial services companies. The terms “federal” or “federal government” refer to the U.S. federal government, and “state and local” or “state and local government” refer to U.S. state (including territories) and local governments, unless otherwise indicated. The Company, incorporated in Delaware, is headquartered in Reston, Virginia. It maintains additional offices throughout the world, including 55 offices in the U.S. and U.S. territories and 15 offices in key markets outside the U.S., including offices in the United Kingdom (“U.K.”), Belgium, India, and Canada.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTE 2 - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent liabilities at the date of the consolidated financial statements, and the reported amounts of revenue and expenses during the reporting periods. Areas of the consolidated financial statements where estimates may have the most significant effect include contractual and regulatory reserves, valuation and lives of tangible and intangible assets, contingent consideration related to business acquisitions and divestitures, impairment of goodwill and long-lived assets, accrued liabilities, revenue recognition (including estimates of variable considerations in determining the total contract price and allocation of performance obligations), the remaining costs to complete fixed-price contracts, bonus and other incentive compensation, stock-based compensation, reserves for tax benefits and valuation allowances on deferred tax assets, provisions for income taxes, collectability of receivables, and loss accruals for litigation. Actual results experienced by the Company may differ from management’s estimates. Revenue Recognition The Company primarily provides services and technology-based solutions for clients that operate in a variety of markets and the solutions may span the entire program life cycle, from initial research and analysis to the design and implementation of solutions. The Company enters into agreements with clients that create enforceable rights and obligations and for which it is probable that the Company will collect the consideration to which it will be entitled as services and solutions are transferred to the client. Except in certain narrowly defined situations, the Company’s agreements with its clients are written and revenue is generally not recognized on oral or implied arrangements. The Company recognizes revenue based on the consideration specified in the applicable agreement and excludes from revenue amounts collected on behalf of third parties. Accordingly, sales and similar taxes which are collected on behalf of third parties are excluded from the transaction price. The Company evaluates whether two or more agreements should be accounted for as one single contract and whether combined or single agreements should be accounted for as more than one performance obligation. For most contracts, the client requires the Company to perform a number of tasks in providing an integrated output for which the client has contracted, and, hence, contracts of this type are tracked as having only one performance obligation since a substantial part of the Company’s promise is to ensure the individual tasks are incorporated into a combined output in accordance with contract requirements. When contracts have multiple performance obligations, the Company allocates the total transaction price to each performance obligation based on the estimated relative standalone selling prices of the promised services underlying each performance obligation. The Company generally provides customized solutions in which the pricing is based on specific negotiations with each client, and, in these cases, the Company uses a cost-plus margin approach to estimate the standalone selling price of each performance obligation. Certain contracts contain award fees, incentive fees or other provisions that can either increase or decrease the transaction price. These variable amounts are generally awarded at the completion of a contractually stipulated performance assessment period based on the achievement of performance metrics, program milestones or cost targets, and the amount awarded may be subject to client discretion. Variable consideration is estimated based on the most likely amount. Once the Company selects a method to estimate variable consideration, it applies that method consistently. Estimates of variable consideration will be constrained only to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur. The Company evaluates contractual arrangements to determine whether revenue should be recognized on a gross versus net basis. The Company’s assessment is based on the nature of the contractual obligation to the client. In most cases, the Company itself agrees to provide specified services to the client as a principal and revenue is recognized on a gross basis. In certain instances, the Company acts as an agent and merely arranges for another party to provide services to the client and revenue is recognized on a net basis in reflection of the fact that the Company does not control the goods or services provided to the client by the other party. Long-term contracts typically contain billing terms that provide for invoicing monthly or upon completion of milestones, and payment on a net 30 -day basis. Therefore, the timing of billings and cash receipts may differ from the timing of revenue recognition resulting in either contract assets or contract liabilities. Exceptions to monthly billing terms are to ensure that the Company performs satisfactorily rather than representing a significant financing component. For cost-based contracts, the Company’s performance is evaluated during a contractually-stipulated performance period and, while contract costs may be billed on a monthly basis, the Company is generally permitted to bill for incentive or award fees only after the completion of the performance assessment period, which may occur quarterly, semi-annually or annually, and after the client completes the performance assessment. Fixed-price contracts may provide for milestone billings based on the attainment of specific project objectives rather than for billing on a monthly basis. Moreover, contracts may require retention or hold backs that are paid at the end of the contract to ensure that the Company performs in accordance with requirements. The Company does not assess whether a contract contains a significant financing component if the Company expects, at contract inception, that the period between payment by the client and the transfer of promised services to the client will be one year or less. The Company generally recognizes revenue over time as control is transferred to a client, based on the extent of progress towards satisfaction of the performance obligation. The selection of the method used to measure progress requires judgment and is dependent, among other factors, on the contract type and the nature of the services provided. For time-and-materials contracts, the Company uses the right-to-invoice practical expedient to recognize revenue earned based on hours worked in contract performance at negotiated billing rates. Fixed-price level-of-effort contracts are substantially similar to time-and-materials contracts except that the Company is required to deliver a specified level of effort over a stated period of time. For these contracts, the Company determines the revenue earned using contract hours worked at negotiated bill rates as the Company delivers the contractually required workforce. For cost-based contracts, the Company uses the right-to-invoice practical expedient to recognize revenue based on the amount to which the Company has a contractual right to invoice. For series-services performance obligations, the Company measures progress using either a cost input measure, a time-elapsed output measure, or the right to invoice practical expedient. Award or incentive fees are allocated to the distinct periods in which they relate to and recognized in that period. For certain fixed-price contracts, the Company uses the percentage-of-completion method to estimate the amount of revenue, based on the ratio of actual costs incurred to total estimated costs, provided that costs incurred (an input method) represents a reasonable measure of progress towards the satisfaction of a performance obligation and transfer of control to the customer. This method provides a faithful depiction of the transfer of value to the client when the Company is satisfying a performance obligation that entails integration of tasks for a combined output, which requires the Company to coordinate the work of employees, subcontractors and delivery of other contract costs. Contract costs that are not reflective of the Company’s progress toward satisfying a performance obligation are not included in the calculation of the measure of progress. When this method is used, the changes in estimated costs to complete the obligations result in adjustments to revenue on a cumulative catch-up basis, which causes the effect of revised estimates for prior periods to be recognized in the current period. Changes in these estimates may routinely occur over contract performance for a variety of reasons, which include: changes in contract scope; changes in contract cost estimates due to unanticipated cost growth or reassessments of risks impacting costs; changes in estimated incentive or award fees; or performing better or worse than previously estimated. For fixed-price contracts in which the estimated cost to perform exceeds the consideration to be received, the Company accrues for the entire estimated loss during the period in which the loss is determined by recording additional direct costs. In some fixed-price service contracts, the Company performs services of a recurring nature, such as maintenance and other services of a “stand ready” nature. For these contracts, the Company has the right to consideration in an amount that corresponds directly with the value that the client has received. Therefore, the Company records revenue on a time-elapsed basis to reflect the transfer of control to the client throughout the contract. Contracts may be modified to reflect changes in contract specifications and requirements, and these changes may create new enforceable rights and obligations. Modifications that are for services that are not distinct from the existing agreement due to the significant integration service that the Company provides are accounted for as part of an existing performance obligation. The effect of these modifications on the transaction price and the Company’s measure of progress in fulfilling the performance obligation to which they relate is recognized as an adjustment to revenue on a cumulative catch-up basis. Revenue from modifications that create new, distinct performance obligations is recognized based on the Company’s progress in fulfilling the requirements of the new obligations. For performance obligations that are satisfied over time, the Company recognizes the cost to fulfill contracts when incurred, unless the costs are within the scope of another topic in which case the guidance of that topic is applied. The Company evaluates incremental costs of obtaining a contract and, if they are recoverable from the client and relate to a specific future contract, they are deferred and recognized over contract performance or the estimated life of the customer relationship if renewals are expected. The Company expenses these costs when incurred if the amortization period is one year or less. Unfulfilled performance obligations represent amounts expected to be earned on non-cancellable contracts or those that the are cancellable but the Company has determined to have substantive termination penalties, and do not include the value of negotiated, unexercised contract options, which are classified as marketing offers. Indefinite delivery/indefinite quantity and similar arrangements provide a framework for the client to issue specific tasks, delivery or purchase orders in the future and these arrangements are considered marketing offers until a specific order is executed. Some of the Company’s contracts include variable consideration, which requires the Company to estimate and, as necessary, revise the most likely amounts that will be earned over the respective performance assessment periods. For these obligations, changes in estimates result in cumulative catch-up adjustments and may have a significant impact on earnings during a given period. The Company’s operating cycle for long-term contracts may be greater than one year and is measured by the average time between the inception and completion of those contracts. Contract-related assets and liabilities are classified as current assets and current liabilities. Cash and Cash Equivalents The Company considers cash on deposit and any highly liquid investments with original maturities of three months or less when purchased to be cash and cash equivalents. Restricted Cash The Company has restricted cash representing amounts held in escrow accounts and/or not readily available due to contractual restrictions. Contract receivables, net Contract receivables represent amounts billed and due from clients in accordance with respective contractual terms. The amounts due are stated at their net realizable value. The Company estimates an allowance for estimated credit loss to reflect the amount of receivables that will not be collected. The Company considers a number of factors in estimating the amount of the allowance, including knowledge of a client’s financial condition, its historical collection experience, and other factors relevant to assessing the collectability of the receivables. The Company writes off specific contract receivables when such amounts are determined to be uncollectible. Property and Equipment Property and equipment are carried at cost and are depreciated using the straight-line method over their estimated useful lives, which range from two to seven years . Leasehold improvements are amortized on a straight-line basis over the shorter of the economic life of the improvement or the related lease term. Goodwill and Indefinite-Lived Assets Goodwill represents the excess of the purchase consideration over the fair value of net assets of businesses acquired. Goodwill and any intangible assets acquired in a business combination that are deemed to have an indefinite useful life are not amortized, but instead are reviewed for impairment annually, or more frequently if impairment indicators arise. Intangible assets with estimable useful lives are amortized over such lives and reviewed for impairment if impairment indicators arise. The Company performs its annual goodwill impairment test as of October 1 of each year. As its business is highly integrated and all of its components have similar economic characteristics, the Company has concluded it has one aggregated reporting unit at the consolidated entity level which it perform the assessment at. The Company have the option to perform a qualitative assessment that determines if it is more likely than not that the estimated fair value of goodwill is greater than its carrying value and, if so, the Company may conclude that no impairment exists. If the Company concludes that an impairment exist, a quantitative test is performed by comparing the reporting unit’s fair value to the carrying amount and recognizing the difference as an impairment loss. Long-Lived Assets The Company reviews its long-lived assets, including property and equipment, operating lease right-of-use (“ROU”) assets, and definite-lived intangible assets, for impairment whenever events or changes in circumstances indicate that the carrying amounts of the long-lived asset group may not be fully recoverable. If the total of the expected undiscounted future net cash flows is less than the carrying amount of the long-lived asset group being evaluated, a loss is recognized for any excess of the carrying amount over the fair value of the asset group. During the years ended December 31, 2023, 2022, and 2021 , the Company recognized impairment losses of $ 6.8 million, $ 8.4 million, and $ 7.9 million, respectively, related to operating facility lease right-of-use assets and leasehold improvements. During the year ended December 31, 2023, the Company recognized an impairment loss of $ 0.9 million related to an amortizable customer-related intangible asset from a prior acquisition. The impairment losses were included in indirect and selling expenses on the Company's consolidated statements of comprehensive income. Leases The Company leases facilities and property and equipment. The Company determines if an arrangement is a lease at its inception and recognizes a right-of-use asset and lease obligation for all leases greater than twelve months based on the present value of the future minimum lease payments as of the commencement date, excluding any lease incentives and initial costs incurred to obtain the lease. Since most lease agreements do not provide an implicit rate, the Company uses its incremental borrowing rate as of the commencement date, based on publicly available yields adjusted for company-specific considerations and terms, in estimating the present value of future payments. Lease terms, for the purpose of determining each lease’s present value, include options to extend or terminate the lease if it is reasonably certain and economically reasonable that the Company will exercise that option. Lease costs from minimum lease payments are recognized on a straight-line basis over the lease term. The leases may contain both lease and non-lease components, which are generally accounted for separately. For office equipment leases (primarily copier leases), the Company elected to account for the lease and non-lease components as a single lease component and not recognize right-of-use assets and lease liabilities for leases with a term less than twelve months. Operating leases are included in operating lease right-of-use assets and operating lease liabilities (current and non-current) and finance leases are included in property and equipment, net and finance lease liabilities (current and non-current) on the consolidated balance sheets. Capitalized Software The Company capitalizes certain costs to develop enhancements and upgrades to internal-use software that are incurred subsequent to the preliminary project stage. Amortization expense is recorded on a straight-line basis over the expected economic life of the software, typically lasting three to five years . As of December 31, 2023, and 2022, capitalized software, net of accumulated amortization, totaled $ 12.8 million and $ 19.0 million , respectively, and is included as part of “other assets” on the consolidated balance sheets. Stock-based Compensation The Company recognizes stock-based compensation expense to employees and non-employee directors, including grants of stock options, restricted stock awards, restricted stock units (“RSUs”), and cash-settled restricted stock units (“CSRSUs”) on a straight-line basis over the requisite service period, which is generally the vesting period. The Company recognizes expense for performance-based share awards (“PSAs”), which have both performance and service conditions, on a straight-line basis over the three-year performance period. Non-employee director awards are granted annually for Board-related services and therefore expensed over the service period. Stock-based compensation expense is based on the estimated fair value of the instruments on the grant date and the estimated number of shares the Company ultimately expects will vest. The Company estimates the rate of future forfeitures based on factors which include the historical forfeiture experience for each applicable employee class. In addition, the estimation of PSAs that will ultimately vest requires judgment based on the performance and market conditions that will be achieved over the performance period. Changes to these estimates are recorded as a cumulative adjustment in the period estimates are revised. The fair value of stock options, restricted stock awards, RSUs, PSAs, and non-employee director awards is estimated based on the fair value of a share of common stock at the grant date. The fair value of PSAs is estimated using a Monte Carlo simulation model. CSRSUs are settled only in cash payments. The cash payment is based on the fair value of the Company’s stock price at the vesting date, calculated by multiplying the number of CSRSUs vested by the Company’s closing stock price on the vesting date, subject to a maximum payment cap and a minimum payment floor. The Company treats these awards as liability-classified awards, and, therefore, accounts for them at fair value estimated based on the closing price of the Company’s stock at the reporting date. Derivative Instruments Derivative instruments include interest rate swaps, foreign currency hedges, and forward contracts. Derivative instruments designated as cash flow hedges are recorded on the consolidated balance sheets at fair value as of the reporting date and reclassified to earnings in the period that the hedged instruments affect earnings, and the effective portion of the hedge is recorded in other comprehensive income (loss) (“AOCI”), net of tax, on the consolidated statements of comprehensive income. Management reviews the effectiveness of the hedges on a quarterly basis. Income Taxes The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates in effect for the year in which those temporary differences are expected to be recovered or settled. The Company evaluates its ability to benefit from all deferred tax assets and establishes valuation allowances for amounts it believes will more likely than not be unrealizable. For uncertain tax positions, the Company uses a more-likely-than-not recognition threshold based on the technical merits of the income tax position taken. Income tax positions that meet the more-likely-than-not recognition threshold are measured in order to determine the tax benefit recognized in the financial statements. Penalties, if probable and reasonably estimable, and interest expense related to uncertain tax positions are not recognized as a component of income tax expense but recorded separately in indirect expenses and interest expense, respectively. Treasury Shares Treasury shares are accounted for under the cost method. Other Comprehensive Income (Loss) Other comprehensive income (loss) includes foreign currency translation adjustments due to fluctuation in foreign currency exchange rates, the gain on the sale of an interest rate hedge agreement designated as a cash flow hedge, and the changes in fair value of interest rate agreements designated as cash flow hedges, net of taxes. The financial positions and results of operations of the Company’s foreign subsidiaries are based on the local currency as the functional currency and are translated to U.S. dollars for financial reporting purposes. Assets and liabilities of the subsidiaries are translated at the exchange rate in effect at each balance sheet date. Income statement accounts are translated at the average rate of exchange prevailing during the period. Translation adjustments are reported in accumulated other comprehensive loss included in stockholders’ equity in the Company’s consolidated balance sheets. Acquisition-Related Costs Costs related to acquisitions include professional fees for legal, financial, and other advisory services and are expensed in the period that they are incurred. Segment, Customer, and Geographic Information The Company operates in one segment based on the consolidated information used by its chief operating decision-maker, currently the Chief Executive Officer, in evaluating the financial performance of its business and allocating resources. This single segment represents the Company’s core business, which is providing professional services. Although the Company disaggregates its revenue by client markets and client types, the Company does not manage its business or allocate resources based on client market or type. No customer accounted for 10% or more of the Company’s revenue during the years ended 2023, 2022, and 2021. The Company provides services to U.S. and international clients, and revenue is attributed to a particular geographic area based on the administrative location of the client that awarded the contract. The Company’s revenue generated from international clients as a percentage of total revenue was approximately 7 % , 8 % , and 11 % for the years 2023, 2022, and 2021, respectively. At December 31, 2023 and 2022, long-lived assets held internationally were 6 % and 7 % of total long-lived assets, respectively. Foreign currency expense, net of impact of hedges, was $ 1.2 million, $ 0.2 million, and $ 0.6 million, for the years ended December 31, 2023 , 2022 and 2021, respectively. Fair Value The Company measures and reports certain financial assets and liabilities at fair value in accordance with ASC 820, Fair Value Measurements and Disclosures. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants on the measurement date. Generally, fair value is based on observable quoted market prices or derived from observable market data when such market prices or data are available. ASC 820 establishes a three-level hierarchy used to estimate fair value by which each level is categorized based on the priority of the inputs used to measure fair value: • Level 1: Quoted prices that are available in active markets for identical assets or liabilities; • Level 2: Quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active; inputs other than quoted prices that are observable for the asset or liability (e.g. interest rates and yield curves that are observable at commonly quoted intervals, and implied volatilities); and inputs derived principally from or corroborated by observable market data by correlation or other means; and • Level 3: Uses inputs that are unobservable and require the Company to make certain assumptions and require significant estimation and judgment from management to use in pricing the fair value of the assets and liabilities. Certain financial instruments, including cash and cash equivalents, contract receivables, and accounts payable are carried at cost, which, due to their short maturities, approximates their fair values. The carrying value of the Company's long-term debt approximates the estimated fair value for debt with similar terms, interest rates, and remaining maturities currently available to companies with similar credit ratings (Level 2). Risks and Uncertainties Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents, derivative financial instruments, and contract receivables. The Company’s domestic bank accounts are insured up to $ 250,000 by the Federal Deposit Insurance Corporation. As of December 31, 2023, the Company had $ 0.3 million in its accounts that exceeded the insured limit. The majority of the Company’s cash transactions are processed through one U.S. commercial bank. Cash held domestically in excess of daily requirements is primarily used to reduce any amounts outstanding under the Company’s Credit Facility. As of December 31, 2023 and 2022, the Company held approximately $ 8.5 million and $ 8.4 million , respectively, of cash and restricted cash in foreign bank accounts. The Company enters into derivative financial instruments with financial institutions that meet certain credit guidelines and limits its risks by continuously monitoring the credit rating of the institutions. The Company’s receivables consist principally of amounts due from agencies and departments of the federal government, state and local governments, and international governments, as well as from commercial organizations. The credit risk, with respect to federal and other government clients, is limited due to the creditworthiness of the respective governmental entity. Amounts due for work performed as a subcontractor also represent limited credit risk when the client is performing as the prime contractor on a government contract due to the ultimate creditworthiness of the end client. Receivables from commercial clients generally pose a greater credit risk, and, as a result, are subject to ongoing monitoring. The Company extends credit in the normal course of operations and does not require collateral from its clients. The Company’s contracts with the federal government are subject to audit by agencies and departments of the federal government. Such audits determine, among other things, whether adjustments to invoices previously rendered are required under regulations as well as the underlying terms of each respective contract. Recent Accounting Pronouncements Accounting Pronouncements Adopted Reference Rate Reform In March 2020, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) 2020-04, Facilitation of the Effects of Reference Rate Reform on Financial Reporting. The standard is intended to provide temporary optional expedients and exceptions to the U.S. GAAP guidance on contract modifications and hedge accounting to ease accounting and financial reporting burdens related to the expected market transition from the London Interbank Offered Rate (“LIBOR”) and other interbank offered rates to alternative reference rates. The provisions of this ASU are elective and apply to all entities, subject to meeting certain criteria, that have debt or hedging contracts, among other contracts, that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. Entities can elect to not apply certain modification accounting requirements to contracts affected by reference rate reform if certain criteria are met. Also, entities can elect various optional expedients that would allow them to continue to apply hedge accounting for hedging relationships affected by reference rate reform if certain criteria are met. This guidance was effective beginning on March 12, 2020 and entities may elect to apply the amendments prospectively through December 31, 2022, the sunset date. In December 2022, the FASB issued ASU 2022-06 Reference Rate Reform (Topic 848): Deferral of the Sunset Date of Topic 848 which extended the sunset date from December 31, 2022 to December 31, 2024. The Company completed its adoption of the provisions of ASU 2020-04 during the second quarter of 2023 upon amendment of its last interest rate swap from LIBOR-based to SOFR-based pricing. The adoption did not have a material impact on the Company's consolidated financial statements. Accounting Pronouncements Not Yet Adopted Segment Reporting In November 2023, the FASB issued ASU 2023-07: Improvements to Reportable Segment Disclosures, that required additional segment disclosures for public entities currently required under the Segment Reporting (Topic 280) of the Accounting Standards Codification (“ASC”). ASU 2023-07 enhances the current segment reporting disclosures of Topic 280 by requiring significant segment expenses that are regularly provided to the Chief Operating Decision Maker (the “CODM”), the amount and description of other segment items, and interim disclosures of reportable segment's profit or loss and assets. ASU 2023-07 also requires public entities that have a single reportable segment to provide all the disclosures required in Topic 280, as amended. The ASU is effective for the Company for the 2024 fiscal year and interim periods within the 2025 fiscal year on a retrospective basis, with early adoption permitted. The Company is currently evaluating the impact of the adoption of ASU 2023-07 but does not expect the adoption to have a material impact, if any, on the consolidated financial statements. Income Taxes In December 2023, the FASB issued ASU 2023-09, Income Taxes: Improvements to Income Tax Disclosures, that require greater disaggregation of income tax rate and amounts paid by entities. ASU 2023-09 specifically requires all entities to disclose, on an annual basis, disaggregated domestic and foreign pre-tax income or loss from continuing operations and the disaggregated income tax expense or benefit by federal, state, and foreign components, and a tabular rate reconciliation, using both percentages and reporting currency amounts, of eight specific categorie

Restricted Cash

Restricted Cash	12 Months Ended
	Dec. 31, 2023
Cash and Cash Equivalents [Abstract]
Restricted Cash	NOTE 3 - RESTRICTED CASH The following table provides a reconciliation of cash and cash equivalents, and restricted cash reported within the consolidated balance sheets at December 31, 2023 and 2022 to the total cash, cash equivalents, and restricted cash shown in the consolidated statements of cash flows for the years ended December 31, 2023, 2022, and 2021: 2023 2022 2021 Beginning Ending Beginning Ending Beginning Ending Cash and cash equivalents $ 11,257 $ 6,361 $ 8,254 $ 11,257 $ 13,841 $ 8,254 Restricted cash (1) 1,711 3,088 12,179 1,711 68,146 12,179 Total cash, cash equivalents, and restricted cash shown in the consolidated statement of cash flows $ 12,968 $ 9,449 $ 20,433 $ 12,968 $ 81,987 $ 20,433 (1) Under a contract with a customer that commenced in the fourth quarter of fiscal year 2020, the Company received advance payments to be used to pay providers of services to the customer, a separate third party. The advanced payments are treated as restricted cash - current as the Company is required under the contract to distribute the advanced funds to the third-party providers of services or return the advanced funds to the customer. Because the Company receives the advance payments from the customer, which must be refunded to the customer or remitted to a third party, the cash receipts are treated as liabilities rather than receipts for the provision of goods or services. Therefore, these cash receipts are presented in the consolidated statements of cash flows as financing cash inflows, “Receipt of restricted contract funds,” with the subsequent payments classified as financing cash outflows, “Payment of restricted contract funds.”

Contract Receivables, Net

Contract Receivables, Net	12 Months Ended
	Dec. 31, 2023
Receivables [Abstract]
Contract Receivables, Net	NOTE 4 - CONTRACT RECEIVABLES, NET Contract receivables, net consisted of the following as of December 31: 2023 2022 Billed and billable $ 210,919 $ 238,449 Allowance for expected credit losses ( 5,435 ) ( 6,112 ) Contract receivables, net $ 205,484 $ 232,337 On December 23, 2022, the Company entered into a Master Receivables Purchase Agreement (the “MRPA”) with MUFG Bank, Ltd. (“MUFG”) for the sale from time to time of certain eligible billed receivables. The receivables are sold without recourse and the Company does not retain any ongoing financial interest in the transferred receivables other than providing servicing activities. The Company accounts for the transfers as sales under ASC 860, Transfers and Servicing, derecognizes the receivables from its consolidated balance sheets at the date of the sale, and includes the cash received from MUFG as part of cash flows from operating activities on its consolidated statement of cash flows. During the years ended December 31, 2023 and 2022, the Company received $ 309.4 million and $ 10.0 million under the MRPA, of which $ 28.7 million and $ 6.2 million , respectively, was collected but not remitted to MUFG. For the years ended December 31, 2023 and 2022, the discount on the sale of receivables under the MRPA totaled $ 1.1 million and less than $ 0.1 million, respectively, and is included as part of “indirect and selling expenses” on the consolidated statements of comprehensive income.

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Property and Equipment	NOTE 5 - PROPERTY AND EQUIPMENT Property and equipment consisted of the following at December 31: 2023 2022 Leasehold improvements $ 54,398 $ 58,131 Software 16,897 17,926 Furniture and office equipment 29,773 28,800 Computer equipment 44,661 45,541 145,729 150,398 Accumulated depreciation and amortization ( 69,781 ) ( 64,996 ) Total property and equipment, net $ 75,948 $ 85,402 Depreciation and amortization expense for the years ended December 31, 2023, 2022, and 2021 totaled $ 25.3 million , $ 21.5 million , and $ 19.5 million , respectively.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	NOTE 6 - GOODWILL AND OTHER INTANGIBLE ASSETS Goodwill The changes in the carrying amount of goodwill for the fiscal years ended December 31 were as follows: 2023 2022 Balance as of January 1, 2023 $ 1,212,898 $ 1,046,760 Add: Goodwill resulting from business combinations 21,133 171,415 Less: Goodwill resulting from business divestitures ( 16,921 ) — Effect of foreign currency translation 2,366 ( 5,277 ) Balance as of December 31, 2023 $ 1,219,476 $ 1,212,898 See “Note 16 – Acquisitions and Divestitures” for the details of the business combination and divestiture resulting in the changes in goodwill. Other Intangible Assets Intangible assets with definite lives are primarily amortized over periods ranging from approximately 1 to 9 years. The weighted-average period of amortization for all intangible assets, calculated as of December 31, 2023, is 5.7 years. The customer-related intangible assets, which consist of customer contracts, backlog, and non-contractual customer relationships, are being amortized based on estimated cash flows and respective estimated economic benefit of the assets. The weighted-average period of amortization of the customer-related intangibles calculated as of December 31, 2023 is 5.7 years. Intangible assets related to developed technology are being amortized on an accelerated basis over a weighted-average period, calculated as of December 31, 2023, of 9.6 years. Intangible assets with an indefinite life consist of a domain name. Other intangibles consisted of the following at December 31: 2023 Gross Accumulated Net Carrying Customer-related $ 185,723 $ ( 93,911 ) $ 91,812 Developed technology 3,902 ( 904 ) 2,998 Trade name 1,280 ( 1,280 ) — Total amortizable intangible assets 190,905 ( 96,095 ) 94,810 Intangible with indefinite life 94 — 94 Total other intangible assets $ 190,999 $ ( 96,095 ) $ 94,904 2022 Gross Accumulated Net Carrying Customer-related $ 240,591 $ ( 118,412 ) $ 122,179 Developed technology 4,480 ( 512 ) 3,968 Trade name 1,180 ( 884 ) 296 Total amortizable intangible assets 246,251 ( 119,808 ) 126,443 Intangible with indefinite life 94 — 94 Total other intangible assets $ 246,345 $ ( 119,808 ) $ 126,537 Aggregate amortization expense for the years ended December 31, 2023, 2022, and 2021, was approximately $ 35.5 million , $ 28.4 million , and $ 12.5 million , respectively. The estimated future amortization expense relating to intangible assets is as follows: Year ending December 31, 2024 $ 32,992 2025 32,074 2026 18,533 2027 3,407 2028 2,047 Thereafter 5,757 Total $ 94,810

Leases

Leases	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Leases	NOTE 7 – LEASES The Company has operating and finance leases for facilities and equipment which have remaining terms ranging from 1 to 15 years . The leases may include options to extend the lease periods for up to 5 years at rates approximating market rates and/or options to terminate the leases within 1 year . The leases may include a residual value guarantee or a responsibility to return the property to its original state of use. A limited number of leases contain provisions that provide for rental increases based on consumer price indices. The change in lease cost resulting from changes in these indices was included within variable lease cost. The Company’s lease cost is recognized on a straight-line basis over the lease term and is primarily included within indirect and selling expenses on the consolidated statements of comprehensive income. Lease cost consisted of the following: Year Ended December 31, 2023 2022 2021 Operating lease cost $ 25,037 $ 37,889 $ 35,469 Finance lease cost - amortization of right-of-use assets 2,040 598 — Finance lease cost - interest 602 179 — Short-term lease cost 669 509 453 Variable lease cost 222 146 43 Sublease income ( 28 ) ( 92 ) — Total lease cost $ 28,542 $ 39,229 $ 35,965 Future minimum lease payments under non-cancellable operating and finance leases as of December 31, 2023 were as follows: Operating Finance December 31, 2024 $ 25,419 $ 3,041 December 31, 2025 26,621 3,041 December 31, 2026 22,899 3,041 December 31, 2027 18,578 3,041 December 31, 2028 15,926 2,985 Thereafter 131,690 2,966 Total future minimum lease payments 241,133 18,115 Less: Interest ( 45,264 ) ( 1,719 ) Total $ 195,869 $ 16,396 Other information related to operating and finance leases is as follows: Year Ended December 31, 2023 2022 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 20,368 $ 40,123 Right-of-use assets obtained in exchange for new operating lease liabilities $ 18,590 $ 13,906 Property and equipment obtained in exchange for finance lease liabilities $ 338 18,319 Weighted-average remaining lease term - operating leases Operating leases 11.6 11.7 Finance leases 6.0 7.0 Weighted-average discount rate - operating leases Operating leases 3.6 % 3.3 % Finance leases 3.4 % 3.4 % The change in operating lease right-of-use assets and lease liabilities are presented within cash flows from operating activities on the consolidated statements of cash flows. During the years ended December 31, 2023 and 2022 , the Company ceased use of office facilities and recorded impairment of $ 6.8 million and $ 8.4 million, respectively, related to operating lease right-of-use asset and leasehold improvement, and accrued other future lease-related expenses of $ 3.2 million and $ 4.9 million, respectively. The amounts are included as part of indirect and selling expenses on the Company's consolidated statements of comprehensive income.

Accrued Salaries and Benefits

Accrued Salaries and Benefits	12 Months Ended
	Dec. 31, 2023
Employee-related Liabilities, Current [Abstract]
Accrued Salaries and Benefits	NOTE 8 - ACCRUED SALARIES AND BENEFITS Accrued salaries and benefits consisted of the following at December 31: 2023 2022 Bonuses, liability-classified awards, and commissions $ 27,371 $ 26,930 Salaries 32,604 31,142 Paid time off and leave 16,415 16,144 Medical 5,685 5,833 Payroll taxes and withholdings 976 1,363 Other 4,970 4,579 Total accrued salaries and benefits $ 88,021 $ 85,991

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2023
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	NOTE 9 - ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES Accrued expenses and other current liabilities consisted of the following at December 31: 2023 2022 Deposits $ 20,246 $ 32,384 Restricted contract funds 2,036 1,701 IT and software licensing costs 583 1,609 Taxes and insurance premiums 7,010 6,633 Facilities rental and lease exit costs 2,754 2,043 Interest 3,218 363 Professional services 1,943 3,617 Dividends 2,636 2,631 Cash collected not yet remitted to purchaser of billed receivables 28,675 6,164 Other accrued expenses and current liabilities 10,028 20,891 Total accrued expenses and other current liabilities $ 79,129 $ 78,036

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2023
Debt Disclosure [Abstract]
Long-Term Debt	NOTE 10 - LONG-TERM DEBT On May 6, 2022, the Company entered into the Restated Credit Agreement with a group of lenders with (a) PNC Bank, National Association as the Administrative Agent and (b) PNC Capital Markets LLC, BOFA Securities, Inc., TD Securities (USA) LLC, Wells Fargo Securities, LLC and Citizens Bank, N.A., as joint lead arrangers. The various facilities under the Restated Credit Agreement are referred to as the “Credit Facility”. The Restated Credit Agreement amended and restated the Company’s prior credit agreement (the “Existing Credit Agreement”) to, among other things: (a) maintain the existing $ 600 million revolving credit facility (together and inclusive of a $ 75 million swing line sublimit and $ 100 million sublimit for letters of credit); (b) increase the existing term loan facility from $ 200 million to $ 300 million; (c) provide for a new delayed draw term loan facility of $ 400 million; (d) maintain the existing incremental credit facility to make, subject to approval of the lenders making such loans, incremental term or revolving credit loan(s) in the aggregate principal amount of not more than $ 300 million; (e) increase the maximum Consolidated Leverage Ratio (as such term is defined in the Restated Credit Agreement) from 4.00 to 1.00 to 4.50 to 1.00 (with temporary increases to 5.00 to 1.00 for the three fiscal quarters following a “Material Permitted Acquisition”, as such term is defined in the Restated Credit Agreement); (f) maintain the minimum Consolidated Interest Coverage Ratio (as such term is defined in the Restated Credit Agreement) of 3.00 to 1.00; (g) increase the foreign currency debt limit in Euro and Sterling Pounds from $ 30 million equivalent to $ 200 million equivalent; (h) modify LIBOR based interest pricing conventions with SOFR based interest pricing conventions; (i) extend the maturity date of the Credit Facility until May 6, 2027 ; (j) incorporate various provisions and conventions encouraged by the Loan Syndication and Trade Association; and (k) modify certain definitions and certain covenants. Under the Restated Credit Agreement, the Company may, at its discretion, borrow funds under the Credit Facility at interest rates based on both term SOFR (i.e., 1, 3, or 6-month rates) and the Base Rate (as defined herein), plus their applicable margins. The Base Rate is a fluctuating rate of interest equal to the highest of (a) the Overnight Bank Funding Rate (as defined in the Restated Credit Agreement), plus 0.5 %, (b) the Prime Rate (as defined in the Restated Credit Agreement) and (c) the Daily Simple SOFR Rate (as defined in the Restated Credit Agreement) plus 1 %, all as then adjusted to include the Applicable Margin (as defined in the Restated Credit Agreement) as then in effect (and as determined pursuant to the then-current Consolidated Leverage Ratio). For the years ended December 31, 2023 and 2022, the average interest rate on borrowings under the Credit Facility was 6.7 % and 3.3 % , respectively. Inclusive of the impact of floating-to-fixed interest rate swaps (see “Note 12 – Derivative Instruments and Hedging Activities”), the average interest rate was 5.6 % and 3.7 % for the years ended December 31, 2023 and 2022, respectively. The Credit Facility is collateralized by substantially all the assets of the Company and its material domestic subsidiaries and requires that the Company remain in compliance with certain financial and non-financial covenants including, but not limited to the Consolidated Leverage Ratio and the Consolidated Interest Coverage Ratio. As of December 31, 2023, the Company was in compliance with its covenants. The Credit Facility also includes other terms and conditions, covenants, and other provisions of the Restated Credit Agreement that are materially consistent with the Existing Credit Agreement. As of December 31, 2023, the Company had $ 430.4 million (net of unamortized debt issuance costs) of long-term debt outstanding from the Credit Facility, unused delayed draw term loan facility of $ 180.0 million (available through January 5, 2024), and unused borrowing capacity of $ 591.9 million from the available $ 600.0 million revolving line of credit under the Credit Facility. The unused borrowing capacity is inclusive of five outstanding letters of credit totaling $ 1.8 million . Considering the financial, performance-based limitations, available borrowing capacity was $ 575.5 million as of December 31, 2023. As of December 31, 2023 and 2022, long-term debt consisted of the following: December 31, 2023 December 31, 2022 Average Outstanding Average Outstanding Term Loan $ 207,750 $ 288,750 Delayed-Draw Term Loan 220,000 220,000 Revolving Credit 6,340 52,616 Total before debt issuance costs 6.7 % 434,090 3.3 % 561,366 Unamortized debt issuance costs ( 3,683 ) ( 5,032 ) $ 430,407 $ 556,334 Current portion of long-term debt $ 26,000 $ 23,250 Long-term debt - non-current 404,407 533,084 Total $ 430,407 $ 556,334 Future scheduled repayments of debt principal are as follows: Payments due by Term Loan Delayed-Draw Term Loan Revolving Credit Total December 31, 2024 $ 15,000 $ 11,000 $ — $ 26,000 December 31, 2025 20,625 15,125 — 35,750 December 31, 2026 22,500 16,500 — 39,000 December 31, 2027 149,625 177,375 6,340 333,340 Total $ 207,750 $ 220,000 $ 6,340 $ 434,090 Debt Issuance Cost The Company’s debt issuance costs are amortized over the term of indebtedness. The balance of net debt issuance costs at December 31, 2023 and 2022 were $ 3.7 million and $ 5.0 million , respectively. Amortization of debt issuance costs totaling $ 2.0 million , $ 1.3 million , and $ 0.6 million was recorded for each of the years ended December 31, 2023, 2022, and 2021 , respectively, and was included as part of interest expense.

Revenue Recognition

Revenue Recognition	12 Months Ended
	Dec. 31, 2023
Revenue from Contract with Customer [Abstract]
Revenue Recognition	NOTE 11 – REVENUE RECOGNITION Disaggregation of Revenue The Company disaggregates revenue from clients into categories that depict how the nature, amount, and uncertainty of revenue and cash flows are affected by economic and business factors. Those categories are client market, client type, and contract mix. Client markets provide insight into the breadth of the Company’s expertise. In classifying revenue by client market, the Company attributes revenue from a client to the market that the Company believes is the client’s primary market. The Company also classifies revenue by the type of client for which it does business, which is an indicator of the diversity of its client base. The Company attributes revenue generated as a subcontractor to the market or type of the ultimate client. Disaggregation by contract mix provides insight in terms of the degree of performance risk that the Company has assumed. Fixed-price contracts are considered to provide the highest amount of performance risk as the Company is required to deliver a scope of work or level of effort for a negotiated fixed price. Time-and-materials contracts require the Company to provide skilled employees for negotiated fixed hourly rates. Since the Company is not required to deliver a scope of work, but merely skilled employees, it considers these contracts to be less risky than a fixed-price agreement. Cost-based contracts are considered to provide the lowest amount of performance risk since the Company is generally reimbursed for all contract costs incurred in performance of contract deliverables with only the amount of incentive or award fees (if applicable) dependent on the achievement of negotiated performance requirements. The Company's revenue by client markets, type, and contract mix are in the following tables. Certain immaterial revenue amounts in the prior years have been reclassified due to minor adjustments and reclassification. Year ended December 31, 2023 2022 2021 Client Markets: Energy, environment, infrastructure, and disaster recovery $ 806,482 $ 714,628 $ 693,572 Health and social programs 814,454 704,465 563,590 Security and other civilian & commercial 342,302 360,871 295,886 Total $ 1,963,238 $ 1,779,964 $ 1,553,048 Year ended December 31, 2023 2022 2021 Client Type: U.S. federal government $ 1,084,043 $ 980,746 $ 735,032 U.S. state and local government 308,134 259,764 235,416 International government 103,399 103,609 139,229 Total Government 1,495,576 1,344,119 1,109,677 Commercial 467,662 435,845 443,371 Total $ 1,963,238 $ 1,779,964 $ 1,553,048 Year ended December 31, 2023 2022 2021 Contract Mix: Time-and-materials $ 812,430 $ 713,693 $ 633,135 Fixed-price 885,465 802,568 645,809 Cost-based 265,343 263,703 274,104 Total $ 1,963,238 $ 1,779,964 $ 1,553,048 Contract Assets and Liabilities: Contract assets consist of unbilled receivables on contracts where revenue recognized exceeds the amount billed. Contract liabilities result from advance payments received on a contract or from billings in excess of revenue recognized on long-term contracts. The following table summarizes the contract balances as of December 31, 2023 and December 31, 2022: December 31, 2023 December 31, 2022 Change Contract assets $ 201,832 $ 169,088 $ 32,744 Contract liabilities ( 21,997 ) ( 25,773 ) 3,776 Net contract assets (liabilities) $ 179,835 $ 143,315 $ 36,520 The net contract assets (liabilities) as of December 31, 2023 increased by $ 36.5 million as compared to December 31, 2022, primarily due to the timing difference between the performance of services and billings to and payments from customers. There were no material changes to contract balances due to impairments or credit losses during the period. During the years ended December 31, 2023 and 2022, the Company recognized $ 17.8 million and $ 27.4 million in revenue related to the contract liabilities balance at December 31, 2022 and 2021, respectively. Unfulfilled Performance Obligations: The Company had $ 1.4 billion in remaining unfulfilled performance obligations (“UPO”) as of December 31, 2023. The Company expects to recognize the remaining UPO as revenue of approximately 57 % by December 31, 2024, 77 % by December 31, 2025, and the remaining thereafter .

Derivative instruments and Hedg

Derivative instruments and Hedges Activities	12 Months Ended
	Dec. 31, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative instruments and Hedges Activities	NOTE 12 - DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES The Company uses interest rate swap agreements (the “Swaps”) to manage its variable interest rate risk associated with its borrowings under the Credit Facility. The Company does not use such instruments for speculative or trading purposes. At December 31, 2023 , the Company had floating-to-fixed interest rate swaps for an aggregate notional amount of $ 275.0 million, of which $ 100.0 million will mature on February 28, 2025 , $ 75.0 million will mature on February 28, 2028 , and $ 100.0 million will mature on June 27, 2028 . The Company has designated the Swaps as cash flow hedges. For the years ended December 31, 2023 and 2022, the effect of the Swaps on the Company’s financial statements are as follows: Cash Flow Hedging Derivatives Total Gain (Loss) Recorded to AOCI Amount of (Gain) or Loss Year Ended December 31, 2023 2022 2023 2022 Interest Rate Swaps $ ( 45 ) $ 11,445 $ ( 6,982 ) $ ( 248 ) As of December 31, 2023 , the net amount of realized losses from the hedge agreements expected to be reclassified from AOCI into earnings within the next twelve months is $ 4.8 million .

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	NOTE 13 - INCOME TAXES The domestic and foreign components of income before provision for income taxes are as follows for the years ended December 31: 2023 2022 2021 Domestic $ 83,742 $ 80,372 $ 97,884 Foreign 12,805 3,608 2,206 Income before income taxes $ 96,547 $ 83,980 $ 100,090 Income tax expense consisted of the following for the years ended December 31: 2023 2022 2021 Current: Federal $ 28,108 $ 8,413 $ 15,961 State 10,380 2,686 3,494 Foreign 2,247 1,661 687 Total current 40,735 12,760 20,142 Deferred: Federal ( 20,279 ) 4,264 4,724 State ( 6,915 ) 3,607 4,395 Foreign 394 ( 894 ) ( 303 ) Total deferred ( 26,800 ) 6,977 8,816 Income tax expense $ 13,935 $ 19,737 $ 28,958 Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and income tax purposes. Deferred tax assets (liabilities) consisted of the following at December 31: 2023 2022 Deferred Tax Assets Allowance for expected credit losses $ 1,213 $ 1,404 Accrued paid time off 3,039 2,801 Foreign net operating loss carryforward — 229 State net operating loss carryforward 500 502 Stock-based compensation 5,523 1,586 Deferred compensation 5,765 4,692 Foreign tax credits 8,035 7,236 Federal and state tax credits 686 384 Foreign exchange 3,591 4,532 Foreign deferred 441 875 Accrued bonus 5,830 5,696 Capital loss 1,054 — Facilities impairment 3,092 2,650 Capitalized research expenses 47,019 990 Accrued liabilities and other 2,682 5,523 Lease liabilities 58,538 56,695 147,008 95,795 Less: Valuation Allowance ( 9,021 ) ( 7,607 ) Total Deferred Tax Assets 137,987 88,188 Deferred Tax Liabilities Retention — ( 407 ) Prepaid expenses — ( 366 ) Payroll taxes ( 725 ) ( 697 ) Unbilled revenue ( 284 ) ( 409 ) Depreciation ( 2,128 ) ( 270 ) Amortization ( 107,201 ) ( 99,045 ) Deferred gain and other ( 2,202 ) ( 2,561 ) Lease assets - Right-of-Use ( 51,622 ) ( 52,471 ) Total Deferred Tax Liabilities ( 164,162 ) ( 156,226 ) Total Net Deferred Tax Liability $ ( 26,175 ) $ ( 68,038 ) The Company measures certain deferred tax assets and liabilities based on the rates at which they are expected to reverse in the future, which is 27.0 %. On December 20, 2017, the U.S. Congress passed the Tax Cuts and Job Act of 2017 (the “TCJA”) which was signed into law on December 22, 2017, and was generally effective beginning January 1, 2018. The TCJA changed the provision for deduction of allowable research and development costs under the Internal Revenue Code (the “IRC”). Effective for tax years beginning after January 1, 2022, research and development costs are required to be capitalized and amortized over a period of five years for domestic and fifteen years for foreign research and development for income tax purposes. As a result of the capitalization, the Company recognized an increase of $ 28.1 million in deferred tax asset for the year ended December 31, 2023. As of December 31, 2023 , the cumulative foreign tax credit carryforward balance increased by approximately $ 0.8 million and the valuation allowance required increased by approximately $ 0.8 million. No additional income taxes have been provided for on any remaining undistributed foreign earnings not subject to the transition tax. No additional deferred income taxes have been provided for the $ 4.9 million of additional unfavorable outside basis differences inherent in these foreign entities as of December 31, 2023 because these amounts continue to be permanently reinvested in foreign operations. As of December 31, 2023 , the Company has net operating loss (“NOL”) carryforwards for state income tax purposes of approximately $ 6.5 million, which expire in 2034 . The Company acquired these NOLs as a result of its purchase of a business in November 2014. IRC Section 382 imposes an annual limitation on the use of a corporation’s NOLs, tax credits and other carryovers after an “ownership change” occurs. Section 382 imposes an annual limitation on the amount of post-ownership change taxable income a corporation may offset with pre-ownership change NOLs and credits. In general, the annual limitation is determined by multiplying the value of the corporation’s stock immediately before the ownership change (subject to certain adjustments) by the applicable long-term tax-exempt rate. Any unused portion of the annual limitation is available for use in future years until such NOLs are scheduled to expire (in general, NOLs may be carried forward 15 to 20 years). The Company established a valuation allowance of approximately $ 0.5 million against the portion of the deferred tax asset which it is more-likely-than-not that it will not be recoverable (e.g. expiration of the statute of limitations, etc.) As of December 31, 2023 , the Company had gross federal and state income tax credit carryforwards of approximately $ 0.7 million, which expire between 2024 and 2034 . A deferred tax asset of approximately $ 0.7 million , net of federal benefit, has been established related to these state income tax credit carryforwards as of December 31, 2023. The need to establish valuation allowances for deferred assets is based on a more-likely-than-not threshold that the benefit of such assets will be realized in future periods. Appropriate consideration has been given to all available evidence, including historical operating results, projections of taxable income, and tax planning alternatives. The Company concluded that a valuation allowance of $ 0.5 million was required for tax attributes related to specified state jurisdictions and an additional $ 8.0 million valuation allowance is required against our U.S. foreign tax credit carryforwards. The total amount of unrecognized tax benefits as of December 31, 2023 and 2022 was $ 24.1 million and $ 0.1 million, respectively, which includes $ 9.0 million and $ 0.1 million, respectively, of tax positions that, if recognized, would impact the effective rate. The unrecognized tax benefits and the related accrued interest are part of other long-term liabilities on the Company’s consolidated balance sheets. The components of unrecognized tax benefits, excluding penalty and interest, are as follows at December 31: 2023 2022 U.S. transfer pricing $ 145 $ 145 India transfer pricing 164 — Section 41 tax credit 8,736 — Section 174 expense capitalization 15,086 Total $ 24,131 $ 145 The unrecognized tax benefit reconciliation, excluding penalty and interest, is as follows: Unrecognized tax benefits at January 1, 2021 $ 811 Decrease attributable to tax positions taken during the current period ( 361 ) Unrecognized tax benefits at December 31, 2021 450 Decrease attributable to tax positions taken during the current period ( 305 ) Unrecognized tax benefits at December 31, 2022 145 Increase attributable to tax positions taken during a prior period 19,845 Increase attributable to tax positions taken during the current period 4,141 Unrecognized tax benefits at December 31, 2023 24,131 The Company’s 2020 through 2022 tax years remain subject to examination by the Internal Revenue Service for federal tax purposes. Certain significant state and foreign tax jurisdictions are also either currently under examination or remain open under the statutes of limitation and subject to examination for the tax years from 2019 to 2022 . Although the Company believes it has adequately provided for all uncertain tax positions, amounts asserted by taxing authorities could be greater than the Company’s accrued position. Accordingly, additional provisions on federal, state, and foreign income tax related matters could be recorded in the future as revised estimates are made or the underlying matters are effectively settled or otherwise resolved. Conversely, the Company could settle positions with the tax authorities for amounts lower than have been accrued. The Company believes it is reasonably possible that, during the next 12 months, the Company’s liability for uncertain tax positions may not change. The Company’s provision for income taxes differs from the federal statutory rate. The differences between the statutory rate and the Company’s provision are as follows for the years ended December 31: 2023 2022 2021 Taxes at statutory rate 21.0 % 21.0 % 21.0 % State taxes, net of federal benefit 6.0 % 5.8 % 5.6 % Foreign tax rate differential ( 0.2 )% 0.1 % 0.1 % Executive compensation 1.7 % 2.2 % 2.1 % Other permanent differences ( 0.3 )% 2.0 % ( 0.4 )% Global intangible low-taxed income (GILTI) 0.3 % — — Prior year tax adjustments ( 6.4 )% ( 1.1 )% 1.5 % Deferred impact of state rate change 0.5 % 0.6 % — Worthless stock deduction ( 5.1 )% ( 4.6 )% — Unrecognized tax benefits 9.0 % ( 0.4 )% ( 0.5 )% Capital loss ( 3.8 )% — — Valuation allowance 2.0 % 0.7 % 1.3 % Equity-based compensation ( 1.1 )% ( 1.3 )% ( 1.0 )% Tax credits ( 9.2 )% ( 1.5 )% ( 0.8 )% Taxes at effective rate 14.4 % 23.5 % 28.9 % During 2023, the Company restructured the ownership of its Canadian entities for tax purposes resulting in a 3.8 % decrease in the Company’s effective income tax rate for the year ended December 31, 2023. During 2023, the Company liquidated one of its U.K. subsidiaries as part of the wind-down of its commercial marketing business resulting in a reduction in the Company’s effective income tax rate of 5.1 % for the year ended December 31, 2023. During 2023, the Company completed its annual true-up of the prior year income tax provision in connection with the filing of its U.S. federal & state income tax returns. As a result of that process, the Company recorded a change in the estimate of certain tax credits it is eligible to claim with its income tax return filings that resulted in a 7.0 % decrease in the Company’s effective income tax rate for the year ended December 31, 2023 .

Accumulated Other Comprehensive

Accumulated Other Comprehensive (Loss) Income	12 Months Ended
	Dec. 31, 2023
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive (Loss) Income	NOTE 14 - ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME Accumulated other comprehensive (loss) income included the following: Foreign Gain on Sale of (1) Changes in (2)(5) Total Accumulated other comprehensive (loss) income at January 1, 2021 $ ( 7,210 ) $ 1,096 $ ( 7,992 ) $ ( 14,106 ) Current period other comprehensive income (loss): Other comprehensive income (loss) before reclassifications ( 1,676 ) — 3,285 1,609 Amounts reclassified from accumulated other comprehensive (loss) income — ( 720 ) 3,728 3,008 Effect of taxes (3) 127 193 ( 1,866 ) ( 1,546 ) Total current period other comprehensive income (loss) ( 1,549 ) ( 527 ) 5,147 3,071 Accumulated other comprehensive (loss) income at December 31, 2021 ( 8,759 ) 569 ( 2,845 ) ( 11,035 ) Current period other comprehensive income (loss): Other comprehensive (loss) income before reclassifications ( 9,259 ) — 11,445 2,186 Amounts reclassified from accumulated other comprehensive (loss) income — ( 720 ) 472 ( 248 ) Effect of taxes (3) 3,962 192 ( 3,190 ) 964 Total current period other comprehensive income (loss) ( 5,297 ) ( 528 ) 8,727 2,902 Accumulated other comprehensive (loss) income at December 31, 2022 ( 14,056 ) 41 5,882 ( 8,133 ) Current period other comprehensive income (loss): Other comprehensive income (loss) before reclassifications 4,158 — ( 45 ) 4,113 Amounts reclassified from accumulated other comprehensive (loss) income (4) — ( 60 ) ( 6,922 ) ( 6,982 ) Effect of taxes (3) ( 2,797 ) 19 1,895 ( 883 ) Total current period other comprehensive income (loss) 1,361 ( 41 ) ( 5,072 ) ( 3,752 ) Accumulated other comprehensive (loss) income at December 31, 2023 $ ( 12,695 ) $ — $ 810 $ ( 11,885 ) (1) Represents the fair value of an interest rate hedge agreement, designated as a cash flow hedge, which was sold on December 1, 2016. The fair value of the interest rate hedge agreement was recorded in other comprehensive income, net of tax, and will be reclassified to earnings when earnings are impacted by the hedged items, as interest payments are made on the Credit Facility from January 31, 2018 to January 31, 2023. (2) Represents the change in fair value of interest rate hedge agreements designated as a cash flow hedges. The fair value of the interest rate hedge agreements was recorded in other comprehensive income, net of tax, and will be reclassified to earnings when earnings are impacted by the hedged items, as interest payments are made on the Credit Facility from through June 27, 2028. See additional details of the hedge agreements in Note 12 - Derivative Instruments and Hedging Activities. (3) The Company’s effective tax rate for the years ended December 31, 2023, 2022, and 2021 was 14.4 % , 23.5 % , and 28.9 % , respectively. (4) The Company expects to reclassify $ 4.8 million in unrealized gains related to the Change in Fair Value of Interest Rate Hedge Agreement from accumulated other comprehensive loss into earnings during the next 12 months. (5) The fair value of the interest rate hedge agreements is included in other current and other long-term assets and liabilities on the consolidated balance sheets. See “Note 19 - Fair Value” for additional details.

Accounting for Stock-based Comp

Accounting for Stock-based Compensation	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Accounting for Stock-based Compensation	NOTE 15 - ACCOUNTING FOR STOCK-BASED COMPENSATION Stock Incentive Plans On April 4, 2018, the Board approved the 2018 Omnibus Incentive Plan (the “2018 Omnibus Plan”), which was subsequently approved by the stockholders and became effective on May 31, 2018 (the “Effective Date”). The 2018 Omnibus Plan replaced the previous 2010 Omnibus Incentive Plan (the “Prior Plan”). The 2018 Omnibus Plan was amended on May 28, 2020 to increase the number of shares available for issuance. On June 1, 2023, the Company’s stockholders approved an amendment and restatement of the 2018 Omnibus Plan (the “2018 A&R Omnibus Plan”) which further increased the number of shares available for issuance, incorporated compensation recovery provisions consistent with new SEC and NASDAQ requirements and made certain other clarifying changes. The A&R 2018 Omnibus Plan, as amended, allows the Company to grant up to 2,050,000 shares using stock options, stock appreciation rights, restricted stock, RSUs, performance units and PSAs, cash-based awards, and other stock-based awards to all key officers, key employees, and non-employee directors of the Company. Outstanding shares granted under the Prior Plan, totaling 2,631 , as of December 31, 2023, remain subject to its terms and conditions, and additional awards from the Prior Plan are prohibited after the Effective Date. As of December 31, 2023, the Company had approximately 1,119,446 shares available for grant under the A&R 2018 Omnibus Plan. CSRSUs have no impact on the shares available for grant under the A&R 2018 Omnibus Plan, nor on the calculated shares used in earnings per share (“EPS”) calculations. Stock-based compensation expense is included as part of direct costs and indirect and selling expenses on the consolidated statements of comprehensive income. The total stock-based compensation expense for the years ended December 31, 2023, 2022, and 2021, the unrecognized compensation expense at December 31, 2023, and the weighted-average period to recognize the remaining unrecognized shares are as follows: Stock-Based Compensation Expense Recognized Unrecognized 2023 2022 2021 2023 Weighted Restricted Stock Units $ 9,413 $ 9,300 $ 8,563 $ 13,517 1.7 Cash-Settled Restricted Stock Units 8,061 5,709 8,251 11,558 1.7 Non-Employee Director Awards 1,029 1,087 937 481 0.4 Performance Shares 4,416 2,784 3,731 4,351 1.5 Total $ 22,919 $ 18,880 $ 21,482 $ 29,907 The assumptions of employment termination forfeiture rates used in the determination of fair value of stock awards during the 2023 calendar year were based on the Company’s historical average of actual forfeitures from the previous 10 years preceding the reporting period. The expected annualized forfeiture rates used during the 2023 calendar year varied from 0 % to 21.59 % . Stock Options Stock options are granted with an exercise price equal to the market value of the Company’s common stock on the date of grant. There were no stock options granted during 2023, 2022, and 2021. The following table summarizes the changes in outstanding stock options: Number of Weighted Aggregate Outstanding at January 1, 2021 38,227 $ 31.93 Exercised ( 8,535 ) $ 27.17 Granted — $ — Forfeited/Expired — $ — Outstanding at December 31, 2021 29,692 $ 33.30 Exercised ( 18,807 ) $ 32.04 Granted — $ — Forfeited/Expired — $ — Outstanding at December 31, 2022 10,885 $ 35.49 Exercised ( 8,254 ) $ 33.84 Granted — $ — Forfeited/Expired — $ — Outstanding at December 31, 2023 2,631 $ 40.68 $ 246 Vested plus expected to vest at December 31, 2023 2,631 $ 40.68 $ 246 Exercisable at December 31, 2023 2,631 $ 40.68 $ 246 The aggregate intrinsic value is based on the Company’s closing stock price of $ 134.09 as of December 31, 2023. The total intrinsic value of options exercised was $ 0.9 million , $ 1.9 million , and $ 0.8 million for the years ended December 31, 2023, 2022, and 2021, respectively. All options have vested as of December 31, 2023, and the weighted-average remaining contractual term for options vested and exercisable was 0.2 years. Information regarding stock options outstanding as of December 31, 2023 is summarized below: OPTIONS OUTSTANDING OPTIONS EXERCISABLE Range of Number Weighted Weighted Number Weighted $ 40.68 to $ 40.68 2,631 0.2 $ 40.68 2,631 $ 40.68 Restricted Stock Units RSUs generally have a vesting term of three years . On vesting the employee is issued one share of stock for each RSU awarded. The fair value of shares vested was $ 7.3 million , $ 10.8 million , and $ 7.9 million for the years ended December 31, 2023, 2022, and 2021, respectively. A summary of the Company’s RSUs is presented below. Number of Weighted- Aggregate Non-vested RSUs at January 1, 2021 305,399 $ 66.51 Granted 132,757 $ 95.68 Vested ( 119,203 ) $ 66.46 Cancelled ( 15,117 ) $ 68.53 Non-vested RSUs at December 31, 2021 303,836 $ 79.17 Granted 148,361 $ 93.70 Vested ( 140,666 ) $ 76.53 Cancelled ( 26,705 ) $ 77.16 Non-vested RSUs at December 31, 2022 284,826 $ 88.23 Granted 89,388 $ 110.80 Vested ( 93,881 ) $ 78.05 Cancelled ( 21,815 ) $ 94.01 Non-vested RSUs at December 31, 2023 258,518 $ 99.25 $ 34,665 RSUs expected to vest in the future 230,953 $ 98.82 $ 30,968 The aggregate intrinsic value in the preceding table is based on the Company’s closing stock price of $ 134.09 per share as of December 31, 2023. Cash-Settled Restricted Stock Units CSRSUs generally have a vesting term of three years . The fair value of CSRSUs vested and settled in cash for the years ended December 31, 2023, 2022, and 2021 was $ 7.9 million , $ 6.6 million and $ 8.7 million , respectively. A summary of the Company’s CSRSUs is presented below. Number of Weighted- Aggregate Non-vested CSRSUs at January 1, 2021 241,481 $ 65.06 Granted 52,246 $ 89.51 Vested ( 104,272 ) $ 63.96 Cancelled ( 23,195 ) $ 69.68 Non-vested CSRSUs at December 31, 2021 166,260 $ 72.79 Granted 115,024 $ 97.88 Vested ( 75,566 ) $ 73.20 Cancelled ( 17,299 ) $ 80.02 Non-vested CSRSUs at December 31, 2022 188,419 $ 87.28 Granted 70,742 $ 110.65 Vested ( 81,537 ) $ 76.26 Cancelled ( 19,040 ) $ 91.94 Non-vested CSRSUs at December 31, 2023 158,584 $ 102.82 $ 21,264 CSRSUs expected to vest in the future 134,808 $ 102.31 $ 18,076 The aggregate intrinsic value in the preceding table is based on the Company’s closing stock price of $ 134.09 per share as of December 31, 2023. Non-Employee Director Awards The Company grants awards of registered shares to its non-employee directors on an annual basis under the A&R Omnibus Plan. A summary of the non-employee director awards is presented below: Number of Weighted- Aggregate Non-vested RSUs at January 1, 2021 6,510 $ 64.47 Granted 11,186 $ 90.73 Vested ( 12,110 ) $ 76.61 Cancelled — $ — Non-vested RSUs at December 31, 2021 5,586 $ 90.73 Granted 11,399 $ 95.35 Vested ( 11,637 ) $ 93.39 Cancelled — $ — Non-vested RSUs at December 31, 2022 5,348 $ 94.79 Granted 8,211 $ 127.81 Vested ( 9,457 ) $ 109.14 Cancelled — $ — Non-vested RSUs at December 31, 2023 4,102 $ 127.81 $ 550 RSUs expected to vest in the future 4,102 $ 127.81 $ 550 The aggregate intrinsic value in the preceding table is based on the Company’s closing stock price of $ 134.09 per share as of December 31, 2023. Performance Share Awards In 2015, the Board approved a performance-based share program (the “Program”) that provides for the issuance of PSAs to its senior management. Under the Program, the number of PSAs that the participant will receive depends on the Company’s achievement of two performance goals during two performance periods. The performance goals under the Program are based on (i) the Company’s compounded annual growth rate in EPS (adjusted to exclude certain items specified in the award's Agreement) during a two-year performance period (the “Initial Period”) and (ii) the Company’s cumulative total shareholder return relative to its peer group (“rTSR”) during a performance period from the first day of the performance period (typically January 1 of the year awarded) to the last day of the third year of the performance period (typically December 31). The PSAs will only be eligible to vest following the expiration of the three-year performance period. The actual shares vested will be subject to both continued employment by the Company (barring certain exceptions allowing for partial performance periods) and actual financial measures achieved. The final number of shares of common stock that will be issued to each participant at the end of the applicable performance period will be determined by multiplying the award by the product of two percentages: the first based on the Company’s EPS performance and the second based on the Company’s rTSR performance, subject to a minimum and maximum performance level. As of December 31, 2023 , shares granted during 2021, 2022, and 2023 are within year three , two , and one of the performance periods, respectively, and therefore have not fully vested. A total of 45,141 shares granted in 2020 vested during 2023 after meeting the performance goals. As of December 31, 2023, a total of 69,650 shares granted in 2021 and 2022 are expected to vest in the future based on estimated financial measures achieved in the Initial Period and rTSR performance. A summary of the Company’s PSAs is presented below. Number of Weighted- Aggregate Non-vested PSAs at January 1, 2021 142,121 $ 68.19 Granted 54,216 $ 85.03 Vested ( 63,258 ) $ 65.05 Cancelled — $ — Non-vested PSAs at December 31, 2021 133,079 $ 76.54 Granted 38,412 $ 93.15 Vested ( 47,634 ) $ 82.38 Cancelled ( 3,170 ) $ 80.64 Non-vested PSAs at December 31, 2022 120,687 $ 79.42 Granted 36,956 $ 115.67 Vested ( 45,141 ) $ 58.76 Cancelled ( 6,934 ) $ 61.49 Non-vested PSAs at December 31, 2023 105,568 $ 102.12 $ 14,156 PSAs expected to vest in the future 69,650 $ 104.95 $ 9,339 The aggregate intrinsic value in the preceding table is based on the Company’s closing stock price of $ 134.09 per share as of December 31, 2023. The fair value of the awards is estimated on the grant date using a Monte Carlo simulation model due to the market condition for the rTSR component. The fair value assumptions using the Monte Carlo simulation model for awards granted in 2023, 2022, and 2021 were: 2023 2022 2021 Dividend Yield 0.5 % 0.6 % 0.6 % Historical Volatility 33.6 % 39.0 % 40.9 % Risk-Free Rate of Returns 3.8 % 2.1 % 0.3 %

Acquisition and Divestiture

Acquisition and Divestiture	12 Months Ended
	Dec. 31, 2023
Business Combinations [Abstract]
Acquisitions and Divestitures	NOTE 16 – ACQUISITIONS AND DIVESTITURES Acquisitions CMY Solutions, LLC On May 1, 2023 , the Company acquired CMY Solutions, LLC (“CMY”), a privately-held company that provides engineering and automation solutions to utilities and organizations, for $ 32.6 million in cash. The acquisition enhances the Company’s offerings in the field of power and energy advisory services. As part of the allocation of purchase consideration, the Company recorded $ 10.3 million of intangible assets, $ 1.2 million in net working capital, and $ 21.1 million of goodwill. The goodwill is deductible for income tax purposes. Intangible assets consist of $ 10.2 million related to existing customer relationships and $ 0.1 million related to trade names and trademarks. The pro-forma impact of the acquisition is not material to the Company’s results of operations. Blanton & Associates On September 1, 2022, the Company completed the acquisition of Blanton & Associates (“Blanton”), an environmental consulting, planning, and project management firm headquartered in Austin, Texas, for $ 22.9 million. Blanton brings domain expertise in environmental regulatory compliance and permitting for the transportation, renewable energy, water, and resource management sectors and adds technically specialized staff in all aspects of environmental services to the Company. As part of the allocation of the purchase consideration, the Company recorded net working capital of $ 4.6 million, property and equipment of $ 0.2 million , deferred income tax liabilities of $ 3.0 million, $ 11.4 million to intangible assets, and $ 9.7 million to goodwill. The goodwill is not deductible for income tax purposes. Intangible assets consisted of $ 10.9 million related to existing customer relationships, $ 0.5 million related to contract backlog, and $ 0.1 million related to trade names and trademarks. The pro-forma impact of the acquisition is not material to the Company’s results of operations. SemanticBits, LLC On July 13, 2022, the Company completed the acquisition of SemanticBits, LLC (“SemanticBits”), a 450-person Virginia limited liability company. SemanticBits is a partner to U.S. federal health agencies for mission-critical digital modernization solutions and provides a suite of scalable digital modernization services using open-source frameworks, including end-to-end agile scale development capabilities, cloud-native solutions, data analytics and human-centered designs. The acquisition provides synergies and scalabilities to support federal agencies with advanced IT solutions, digital modernization, and health expertise to solve complex customer challenges. The purchase price was $ 216.0 million in cash and was funded by the existing Credit Facility. T he final purchase price allocation is summarized as follows: Contract receivables $ 12,699 Contract assets 6,071 Customer-related intangibles 62,967 Trade names and trademarks 1,120 Other current and non-current assets 407 Accrued salaries and benefits ( 3,998 ) Accrued expenses and other liabilities ( 6,244 ) Deferred tax liability ( 16,701 ) Net assets acquired 56,321 Goodwill 159,677 Purchase consideration $ 215,998 Goodwill is reflective of the existing workforce of SemanticBits and the expected synergies created with the Company as part of the acquisition. The useful lives associated with the customer-related intangible asset and trade names and trademarks are 4.0 years and 0.7 years, respectively. The goodwill and intangible assets are not deductible for income tax purposes. Acquisition-related costs and integration costs totaled $ 4.3 million and are included as part of indirect and selling expenses in the Company’s consolidated statements of comprehensive income. For the year ended December 31, 2022, SemanticBits contributed revenues of $ 64.3 million and gross profit of $ 26.7 million. Computation of an earnings measure other than gross profit is impracticable due to SemanticBits’ operations and financial systems being integrated with those of the Company. The following unaudited condensed pro forma information presents combined financial information as if the acquisition of SemanticBits had been effective at January 1, 2021, the beginning of the 2021 fiscal year. As a result, fiscal year 2022 represents the pro forma results for year two of the acquisition. The pro forma information includes alignment of SemanticBits’ revenue recognition policy, corrections of employee-related expenses, and adjustments reflecting changes in the amortization of intangibles, acquisition-related costs, interest expense, and records income tax effects as if SemanticBits had been included in the Company’s results of operations. The pro forma information is not intended to reflect the actual combined results of operations that would have occurred if the acquisition was completed on January 1, 2021, nor is it indicative of future operating results after the acquisition date of July 13, 2022. (Unaudited) Year Ended (in thousands) 2022 2021 Revenue $ 1,856,399 $ 1,667,425 Net income 75,999 63,752 Creative Systems and Consulting On December 31, 2021 , the Company acquired Creative Systems, a provider of IT modernization and digital transformation solutions to federal agencies, for cash purchase price of $ 156.6 million. The Company recognized fair value of the assets acquired and liabilities assumed, and allocated $ 128.1 million and $ 28.9 million of the purchase price to intangible assets and goodwill. The goodwill is deductible for income tax purposes. Intangible assets consisted of $ 24.5 million in customer relationships, $ 3.7 million related to developed technology, $ 0.6 million related to trade names and trademarks, and $ 0.1 million related to non-compete agreements. The customer-related and technology-related intangibles are being amortized on a straight-line basis over 4 years and 10 years , respectively, while trade names and trademarks and non-compete agreements will be amortized in less than one year from the acquisition date. Goodwill is reflective of the existing workforce at Creative Systems and the expected synergies created with the Company as a result of the acquisition. The pro-forma impact of the acquisition is not material to the Company’s results of operations. ESAC On November 1, 2021, the Company completed the acquisition of ESAC, which specializes in providing advanced health analytics, research data management and bioinformatics solutions to U.S. federal health agencies, for a cash purchase price of $ 17.3 million. In addition to working capital acquired of $ 2.6 million, the Company recognized fair value of the assets acquired and liabilities assumed and allocated $ 11.3 million to goodwill and $ 3.4 million to intangible assets. The goodwill is deductible for income tax purposes. Intangible assets included $ 3.1 million related to customer relationships and $ 0.3 million related to technology and other intangibles, which are amortized over 3 years and less than 1 year , respectively. The pro-forma impact of the acquisition is not material to the Company’s results of operations. Divestitures Commercial Marketing On July 21, 2023, the Company entered into an Asset Purchase Agreement to sell its U.S. commercial marketing business, including certain assets of the business, for initial cash considerations of $ 49.5 million before final net working capital adjustments. On September 12, 2023 , the Company completed the divesture and received $ 47.1 million in cash, net of working capital adjustments and certain amounts held in escrow. The disposal of the commercial marketing business was not a major strategic shift that was, or will be, significant to the Company’s operations and financial results. In connection with the sale, the Company recorded a gross gain of $ 4.4 million and transactions fees of $ 1.9 million, for a total pre-tax gain of $ 2.5 million, that is included as part of other income on the Company’s consolidated statements of comprehensive income. Mobile and SMS Messaging Aggregator Business On July 24, 2023, the Company entered into an Asset Purchase Agreement to sell its mobile and Short Message Service (“SMS”) messaging aggregator business, including certain assets of the business, for the equivalent of $ 5.4 million in cash. The sale was completed on November 1, 2023 . The disposal of the mobile aggregation and SMS messaging aggregator business was not a major strategic shift that was, or will be, significant to the Company’s operations and financial results. In connection with the sale, the Company recorded a pre-tax gain of $ 3.2 million that is included as part of other income on the Company’s consolidated statements of comprehensive income.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2023
Earnings Per Share [Abstract]
Earnings Per Share	NOTE 17 - EARNINGS PER SHARE The Company’s EPS is computed by dividing reported net income by the weighted-average number of shares outstanding. Diluted EPS considers the potential dilution that could occur if common stock equivalents of stock options, RSUs, and PSAs were exercised or converted into stock. PSAs are included in the computation of diluted shares only to the extent that the underlying performance conditions: (i) are satisfied as of the end of the reporting period or (ii) would be considered satisfied if the end of the reporting period were the end of the related performance period and the result would be dilutive under the treasury stock method. As of December 31, 2023, the PSAs granted during the year ended December 31, 2021 and 2022 met the related performance conditions for the initial performance period and were included in the calculation of diluted EPS; however, the PSAs granted during the year ended December 31, 2023 have not yet completed their initial two-year performance period and therefore were excluded in the calculation of diluted EPS. The dilutive effect of stock options, RSUs, and performance shares for each period reported is summarized below: 2023 2022 2021 Net Income $ 82,612 $ 64,243 $ 71,132 Weighted-average number of basic shares outstanding during the period 18,802 18,818 18,868 Dilutive effect of stock options, RSUs, and performance shares 192 215 256 Weighted-average number of diluted shares outstanding during the period 18,994 19,033 19,124 Basic earnings per share $ 4.39 $ 3.41 $ 3.77 Diluted earnings per share $ 4.35 $ 3.38 $ 3.72

Share Repurchase Program

Share Repurchase Program	12 Months Ended
	Dec. 31, 2023
Equity [Abstract]
Share Repurchase Program	NOTE 18 - SHARE REPURCHASE PROGRAM In September 2017, the Board approved a share repurchase program that allows for share repurchases in the aggregate up to $ 100.0 million under approved share repurchase plans pursuant to Rules 10b5-1 and 10b-18 under the Exchange Act. In November 2021, the Board amended and increased the previously authorized aggregate repurchase limit from $ 100.0 million to $ 200.0 million. The Credit Facility (see Note 10 – Long-Term Debt) permits annual share repurchases of at least $ 25.0 million provided that the Company is not in default of its covenants, and higher amounts provided that the Company’s Consolidated Leverage Ratio, prior to and after giving effect to such repurchases, is 0.50 to 1.00 less than the then-applicable maximum Consolidated Leverage Ratio and subject to the Company having net liquidity of at least $ 100.0 million after giving effect to such repurchases. Purchases under this program may be made from time to time at prevailing market prices in open market purchases or in privately negotiated transactions pursuant to Rule 10b-18 under the Exchange Act and in accordance with applicable insider trading and other securities laws and regulations. The purchases are funded from existing cash balances and/or borrowings, and the repurchased shares are held in treasury. The timing and extent to which the Company repurchases its shares will depend on market conditions and other corporate considerations in the Company’s sole discretion. For the years ended December 31, 2023 and 2022, the Company used $ 18.1 million to repurchase 180,000 shares at an average price of $ 100.70 per share and $ 17.0 million to repurchase 176,375 shares at an average price of $ 96.18 per share, respectively, under this program. As of December 31, 2023, approximately $ 93.7 million of authority remained available under the share repurchase plan.

Fair Value

Fair Value	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value	NOTE 19 - FAIR VALUE Financial instruments measured at fair value on a recurring basis and their location within the accompanying consolidated financial statements are as follows: December 31, 2023 (in thousands) Level 1 Level 2 Level 3 Total Location on Balance Sheet Assets: Interest rate swaps - current portion $ — $ 4,820 $ — $ 4,820 Prepaid expenses and other assets Foreign currency forward and swap contracts — 6 — 6 Prepaid expenses and other assets Interest rate swaps - long-term portion — 398 — 398 Other assets Company-owned life insurance policies — 20,438 — 20,438 Other assets Liabilities: Interest swaps - long-term portion $ — $ 4,184 $ — $ 4,184 Other long-term liabilities December 31, 2022 (in thousands) Level 1 Level 2 Level 3 Total Location on Balance Sheet Assets: Interest rate swaps - current portion $ — $ 5,051 $ — $ 5,051 Prepaid expenses and other Interest rate swaps - long-term portion 2,950 2,950 Other assets Company-owned life insurance policies — 17,869 — 17,869 Other assets

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	NOTE 20 - COMMITMENTS AND CONTINGENCIES Letters of Credit and Guarantees At December 31, 2023 and 2022, the Company had open standby letters of credit totaling $ 1.8 million and $ 2.0 million , respectively, and guarantees of $ 7.9 million and $ 9.2 million issued by its banks. The letters of credit and guarantees were primarily for the Company’s facility leases and contract performance obligations. The open standby letters of credit reduce the Company’s unused borrowing capacity under its Credit Facility. Litigation and Claims The Company is involved in various legal matters and proceedings arising in the ordinary course of business. While these matters and proceedings cause it to incur costs, including, but not limited to, attorneys’ fees, the Company currently believes it is not reasonably possible that any ultimate liability arising out of these matters and proceedings will have a material adverse effect on the Company’s financial position, results of operations, or cash flows.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Employee Benefit Plans	NOTE 21 - EMPLOYEE BENEFIT PLANS Defined Contribution Plan Effective June 30, 1999, the Company established the ICF Consulting Group Retirement Savings Plan (the “Retirement Savings Plan”). The Retirement Savings Plan is a defined contribution profit sharing plan with a cash or deferred arrangement under Section 401(k) of the Internal Revenue Code. Participants are able to elect to defer up to 70 % of their compensation, subject to statutory limitations, and are entitled to receive 100 % employer matching contributions for the first 3 % and 50 % for the next 2 % of their compensation. Contribution expense for the years ended December 31, 2023, 2022, and 2021 was $ 25.4 million , $ 22.9 million , and $ 19.0 million , respectively. Deferred Compensation Plan Certain key employees of the Company are eligible to defer a specified percentage of their cash compensation by having it contributed to a nonqualified deferred compensation plan. Eligible employees may elect to defer up to 80 % of their base salary and up to 100 % of performance bonuses, reduced by any amounts withheld for the payment of taxes or other deductions required by law. Participants are at all times 100 % vested in their account balances. The Company funds its deferred compensation liabilities by making cash contributions to a Rabbi Trust at the time the salary or bonus being deferred would otherwise be payable to the employee. The liability to plan participants is materially funded at all times and the plan does not have a material net impact on the Company’s results of operations. Employee Stock Purchase Plan The Company has a Employee Stock Purchase Plan (“ESPP”) under which one million shares have been authorized for issuance. The ESPP allows eligible employees to purchase shares of the Company’s common stock through payroll deductions up to $ 25,000 per calendar year over six-month offering periods at a discount not to exceed 5 % of the market value on the date of each purchase period, and therefore the Company does not recognize compensation expense related to the ESPP. For the years ended December 31, 2023 and 2022, employees purchased a total of 36,140 and 34,844 shares at an average purchase price of $ 121.96 and $ 91.84 , respectively. At December 31, 2023 and 2022, there were 548,832 and 584,972 shares remaining available for future issuance under this plan.

Exit Activities

Exit Activities	12 Months Ended
	Dec. 31, 2023
Restructuring and Related Activities [Abstract]
Exit Activities	NOTE 22 - EXIT ACTIVITIES During the year ended December 31, 2022, the Company incurred charges related to: (i) the reduction and wind-down of certain non-core commercial marketing businesses, and (ii) the reduction of facilities utilized by the remaining elements of the commercial marketing group. Specifically, these charges included the impairment of certain right-of-use operating leases and related assets associated with exited facilities of $ 8.2 million, $ 4.8 million in other facility costs recorded within indirect and selling expenses, and retention and severance of $ 2.3 million primarily recorded within direct costs. Of the $ 2.3 million in retention and severance, $ 1.3 million was paid during the 2022 fiscal year and the remaining liability was paid during the 2023 fiscal year. During the year ended December 31, 2023, the Company incurred and paid $ 2.5 million in retention and severance related to the wind-down of its non-core commercial marketing and communication businesses in the U.K. and Belgium. The exit activity was completed as of December 31, 2023 . During the year ended December 31, 2023, the Company completed the divestitures of its non-core U.S. commercial marketing and Canadian mobile and SMS messaging aggregator businesses . As a result of the divestitures, the Company incurred retention and severance of $ 1.9 million and $ 1.7 million for the years ended December 31, 2023 and 2022, respectively, which was primarily recorded within direct costs. As part of the sale of the businesses, the Company incurred $ 0.6 million in related compensation expense which was recorded within indirect and selling expenses. The retention and severance and compensation expenses were paid during the 2023 fiscal year. As a result of these wind-down and divestitures that were completed during the year ended December 31, 2023, the Company recognized impairment losses of $ 0.9 million related to a prior acquisition, $ 3.0 million related to right-of-use operating leases, and $ 2.4 million in other facility costs.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2023
Subsequent Events [Abstract]
Subsequent Events	NOTE 23 - SUBSEQUENT EVENTS Share Buyback Program On November 14, 2023, the Board of directors authorized and approved a plan to repurchase up to 191,000 shares of the Company’s common stock pursuant to Rule 10b5-1 (the “Plan”) of the current repurchase program. The Plan is effective January 2, 2024 through June 30, 2024 . As of February 23, 2024, the Company repurchased 159,681 shares at a total cost of $ 21.9 million, or $ 136.94 per share under the plan.

Supplemental Information

Supplemental Information	12 Months Ended
	Dec. 31, 2023
Disclosure Text Block Supplement [Abstract]
Supplemental Information	NOTE 24 - SUPPLEMENTAL INFORMATION Valuation and Qualifying Accounts Allowance for Credit Losses 2023 2022 2021 Balance at beginning of period $ 6,112 $ 7,741 $ 7,616 Provision for credit losses 1,164 248 10,912 Write-offs, net of recoveries ( 1,886 ) ( 1,782 ) ( 10,723 ) Effect of foreign currency translation 45 ( 95 ) ( 64 ) Balance at end of period $ 5,435 $ 6,112 $ 7,741 Income Tax Valuation Allowance 2023 2022 2021 Balance at beginning of period $ 7,607 $ 7,048 $ 6,839 Provision for income taxes - valuation allowance 1,414 559 209 Balance at end of period $ 9,021 $ 7,607 $ 7,048

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements include the accounts of ICF International, Inc. (“ICFI”) and its principal subsidiary, ICF Consulting Group, Inc. (“Consulting,” and together with ICFI, the “Company”), and have been prepared in accordance with United States (“U.S.”) generally accepted accounting principles (“U.S. GAAP”). Consulting is a wholly owned subsidiary of ICFI. ICFI is a holding company with no operations or assets other than its investment in the common stock of Consulting. All other subsidiaries of the Company are wholly owned by Consulting. Intercompany transactions and balances have been eliminated.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent liabilities at the date of the consolidated financial statements, and the reported amounts of revenue and expenses during the reporting periods. Areas of the consolidated financial statements where estimates may have the most significant effect include contractual and regulatory reserves, valuation and lives of tangible and intangible assets, contingent consideration related to business acquisitions and divestitures, impairment of goodwill and long-lived assets, accrued liabilities, revenue recognition (including estimates of variable considerations in determining the total contract price and allocation of performance obligations), the remaining costs to complete fixed-price contracts, bonus and other incentive compensation, stock-based compensation, reserves for tax benefits and valuation allowances on deferred tax assets, provisions for income taxes, collectability of receivables, and loss accruals for litigation. Actual results experienced by the Company may differ from management’s estimates.
Revenue Recognition	Revenue Recognition The Company primarily provides services and technology-based solutions for clients that operate in a variety of markets and the solutions may span the entire program life cycle, from initial research and analysis to the design and implementation of solutions. The Company enters into agreements with clients that create enforceable rights and obligations and for which it is probable that the Company will collect the consideration to which it will be entitled as services and solutions are transferred to the client. Except in certain narrowly defined situations, the Company’s agreements with its clients are written and revenue is generally not recognized on oral or implied arrangements. The Company recognizes revenue based on the consideration specified in the applicable agreement and excludes from revenue amounts collected on behalf of third parties. Accordingly, sales and similar taxes which are collected on behalf of third parties are excluded from the transaction price. The Company evaluates whether two or more agreements should be accounted for as one single contract and whether combined or single agreements should be accounted for as more than one performance obligation. For most contracts, the client requires the Company to perform a number of tasks in providing an integrated output for which the client has contracted, and, hence, contracts of this type are tracked as having only one performance obligation since a substantial part of the Company’s promise is to ensure the individual tasks are incorporated into a combined output in accordance with contract requirements. When contracts have multiple performance obligations, the Company allocates the total transaction price to each performance obligation based on the estimated relative standalone selling prices of the promised services underlying each performance obligation. The Company generally provides customized solutions in which the pricing is based on specific negotiations with each client, and, in these cases, the Company uses a cost-plus margin approach to estimate the standalone selling price of each performance obligation. Certain contracts contain award fees, incentive fees or other provisions that can either increase or decrease the transaction price. These variable amounts are generally awarded at the completion of a contractually stipulated performance assessment period based on the achievement of performance metrics, program milestones or cost targets, and the amount awarded may be subject to client discretion. Variable consideration is estimated based on the most likely amount. Once the Company selects a method to estimate variable consideration, it applies that method consistently. Estimates of variable consideration will be constrained only to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur. The Company evaluates contractual arrangements to determine whether revenue should be recognized on a gross versus net basis. The Company’s assessment is based on the nature of the contractual obligation to the client. In most cases, the Company itself agrees to provide specified services to the client as a principal and revenue is recognized on a gross basis. In certain instances, the Company acts as an agent and merely arranges for another party to provide services to the client and revenue is recognized on a net basis in reflection of the fact that the Company does not control the goods or services provided to the client by the other party. Long-term contracts typically contain billing terms that provide for invoicing monthly or upon completion of milestones, and payment on a net 30 -day basis. Therefore, the timing of billings and cash receipts may differ from the timing of revenue recognition resulting in either contract assets or contract liabilities. Exceptions to monthly billing terms are to ensure that the Company performs satisfactorily rather than representing a significant financing component. For cost-based contracts, the Company’s performance is evaluated during a contractually-stipulated performance period and, while contract costs may be billed on a monthly basis, the Company is generally permitted to bill for incentive or award fees only after the completion of the performance assessment period, which may occur quarterly, semi-annually or annually, and after the client completes the performance assessment. Fixed-price contracts may provide for milestone billings based on the attainment of specific project objectives rather than for billing on a monthly basis. Moreover, contracts may require retention or hold backs that are paid at the end of the contract to ensure that the Company performs in accordance with requirements. The Company does not assess whether a contract contains a significant financing component if the Company expects, at contract inception, that the period between payment by the client and the transfer of promised services to the client will be one year or less. The Company generally recognizes revenue over time as control is transferred to a client, based on the extent of progress towards satisfaction of the performance obligation. The selection of the method used to measure progress requires judgment and is dependent, among other factors, on the contract type and the nature of the services provided. For time-and-materials contracts, the Company uses the right-to-invoice practical expedient to recognize revenue earned based on hours worked in contract performance at negotiated billing rates. Fixed-price level-of-effort contracts are substantially similar to time-and-materials contracts except that the Company is required to deliver a specified level of effort over a stated period of time. For these contracts, the Company determines the revenue earned using contract hours worked at negotiated bill rates as the Company delivers the contractually required workforce. For cost-based contracts, the Company uses the right-to-invoice practical expedient to recognize revenue based on the amount to which the Company has a contractual right to invoice. For series-services performance obligations, the Company measures progress using either a cost input measure, a time-elapsed output measure, or the right to invoice practical expedient. Award or incentive fees are allocated to the distinct periods in which they relate to and recognized in that period. For certain fixed-price contracts, the Company uses the percentage-of-completion method to estimate the amount of revenue, based on the ratio of actual costs incurred to total estimated costs, provided that costs incurred (an input method) represents a reasonable measure of progress towards the satisfaction of a performance obligation and transfer of control to the customer. This method provides a faithful depiction of the transfer of value to the client when the Company is satisfying a performance obligation that entails integration of tasks for a combined output, which requires the Company to coordinate the work of employees, subcontractors and delivery of other contract costs. Contract costs that are not reflective of the Company’s progress toward satisfying a performance obligation are not included in the calculation of the measure of progress. When this method is used, the changes in estimated costs to complete the obligations result in adjustments to revenue on a cumulative catch-up basis, which causes the effect of revised estimates for prior periods to be recognized in the current period. Changes in these estimates may routinely occur over contract performance for a variety of reasons, which include: changes in contract scope; changes in contract cost estimates due to unanticipated cost growth or reassessments of risks impacting costs; changes in estimated incentive or award fees; or performing better or worse than previously estimated. For fixed-price contracts in which the estimated cost to perform exceeds the consideration to be received, the Company accrues for the entire estimated loss during the period in which the loss is determined by recording additional direct costs. In some fixed-price service contracts, the Company performs services of a recurring nature, such as maintenance and other services of a “stand ready” nature. For these contracts, the Company has the right to consideration in an amount that corresponds directly with the value that the client has received. Therefore, the Company records revenue on a time-elapsed basis to reflect the transfer of control to the client throughout the contract. Contracts may be modified to reflect changes in contract specifications and requirements, and these changes may create new enforceable rights and obligations. Modifications that are for services that are not distinct from the existing agreement due to the significant integration service that the Company provides are accounted for as part of an existing performance obligation. The effect of these modifications on the transaction price and the Company’s measure of progress in fulfilling the performance obligation to which they relate is recognized as an adjustment to revenue on a cumulative catch-up basis. Revenue from modifications that create new, distinct performance obligations is recognized based on the Company’s progress in fulfilling the requirements of the new obligations. For performance obligations that are satisfied over time, the Company recognizes the cost to fulfill contracts when incurred, unless the costs are within the scope of another topic in which case the guidance of that topic is applied. The Company evaluates incremental costs of obtaining a contract and, if they are recoverable from the client and relate to a specific future contract, they are deferred and recognized over contract performance or the estimated life of the customer relationship if renewals are expected. The Company expenses these costs when incurred if the amortization period is one year or less. Unfulfilled performance obligations represent amounts expected to be earned on non-cancellable contracts or those that the are cancellable but the Company has determined to have substantive termination penalties, and do not include the value of negotiated, unexercised contract options, which are classified as marketing offers. Indefinite delivery/indefinite quantity and similar arrangements provide a framework for the client to issue specific tasks, delivery or purchase orders in the future and these arrangements are considered marketing offers until a specific order is executed. Some of the Company’s contracts include variable consideration, which requires the Company to estimate and, as necessary, revise the most likely amounts that will be earned over the respective performance assessment periods. For these obligations, changes in estimates result in cumulative catch-up adjustments and may have a significant impact on earnings during a given period. The Company’s operating cycle for long-term contracts may be greater than one year and is measured by the average time between the inception and completion of those contracts. Contract-related assets and liabilities are classified as current assets and current liabilities.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers cash on deposit and any highly liquid investments with original maturities of three months or less when purchased to be cash and cash equivalents.
Restricted Cash	Restricted Cash The Company has restricted cash representing amounts held in escrow accounts and/or not readily available due to contractual restrictions.
Contract receivables, net	Contract receivables, net Contract receivables represent amounts billed and due from clients in accordance with respective contractual terms. The amounts due are stated at their net realizable value. The Company estimates an allowance for estimated credit loss to reflect the amount of receivables that will not be collected. The Company considers a number of factors in estimating the amount of the allowance, including knowledge of a client’s financial condition, its historical collection experience, and other factors relevant to assessing the collectability of the receivables. The Company writes off specific contract receivables when such amounts are determined to be uncollectible.
Property and Equipment	Property and Equipment Property and equipment are carried at cost and are depreciated using the straight-line method over their estimated useful lives, which range from two to seven years . Leasehold improvements are amortized on a straight-line basis over the shorter of the economic life of the improvement or the related lease term.
Goodwill and Indefinite-Lived Assets	Goodwill and Indefinite-Lived Assets Goodwill represents the excess of the purchase consideration over the fair value of net assets of businesses acquired. Goodwill and any intangible assets acquired in a business combination that are deemed to have an indefinite useful life are not amortized, but instead are reviewed for impairment annually, or more frequently if impairment indicators arise. Intangible assets with estimable useful lives are amortized over such lives and reviewed for impairment if impairment indicators arise. The Company performs its annual goodwill impairment test as of October 1 of each year. As its business is highly integrated and all of its components have similar economic characteristics, the Company has concluded it has one aggregated reporting unit at the consolidated entity level which it perform the assessment at. The Company have the option to perform a qualitative assessment that determines if it is more likely than not that the estimated fair value of goodwill is greater than its carrying value and, if so, the Company may conclude that no impairment exists. If the Company concludes that an impairment exist, a quantitative test is performed by comparing the reporting unit’s fair value to the carrying amount and recognizing the difference as an impairment loss.
Long-Lived Assets	Long-Lived Assets The Company reviews its long-lived assets, including property and equipment, operating lease right-of-use (“ROU”) assets, and definite-lived intangible assets, for impairment whenever events or changes in circumstances indicate that the carrying amounts of the long-lived asset group may not be fully recoverable. If the total of the expected undiscounted future net cash flows is less than the carrying amount of the long-lived asset group being evaluated, a loss is recognized for any excess of the carrying amount over the fair value of the asset group. During the years ended December 31, 2023, 2022, and 2021 , the Company recognized impairment losses of $ 6.8 million, $ 8.4 million, and $ 7.9 million, respectively, related to operating facility lease right-of-use assets and leasehold improvements. During the year ended December 31, 2023, the Company recognized an impairment loss of $ 0.9 million related to an amortizable customer-related intangible asset from a prior acquisition. The impairment losses were included in indirect and selling expenses on the Company's consolidated statements of comprehensive income.
Leases	Leases The Company leases facilities and property and equipment. The Company determines if an arrangement is a lease at its inception and recognizes a right-of-use asset and lease obligation for all leases greater than twelve months based on the present value of the future minimum lease payments as of the commencement date, excluding any lease incentives and initial costs incurred to obtain the lease. Since most lease agreements do not provide an implicit rate, the Company uses its incremental borrowing rate as of the commencement date, based on publicly available yields adjusted for company-specific considerations and terms, in estimating the present value of future payments. Lease terms, for the purpose of determining each lease’s present value, include options to extend or terminate the lease if it is reasonably certain and economically reasonable that the Company will exercise that option. Lease costs from minimum lease payments are recognized on a straight-line basis over the lease term. The leases may contain both lease and non-lease components, which are generally accounted for separately. For office equipment leases (primarily copier leases), the Company elected to account for the lease and non-lease components as a single lease component and not recognize right-of-use assets and lease liabilities for leases with a term less than twelve months. Operating leases are included in operating lease right-of-use assets and operating lease liabilities (current and non-current) and finance leases are included in property and equipment, net and finance lease liabilities (current and non-current) on the consolidated balance sheets.
Capitalized Software	Capitalized Software The Company capitalizes certain costs to develop enhancements and upgrades to internal-use software that are incurred subsequent to the preliminary project stage. Amortization expense is recorded on a straight-line basis over the expected economic life of the software, typically lasting three to five years . As of December 31, 2023, and 2022, capitalized software, net of accumulated amortization, totaled $ 12.8 million and $ 19.0 million , respectively, and is included as part of “other assets” on the consolidated balance sheets.
Stock-based Compensation	Stock-based Compensation The Company recognizes stock-based compensation expense to employees and non-employee directors, including grants of stock options, restricted stock awards, restricted stock units (“RSUs”), and cash-settled restricted stock units (“CSRSUs”) on a straight-line basis over the requisite service period, which is generally the vesting period. The Company recognizes expense for performance-based share awards (“PSAs”), which have both performance and service conditions, on a straight-line basis over the three-year performance period. Non-employee director awards are granted annually for Board-related services and therefore expensed over the service period. Stock-based compensation expense is based on the estimated fair value of the instruments on the grant date and the estimated number of shares the Company ultimately expects will vest. The Company estimates the rate of future forfeitures based on factors which include the historical forfeiture experience for each applicable employee class. In addition, the estimation of PSAs that will ultimately vest requires judgment based on the performance and market conditions that will be achieved over the performance period. Changes to these estimates are recorded as a cumulative adjustment in the period estimates are revised. The fair value of stock options, restricted stock awards, RSUs, PSAs, and non-employee director awards is estimated based on the fair value of a share of common stock at the grant date. The fair value of PSAs is estimated using a Monte Carlo simulation model. CSRSUs are settled only in cash payments. The cash payment is based on the fair value of the Company’s stock price at the vesting date, calculated by multiplying the number of CSRSUs vested by the Company’s closing stock price on the vesting date, subject to a maximum payment cap and a minimum payment floor. The Company treats these awards as liability-classified awards, and, therefore, accounts for them at fair value estimated based on the closing price of the Company’s stock at the reporting date.
Derivative Instruments	Derivative Instruments Derivative instruments include interest rate swaps, foreign currency hedges, and forward contracts. Derivative instruments designated as cash flow hedges are recorded on the consolidated balance sheets at fair value as of the reporting date and reclassified to earnings in the period that the hedged instruments affect earnings, and the effective portion of the hedge is recorded in other comprehensive income (loss) (“AOCI”), net of tax, on the consolidated statements of comprehensive income. Management reviews the effectiveness of the hedges on a quarterly basis.
Income Taxes	Income Taxes The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates in effect for the year in which those temporary differences are expected to be recovered or settled. The Company evaluates its ability to benefit from all deferred tax assets and establishes valuation allowances for amounts it believes will more likely than not be unrealizable. For uncertain tax positions, the Company uses a more-likely-than-not recognition threshold based on the technical merits of the income tax position taken. Income tax positions that meet the more-likely-than-not recognition threshold are measured in order to determine the tax benefit recognized in the financial statements. Penalties, if probable and reasonably estimable, and interest expense related to uncertain tax positions are not recognized as a component of income tax expense but recorded separately in indirect expenses and interest expense, respectively.
Treasury Shares	Treasury Shares Treasury shares are accounted for under the cost method.
Other Comprehensive Income (Loss)	Other Comprehensive Income (Loss) Other comprehensive income (loss) includes foreign currency translation adjustments due to fluctuation in foreign currency exchange rates, the gain on the sale of an interest rate hedge agreement designated as a cash flow hedge, and the changes in fair value of interest rate agreements designated as cash flow hedges, net of taxes. The financial positions and results of operations of the Company’s foreign subsidiaries are based on the local currency as the functional currency and are translated to U.S. dollars for financial reporting purposes. Assets and liabilities of the subsidiaries are translated at the exchange rate in effect at each balance sheet date. Income statement accounts are translated at the average rate of exchange prevailing during the period. Translation adjustments are reported in accumulated other comprehensive loss included in stockholders’ equity in the Company’s consolidated balance sheets.
Acquisition-Related Costs	Acquisition-Related Costs Costs related to acquisitions include professional fees for legal, financial, and other advisory services and are expensed in the period that they are incurred.
Segment, Customer and Geographic Information	Segment, Customer, and Geographic Information The Company operates in one segment based on the consolidated information used by its chief operating decision-maker, currently the Chief Executive Officer, in evaluating the financial performance of its business and allocating resources. This single segment represents the Company’s core business, which is providing professional services. Although the Company disaggregates its revenue by client markets and client types, the Company does not manage its business or allocate resources based on client market or type. No customer accounted for 10% or more of the Company’s revenue during the years ended 2023, 2022, and 2021. The Company provides services to U.S. and international clients, and revenue is attributed to a particular geographic area based on the administrative location of the client that awarded the contract. The Company’s revenue generated from international clients as a percentage of total revenue was approximately 7 % , 8 % , and 11 % for the years 2023, 2022, and 2021, respectively. At December 31, 2023 and 2022, long-lived assets held internationally were 6 % and 7 % of total long-lived assets, respectively. Foreign currency expense, net of impact of hedges, was $ 1.2 million, $ 0.2 million, and $ 0.6 million, for the years ended December 31, 2023 , 2022 and 2021, respectively.
Fair Value	Fair Value The Company measures and reports certain financial assets and liabilities at fair value in accordance with ASC 820, Fair Value Measurements and Disclosures. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants on the measurement date. Generally, fair value is based on observable quoted market prices or derived from observable market data when such market prices or data are available. ASC 820 establishes a three-level hierarchy used to estimate fair value by which each level is categorized based on the priority of the inputs used to measure fair value: • Level 1: Quoted prices that are available in active markets for identical assets or liabilities; • Level 2: Quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active; inputs other than quoted prices that are observable for the asset or liability (e.g. interest rates and yield curves that are observable at commonly quoted intervals, and implied volatilities); and inputs derived principally from or corroborated by observable market data by correlation or other means; and • Level 3: Uses inputs that are unobservable and require the Company to make certain assumptions and require significant estimation and judgment from management to use in pricing the fair value of the assets and liabilities. Certain financial instruments, including cash and cash equivalents, contract receivables, and accounts payable are carried at cost, which, due to their short maturities, approximates their fair values. The carrying value of the Company's long-term debt approximates the estimated fair value for debt with similar terms, interest rates, and remaining maturities currently available to companies with similar credit ratings (Level 2).
Risk and Uncertainties	Risks and Uncertainties Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents, derivative financial instruments, and contract receivables. The Company’s domestic bank accounts are insured up to $ 250,000 by the Federal Deposit Insurance Corporation. As of December 31, 2023, the Company had $ 0.3 million in its accounts that exceeded the insured limit. The majority of the Company’s cash transactions are processed through one U.S. commercial bank. Cash held domestically in excess of daily requirements is primarily used to reduce any amounts outstanding under the Company’s Credit Facility. As of December 31, 2023 and 2022, the Company held approximately $ 8.5 million and $ 8.4 million , respectively, of cash and restricted cash in foreign bank accounts. The Company enters into derivative financial instruments with financial institutions that meet certain credit guidelines and limits its risks by continuously monitoring the credit rating of the institutions. The Company’s receivables consist principally of amounts due from agencies and departments of the federal government, state and local governments, and international governments, as well as from commercial organizations. The credit risk, with respect to federal and other government clients, is limited due to the creditworthiness of the respective governmental entity. Amounts due for work performed as a subcontractor also represent limited credit risk when the client is performing as the prime contractor on a government contract due to the ultimate creditworthiness of the end client. Receivables from commercial clients generally pose a greater credit risk, and, as a result, are subject to ongoing monitoring. The Company extends credit in the normal course of operations and does not require collateral from its clients. The Company’s contracts with the federal government are subject to audit by agencies and departments of the federal government. Such audits determine, among other things, whether adjustments to invoices previously rendered are required under regulations as well as the underlying terms of each respective contract.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Accounting Pronouncements Adopted Reference Rate Reform In March 2020, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) 2020-04, Facilitation of the Effects of Reference Rate Reform on Financial Reporting. The standard is intended to provide temporary optional expedients and exceptions to the U.S. GAAP guidance on contract modifications and hedge accounting to ease accounting and financial reporting burdens related to the expected market transition from the London Interbank Offered Rate (“LIBOR”) and other interbank offered rates to alternative reference rates. The provisions of this ASU are elective and apply to all entities, subject to meeting certain criteria, that have debt or hedging contracts, among other contracts, that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. Entities can elect to not apply certain modification accounting requirements to contracts affected by reference rate reform if certain criteria are met. Also, entities can elect various optional expedients that would allow them to continue to apply hedge accounting for hedging relationships affected by reference rate reform if certain criteria are met. This guidance was effective beginning on March 12, 2020 and entities may elect to apply the amendments prospectively through December 31, 2022, the sunset date. In December 2022, the FASB issued ASU 2022-06 Reference Rate Reform (Topic 848): Deferral of the Sunset Date of Topic 848 which extended the sunset date from December 31, 2022 to December 31, 2024. The Company completed its adoption of the provisions of ASU 2020-04 during the second quarter of 2023 upon amendment of its last interest rate swap from LIBOR-based to SOFR-based pricing. The adoption did not have a material impact on the Company's consolidated financial statements. Accounting Pronouncements Not Yet Adopted Segment Reporting In November 2023, the FASB issued ASU 2023-07: Improvements to Reportable Segment Disclosures, that required additional segment disclosures for public entities currently required under the Segment Reporting (Topic 280) of the Accounting Standards Codification (“ASC”). ASU 2023-07 enhances the current segment reporting disclosures of Topic 280 by requiring significant segment expenses that are regularly provided to the Chief Operating Decision Maker (the “CODM”), the amount and description of other segment items, and interim disclosures of reportable segment's profit or loss and assets. ASU 2023-07 also requires public entities that have a single reportable segment to provide all the disclosures required in Topic 280, as amended. The ASU is effective for the Company for the 2024 fiscal year and interim periods within the 2025 fiscal year on a retrospective basis, with early adoption permitted. The Company is currently evaluating the impact of the adoption of ASU 2023-07 but does not expect the adoption to have a material impact, if any, on the consolidated financial statements. Income Taxes In December 2023, the FASB issued ASU 2023-09, Income Taxes: Improvements to Income Tax Disclosures, that require greater disaggregation of income tax rate and amounts paid by entities. ASU 2023-09 specifically requires all entities to disclose, on an annual basis, disaggregated domestic and foreign pre-tax income or loss from continuing operations and the disaggregated income tax expense or benefit by federal, state, and foreign components, and a tabular rate reconciliation, using both percentages and reporting currency amounts, of eight specific categories as well as any individual reconciling items that are equal to or greater than 5% of a threshold computed by multiplying pretax income or loss from continuing operations by the applicable federal rate. Additionally, the amendments also require disclosure of income taxes paid disaggregated by federal, state, and foreign jurisdictions as well as any individual jurisdictions over 5% of the total income taxes paid. ASU 2023-09 is effective for the Company for the 2025 fiscal year, with early adoption permitted. The amendments may be adopted on a prospective or retrospective basis. The Company is currently evaluating the impact of the adoption of ASU 2023-09 but does not expect the adoption to have a material impact, if any, on the consolidated financial statements.

Restricted Cash (Tables)

Restricted Cash (Tables)	12 Months Ended
	Dec. 31, 2023
Restricted Cash and Cash Equivalents, Current [Abstract]
Reconciliation of Cash and Cash Equivalents, and Restricted Cash	The following table provides a reconciliation of cash and cash equivalents, and restricted cash reported within the consolidated balance sheets at December 31, 2023 and 2022 to the total cash, cash equivalents, and restricted cash shown in the consolidated statements of cash flows for the years ended December 31, 2023, 2022, and 2021: 2023 2022 2021 Beginning Ending Beginning Ending Beginning Ending Cash and cash equivalents $ 11,257 $ 6,361 $ 8,254 $ 11,257 $ 13,841 $ 8,254 Restricted cash (1) 1,711 3,088 12,179 1,711 68,146 12,179 Total cash, cash equivalents, and restricted cash shown in the consolidated statement of cash flows $ 12,968 $ 9,449 $ 20,433 $ 12,968 $ 81,987 $ 20,433

Contract Receivables, Net (Tabl

Contract Receivables, Net (Tables)	12 Months Ended
	Dec. 31, 2023
Receivables [Abstract]
Summary of Contract Receivables, Net	Contract receivables, net consisted of the following as of December 31: 2023 2022 Billed and billable $ 210,919 $ 238,449 Allowance for expected credit losses ( 5,435 ) ( 6,112 ) Contract receivables, net $ 205,484 $ 232,337

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and equipment consisted of the following at December 31: 2023 2022 Leasehold improvements $ 54,398 $ 58,131 Software 16,897 17,926 Furniture and office equipment 29,773 28,800 Computer equipment 44,661 45,541 145,729 150,398 Accumulated depreciation and amortization ( 69,781 ) ( 64,996 ) Total property and equipment, net $ 75,948 $ 85,402

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Changes in Carrying Amount of Goodwill	The changes in the carrying amount of goodwill for the fiscal years ended December 31 were as follows: 2023 2022 Balance as of January 1, 2023 $ 1,212,898 $ 1,046,760 Add: Goodwill resulting from business combinations 21,133 171,415 Less: Goodwill resulting from business divestitures ( 16,921 ) — Effect of foreign currency translation 2,366 ( 5,277 ) Balance as of December 31, 2023 $ 1,219,476 $ 1,212,898 See “Note 16 – Acquisitions and Divestitures” for the details of the business combination and divestiture resulting in the changes in goodwill.
Schedule of Other Intangibles	Other intangibles consisted of the following at December 31: 2023 Gross Accumulated Net Carrying Customer-related $ 185,723 $ ( 93,911 ) $ 91,812 Developed technology 3,902 ( 904 ) 2,998 Trade name 1,280 ( 1,280 ) — Total amortizable intangible assets 190,905 ( 96,095 ) 94,810 Intangible with indefinite life 94 — 94 Total other intangible assets $ 190,999 $ ( 96,095 ) $ 94,904 2022 Gross Accumulated Net Carrying Customer-related $ 240,591 $ ( 118,412 ) $ 122,179 Developed technology 4,480 ( 512 ) 3,968 Trade name 1,180 ( 884 ) 296 Total amortizable intangible assets 246,251 ( 119,808 ) 126,443 Intangible with indefinite life 94 — 94 Total other intangible assets $ 246,345 $ ( 119,808 ) $ 126,537
Schedule of Estimated Future Amortization Expense Relating to Intangible Assets	The estimated future amortization expense relating to intangible assets is as follows: Year ending December 31, 2024 $ 32,992 2025 32,074 2026 18,533 2027 3,407 2028 2,047 Thereafter 5,757 Total $ 94,810

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Summary of Lease Cost	The Company’s lease cost is recognized on a straight-line basis over the lease term and is primarily included within indirect and selling expenses on the consolidated statements of comprehensive income. Lease cost consisted of the following: Year Ended December 31, 2023 2022 2021 Operating lease cost $ 25,037 $ 37,889 $ 35,469 Finance lease cost - amortization of right-of-use assets 2,040 598 — Finance lease cost - interest 602 179 — Short-term lease cost 669 509 453 Variable lease cost 222 146 43 Sublease income ( 28 ) ( 92 ) — Total lease cost $ 28,542 $ 39,229 $ 35,965
Summary of Future Minimum Lease Payments Under Non-Cancellable Operating and Finance Leases	Future minimum lease payments under non-cancellable operating and finance leases as of December 31, 2023 were as follows: Operating Finance December 31, 2024 $ 25,419 $ 3,041 December 31, 2025 26,621 3,041 December 31, 2026 22,899 3,041 December 31, 2027 18,578 3,041 December 31, 2028 15,926 2,985 Thereafter 131,690 2,966 Total future minimum lease payments 241,133 18,115 Less: Interest ( 45,264 ) ( 1,719 ) Total $ 195,869 $ 16,396
Summary of Other Information Related to Operating and Finance Leases	Other information related to operating and finance leases is as follows: Year Ended December 31, 2023 2022 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 20,368 $ 40,123 Right-of-use assets obtained in exchange for new operating lease liabilities $ 18,590 $ 13,906 Property and equipment obtained in exchange for finance lease liabilities $ 338 18,319 Weighted-average remaining lease term - operating leases Operating leases 11.6 11.7 Finance leases 6.0 7.0 Weighted-average discount rate - operating leases Operating leases 3.6 % 3.3 % Finance leases 3.4 % 3.4 %

Accrued Salaries and Benefits (

Accrued Salaries and Benefits (Tables)	12 Months Ended
	Dec. 31, 2023
Employee-related Liabilities, Current [Abstract]
Schedule of Accrued Salaries and Benefits	Accrued salaries and benefits consisted of the following at December 31: 2023 2022 Bonuses, liability-classified awards, and commissions $ 27,371 $ 26,930 Salaries 32,604 31,142 Paid time off and leave 16,415 16,144 Medical 5,685 5,833 Payroll taxes and withholdings 976 1,363 Other 4,970 4,579 Total accrued salaries and benefits $ 88,021 $ 85,991

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2023
Payables and Accruals [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consisted of the following at December 31: 2023 2022 Deposits $ 20,246 $ 32,384 Restricted contract funds 2,036 1,701 IT and software licensing costs 583 1,609 Taxes and insurance premiums 7,010 6,633 Facilities rental and lease exit costs 2,754 2,043 Interest 3,218 363 Professional services 1,943 3,617 Dividends 2,636 2,631 Cash collected not yet remitted to purchaser of billed receivables 28,675 6,164 Other accrued expenses and current liabilities 10,028 20,891 Total accrued expenses and other current liabilities $ 79,129 $ 78,036

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2023
Debt Disclosure [Abstract]
Schedule of Long-term Debt	As of December 31, 2023 and 2022, long-term debt consisted of the following: December 31, 2023 December 31, 2022 Average Outstanding Average Outstanding Term Loan $ 207,750 $ 288,750 Delayed-Draw Term Loan 220,000 220,000 Revolving Credit 6,340 52,616 Total before debt issuance costs 6.7 % 434,090 3.3 % 561,366 Unamortized debt issuance costs ( 3,683 ) ( 5,032 ) $ 430,407 $ 556,334 Current portion of long-term debt $ 26,000 $ 23,250 Long-term debt - non-current 404,407 533,084 Total $ 430,407 $ 556,334
Schedule of Future Scheduled Repayments of Debt Principal	Future scheduled repayments of debt principal are as follows: Payments due by Term Loan Delayed-Draw Term Loan Revolving Credit Total December 31, 2024 $ 15,000 $ 11,000 $ — $ 26,000 December 31, 2025 20,625 15,125 — 35,750 December 31, 2026 22,500 16,500 — 39,000 December 31, 2027 149,625 177,375 6,340 333,340 Total $ 207,750 $ 220,000 $ 6,340 $ 434,090

Revenue Recognition (Tables)

Revenue Recognition (Tables)	12 Months Ended
	Dec. 31, 2023
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The Company's revenue by client markets, type, and contract mix are in the following tables. Certain immaterial revenue amounts in the prior years have been reclassified due to minor adjustments and reclassification. Year ended December 31, 2023 2022 2021 Client Markets: Energy, environment, infrastructure, and disaster recovery $ 806,482 $ 714,628 $ 693,572 Health and social programs 814,454 704,465 563,590 Security and other civilian & commercial 342,302 360,871 295,886 Total $ 1,963,238 $ 1,779,964 $ 1,553,048 Year ended December 31, 2023 2022 2021 Client Type: U.S. federal government $ 1,084,043 $ 980,746 $ 735,032 U.S. state and local government 308,134 259,764 235,416 International government 103,399 103,609 139,229 Total Government 1,495,576 1,344,119 1,109,677 Commercial 467,662 435,845 443,371 Total $ 1,963,238 $ 1,779,964 $ 1,553,048 Year ended December 31, 2023 2022 2021 Contract Mix: Time-and-materials $ 812,430 $ 713,693 $ 633,135 Fixed-price 885,465 802,568 645,809 Cost-based 265,343 263,703 274,104 Total $ 1,963,238 $ 1,779,964 $ 1,553,048
Schedule of Contract Assets and Liabilities and Changes in Contract Balances	Contract Assets and Liabilities: Contract assets consist of unbilled receivables on contracts where revenue recognized exceeds the amount billed. Contract liabilities result from advance payments received on a contract or from billings in excess of revenue recognized on long-term contracts. The following table summarizes the contract balances as of December 31, 2023 and December 31, 2022: December 31, 2023 December 31, 2022 Change Contract assets $ 201,832 $ 169,088 $ 32,744 Contract liabilities ( 21,997 ) ( 25,773 ) 3,776 Net contract assets (liabilities) $ 179,835 $ 143,315 $ 36,520 The net contract assets (liabilities) as of December 31, 2023 increased by $ 36.5 million as compared to December 31, 2022, primarily due to the timing difference between the performance of services and billings to and payments from customers. There were no material changes to contract balances due to impairments or credit losses during the period. During the years ended December 31, 2023 and 2022, the Company recognized $ 17.8 million and $ 27.4 million in revenue related to the contract liabilities balance at December 31, 2022 and 2021, respectively. Unfulfilled

Derivative instruments and He_2

Derivative instruments and Hedges Activities (Tables)	12 Months Ended
	Dec. 31, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of Effect of Swaps on Company's Financial Statements	For the years ended December 31, 2023 and 2022, the effect of the Swaps on the Company’s financial statements are as follows: Cash Flow Hedging Derivatives Total Gain (Loss) Recorded to AOCI Amount of (Gain) or Loss Year Ended December 31, 2023 2022 2023 2022 Interest Rate Swaps $ ( 45 ) $ 11,445 $ ( 6,982 ) $ ( 248 )

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Income Before Income Taxes	The domestic and foreign components of income before provision for income taxes are as follows for the years ended December 31: 2023 2022 2021 Domestic $ 83,742 $ 80,372 $ 97,884 Foreign 12,805 3,608 2,206 Income before income taxes $ 96,547 $ 83,980 $ 100,090
Income Tax Expense Components	Income tax expense consisted of the following for the years ended December 31: 2023 2022 2021 Current: Federal $ 28,108 $ 8,413 $ 15,961 State 10,380 2,686 3,494 Foreign 2,247 1,661 687 Total current 40,735 12,760 20,142 Deferred: Federal ( 20,279 ) 4,264 4,724 State ( 6,915 ) 3,607 4,395 Foreign 394 ( 894 ) ( 303 ) Total deferred ( 26,800 ) 6,977 8,816 Income tax expense $ 13,935 $ 19,737 $ 28,958
Deferred Tax Assets (Liabilities)	Deferred tax assets (liabilities) consisted of the following at December 31: 2023 2022 Deferred Tax Assets Allowance for expected credit losses $ 1,213 $ 1,404 Accrued paid time off 3,039 2,801 Foreign net operating loss carryforward — 229 State net operating loss carryforward 500 502 Stock-based compensation 5,523 1,586 Deferred compensation 5,765 4,692 Foreign tax credits 8,035 7,236 Federal and state tax credits 686 384 Foreign exchange 3,591 4,532 Foreign deferred 441 875 Accrued bonus 5,830 5,696 Capital loss 1,054 — Facilities impairment 3,092 2,650 Capitalized research expenses 47,019 990 Accrued liabilities and other 2,682 5,523 Lease liabilities 58,538 56,695 147,008 95,795 Less: Valuation Allowance ( 9,021 ) ( 7,607 ) Total Deferred Tax Assets 137,987 88,188 Deferred Tax Liabilities Retention — ( 407 ) Prepaid expenses — ( 366 ) Payroll taxes ( 725 ) ( 697 ) Unbilled revenue ( 284 ) ( 409 ) Depreciation ( 2,128 ) ( 270 ) Amortization ( 107,201 ) ( 99,045 ) Deferred gain and other ( 2,202 ) ( 2,561 ) Lease assets - Right-of-Use ( 51,622 ) ( 52,471 ) Total Deferred Tax Liabilities ( 164,162 ) ( 156,226 ) Total Net Deferred Tax Liability $ ( 26,175 ) $ ( 68,038 )
Components of Unrecognized Tax Benefits, Excluding Penalty and Interest	The components of unrecognized tax benefits, excluding penalty and interest, are as follows at December 31: 2023 2022 U.S. transfer pricing $ 145 $ 145 India transfer pricing 164 — Section 41 tax credit 8,736 — Section 174 expense capitalization 15,086 Total $ 24,131 $ 145 The unrecognized tax benefit reconciliation, excluding penalty and interest, is as follows: Unrecognized tax benefits at January 1, 2021 $ 811 Decrease attributable to tax positions taken during the current period ( 361 ) Unrecognized tax benefits at December 31, 2021 450 Decrease attributable to tax positions taken during the current period ( 305 ) Unrecognized tax benefits at December 31, 2022 145 Increase attributable to tax positions taken during a prior period 19,845 Increase attributable to tax positions taken during the current period 4,141 Unrecognized tax benefits at December 31, 2023 24,131
Effective Income Tax Rate Reconciliation	The Company’s provision for income taxes differs from the federal statutory rate. The differences between the statutory rate and the Company’s provision are as follows for the years ended December 31: 2023 2022 2021 Taxes at statutory rate 21.0 % 21.0 % 21.0 % State taxes, net of federal benefit 6.0 % 5.8 % 5.6 % Foreign tax rate differential ( 0.2 )% 0.1 % 0.1 % Executive compensation 1.7 % 2.2 % 2.1 % Other permanent differences ( 0.3 )% 2.0 % ( 0.4 )% Global intangible low-taxed income (GILTI) 0.3 % — — Prior year tax adjustments ( 6.4 )% ( 1.1 )% 1.5 % Deferred impact of state rate change 0.5 % 0.6 % — Worthless stock deduction ( 5.1 )% ( 4.6 )% — Unrecognized tax benefits 9.0 % ( 0.4 )% ( 0.5 )% Capital loss ( 3.8 )% — — Valuation allowance 2.0 % 0.7 % 1.3 % Equity-based compensation ( 1.1 )% ( 1.3 )% ( 1.0 )% Tax credits ( 9.2 )% ( 1.5 )% ( 0.8 )% Taxes at effective rate 14.4 % 23.5 % 28.9 %

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive (Loss) Income (Tables)	12 Months Ended
	Dec. 31, 2023
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Components of Accumulated Other Comprehensive (Loss) Income	Accumulated other comprehensive (loss) income included the following: Foreign Gain on Sale of (1) Changes in (2)(5) Total Accumulated other comprehensive (loss) income at January 1, 2021 $ ( 7,210 ) $ 1,096 $ ( 7,992 ) $ ( 14,106 ) Current period other comprehensive income (loss): Other comprehensive income (loss) before reclassifications ( 1,676 ) — 3,285 1,609 Amounts reclassified from accumulated other comprehensive (loss) income — ( 720 ) 3,728 3,008 Effect of taxes (3) 127 193 ( 1,866 ) ( 1,546 ) Total current period other comprehensive income (loss) ( 1,549 ) ( 527 ) 5,147 3,071 Accumulated other comprehensive (loss) income at December 31, 2021 ( 8,759 ) 569 ( 2,845 ) ( 11,035 ) Current period other comprehensive income (loss): Other comprehensive (loss) income before reclassifications ( 9,259 ) — 11,445 2,186 Amounts reclassified from accumulated other comprehensive (loss) income — ( 720 ) 472 ( 248 ) Effect of taxes (3) 3,962 192 ( 3,190 ) 964 Total current period other comprehensive income (loss) ( 5,297 ) ( 528 ) 8,727 2,902 Accumulated other comprehensive (loss) income at December 31, 2022 ( 14,056 ) 41 5,882 ( 8,133 ) Current period other comprehensive income (loss): Other comprehensive income (loss) before reclassifications 4,158 — ( 45 ) 4,113 Amounts reclassified from accumulated other comprehensive (loss) income (4) — ( 60 ) ( 6,922 ) ( 6,982 ) Effect of taxes (3) ( 2,797 ) 19 1,895 ( 883 ) Total current period other comprehensive income (loss) 1,361 ( 41 ) ( 5,072 ) ( 3,752 ) Accumulated other comprehensive (loss) income at December 31, 2023 $ ( 12,695 ) $ — $ 810 $ ( 11,885 ) (1) Represents the fair value of an interest rate hedge agreement, designated as a cash flow hedge, which was sold on December 1, 2016. The fair value of the interest rate hedge agreement was recorded in other comprehensive income, net of tax, and will be reclassified to earnings when earnings are impacted by the hedged items, as interest payments are made on the Credit Facility from January 31, 2018 to January 31, 2023. (2) Represents the change in fair value of interest rate hedge agreements designated as a cash flow hedges. The fair value of the interest rate hedge agreements was recorded in other comprehensive income, net of tax, and will be reclassified to earnings when earnings are impacted by the hedged items, as interest payments are made on the Credit Facility from through June 27, 2028. See additional details of the hedge agreements in Note 12 - Derivative Instruments and Hedging Activities. (3) The Company’s effective tax rate for the years ended December 31, 2023, 2022, and 2021 was 14.4 % , 23.5 % , and 28.9 % , respectively. (4) The Company expects to reclassify $ 4.8 million in unrealized gains related to the Change in Fair Value of Interest Rate Hedge Agreement from accumulated other comprehensive loss into earnings during the next 12 months. (5) The fair value of the interest rate hedge agreements is included in other current and other long-term assets and liabilities on the consolidated balance sheets. See “Note 19 - Fair Value” for additional details.

Accounting for Stock-based Co_2

Accounting for Stock-based Compensation (Tables)	12 Months Ended
	Dec. 31, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Schedule of Stock-based Compensation Expense	The total stock-based compensation expense for the years ended December 31, 2023, 2022, and 2021, the unrecognized compensation expense at December 31, 2023, and the weighted-average period to recognize the remaining unrecognized shares are as follows: Stock-Based Compensation Expense Recognized Unrecognized 2023 2022 2021 2023 Weighted Restricted Stock Units $ 9,413 $ 9,300 $ 8,563 $ 13,517 1.7 Cash-Settled Restricted Stock Units 8,061 5,709 8,251 11,558 1.7 Non-Employee Director Awards 1,029 1,087 937 481 0.4 Performance Shares 4,416 2,784 3,731 4,351 1.5 Total $ 22,919 $ 18,880 $ 21,482 $ 29,907
Outstanding Stock Option Activity	The following table summarizes the changes in outstanding stock options: Number of Weighted Aggregate Outstanding at January 1, 2021 38,227 $ 31.93 Exercised ( 8,535 ) $ 27.17 Granted — $ — Forfeited/Expired — $ — Outstanding at December 31, 2021 29,692 $ 33.30 Exercised ( 18,807 ) $ 32.04 Granted — $ — Forfeited/Expired — $ — Outstanding at December 31, 2022 10,885 $ 35.49 Exercised ( 8,254 ) $ 33.84 Granted — $ — Forfeited/Expired — $ — Outstanding at December 31, 2023 2,631 $ 40.68 $ 246 Vested plus expected to vest at December 31, 2023 2,631 $ 40.68 $ 246 Exercisable at December 31, 2023 2,631 $ 40.68 $ 246
Schedule of Stock Options Outstanding by Exercise Price Range	Information regarding stock options outstanding as of December 31, 2023 is summarized below: OPTIONS OUTSTANDING OPTIONS EXERCISABLE Range of Number Weighted Weighted Number Weighted $ 40.68 to $ 40.68 2,631 0.2 $ 40.68 2,631 $ 40.68
Summary of Non-employee Director Awards	The Company grants awards of registered shares to its non-employee directors on an annual basis under the A&R Omnibus Plan. A summary of the non-employee director awards is presented below: Number of Weighted- Aggregate Non-vested RSUs at January 1, 2021 6,510 $ 64.47 Granted 11,186 $ 90.73 Vested ( 12,110 ) $ 76.61 Cancelled — $ — Non-vested RSUs at December 31, 2021 5,586 $ 90.73 Granted 11,399 $ 95.35 Vested ( 11,637 ) $ 93.39 Cancelled — $ — Non-vested RSUs at December 31, 2022 5,348 $ 94.79 Granted 8,211 $ 127.81 Vested ( 9,457 ) $ 109.14 Cancelled — $ — Non-vested RSUs at December 31, 2023 4,102 $ 127.81 $ 550 RSUs expected to vest in the future 4,102 $ 127.81 $ 550
Summary of Performance Shares Activity	A summary of the Company’s PSAs is presented below. Number of Weighted- Aggregate Non-vested PSAs at January 1, 2021 142,121 $ 68.19 Granted 54,216 $ 85.03 Vested ( 63,258 ) $ 65.05 Cancelled — $ — Non-vested PSAs at December 31, 2021 133,079 $ 76.54 Granted 38,412 $ 93.15 Vested ( 47,634 ) $ 82.38 Cancelled ( 3,170 ) $ 80.64 Non-vested PSAs at December 31, 2022 120,687 $ 79.42 Granted 36,956 $ 115.67 Vested ( 45,141 ) $ 58.76 Cancelled ( 6,934 ) $ 61.49 Non-vested PSAs at December 31, 2023 105,568 $ 102.12 $ 14,156 PSAs expected to vest in the future 69,650 $ 104.95 $ 9,339
Schedule of Fair Value Assumptions using Monte Carlo Simulation Model for Awards Granted	The fair value assumptions using the Monte Carlo simulation model for awards granted in 2023, 2022, and 2021 were: 2023 2022 2021 Dividend Yield 0.5 % 0.6 % 0.6 % Historical Volatility 33.6 % 39.0 % 40.9 % Risk-Free Rate of Returns 3.8 % 2.1 % 0.3 %
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Schedule of Restricted Stock Unit Activity	A summary of the Company’s RSUs is presented below. Number of Weighted- Aggregate Non-vested RSUs at January 1, 2021 305,399 $ 66.51 Granted 132,757 $ 95.68 Vested ( 119,203 ) $ 66.46 Cancelled ( 15,117 ) $ 68.53 Non-vested RSUs at December 31, 2021 303,836 $ 79.17 Granted 148,361 $ 93.70 Vested ( 140,666 ) $ 76.53 Cancelled ( 26,705 ) $ 77.16 Non-vested RSUs at December 31, 2022 284,826 $ 88.23 Granted 89,388 $ 110.80 Vested ( 93,881 ) $ 78.05 Cancelled ( 21,815 ) $ 94.01 Non-vested RSUs at December 31, 2023 258,518 $ 99.25 $ 34,665 RSUs expected to vest in the future 230,953 $ 98.82 $ 30,968
Cash Settled RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Schedule of Restricted Stock Unit Activity	CSRSUs generally have a vesting term of three years . The fair value of CSRSUs vested and settled in cash for the years ended December 31, 2023, 2022, and 2021 was $ 7.9 million , $ 6.6 million and $ 8.7 million , respectively. A summary of the Company’s CSRSUs is presented below. Number of Weighted- Aggregate Non-vested CSRSUs at January 1, 2021 241,481 $ 65.06 Granted 52,246 $ 89.51 Vested ( 104,272 ) $ 63.96 Cancelled ( 23,195 ) $ 69.68 Non-vested CSRSUs at December 31, 2021 166,260 $ 72.79 Granted 115,024 $ 97.88 Vested ( 75,566 ) $ 73.20 Cancelled ( 17,299 ) $ 80.02 Non-vested CSRSUs at December 31, 2022 188,419 $ 87.28 Granted 70,742 $ 110.65 Vested ( 81,537 ) $ 76.26 Cancelled ( 19,040 ) $ 91.94 Non-vested CSRSUs at December 31, 2023 158,584 $ 102.82 $ 21,264 CSRSUs expected to vest in the future 134,808 $ 102.31 $ 18,076

Acquisitions and Divestitures (

Acquisitions and Divestitures (Tables)	12 Months Ended
	Dec. 31, 2023
Business Combinations [Abstract]
Summary of Preliminary Purchase Price Allocation	he final purchase price allocation is summarized as follows: Contract receivables $ 12,699 Contract assets 6,071 Customer-related intangibles 62,967 Trade names and trademarks 1,120 Other current and non-current assets 407 Accrued salaries and benefits ( 3,998 ) Accrued expenses and other liabilities ( 6,244 ) Deferred tax liability ( 16,701 ) Net assets acquired 56,321 Goodwill 159,677 Purchase consideration $ 215,998
Schedule of Unaudited Condensed Pro Forma Financial Information	The following unaudited condensed pro forma information presents combined financial information as if the acquisition of SemanticBits had been effective at January 1, 2021, the beginning of the 2021 fiscal year. As a result, fiscal year 2022 represents the pro forma results for year two of the acquisition. The pro forma information includes alignment of SemanticBits’ revenue recognition policy, corrections of employee-related expenses, and adjustments reflecting changes in the amortization of intangibles, acquisition-related costs, interest expense, and records income tax effects as if SemanticBits had been included in the Company’s results of operations. The pro forma information is not intended to reflect the actual combined results of operations that would have occurred if the acquisition was completed on January 1, 2021, nor is it indicative of future operating results after the acquisition date of July 13, 2022. (Unaudited) Year Ended (in thousands) 2022 2021 Revenue $ 1,856,399 $ 1,667,425 Net income 75,999 63,752

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2023
Earnings Per Share [Abstract]
Schedule of Dilutive Effect of Stock Options RSUs and PSAs	The dilutive effect of stock options, RSUs, and performance shares for each period reported is summarized below: 2023 2022 2021 Net Income $ 82,612 $ 64,243 $ 71,132 Weighted-average number of basic shares outstanding during the period 18,802 18,818 18,868 Dilutive effect of stock options, RSUs, and performance shares 192 215 256 Weighted-average number of diluted shares outstanding during the period 18,994 19,033 19,124 Basic earnings per share $ 4.39 $ 3.41 $ 3.77 Diluted earnings per share $ 4.35 $ 3.38 $ 3.72

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Schedule of Financial Instruments Measured at Fair Value on Recurring Basis	Financial instruments measured at fair value on a recurring basis and their location within the accompanying consolidated financial statements are as follows: December 31, 2023 (in thousands) Level 1 Level 2 Level 3 Total Location on Balance Sheet Assets: Interest rate swaps - current portion $ — $ 4,820 $ — $ 4,820 Prepaid expenses and other assets Foreign currency forward and swap contracts — 6 — 6 Prepaid expenses and other assets Interest rate swaps - long-term portion — 398 — 398 Other assets Company-owned life insurance policies — 20,438 — 20,438 Other assets Liabilities: Interest swaps - long-term portion $ — $ 4,184 $ — $ 4,184 Other long-term liabilities December 31, 2022 (in thousands) Level 1 Level 2 Level 3 Total Location on Balance Sheet Assets: Interest rate swaps - current portion $ — $ 5,051 $ — $ 5,051 Prepaid expenses and other Interest rate swaps - long-term portion 2,950 2,950 Other assets Company-owned life insurance policies — 17,869 — 17,869 Other assets

Supplemental Information (Table

Supplemental Information (Tables)	12 Months Ended
	Dec. 31, 2023
Disclosure Text Block Supplement [Abstract]
Schedule of Allowance for Doubtful Accounts	Allowance for Credit Losses 2023 2022 2021 Balance at beginning of period $ 6,112 $ 7,741 $ 7,616 Provision for credit losses 1,164 248 10,912 Write-offs, net of recoveries ( 1,886 ) ( 1,782 ) ( 10,723 ) Effect of foreign currency translation 45 ( 95 ) ( 64 ) Balance at end of period $ 5,435 $ 6,112 $ 7,741
Schedule of Income Tax Valuation Allowance	Income Tax Valuation Allowance 2023 2022 2021 Balance at beginning of period $ 7,607 $ 7,048 $ 6,839 Provision for income taxes - valuation allowance 1,414 559 209 Balance at end of period $ 9,021 $ 7,607 $ 7,048

Basis of Presentation and Nat_2

Basis of Presentation and Nature of Operations - Additional Information (Details) - Minimum	Dec. 31, 2023 Office
Domestic
Basis of Presentation and Nature of Operations [Line Items]
Number of offices	55
International
Basis of Presentation and Nature of Operations [Line Items]
Number of offices	15

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) Segment	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Contract payment term description	contracts typically contain billing terms that provide for invoicing monthly or upon completion of milestones, and payment on a net 30-day basis.
Contracts payment, term	30 days
Number of reportable segments | Segment	1
Goodwill, impaired, accumulated impairment loss	$ 0
Number of operating segments | Segment	1
Revenue	$ 1,963,238,000	$ 1,779,964,000	$ 1,553,048,000
Foreign currency expense, net of impact of hedges	1,200,000	200,000	$ 600,000
Foreign financial institutions, actual deposits	8,500,000	$ 8,400,000
Domestic bank accounts exceeded FDIC insurance limit	$ 300,000
International Clients | Geographic Concentration Risk | Sales Revenue, Net
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	7%	8%	11%
International | Geographic Concentration Risk | Long-Lived Assets
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	6%	7%
Other Assets
Summary Of Significant Accounting Policies [Line Items]
Capitalized software, net of accumulated amortization	$ 12,800,000	$ 19,000,000
Indirect and Selling Expenses
Summary Of Significant Accounting Policies [Line Items]
Impairment losses	900,000
Indirect and Selling Expenses | Operating Facility Lease Right-of-Use Assets and Leasehold Improvements
Summary Of Significant Accounting Policies [Line Items]
Impairment losses	$ 6,800,000	$ 8,400,000	$ 7,900,000
Minimum
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful life	2 years
Finite-lived intangible asset, useful life	1 year
Minimum | Other Assets
Summary Of Significant Accounting Policies [Line Items]
Finite-lived intangible asset, useful life	3 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful life	7 years
Finite-lived intangible asset, useful life	9 years
Insured domestic bank accounts	$ 250,000
Maximum | Other Assets
Summary Of Significant Accounting Policies [Line Items]
Finite-lived intangible asset, useful life	5 years

Restricted Cash - Reconciliatio

Restricted Cash - Reconciliation of Cash and Cash Equivalents, and Restricted Cash to the Total of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 6,361	$ 11,257	$ 8,254	$ 13,841
Restricted cash	3,088	1,711	12,179	68,146
Total cash, cash equivalents, and restricted cash shown in the consolidated statement of cash flows	$ 9,449	$ 12,968	$ 20,433	$ 81,987

Contract Receivables, Net - Sum

Contract Receivables, Net - Summary of Contract Receivables, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Receivables [Abstract]
Billed and billable	$ 210,919	$ 238,449
Allowance for expected credit losses	(5,435)	(6,112)
Contract receivables, net	$ 205,484	$ 232,337

Contract Receivables, Net - Add

Contract Receivables, Net - Additional Information (Details) - Master Receivables Purchase Agreement with MUFG Bank [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Past Due [Line Items]
Received contract receivables	$ 309.4	$ 10
Bills receivables collected but not remitted to MUFG	28.7	6.2
Discount on sale of receivables	$ 1.1
Maximum
Financing Receivable, Past Due [Line Items]
Discount on sale of receivables		$ 0.1

Property and Equipment - Proper

Property and Equipment - Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 145,729	$ 150,398
Accumulated depreciation and amortization	(69,781)	(64,996)
Total property and equipment, net	75,948	85,402
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	54,398	58,131
Software and Software Development Costs
Property Plant And Equipment [Line Items]
Property and equipment, gross	16,897	17,926
Furniture and Office Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	29,773	28,800
Computer Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 44,661	$ 45,541

Property and Equipment - Additi

Property and Equipment - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense	$ 25,277	$ 21,482	$ 19,478

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Schedule of Changes in Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Goodwill [Line Items]
Balance as of January 1, 2023	$ 1,212,898	$ 1,046,760
Add: Goodwill resulting from business combinations	21,133	171,415
Less: Goodwill resulting from business divestitures	(16,921)
Effect of foreign currency translation	2,366	(5,277)
Balance as of December 31, 2023	$ 1,219,476	$ 1,212,898

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Amortization of Intangible Assets	$ 35.5	$ 28.4	$ 12.5
Minimum
Finite-lived intangible asset, useful life	1 year
Maximum
Finite-lived intangible asset, useful life	9 years
Weighted Average
Finite-lived intangible asset, useful life	5 years 8 months 12 days
Weighted Average | Customer Relationships
Finite-lived intangible asset, useful life	5 years 8 months 12 days
Weighted Average | Technology-Based Intangible Assets
Finite-lived intangible asset, useful life	9 years 7 months 6 days

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Schedule of Other Intangibles (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Finite lived intangible assets, gross carrying value	$ 190,905	$ 246,251
Accumulated amortization	(96,095)	(119,808)
Finite lived intangible assets, net carrying value	94,810	126,443
Indefinite lived intangible assets, gross carrying value	94	94
Total intangible assets, gross carrying value	190,999	246,345
Other intangible assets, net	94,904	126,537
Customer-Related Intangible Assets
Finite lived intangible assets, gross carrying value	185,723	240,591
Accumulated amortization	(93,911)	(118,412)
Finite lived intangible assets, net carrying value	91,812	122,179
Developed Technology Rights
Finite lived intangible assets, gross carrying value	3,902	4,480
Accumulated amortization	(904)	(512)
Finite lived intangible assets, net carrying value	2,998	3,968
Trade Name
Finite lived intangible assets, gross carrying value	1,280	1,180
Accumulated amortization	$ (1,280)	(884)
Finite lived intangible assets, net carrying value		$ 296

Goodwill and Other Intangible_6

Goodwill and Other Intangible Assets - Schedule of Estimated Future Amortization Expense Relating to Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
2024	$ 32,992
2025	32,074
2026	18,533
2027	3,407
2028	2,047
Thereafter	5,757
Finite lived intangible assets, net carrying value	$ 94,810	$ 126,443

Leases - Additional Information

Leases - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Lessee Lease Description [Line Items]
Operating leases, option to extend lease	The leases may include options to extend the lease periods for up to 5 years
Finance leases, option to extend lease	The leases may include options to extend the lease periods for up to 5 years
Operating leases, existence of option to extend	true
Operating leases, option to terminate lease	options to terminate the leases within 1 year
Finance leases, option to terminate lease	options to terminate the leases within 1 year
Operating leases, existence of option to terminate	true
Operating leases, residual value guarantee description	The leases may include a residual value guarantee or a responsibility to return the property to its original state of use.
Finance leases, residual value guarantee description	The leases may include a residual value guarantee or a responsibility to return the property to its original state of use.
Operating leases, existence of residual value guarantee	true
Impairment related to leasehold improvement	$ 6.8	$ 8.4
Accrued other future lease-related expenses	$ 3.2	$ 4.9
Minimum
Lessee Lease Description [Line Items]
Operating leases, remaining lease term	1 year
Finance leases, remaining lease term	1 year
Maximum
Lessee Lease Description [Line Items]
Operating leases, remaining lease term	15 years
Finance leases, remaining lease term	15 years
Operating leases, termination lease term	1 year
Operating leases, extendable lease term	5 years
Finance leases, extendable lease term	5 years
Finance leases, termination lease term	1 year

Leases - Summary of Lease Cost

Leases - Summary of Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Operating lease cost	$ 25,037	$ 37,889	$ 35,469
Finance lease cost - amortization of right-of-use assets	2,040	598
Finance lease cost - interest	602	179
Short-term lease cost	669	509	453
Variable lease cost	222	146	43
Sublease income	(28)	(92)
Total lease cost	$ 28,542	$ 39,229	$ 35,965

Leases - Summary of Future Mini

Leases - Summary of Future Minimum Lease Payments Under Non-Cancellable Operating and Finance Leases (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Leases [Abstract]
December 31, 2024	$ 25,419
December 31, 2025	26,621
December 31, 2026	18,578
December 31, 2027	22,899
December 31, 2028	15,926
Thereafter	131,690
Total future minimum lease payments	241,133
Less: Interest	(45,264)
Total lease liabilities	195,869
December 31, 2024	3,041
December 31, 2025	3,041
December 31, 2026	3,041
December 31, 2027	3,041
December 31, 2028	2,985
Thereafter	2,966
Total future minimum lease payments	18,115
Less: Interest	(1,719)
Total lease liabilities	$ 16,396

Leases - Summary of Other Infor

Leases - Summary of Other Information Related to Operating and Finance Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Operating cash flows from operating leases	$ 20,368	$ 40,123
Right-of-use assets obtained in exchange for new operating lease liabilities	18,590	13,906
Property and equipment obtained in exchange for finance lease liabilities	$ 338	$ 18,319
Weighted-average remaining lease term - Operating leases	11 years 7 months 6 days	11 years 8 months 12 days
Weighted-average remaining lease term - Finance leases	6 years	7 years
Weighted-average discount rate - Operating leases	3.60%	3.30%
Weighted-average discount rate - Finance leases	3.40%	3.40%

Accrued Salaries and Benefits -

Accrued Salaries and Benefits - Schedule of Accrued Salaries and Benefits (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Employee-related Liabilities, Current [Abstract]
Bonuses, liability-classified awards, and commissions	$ 27,371	$ 26,930
Salaries	32,604	31,142
Paid time off and leave	16,415	16,144
Medical	5,685	5,833
Payroll taxes and withholdings	976	1,363
Other	4,970	4,579
Total accrued salaries and benefits	$ 88,021	$ 85,991

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Payables and Accruals [Abstract]
Deposits	$ 20,246	$ 32,384
Restricted contract funds	2,036	1,701
IT and software licensing costs	583	1,609
Taxes and insurance premiums	7,010	6,633
Facilities rental and lease exit costs	2,754	2,043
Interest	3,218	363
Professional services	1,943	3,617
Dividends	2,636	2,631
Cash collected not yet remitted to purchaser of billed receivables	28,675	6,164
Other accrued expenses and current liabilities	10,028	20,891
Total accrued expenses and other current liabilities	$ 79,129	$ 78,036

Long-Term Debt - Additional Inf

Long-Term Debt - Additional Information (Details) - USD ($)		12 Months Ended
	May 06, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Line of credit facility, expiration date		May 06, 2027
Letters of credit sublimit	$ 100,000,000
Line of credit facility, swing line commitment amount	75,000,000
Line of credit facility, additional revolving credit commitments under existing loan facility	$ 300,000,000
Outstanding balance net of unamortized debt issuance costs		$ 430,407,000	$ 556,334,000
Line of credit facility		180,000,000
Line of credit facility leverage ratio covenant temporary increment	5%
Line of credit facility, interest coverage ratio covenant	3%
Line of credit facility, current borrowing capacity		575,500,000
Amortization of debt issuance costs		$ 1,996,000	1,305,000	$ 617,000
Number of letters of credit, outstanding		5
Letters of credit outstanding, amount		$ 1,800,000
Net debt issuance costs		$ 3,700,000	$ 5,000,000
Interest Rate Swap | Cash Flow Hedging | Designated as Hedging Instrument
Debt Instrument [Line Items]
Derivative fixed interest rate		5.60%	3.70%
Federal Funds Open Rate
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	0.50%
Secured Overnight Financing Rate
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1%
Revolving Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 600,000,000	$ 600,000,000
Unused borrowing capacity amount		$ 591,900,000
Interest rate on credit facility		6.70%	3.30%
Delayed Draw Term Loan Facility
Debt Instrument [Line Items]
Line of credit facility	400,000,000
Maximum
Debt Instrument [Line Items]
Debt instrument, principal amount	$ 300,000,000
Line of credit facility, leverage ratio covenant	4.50%
Foreign currency debt limit	$ 200,000,000
Minimum
Debt Instrument [Line Items]
Debt instrument, principal amount	$ 200,000,000
Line of credit facility, leverage ratio covenant	4%
Foreign currency debt limit	$ 30,000,000

Long-Term Debt - Schedule of Lo

Long-Term Debt - Schedule of Long Term Debt (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Average Interest Rate	6.70%	3.30%
Outstanding Balance before debt issuance costs	$ 434,090	$ 561,366
Unamortized debt issuance costs	(3,683)	(5,032)
Total	430,407	556,334
Current portion of long-term debt	26,000	23,250
Total	404,407	533,084
Term Loan
Debt Instrument [Line Items]
Outstanding Balance before debt issuance costs	207,750	288,750
Delayed-Draw Term Loan
Debt Instrument [Line Items]
Outstanding Balance before debt issuance costs	220,000	220,000
Revolving Credit
Debt Instrument [Line Items]
Outstanding Balance before debt issuance costs	$ 6,340	$ 52,616

Long Term Debt - Schedule of Fu

Long Term Debt - Schedule of Future Scheduled Repayments of Term Loan Principal (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
December 31, 2024	$ 26,000
December 31, 2025	35,750
December 31, 2026	39,000
December 31, 2027	333,340
Total	434,090	$ 561,366
Term Loan
Debt Instrument [Line Items]
December 31, 2024	15,000
December 31, 2025	20,625
December 31, 2026	22,500
December 31, 2027	149,625
Total	207,750	288,750
Delayed-Draw Term Loan
Debt Instrument [Line Items]
December 31, 2024	11,000
December 31, 2025	15,125
December 31, 2026	16,500
December 31, 2027	177,375
Total	220,000	220,000
Revolving Credit
Debt Instrument [Line Items]
December 31, 2027	6,340
Total	$ 6,340	$ 52,616

Revenue Recognition - Disaggreg

Revenue Recognition - Disaggregation of Revenue (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation Of Revenue [Line Items]
Revenue from clients	$ 1,963,238	$ 1,779,964	$ 1,553,048
Time-and-Materials
Disaggregation Of Revenue [Line Items]
Revenue from clients	812,430	713,693	633,135
Fixed-Price
Disaggregation Of Revenue [Line Items]
Revenue from clients	885,465	802,568	645,809
Cost-Based
Disaggregation Of Revenue [Line Items]
Revenue from clients	265,343	263,703	274,104
U.S. Federal Government
Disaggregation Of Revenue [Line Items]
Revenue from clients	1,084,043	980,746	735,032
U.S. State and Local Government
Disaggregation Of Revenue [Line Items]
Revenue from clients	308,134	259,764	235,416
International Government
Disaggregation Of Revenue [Line Items]
Revenue from clients	103,399	103,609	139,229
Total Government
Disaggregation Of Revenue [Line Items]
Revenue from clients	1,495,576	1,344,119	1,109,677
Commercial
Disaggregation Of Revenue [Line Items]
Revenue from clients	467,662	435,845	443,371
Energy, Environment, Infrastructure, and Disaster Recovery
Disaggregation Of Revenue [Line Items]
Revenue from clients	806,482	714,628	693,572
Health and Social Programs
Disaggregation Of Revenue [Line Items]
Revenue from clients	814,454	704,465	563,590
Security and Other Civilian & Commercial
Disaggregation Of Revenue [Line Items]
Revenue from clients	$ 342,302	$ 360,871	$ 295,886

Revenue Recognition - Additiona

Revenue Recognition - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Net contract assets (liabilities)	$ 36,520
Revenue related to contract liabilities	$ 17,800	$ 27,400

Revenue Recognition - Schedule

Revenue Recognition - Schedule of Changes in Contract Balances Due to Adoption of New Accounting Standards (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Contract assets	$ 201,832	$ 169,088
Contract liabilities	(21,997)	(25,773)
Net contract assets (liabilities)	179,835	$ 143,315
Change in contract assets	32,744
Change in contract liabilities	3,776
Change in net contract assets (liabilities)	$ 36,520

Revenue Recognition - Additio_2

Revenue Recognition - Additional Information (Detail1) $ in Billions	Dec. 31, 2023 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2024-01-01
Revenue From Contract With Customer [Line Items]
Unfulfilled performance obligation	$ 1.4
Expected period to satisfy performance obligations	1 year
Revenue, remaining performance obligation, percentage	57%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2025-01-01
Revenue From Contract With Customer [Line Items]
Expected period to satisfy performance obligations	1 year
Revenue, remaining performance obligation, percentage	77%

Derivative Instruments and He_3

Derivative Instruments and Hedging Activities - Summary of Effect of Swaps on Company's Financial Statements (Details) - Interest Rate Swaps - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Derivative [Line Items]
Total Gain (Loss) Recorded to AOCI	$ (45)	$ 11,445
Amount of (Gain) or Loss Reclassified from AOCI into Income	$ (6,982)	$ (248)

Derivative Instruments and He_4

Derivative Instruments and Hedging Activities - Additional Information (Details)	12 Months Ended
	Dec. 31, 2023 USD ($)
Derivative [Line Items]
Net amount of realized losses from AOCI into earnings	$ 4,800,000
Estimate of time to transfer of realized losses from AOCI into earnings	12 months
Designated as Hedging Instrument | Cash Flow Hedging | Interest Rate Swaps
Derivative [Line Items]
Notional amount	$ 275,000,000
Designated as Hedging Instrument | Cash Flow Hedging | Interest Rate Swaps | June 27, 2028
Derivative [Line Items]
Notional amount	$ 100,000,000
Maturity date	Jun. 27, 2028
Designated as Hedging Instrument | Cash Flow Hedging | Interest Rate Swaps | February 28, 2025
Derivative [Line Items]
Notional amount	$ 100,000,000
Maturity date	Feb. 28, 2025
Designated as Hedging Instrument | Cash Flow Hedging | Interest Rate Swaps | February 28, 2028
Derivative [Line Items]
Notional amount	$ 75,000
Maturity date	Feb. 28, 2028

Income Taxes - Income Before In

Income Taxes - Income Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Domestic	$ 83,742	$ 80,372	$ 97,884
Foreign	12,805	3,608	2,206
Income before income taxes	$ 96,547	$ 83,980	$ 100,090

Income Taxes - Income Tax Expen

Income Taxes - Income Tax Expense Components (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Current:
Federal	$ 28,108	$ 8,413	$ 15,961
State	10,380	2,686	3,494
Foreign	2,247	1,661	687
Total current	40,735	12,760	20,142
Deferred:
Federal	(20,279)	4,264	4,724
State	(6,915)	3,607	4,395
Foreign	394	(894)	(303)
Total deferred	26,800	6,977	8,816
Income tax expense	$ 13,935	$ 19,737	$ 28,958

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Deferred Tax Assets
Allowance for expected credit losses	$ 1,213	$ 1,404
Accrued paid time off	3,039	2,801
Foreign net operating loss carry forward		229
State net operating loss carry forward	500	502
Stock based compensation	5,523	1,586
Deferred compensation	5,765	4,692
Foreign tax credits	8,035	7,236
Federal and state tax credits	686	384
Foreign exchange	3,591	4,532
Foreign deferred	441	875
Accrued bonus	5,830	5,696
Capital loss	1,054
Facilities impairment	3,092	2,650
Capitalized research expenses	47,019	990
Accrued liabilities and other	2,682	5,523
Lease liabilities	58,538	56,695
Deferred Tax Assets, gross, before valuation allowance	147,008	95,795
Less: Valuation Allowance	(9,021)	(7,607)	$ (7,048)	$ (6,839)
Total Deferred Tax Assets	137,987	88,188
Deferred Tax Liabilities
Retention		(407)
Prepaid expenses		(366)
Payroll taxes	(725)	(697)
Unbilled revenue	(284)	(409)
Depreciation	(2,128)	(270)
Amortization	(107,201)	(99,045)
Deferred gain and other	(2,202)	(2,561)
Lease assets - Right-of-Use	(51,622)	(52,471)
Total Deferred Tax Liabilities	(164,162)	(156,226)
Total Net Deferred Tax Liability	$ (26,175)	$ (68,038)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Taxes [Line Items]
Deferred tax assets and liabilities income tax rate expected to reverse in future	27%
Increase in valuation allowance	$ 800
Increase in cumulative foreign tax credit carryforward	800
Income taxes provided for additional outside basis difference inherent in entities as result of reinvestment	4,900
Operating loss carryforwards valuation allowance	500
Deferred tax assets, tax credit carryforwards	686	$ 384
Deferred tax assets, valuation allowance	9,021	7,607	$ 7,048	$ 6,839
Valuation allowance, deferred tax asset, increase (decrease), amount	1,414	559	209
Unrecognized tax benefits	24,131	145	$ 450	$ 811
Unrecognized tax benefits that would impact effective tax rate	$ 9,000	$ 100
Decrease in effective income tax rate	7%
Increase in unrecognized tax benefits	$ 28,100
Minimum
Income Taxes [Line Items]
Operating loss carryforwards expiration term	15 years
Maximum
Income Taxes [Line Items]
Operating loss carryforwards expiration term	20 years
Canadian Entities [Member]
Income Taxes [Line Items]
Decrease in effective income tax rate	3.80%
UK Subsidiaries [Member]
Income Taxes [Line Items]
Decrease in effective income tax rate	5.10%
Earliest Tax Year | Internal Revenue Service (IRS)
Income Taxes [Line Items]
Open tax year	2020
Earliest Tax Year | State and Foreign Jurisdictions
Income Taxes [Line Items]
Open tax year	2019
Latest Tax Year | Internal Revenue Service (IRS)
Income Taxes [Line Items]
Open tax year	2022
Latest Tax Year | State and Foreign Jurisdictions
Income Taxes [Line Items]
Open tax year	2022
Foreign Tax Authority
Income Taxes [Line Items]
Research and development costs amortization period	15 years
Deferred tax assets, valuation allowance	$ 500
Valuation allowance, deferred tax asset, increase (decrease), amount	$ 8,000
Domestic Tax Authority
Income Taxes [Line Items]
Research and development costs amortization period	5 years
Operating loss carryforwards	$ 6,500
Net operating loss carryforwards, expiration year	2034
Federal and State Jurisdiction
Income Taxes [Line Items]
Tax credit carryforward, amount	$ 700
Deferred tax assets, tax credit carryforwards	$ 700
Federal and State Jurisdiction | Earliest Tax Year
Income Taxes [Line Items]
Tax credit carryforwards, expiration year	2024
Federal and State Jurisdiction | Latest Tax Year
Income Taxes [Line Items]
Tax credit carryforwards, expiration year	2034

Income Taxes - Components of Un

Income Taxes - Components of Unrecognized Tax Benefits, Excluding Penalty and Interest (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Income Tax Contingency [Line Items]
Section 41 tax credit	$ 8,736
Section 174 expense capitalization	15,086
Total	24,131	$ 145
U.S
Income Tax Contingency [Line Items]
Transfer pricing	145	$ 145
India
Income Tax Contingency [Line Items]
Transfer pricing	$ 164

Income Taxes - Unrecognized Tax

Income Taxes - Unrecognized Tax Benefit Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Unrecognized tax benefits, beginning balance	$ 145	$ 450	$ 811
Decrease attributable to tax positions taken during the current period		(305)	(361)
Increase attributable to tax positions taken during a prior period	19,845
Increase attributable to tax positions taken during the current period	4,141
Unrecognized tax benefits, ending balance	$ 24,131	$ 145	$ 450

Income Taxes - Effective Income

Income Taxes - Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Taxes at statutory rate	21%	21%	21%
State taxes, net of federal benefit	6%	5.80%	5.60%
Foreign tax rate differential	(0.20%)	0.10%	0.10%
Executive compensation	1.70%	2.20%	2.10%
Other permanent differences	(0.30%)	2%	(0.40%)
Global intangible low-taxed income (GILTI)	0.30%
Prior year tax adjustments	(6.40%)	(1.10%)	1.50%
Deferred impact of state rate change	0.50%	0.60%
Worthless Stock Deduction	(5.10%)	(4.60%)
Unrecognized tax benefits	9%	(0.40%)	(0.50%)
Capital loss	(3.80%)
Valuation allowance	2%	0.70%	1.30%
Equity-based compensation	(1.10%)	(1.30%)	(1.00%)
Tax credits	(9.20%)	(1.50%)	(0.80%)
Taxes at effective rate	14.40%	23.50%	28.90%

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive (Loss) Income - Components of Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023		Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income Loss [Line Items]
Balance		$ 853,211		$ 803,470	$ 746,961
Current period other comprehensive income (loss):
Total current period other comprehensive income (loss)		(3,752)		2,902	3,071
Balance		917,585		853,211	803,470
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income Loss [Line Items]
Balance		(14,056)		(8,759)	(7,210)
Current period other comprehensive income (loss):
Other comprehensive income (loss) before reclassifications		4,158		(9,259)	(1,676)
Effect of taxes	[1]	(2,797)		3,962	127
Total current period other comprehensive income (loss)		1,361		(5,297)	(1,549)
Balance		(12,695)		(14,056)	(8,759)
Gain on Sale of Interest Rate Hedge Agreement
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	[2]	41		569	1,096
Current period other comprehensive income (loss):
Amounts reclassified from accumulated other comprehensive (loss) income	[2]	(60)	[3]	(720)	(720)
Effect of taxes	[1],[2]	19		192	193
Total current period other comprehensive income (loss)	[2]	(41)		(528)	(527)
Balance	[2]			41	569
Changes in Fair Value of Interest Rate Hedge Agreements
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	[4],[5]	5,882		(2,845)	(7,992)
Current period other comprehensive income (loss):
Other comprehensive income (loss) before reclassifications	[4],[5]	(45)		11,445	3,285
Amounts reclassified from accumulated other comprehensive (loss) income	[4],[5]	(6,922)	[3]	472	3,728
Effect of taxes	[1],[4],[5]	1,895		(3,190)	(1,866)
Total current period other comprehensive income (loss)	[4],[5]	(5,072)		8,727	5,147
Balance	[4],[5]	810		5,882	(2,845)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income Loss [Line Items]
Balance		(8,133)		(11,035)	(14,106)
Current period other comprehensive income (loss):
Other comprehensive income (loss) before reclassifications		4,113		2,186	1,609
Amounts reclassified from accumulated other comprehensive (loss) income		(6,982)	[3]	(248)	3,008
Effect of taxes	[1]	(883)		964	(1,546)
Total current period other comprehensive income (loss)		(3,752)		2,902	3,071
Balance		$ (11,885)		$ (8,133)	$ (11,035)
[1] The Company’s effective tax rate for the years ended December 31, 2023, 2022, and 2021 was 14.4 % , 23.5 % , and 28.9 % , respectively. Represents the fair value of an interest rate hedge agreement, designated as a cash flow hedge, which was sold on December 1, 2016. The fair value of the interest rate hedge agreement was recorded in other comprehensive income, net of tax, and will be reclassified to earnings when earnings are impacted by the hedged items, as interest payments are made on the Credit Facility from January 31, 2018 to January 31, 2023. The Company expects to reclassify $ 4.8 million in unrealized gains related to the Change in Fair Value of Interest Rate Hedge Agreement from accumulated other comprehensive loss into earnings during the next 12 months. Represents the change in fair value of interest rate hedge agreements designated as a cash flow hedges. The fair value of the interest rate hedge agreements was recorded in other comprehensive income, net of tax, and will be reclassified to earnings when earnings are impacted by the hedged items, as interest payments are made on the Credit Facility from through June 27, 2028. See additional details of the hedge agreements in Note 12 - Derivative Instruments and Hedging Activities. The fair value of the interest rate hedge agreements is included in other current and other long-term assets and liabilities on the consolidated balance sheets. See “Note 19 - Fair Value” for additional details.

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive (Loss) Income - Components of Accumulated Other Comprehensive (Loss) Income (Parenthetical) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Effective tax rate	14.40%	23.50%	28.90%
Expects to reclassify net losses related to change in fair value of interest rate hedge agreement from accumulated other comprehensive loss into earnings	$ 4.8

Accounting for Stock-based Co_3

Accounting for Stock-based Compensation - Additional Information (Details) $ / shares in Units, $ in Millions		12 Months Ended					24 Months Ended
	Apr. 04, 2018 shares	Dec. 31, 2023 USD ($) PerformancePeriod $ / shares shares	Dec. 31, 2022 USD ($) PerformancePeriod shares	Dec. 31, 2021 USD ($) PerformancePeriod shares	Dec. 31, 2020 shares	Dec. 31, 2015 PerformancePeriod	Dec. 31, 2022 shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, options, vested and expected to vest, exercisable, weighted average remaining contractual term		2 months 12 days
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares grants			0	0	0
Share price | $ / shares		$ 134.09
Share-based compensation arrangement by share-based payment award, options, exercises in period, intrinsic value | $		$ 0.9	$ 1.9	$ 0.8
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting period		3 years
Share price | $ / shares		$ 134.09
Share-based compensation arrangement by share-based payment award, equity instruments other than options, vested in period, fair value | $		$ 7.3	$ 10.8	$ 7.9
Number of shares, granted		89,388	148,361	132,757
Number of shares, vested		93,881	140,666	119,203
Cash Settled RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting period			3 years
Share price | $ / shares		$ 134.09
Share-based compensation arrangement by share-based payment award, equity instruments other than options, vested in period, fair value | $		$ 7.9	$ 6.6	$ 8.7
Number of shares, granted		70,742	115,024	52,246
Number of shares, vested		81,537	75,566	104,272
Performance Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share price | $ / shares		$ 134.09
Number of performance period in performance based share program | PerformancePeriod		1	2	3		2
Percentage of multiplication award by product		2%
Number of shares, granted		36,956	38,412	54,216	45,141		69,650
Number of shares, vested		45,141	47,634	63,258
Number of shares, expected to vest		69,650
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, fair value assumptions, expected forfeiture rate		0%
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, fair value assumptions, expected forfeiture rate		21.59%
Omnibus Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares grants	2,050,000	2,631
Share-based compensation arrangement by share-based payment award, number of shares available for grant		1,119,446
Share-based compensation arrangement by share-based payment award, options, outstanding, weighted average remaining contractual term		10 years
Omnibus Plan | Non-Employee Director Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share price | $ / shares		$ 134.09
Number of shares, granted		8,211	11,399	11,186
Number of shares, vested		9,457	11,637	12,110

Accounting for Stock-based Co_4

Accounting for Stock-based Compensation - Schedule of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-Based Compensation Recognized	$ 22,919	$ 18,880	$ 21,482
Stock-Based Compensation Unrecognized	29,907
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-Based Compensation Recognized	9,413	9,300	8,563
Stock-Based Compensation Unrecognized	$ 13,517
Stock-Based Compensation Unrecognized Weighted- Average Period to Recognize (Years)	1 year 8 months 12 days
Cash Settled RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-Based Compensation Recognized	$ 8,061	5,709	8,251
Stock-Based Compensation Unrecognized	$ 11,558
Stock-Based Compensation Unrecognized Weighted- Average Period to Recognize (Years)	1 year 8 months 12 days
Non-Employee Director Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-Based Compensation Recognized	$ 1,029	1,087	937
Stock-Based Compensation Unrecognized	$ 481
Stock-Based Compensation Unrecognized Weighted- Average Period to Recognize (Years)	4 months 24 days
Performance Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-Based Compensation Recognized	$ 4,416	$ 2,784	$ 3,731
Stock-Based Compensation Unrecognized	$ 4,351
Stock-Based Compensation Unrecognized Weighted- Average Period to Recognize (Years)	1 year 6 months

Accounting for Stock-based Co_5

Accounting for Stock-based Compensation - Outstanding Stock Option Activity (Details) - Employee Stock Option - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Outstanding Beginning Balance	10,885	29,692	38,227
Number of Shares, Exercised	(8,254)	(18,807)	(8,535)
Number of Shares, Granted		0	0	0
Number of Shares, Outstanding Ending Balance	2,631	10,885	29,692	38,227
Number of Shares, Vested plus expected to vest at December 31, 2022	2,631
Number of Shares, Exercisable at December 31, 2022	2,631
Weighted Average Exercise Price, Outstanding Beginning Balance	$ 35.49	$ 33.30	$ 31.93
Weighted Average Exercise Price, Exercised	33.84	32.04	27.17
Weighted Average Exercise Price, Outstanding Ending Balance	40.68	$ 35.49	$ 33.30	$ 31.93
Weighted Average Exercise Price, Vested plus expected to vest at December 31, 2022	40.68
Weighted Average Exercise Price, Exercisable at December 31, 2022	$ 40.68
Aggregate Intrinsic Value, Outstanding at December 31, 2022	$ 246
Aggregate Intrinsic Value, Vested plus expected to vest at December 31, 2022	246
Aggregate Intrinsic Value, Exercisable at December 31, 2022	$ 246

Accounting for Stock-based Co_6

Accounting for Stock-based Compensation - Stock Options Outstanding by Exercise Price Range (Details) - Price Range 1	12 Months Ended
	Dec. 31, 2023 $ / shares shares
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices, Lower range	$ 40.68
Range of Exercise Prices, Upper range	$ 40.68
Number Outstanding | shares	2,631
Weighted Average Remaining Contractual Term	2 months 12 days
Weighted Average Exercise Price	$ 40.68
Number Exercisable | shares	2,631
Weighted Average Exercise Price	$ 40.68

Accounting for Stock-based Co_7

Accounting for Stock-based Compensation - Restricted Stock Unit Activity (Details) - Restricted Stock Units (RSUs) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended			24 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Non-vested Beginning Balance	284,826	303,836	305,399	305,399
Number of Shares, Granted	89,388	148,361	132,757
Number of Shares, Vested	(93,881)	(140,666)	(119,203)
Number of Shares, Cancelled	(21,815)	(26,705)	(15,117)
Number of Shares, Non-vested Ending Balance	258,518	284,826	303,836	284,826
Number of Shares, expected to vest in the future	230,953
Weighted-Average Grant Date Fair Value, Non-vested Beginning Balance	$ 88.23	$ 79.17	$ 66.51	$ 66.51
Weighted-Average Grant Date Fair Value, Granted	110.80	93.70	95.68
Weighted-Average Grant Date Fair Value, Vested	78.05	76.53	66.46
Weighted-Average Grant Date Fair Value, Cancelled	94.01	77.16	68.53
Weighted-Average Grant Date Fair Value, Non-vested Ending Balance	99.25	$ 88.23	$ 79.17	$ 88.23
Weighted-Average Grant Date Fair Value, expected to vest in the future	$ 98.82
Aggregate Intrinsic Value, Non-vested	$ 34,665
Aggregate Intrinsic Value, expected to vest in the future	$ 30,968

Accounting for Stock-based Co_8

Accounting for Stock-based Compensation - Cash-settled Restricted Stock Unit Activity (Details) - Cash Settled RSUs - USD ($)	12 Months Ended			24 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Non-vested Beginning Balance	188,419	166,260	241,481	241,481
Number of Shares, Granted	70,742	115,024	52,246
Number of Shares, Vested	(81,537)	(75,566)	(104,272)
Number of Shares, Cancelled	(19,040)	(17,299)	(23,195)
Number of Shares, Non-vested Ending Balance	158,584	188,419	166,260	188,419
Number of Shares, expected to vest in the future	134,808
Weighted-Average Grant Date Fair Value, Non-vested Beginning Balance	$ 87.28	$ 72.79	$ 65.06	$ 65.06
Weighted-Average Grant Date Fair Value, Granted	110.65	97.88	89.51
Weighted-Average Grant Date Fair Value, Vested	76.26	73.20	63.96
Weighted-Average Grant Date Fair Value, Cancelled	91.94	80.02	69.68
Weighted-Average Grant Date Fair Value, Non-vested Ending Balance	102.82	$ 87.28	$ 72.79	$ 87.28
Weighted-Average Grant Date Fair Value, expected to vest in the future	$ 102.31
Aggregate Intrinsic Value, Non-vested	$ 21,264,000
Aggregate Intrinsic Value, expected to vest in the future	$ 18,076,000

Accounting for Stock-based Co_9

Accounting for Stock-based Compensation - Summary of Non-employee Director Awards Activity (Details) - Non-Employee Director Awards - Omnibus Plan - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended			24 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Non-vested Beginning Balance	5,348	5,586	6,510	6,510
Number of Shares, Granted	8,211	11,399	11,186
Number of Shares, Vested	(9,457)	(11,637)	(12,110)
Number of Shares, Non-vested Ending Balance	4,102	5,348	5,586	5,348
Number of Shares, expected to vest in the future	4,102
Weighted-Average Grant Date Fair Value, Non-vested Beginning Balance	$ 94.79	$ 90.73	$ 64.47	$ 64.47
Weighted-Average Grant Date Fair Value, Granted	127.81	95.35	90.73
Weighted-Average Grant Date Fair Value, Vested	109.14	93.39	76.61
Weighted-Average Grant Date Fair Value, Non-vested Ending Balance	127.81	$ 94.79	$ 90.73	$ 94.79
Weighted-Average Grant Date Fair Value, expected to vest in the future	$ 127.81
Aggregate Intrinsic Value, Non-vested	$ 550
Aggregate Intrinsic Value, expected to vest in the future	$ 550

Accounting for Stock-based C_10

Accounting for Stock-based Compensation - Summary of Performance Shares Activity (Details) - Performance Shares - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended				24 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2022
Number of Shares
Number of Shares, Non-vested Beginning Balance	120,687	133,079	142,121		142,121
Number of Shares, Granted	36,956	38,412	54,216	45,141	69,650
Number of Shares, Vested	(45,141)	(47,634)	(63,258)
Number of Shares, Cancelled	(6,934)	(3,170)
Number of Shares, Non-vested Ending Balance	105,568	120,687	133,079	142,121	120,687
Number of Shares, expected to vest in the future	69,650
Weighted-Average Grant Date Fair Value
Weighted-Average Grant Date Fair Value, Non-vested Beginning Balance	$ 79.42	$ 76.54	$ 68.19		$ 68.19
Weighted-Average Grant Date Fair Value, Granted	115.67	93.15	85.03
Weighted-Average Grant Date Fair Value, Vested	58.76	82.38	65.05
Weighted-Average Grant Date Fair Value, Cancelled	61.49	80.64
Weighted-Average Grant Date Fair Value, Non-vested Ending Balance	102.12	$ 79.42	$ 76.54	$ 68.19	$ 79.42
Weighted-Average Grant Date Fair Value, expected to vest in the future	$ 104.95
Aggregate Intrinsic Value
Aggregate Intrinsic Value, Non-vested	$ 14,156
Aggregate Intrinsic Value, expected to vest in the future	$ 9,339

Accounting for Stock-based C_11

Accounting for Stock-based Compensation - Schedule of Fair Value Assumptions using Monte Carlo Simulation Model for Awards Granted (Details) - Performance Shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Dividend Yield	0.50%	0.60%	0.60%
Historical Volatility	33.60%	39%	40.90%
Risk-Free Rate of Returns	3.80%	2.10%	0.30%

Acquisitions and Divestitures -

Acquisitions and Divestitures - Additional Information (Details) - USD ($) $ in Thousands

1 Months Ended

12 Months Ended

Nov. 01, 2023

Sep. 12, 2023

May 01, 2023

Sep. 01, 2022

Jul. 13, 2022

Nov. 01, 2021

Dec. 31, 2021

Dec. 31, 2023

Dec. 31, 2022

Dec. 31, 2021

Jul. 24, 2023

Jul. 21, 2023

Acquisition and Divestiture [Line Items]

Goodwill

$ 1,046,760

$ 1,219,476

$ 1,212,898

$ 1,046,760

Goodwill resulting from business combination

21,133

171,415

Revenue

1,963,238

1,779,964

1,553,048

Goodwill, Purchase Accounting Adjustments

21,133

171,415

Business Acquisition and Integration Related Costs

4,300

Proceeds from divestiture of a business

51,328

Gain on divestiture

$ 7,590

Commercial Marketing

Acquisition and Divestiture [Line Items]

Initial cash consideration

$ 49,500

Asset purchase agreement date

Sep. 12, 2023

Proceeds from divestiture of a business

$ 47,100

Gain on divestiture

4,400

Divestiture transactions fees

1,900

Pre-tax gain on divestiture, net of transactions fees

$ 2,500

Mobile Aggregation Business

Acquisition and Divestiture [Line Items]

Initial cash consideration

$ 5,400

Asset purchase agreement date

Nov. 01, 2023

Pre-tax gain on divestiture, net of transactions fees

$ 3,200

CMY Solutions, LLC.

Acquisition and Divestiture [Line Items]

Business acquisition date

May 01, 2023

Working capital acquired

$ 1,200

Goodwill

21,100

Purchase price allocated to intangibles

10,300

Cash purchase price

32,600

CMY Solutions, LLC. | Customer Relationships

Acquisition and Divestiture [Line Items]

Purchase price allocated to intangibles

10,200

CMY Solutions, LLC. | Trade Names and Trademarks

Acquisition and Divestiture [Line Items]

Purchase price allocated to intangibles

$ 100

Blanton & Associates

Acquisition and Divestiture [Line Items]

Working capital acquired

$ 4,600

Purchase price allocated to property and equipment

200

Deferred income tax liabilities

3,000

Goodwill

9,700

Purchase price allocated to intangibles

11,400

Cash purchase price

22,900

Blanton & Associates | Customer Relationships

Acquisition and Divestiture [Line Items]

Purchase price allocated to intangibles

10,900

Blanton & Associates | Trade Names and Trademarks

Acquisition and Divestiture [Line Items]

Purchase price allocated to intangibles

100

Blanton & Associates | Contract Backlog

Acquisition and Divestiture [Line Items]

Purchase price allocated to intangibles

$ 500

SemanticBits LLC

Acquisition and Divestiture [Line Items]

Purchase price acquisition

$ 215,998

Deferred income tax liabilities

16,701

Cash purchase price

$ 216,000

Revenue

64,300

Gross Profit

$ 26,700

SemanticBits LLC | Customer Relationships

Acquisition and Divestiture [Line Items]

Weighted average amortization period for intangibles

4 years

SemanticBits LLC | Trade Names and Trademarks

Acquisition and Divestiture [Line Items]

Purchase price allocated to intangibles

$ 1,120

Weighted average amortization period for intangibles

8 months 12 days

Creative Systems

Acquisition and Divestiture [Line Items]

Business acquisition date

Dec. 31, 2021

Purchase price acquisition

$ 156,600

Goodwill resulting from business combination

28,900

Goodwill, Purchase Accounting Adjustments

28,900

Creative Systems | Customer Relationships

Acquisition and Divestiture [Line Items]

Purchase price allocated to intangibles

$ 24,500

$ 24,500

Amortization Period of intangible assets

4 years

4 years

Creative Systems | Intangible Assets

Acquisition and Divestiture [Line Items]

Purchase price allocated to intangibles

$ 128,100

$ 128,100

Creative Systems | Developed Technology

Acquisition and Divestiture [Line Items]

Purchase price allocated to intangibles

$ 3,700

$ 3,700

Amortization Period of intangible assets

10 years

10 years

Creative Systems | Trade Names and Trademarks

Acquisition and Divestiture [Line Items]

Purchase price allocated to intangibles

$ 600

$ 600

Creative Systems | Non-compete Agreements

Acquisition and Divestiture [Line Items]

Purchase price allocated to intangibles

$ 100

$ 100

Creative Systems | Non-compete Agreements | Maximum

Acquisition and Divestiture [Line Items]

Amortization Period of intangible assets

1 year

1 year

ESAC

Acquisition and Divestiture [Line Items]

Working capital acquired

$ 2,600

Goodwill

11,300

Cash purchase price

17,300

ESAC | Customer Relationships

Acquisition and Divestiture [Line Items]

Purchase price allocated to intangibles

$ 3,100

Amortization Period of intangible assets

3 years

ESAC | Technology and other intangibles

Acquisition and Divestiture [Line Items]

Purchase price allocated to intangibles

$ 300

Amortization Period of intangible assets

1 year

ESAC | Intangible Assets

Acquisition and Divestiture [Line Items]

Purchase price allocated to intangibles

$ 3,400

Acquisitions and Divestitures_2

Acquisitions and Divestitures - Summary of Preliminary Purchase Price Allocation (Details) - SemanticBits LLC $ in Thousands	Jul. 13, 2022 USD ($)
Acquisition and Divestiture [Line Items]
Contract receivables, net	$ 12,699
Contract assets	6,071
Other current and non-current assets	407
Accrued salaries and benefits	(3,998)
Accrued expenses and other liabilities	(6,244)
Deferred tax liability	(16,701)
Net assets acquired	56,321
Goodwill	159,677
Purchase price acquisition	215,998
Customer-Related Intangible Assets
Acquisition and Divestiture [Line Items]
Customer-related intangibles	62,967
Trade Names and Trademarks
Acquisition and Divestiture [Line Items]
Customer-related intangibles	$ 1,120

Acquisitions and Divestitures_3

Acquisitions and Divestitures - Schedule of Unaudited Condensed Pro Forma Financial Information (Details) - Semantic Bits L L C [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Acquisition and Divestiture [Line Items]
Revenue	$ 1,856,399	$ 1,667,425
Net income	$ 75,999	$ 63,752

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Details)	12 Months Ended
	Dec. 31, 2023
Performance Shares | Initial Performance Vesting Period
Share-based compensation arrangement by share-based payment award, award vesting period	2 years

Earnings Per Share - Schedule o

Earnings Per Share - Schedule of Dilutive Effect of Stock Options RSUs and PSAs (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Earnings Per Share [Abstract]
Net Income	$ 82,612	$ 64,243	$ 71,132
Weighted-average number of basic shares outstanding during the period	18,802	18,818	18,868
Dilutive effect of stock options, RSUs, and performance shares	192	215	256
Weighted-average number of diluted shares outstanding during the period	18,994	19,033	19,124
Basic earnings per share	$ 4.39	$ 3.41	$ 3.77
Diluted earnings per share	$ 4.35	$ 3.38	$ 3.72

Share Repurchase Program - Addi

Share Repurchase Program - Additional Information (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Nov. 14, 2023 USD ($)	Nov. 30, 2021 USD ($)	Sep. 30, 2017 USD ($)
Equity Class Of Treasury Stock [Line Items]
Stock repurchase program, authorized amount			$ 191,000	$ 200,000,000	$ 100,000,000
Line of credit facility, condition permitted for unlimited share repurchases, leverage ratio				0.5
Net liquidity amount				$ 100,000,000
Stock Repurchased During Period, Shares | shares	180,000	176,375
Stock Repurchased During Period, Value	$ 18,100,000	$ 17,000,000
Share repurchase amount				$ 25,000,000
Average price per share | $ / shares	$ 100.7	$ 96.18
Credit Facility
Equity Class Of Treasury Stock [Line Items]
Share repurchase amount	$ 93,700,000

Fair Value - Schedule of Financ

Fair Value - Schedule of Financial Instruments Measured at Fair Value on Recurring Basis (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Interest Rate Swap | Prepaid Expenses and Other Current Assets
Assets:
Assets, Total	$ 4,820	$ 5,051
Interest Rate Swap | Other Assets
Assets:
Assets, Total	398	2,950
Interest Rate Swap | Other Long-Term Liabilities
Liabilities:
Liabilities, Total	4,184
Foreign Currency Forward and Swap Contracts | Prepaid Expenses and Other Current Assets
Assets:
Assets, Total	6
Company Owned Life Insurance Policies | Other Assets
Assets:
Assets, Total	20,438	17,869
Level 2 | Interest Rate Swap | Prepaid Expenses and Other Current Assets
Assets:
Assets, Total	4,820	5,051
Level 2 | Interest Rate Swap | Other Assets
Assets:
Assets, Total	398	2,950
Level 2 | Interest Rate Swap | Other Long-Term Liabilities
Liabilities:
Liabilities, Total	4,184
Level 2 | Foreign Currency Forward and Swap Contracts | Prepaid Expenses and Other Current Assets
Assets:
Assets, Total	6
Level 2 | Company Owned Life Insurance Policies | Other Assets
Assets:
Assets, Total	$ 20,438	$ 17,869

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Loss Contingencies [Line Items]
Letters of credit	$ 1.8
Standby Letters of Credit
Loss Contingencies [Line Items]
Letters of credit	1.8	$ 2
Letters of credit guarantees	$ 7.9	$ 9.2

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-Based Payment Arrangement [Abstract]
Maximum defer of compensation subject to statutory limitations, percentage	70%
Percentage of employer matching contributions condition, one	100%
Percentage of employee entitled to employer matching contribution condition, one	3%
Percentage of employer matching contributions condition, two	50%
Percentage of employee entitled to employer matching contribution condition, two	2%
Defined contribution plan, employer discretionary contribution amount	$ 25,400,000	$ 22,900,000	$ 19,000,000
Deferred compensation arrangement with individual, cash awards granted, percentage	80%
Deferred compensation on performance bonuses that eligible employee, percentage	100%
Defined contribution plan, employers matching contribution, annual vesting percentage	100%
Employee stock purchase plan shares authorized	1,000,000
Employee stock purchase plan annual maximum payroll deduction	$ 25,000
Share-based compensation arrangement by share-based payment award, discount from market price, purchase date	5%
Stock issued during period, shares, employee stock purchase plans	36,140	34,844
Stock issued during period, value, employee stock purchase plans, per share	$ 121.96	$ 91.84
Employee stock purchase plan, number of shares available for grant	548,832	584,972

Exit Activities - Additional In

Exit Activities - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
U.K. and Belgium
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Exit activity completed date	Dec. 31, 2023
Indirect and Selling Expenses
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Compensation expense related to sale of business	$ 0.6
Certain Non-Core Commercial Marketing Businesses
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of right-of-use operating leases and related assets associated with exited facilities		$ 8.2
Retention and severance paid		1.3
Certain Non-Core Commercial Marketing Businesses | Indirect and Selling Expenses
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Other facility costs		4.8
Certain Non-Core Commercial Marketing Businesses | Direct Costs
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Retention and severance		2.3
Wind-down of Non-core Commercial Marketing and Communication Businesses | U.K. and Belgium
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Retention and severance incurred and paid	2.5
Divestiture of Non-core Commercial Marketing Businesses | Direct Costs
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Retention and severance	1.9	$ 1.7
Wind Down and Divestiture of Commercial Marketing Businesses
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment losses related to prior acquisition	0.9
Impairment losses related to right-of-use operating leases	3
Impairment losses related to other facility costs	$ 2.4

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - USD ($)		12 Months Ended
	Feb. 23, 2024	Dec. 31, 2023	Dec. 31, 2022	Nov. 14, 2023	Nov. 30, 2021	Sep. 30, 2017
Subsequent Event [Line Items]
Stock repurchase program, authorized amount				$ 191,000	$ 200,000,000	$ 100,000,000
Stock Repurchased During Period, Shares		180,000	176,375
Share repurchase amount		$ 18,100,000	$ 17,000,000
Average price per share		$ 100.7	$ 96.18
Subsequent Event
Subsequent Event [Line Items]
Stock Repurchased During Period, Shares	159,681
Share repurchase amount	$ 21,900,000
Average price per share	$ 136.94

Supplemental Information - Sche

Supplemental Information - Schedule of Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 6,112	$ 7,741	$ 7,616
Provision for credit losses	1,164	248	10,912
Write-offs, net of recoveries	(1,886)	(1,782)	(10,723)
Effect of foreign currency translation	45	(95)	(64)
Balance at end of period	$ 5,435	$ 6,112	$ 7,741

Supplemental Information - Sc_2

Supplemental Information - Schedule of Income Tax Valuation Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Valuation Allowance [Abstract]
Balance at beginning of period	$ 7,607	$ 7,048	$ 6,839
Provision for income taxes - valuation allowance	1,414	559	209
Balance at end of period	$ 9,021	$ 7,607	$ 7,048