Exponent (EXPO) 10-K 28 Feb 25 2024 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Jan. 03, 2025	Feb. 21, 2025	Jun. 28, 2024
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Jan. 03, 2025
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	FY
Entity Registrant Name	EXPONENT, INC.
Entity Central Index Key	0000851520
Current Fiscal Year End Date	--01-03
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 3.7
Trading Symbol	EXPO
Entity Common Stock, Shares Outstanding		50,818,234
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Small Business	false
Entity File Number	0-18655
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	77-0218904
Entity Address, Address Line One	149 Commonwealth Drive
Entity Address, City or Town	Menlo Park
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94025
City Area Code	650
Local Phone Number	326-9400
Document Annual Report	true
Document Transition Report	false
ICFR Auditor Attestation Flag	true
Entity Interactive Data Current	Yes
Title of each class	Common Stock, par value $0.001 per share
Name of each exchange on which registered	NASDAQ
Auditor Firm ID	185
Auditor Name	KPMG, LLP
Auditor Location	San Francisco, California
Document Financial Statement Error Correction [Flag]	false
Documents Incorporated by Reference	Portions of the registrant’s Definitive Proxy Statement for the registrant’ s 2025 Annual Meeting of Stockholders to be held on June 5, 2025 a re incorporated by reference into Part III of this Annual Report on Form 10-K.
Auditor Opinion	Opinions on the Consolidated Financial Statements and Internal Control Over Financial Reporting We have audited the accompanying consolidated balance sheets of Exponent, Inc. and subsidiaries (the Company) as of January 3, 2025 and December 29, 2023, the related consolidated statements of income, comprehensive income, stockholders’ equity, and cash flows for each of the fiscal years in the three-year period ended January 3, 2025, and the related notes and financial statement schedule II (collectively, the consolidated financial statements). We also have audited the Company’s internal control over financial reporting as of January 3, 2025, based on criteria established in Internal Control – Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission. In our opinion, the consolidated financial statements referred to above present fairly, in all material respects, the financial position of the Company as of January 3, 2025 and December 29, 2023, and the results of its operations and its cash flows for each of the fiscal years in the three-year period ended January 3, 2025, in conformity with U.S. generally accepted accounting principles. Also in our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of January 3, 2025 based on criteria established in Internal Control – Integrated Framework (2013)issued by the Committee of Sponsoring Organizations of the Treadway Commission.

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Revenues:
Revenues before reimbursements	$ 518,490	$ 497,189	$ 463,820
Reimbursements	40,024	39,577	49,473
Revenues	558,514	536,766	513,293
Operating expenses:
Compensation and related expenses	330,011	319,886	264,235
Other operating expenses	46,196	41,541	35,083
Reimbursable expenses	40,024	39,577	49,473
General and administrative expenses	22,726	24,440	23,660
Total operating expenses	438,957	425,444	372,451
Operating income	119,557	111,322	140,842
Other income:
Interest income	10,001	7,150	2,096
Miscellaneous income, net	17,812	17,424	(10,704)
Income before income taxes	147,370	135,896	132,234
Provision for income taxes	38,368	35,557	29,904
Net income	$ 109,002	$ 100,339	$ 102,330
Net income per share:
Basic (in dollars per share)	$ 2.13	$ 1.96	$ 1.98
Diluted (in dollars per share)	$ 2.11	$ 1.94	$ 1.96
Shares used in per share computations:
Basic (in shares)	51,129	51,152	51,727
Diluted (in shares)	51,569	51,635	52,280
Cash dividends declared per common share (in dollars per share)	$ 1.12	$ 1.04	$ 0.96

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Statement of Comprehensive Income [Abstract]
Net Income (Loss)	$ 109,002	$ 100,339	$ 102,330
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments, net of tax of $0, $0, and $0, respectively	(814)	610	(1,604)
Comprehensive income	$ 108,188	$ 100,949	$ 100,726

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Statement of Comprehensive Income [Abstract]
Foreign currency translation adjustments, tax	$ 0	$ 0	$ 0

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jan. 03, 2025	Dec. 29, 2023
Current assets:
Cash and cash equivalents	$ 258,901	$ 187,150
Accounts receivable, net of allowance for contract losses and doubtful accounts of $6,141 and $5,281, respectively	161,407	167,360
Prepaid expenses and other current assets	26,573	25,022
Total current assets	446,881	379,532
Property, equipment and leasehold improvements, net	73,007	75,318
Operating lease right-of-use assets	75,248	24,600
Goodwill	8,607	8,607
Deferred income taxes	57,127	53,824
Deferred compensation plan assets	110,259	101,169
Other assets	6,141	3,727
Total assets	777,270	646,777
Current liabilities:
Accounts payable and accrued liabilities	22,136	22,125
Accrued payroll and employee benefits	119,285	111,773
Deferred revenues	16,369	21,709
Operating lease liabilities	5,393	6,302
Total current liabilities	163,183	161,909
Other liabilities	4,289	3,426
Deferred compensation plan liabilities	112,646	103,398
Operating lease liabilities	76,084	21,959
Total liabilities	356,202	290,692
Commitments and contingencies (Note 13)
Stockholders’ equity:
Preferred stock, $0.001 par value; 2,000 shares authorized; no shares outstanding
Common stock, $0.001 par value; 120,000 shares authorized; 65,707 shares issued	66	66
Additional paid-in capital	345,689	321,448
Accumulated other comprehensive income/(loss)
Foreign currency translation adjustments	(3,791)	(2,977)
Retained earnings	624,151	574,082
Treasury stock, at cost: 14,893 and 15,134 shares held, respectively	(545,047)	(536,534)
Total stockholders’ equity	421,068	356,085
Total liabilities and stockholders’ equity	$ 777,270	$ 646,777

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jan. 03, 2025	Dec. 29, 2023
Statement of Financial Position [Abstract]
Accounts receivable, net of allowance for contract losses and doubtful accounts	$ 6,141	$ 5,281
Preferred stock, par or stated value per share	$ 0.001	$ 0.001
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	120,000,000	120,000,000
Common stock, shares issued	65,707,000	65,707,000
Treasury stock, shares	14,893,000	15,134,000

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total		Common Stock [Member]	Additional paid-in capital [Member]	Accumulated other comprehensive income (loss) [Member]	Retained earnings [Member]	Treasury Stock [Member]
Balance at Dec. 31, 2021	$ 417,065		$ 66	$ 281,419	$ (1,983)	$ 478,370	$ (340,807)
Balances (in shares) at Dec. 31, 2021			65,707,000				13,591,000
Employee stock purchase plan	2,020			1,805			$ 215
Employee stock purchase plan (in shares)							(22,000)
Amortization of unrecognized stock-based compensation	9,999			9,999
Purchase of treasury shares	(155,856)						$ (155,856)
Purchase of treasury shares (in shares)							1,756,000
Foreign currency translation adjustments	(1,604)				(1,604)
Grant of restricted stock units to settle accrued bonus	10,200			10,200
Settlement of restricted stock units	(12,904)			(2,421)		(1,392)	$ (9,091)
Settlement of restricted stock units (in shares)							(261,000)
Dividends and dividend equivalent rights	(50,498)			0		(50,498)
Net Income (Loss)	102,330					102,330
Balance at Dec. 30, 2022	320,752		$ 66	301,002	(3,587)	528,810	$ (505,539)
Balances (in shares) at Dec. 30, 2022			65,707,000				15,064,000
Employee stock purchase plan	2,084			1,840			$ 244
Employee stock purchase plan (in shares)							(24,000)
Exercise of stock options	100			22			$ 78
Exercise of stock options (in shares)							(8,000)
Amortization of unrecognized stock-based compensation	9,912			9,912
Purchase of treasury shares	(24,208)						$ (24,208)
Purchase of treasury shares (in shares)							288,000
Foreign currency translation adjustments	610				610
Grant of restricted stock units to settle accrued bonus	10,496			10,496
Settlement of restricted stock units	(9,942)			(1,824)		(1,009)	$ (7,109)
Settlement of restricted stock units (in shares)							(186,000)
Dividends and dividend equivalent rights	(54,058)					(54,058)
Net Income (Loss)	100,339					100,339
Balance at Dec. 29, 2023	356,085		$ 66	321,448	(2,977)	574,082	$ (536,534)
Balances (in shares) at Dec. 29, 2023			65,707,000				15,134,000
Employee stock purchase plan	1,839			1,627			$ 212
Employee stock purchase plan (in shares)							(21,000)
Exercise of stock options	$ 3,897			2,633			$ 1,264
Exercise of stock options (in shares)	(124,206)	[1]					(124,000)
Amortization of unrecognized stock-based compensation	$ 11,057			11,057
Purchase of treasury shares	(5,710)						$ (5,710)
Purchase of treasury shares (in shares)							74,000
Foreign currency translation adjustments	(814)				(814)
Grant of restricted stock units to settle accrued bonus	10,846			10,846
Settlement of restricted stock units	(6,920)			(1,922)		(719)	$ (4,279)
Settlement of restricted stock units (in shares)							(170,000)
Dividends and dividend equivalent rights	(58,214)					(58,214)
Net Income (Loss)	109,002					109,002
Balance at Jan. 03, 2025	$ 421,068		$ 66	$ 345,689	$ (3,791)	$ 624,151	$ (545,047)
Balances (in shares) at Jan. 03, 2025			65,707,000				14,893,000
[1] Does not include restricted stock or employee stock purchase plans.

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Cash flows from operating activities:
Net income	$ 109,002,000	$ 100,339,000	$ 102,330,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of property, equipment and leasehold improvements	9,689,000	8,916,000	7,079,000
Provision for contract losses and doubtful accounts	4,450,000	3,225,000	3,081,000
Stock-based compensation	23,239,000	20,357,000	20,364,000
Deferred income tax provision	(3,303,000)	85,000	(7,363,000)
Changes in operating assets and liabilities:
Accounts receivable	1,503,000	(471,000)	(33,334,000)
Prepaid expenses and other current assets	1,798,000	(6,669,000)	(6,124,000)
Change in operating leases	2,568,000	(152,000)	(7,000)
Accounts payable and accrued liabilities	436,000	(5,055,000)	2,215,000
Accrued payroll and employee benefits	495,000	3,902,000	6,494,000
Deferred revenues	(5,340,000)	2,875,000	(928,000)
Net cash provided by operating activities	144,537,000	127,352,000	93,807,000
Cash flows from investing activities:
Capital expenditures	(6,939,000)	(16,356,000)	(12,043,000)
Net cash used in investing activities	(6,939,000)	(16,356,000)	(12,043,000)
Cash flows from financing activities:
Payroll taxes for restricted stock units	(6,920,000)	(9,942,000)	(12,904,000)
Repurchase of common stock	(5,710,000)	(24,208,000)	(155,856,000)
Exercise of stock-based payment awards	5,736,000	2,184,000	2,020,000
Dividends and dividend equivalent rights	(58,214,000)	(54,043,000)	(49,237,000)
Net cash used in financing activities	(65,108,000)	(86,009,000)	(215,977,000)
Effect of foreign currency exchange rates on cash and cash equivalents	(739,000)	705,000	(2,016,000)
Net change in cash and cash equivalents	71,751,000	25,692,000	(136,229,000)
Cash and cash equivalents at beginning of year	187,150,000	161,458,000	297,687,000
Cash and cash equivalents at end of year	$ 258,901,000	$ 187,150,000	$ 161,458,000

Cybersecurity Risk Management,

Cybersecurity Risk Management, Strategy and Governance	12 Months Ended
	Jan. 03, 2025
Cybersecurity Risk Management, Strategy, and Governance [Line Items]
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]	Risk Management and Strategy We recognize the critical importance of cybersecurity and data privacy in safeguarding our operations, sensitive data, and maintaining the trust of our stakeholders. We acknowledge the significance of cybersecurity incidents and threats as potential risks that may impact our operations and information systems. We have developed and implemented cybersecurity and data privacy programs in accordance with the requirements of ISO standards 27001:2022 and 27701:2019, which are intended to appropriately preserve the confidentiality, integrity, and availability of information maintained by our company. These programs identify, select, maintain, operate, and improve cybersecurity and privacy controls. We have implemented processes for assessing, identifying, and managing material risks from cybersecurity threats. These processes are designed to preserve the confidentiality, integrity, and availability of our information systems and the information residing therein. Our cybersecurity incident response plan is based on the NIST 800-61r2 “Computer Security Incident Handling Guide.” This plan is used to process security events identified through our real-time, 24x7 monitoring, and is also used to conduct security incident tabletop exercises. The incident response plan includes detailed steps for incident leadership, escalation to established partners, response protocols based on the type of incident, responsibilities for follow-up and reporting, and steps to capture lessons learned and improvement opportunities. Our vulnerability management processes include real-time monitoring for vulnerabilities and standardized reporting for managing remediation efforts. Our cybersecurity risk management processes are integrated into our overall risk management system to ensure alignment with our business objectives and strategies. We engage assessors, consultants, auditors and other third parties to execute certification audits, penetration tests, and security framework risk assessments. These external entities provide specialized expertise and insights to enhance the effectiveness of our cybersecurity risk management processes. We have established processes to oversee and identify cybersecurity risks associated with our use of third-party service providers, including cloud service providers and AI system. We conduct due diligence assessments and evaluate contractual obligations to mitigate potential risks arising from third-party relationships. Cybersecurity threats, including previous incidents, have the potential to materially affect our company, including our business strategy, results of operations, and financial condition. While we have not experienced material adverse effects from cybersecurity threats to date, we recognize the evolving nature of these risks and remain vigilant in our efforts to mitigate potential impacts.
Cybersecurity Risk Management Processes Integrated [Flag]	true
Cybersecurity Risk Management Processes Integrated [Text Block]	Our cybersecurity risk management processes are integrated into our overall risk management system to ensure alignment with our business objectives and strategies.
Cybersecurity Risk Management Third Party Engaged [Flag]	true
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag]	true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag]	true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Text Block]	Cybersecurity threats, including previous incidents, have the potential to materially affect our company, including our business strategy, results of operations, and financial condition. While we have not experienced material adverse effects from cybersecurity threats to date, we recognize the evolving nature of these risks and remain vigilant in our efforts to mitigate potential impacts.
Cybersecurity Risk Board of Directors Oversight [Text Block]	Governance Our Board of Directors provides oversight of risks from cybersecurity threats. The Security and Privacy Management Committee (the “SPMC”) consists of our Chief Financial Officer, General Counsel, Vice President of Information Technology, Chief Human Resources Officer, Director of Information Security and Director of Environmental Health and Safety. The SPMC is tasked with ensuring risks are adequately addressed within our governance framework. We maintain a dedicated team of cybersecurity professionals. The Director of Information Security, the Information Security team, the SPMC, the Vice President of Information Technology, and the Information Technology leadership team are principally responsible for assessing and managing cybersecurity risks for our company. These individuals possess relevant expertise in cybersecurity risk management and are equipped to address the evolving nature of cyber threats. Our Director of Information Security has over 20 years of cybersecurity experience , holds several professional certifications and is an adjunct faculty member teaching courses on information security management and governance. Our cybersecurity professionals have a proven track record of executing strategic security objectives across various sectors, including utility, government, healthcare, and consulting. They bring with them experience in designing, implementing, and managing information security programs focused on quality, performance, and compliance. Our information security team and our third-party security service providers actively monitor the prevention, detection, mitigation, and remediation of cybersecurity incidents, ensuring timely response and resolution. Processes are in place to inform relevant management positions and committees about emerging threats and incident response activities. The Director of Information Security provides regular updates on cybersecurity risks and incidents to the Board of Directors, the SPMC, and IT leadership.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]	Our Board of Directors provides oversight of risks from cybersecurity threats. The Security and Privacy Management Committee (the “SPMC”) consists of our Chief Financial Officer, General Counsel, Vice President of Information Technology, Chief Human Resources Officer, Director of Information Security and Director of Environmental Health and Safety. The SPMC is tasked with ensuring risks are adequately addressed within our governance framework.
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block]	Processes are in place to inform relevant management positions and committees about emerging threats and incident response activities. The Director of Information Security provides regular updates on cybersecurity risks and incidents to the Board of Directors, the SPMC, and IT leadership.
Cybersecurity Risk Role of Management [Text Block]	We maintain a dedicated team of cybersecurity professionals. The Director of Information Security, the Information Security team, the SPMC, the Vice President of Information Technology, and the Information Technology leadership team are principally responsible for assessing and managing cybersecurity risks for our company. These individuals possess relevant expertise in cybersecurity risk management and are equipped to address the evolving nature of cyber threats.
Cybersecurity Risk Management Positions or Committees Responsible [Flag]	true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block]	The Director of Information Security, the Information Security team, the SPMC, the Vice President of Information Technology, and the Information Technology leadership team are principally responsible for assessing and managing cybersecurity risks for our company. These individuals possess relevant expertise in cybersecurity risk management and are equipped to address the evolving nature of cyber threats.
Cybersecurity Risk Management Expertise of Management Responsible [Text Block]	Our Director of Information Security has over 20 years of cybersecurity experience
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block]	Our information security team and our third-party security service providers actively monitor the prevention, detection, mitigation, and remediation of cybersecurity incidents, ensuring timely response and resolution. Processes are in place to inform relevant management positions and committees about emerging threats and incident response activities. The Director of Information Security provides regular updates on cybersecurity risks and incidents to the Board of Directors, the SPMC, and IT leadership.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag]	true

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Pay vs Performance Disclosure
Net Income (Loss)	$ 109,002	$ 100,339	$ 102,330

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Jan. 03, 2025
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Rule 10b5-1 Arrangement Modified	false
Non-Rule 10b5-1 Arrangement Modified	false

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Jan. 03, 2025
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 1: Summary of Significant Accounting Policies Basis of Presentation Exponent, Inc. together with its subsidiaries (collectively referred to as the “Company”) is a science and engineering consulting firm that provides solutions to complex problems. The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. The Company operates on a 52-53 week fiscal year with each year ending on the Friday closest to December 31 st . Fiscal period 2024 included 53 weeks of activity and ended on January 3, 2025. Fiscal period 2023 included 52 weeks of activity and ended on December 29, 2023. Fiscal period 2022 included 52 weeks of activity and ended on December 30, 2022. Fiscal period 2025 is 52 weeks and will end on January 2, 2026. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the period. Estimates are used for, but not limited to, revenue recognition, allowance for contract losses and doubtful accounts, stock-based compensation, income taxes, goodwill, the useful life of property, equipment and leasehold improvements, and operating lease liabilities. Actual results could differ from those estimates. Foreign Currency Translation The Company translates the assets and liabilities of foreign subsidiaries, whose functional currency is the local currency, at exchange rates in effect at the balance sheet date. Revenues and expenses are translated at the average rates of exchange prevailing during the year. The adjustment resulting from translating the financial statements of such foreign subsidiaries is included in accumulated other comprehensive income/(loss), which is reflected as a separate component of stockholders’ equity. Cash Equivalents Cash equivalents consist of highly liquid investments such as money market mutual funds, commercial paper and debt securities with original remaining maturities of three months or less from the date of purchase. Allowances for Contract Losses and Doubtful Accounts The Company maintains allowances for estimated losses resulting from the inability of customers to meet their financial obligations or for disputes that affect the Company’s ability to fully collect amounts due. In circumstances where the Company is aware of a specific customer’s inability to meet its financial obligations or is aware of a dispute with a specific customer, a specific allowance is recorded to reduce the net recognized receivable to the amount the Company reasonably believes will be collected. For all other customers the Company recognizes allowances for doubtful accounts based upon historical write-offs, customer concentration, customer creditworthiness, current and forecasts of future economic conditions, aging of amounts due and changes in customer payment terms. Property, Equipment and Leasehold Improvements Property, equipment and leasehold improvements are stated at cost less accumulated depreciation and amortization. Depreciation and amortization are recognized using the straight-line method. Buildings are depreciated over their estimated useful lives ranging from 30 to 40 years. Equipment is depreciated over its estimated useful life, which generally ranges from 3 to 7 years. Leasehold improvements are amortized over the shorter of their estimated useful lives, generally 7 years, or the term of the related lease. Impairment of Long-Lived Assets The Company evaluates long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of the assets to future undiscounted cash flows to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured as the amount by which the carrying amount of the assets exceeds the fair value of the assets. The Company has not recognized impairment losses on any long-lived assets in 2024, 2023 or 2022. Goodwill The Company assesses the impairment of goodwill annually and whenever events or changes in circumstances indicate that the carrying amount may be impaired. The Company’s annual goodwill impairment review is completed during the fourth quarter of each year. The Company evaluates goodwill for each reporting unit for impairment by assessing qualitative factors to determine whether it is necessary to perform a quantitative goodwill impairment test. The Company considers events and circumstances, including but not limited to, macroeconomic conditions, industry and market considerations, cost factors, overall financial performance, changes in management or key personnel, changes in strategy, changes in customers, a change in the composition or carrying amount of a reporting unit’s net assets and changes in the price of its common stock. If, after assessing the totality of events or circumstances, the Company determines that it is more likely than not that the fair value of a reporting unit is greater than its carrying amount, then the quantitative goodwill impairment test is not performed. The Company completed its annual assessment for all reporting units with goodwill for 2024 and determined, after assessing the totality of the qualitative factors, that it is more likely than not that the fair value of each reporting unit is greater than its respective carrying amount. Accordingly, there was no indication of impairment of goodwill for any of the Company’s reporting units and the quantitative goodwill impairment test was not performed. The Company did not recognize any goodwill impairment losses in 2024, 2023 or 2022. Deferred Revenues Deferred revenues represent amounts billed to clients in advance of services provided. Income Taxes Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the expected tax consequences of temporary differences between the tax basis and the financial reporting basis of assets and liabilities. Deferred tax assets and liabilities are measured using the enacted tax rates and laws in effect when the differences are expected to reverse. The effect on deferred tax assets and liabilities from changes in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance is recorded for deferred tax assets if it is more likely than not that some portion or all of the deferred tax assets will not be realized. An uncertain tax position is recognized if it is determined that it is more likely than not to be sustained upon examination. The tax position is measured as the largest amount of benefit that is greater than 50% likely of being realized upon ultimate settlement. The Company’s policy is to recognize interest and penalties related to unrecognized tax benefits as income tax expense. Accrued interest and penalties are insignificant at January 3, 2025 and December 29, 2023. Fair Value of Financial Instruments Financial instruments consist of cash and cash equivalents, short-term investments, accounts receivable, other assets and accounts payable. Cash, cash equivalents and short-term investments are recorded at fair value. The carrying amount of the Company’s accounts receivable, other assets and accounts payable approximates their fair values due to their short maturities. Stock-Based Compensation Stock-based compensation is measured at the grant date based on the fair value of the award and is recognized as expense on a straight-line basis over the requisite service period of the entire award. The Company accounts for forfeitures of stock-based awards when they occur. Net Income Per Share Basic per share amounts are computed using the weighted-average number of common shares outstanding during the period. Diluted per share amounts are computed using the weighted-average number of common shares outstanding and potentially dilutive securities, using the treasury stock method if their effect would be dilutive. The following schedule reconciles the denominators of the Company’s calculation for basic and diluted net income per share: Fiscal Years (In thousands) 2024 2023 2022 Shares used in basic per share computation 51,129 51,152 51,727 Effect of dilutive common stock options outstanding 166 188 204 Effect of unvested restricted stock units outstanding 274 295 349 Shares used in diluted per share computation 51,569 51,635 52,280 Common stock options to purchase 30,000 shares were excluded from the diluted per share calculation for 2024 due to their anti-dilutive effect. Common stock options to purchase 59,459 shares were excluded from the diluted per share calculation for 2023 due to their anti-dilutive effect. There were no equity awards excluded from the diluted per share calculation for 2022. Recently Adopted Accounting Pronouncements On November 27, 2023, the Financial Accounting Standards Board (the "FASB") issued Accounting Standards Update ("ASU") 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures . This standard improves reportable segment disclosures by adding and enhancing interim disclosure requirements, clarifying circumstances in which entities can disclose multiple segment measures of profit or loss, providing new segment disclosure requirements for entities with a single reportable segment, and adding the disclosure of significant segment expenses that are regularly provided to the chief operating decision maker within each reported measure of segment profit and loss. This standard is effective for all entities that are subject to Topic 280, Segment Reporting for annual periods beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. The Company has included all required disclosures within its Form 10-K for the year ended December 31, 2024. See Note 17 for further information on segment disclosures. Recent Accounting Pronouncements Not Yet Adopted In November 2024, the FASB issued ASU 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (subtopic 220-40) , which requires disclosure of disaggregation of certain relevant expenses included in the statements of operations on an annual and interim basis. ASU 2024-03 will be effective for our annual periods beginning January 1, 2027 and interim periods beginning January 1, 2028. The amendments must be applied retrospectively, and early adoption is permitted. The Company is currently evaluating the effects of adoption on our consolidated financial statements.

Revenue Recognition

Revenue Recognition	12 Months Ended
	Jan. 03, 2025
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Note 2: Revenue Recognition Substantially all of the Company’s engagements are performed under time and materials or fixed-price arrangements. For time and materials contracts, the Company utilizes the practical expedient under Accounting Standards Codification 606 – Revenue from Contracts with Customers , which states, if an entity has a right to consideration from a customer in an amount that corresponds directly with the value of the entity’s performance completed to date (for example, a service contract in which an entity bills a fixed amount for each hour of service provided), the entity may recognize revenue in the amount to which the entity has a right to invoice. The following table discloses the percent of the Company’s revenue generated from time and materials contracts: Fiscal Years 2024 2023 2022 Engineering & Other Scientific 64 % 63 % 63 % Environmental and Health 15 % 15 % 16 % Total time and materials revenues 79 % 78 % 79 % For fixed-price contracts, the Company recognizes revenue over time because of the continuous transfer of control to the customer. The customer typically controls the work in process as evidenced either by contractual termination clauses or by the Company’s rights to payment for work performed to date to deliver services that do not have an alternative use to the Company. Revenue for fixed-price contracts is recognized based on the relationship of incurred labor hours at standard rates to the Company’s estimate of the total labor hours at standard rates it expects to incur over the term of the contract. The Company believes this methodology achieves a reliable measure of the revenue from the consulting services it provides to its customers under fixed-price contracts given the nature of the consulting services the Company provides. The following table discloses the percent of the Company’s revenue generated from fixed price contracts: Fiscal Years 2024 2023 2022 Engineering & Other Scientific 20 % 20 % 20 % Environmental and Health 1 % 2 % 1 % Total fixed price revenues 21 % 22 % 21 % Deferred revenues represent amounts billed to clients in advance of services provided. During 2024, $ 14,173,000 of revenues were recognized that were included in the deferred revenue balance at December 29, 2023. During 2023, $ 14,463,000 of revenues were recognized that were included in the deferred revenue balance at December 30, 2022. During 2022, $ 15,384,000 of revenues were recognized that were included in the deferred revenue balance at December 31, 2021. Reimbursements, including those related to travel and other out-of-pocket expenses, and other similar third-party costs such as the cost of materials and certain subcontracts, are included in revenues, and an equivalent amount of reimbursable expenses are included in operating expenses. Any service fee associated with reimbursable expenses is included in revenues before reimbursements. The Company reports revenues net of subcontractor fees for certain subcontracts where the Company has determined that it is acting as an agent because its performance obligation is to arrange for and not control the provision of goods or services by another party. The total amount of subcontractor fees not included in revenues because the Company was acting as an agent were $ 10,970,000 , $ 12,268,000 and $ 28,754,000 during 2024, 2023 and 2022, respectively.

Cash and cash equivalents

Cash and cash equivalents	12 Months Ended
	Jan. 03, 2025
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	Note 3: Cash and cash equivalents Cash and cash equivalents consisted of the following as of January 3, 2025: Estimated (In thousands) Amortized Unrealized Unrealized Fair Classified as current assets: Cash $ 201,352 $ — $ — $ 201,352 Cash equivalents: Money market securities 57,549 — — 57,549 Total cash equivalents 57,549 — — 57,549 Total cash and cash equivalents 258,901 — — 258,901 Cash and cash equivalents consisted of the following as of December 29, 2023: Estimated (In thousands) Amortized Unrealized Unrealized Fair Classified as current assets: Cash $ 132,464 $ — $ — $ 132,464 Cash equivalents: Money market securities 54,686 — — 54,686 Total cash equivalents 54,686 — — 54,686 Total cash and cash equivalents 187,150 — — 187,150

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Jan. 03, 2025
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 4: Fair Value Measurements The Company measures certain financial assets and liabilities at fair value on a recurring basis, including available-for-sale fixed income securities, trading fixed income and equity securities held in its deferred compensation plan and the liability associated with its deferred compensation plan. There have been no transfers between fair value measurement levels during 2024, 2023 and 2022. Any transfers between fair value measurement levels would be recorded on the actual date of the event or change in circumstances that caused the transfer. The fair value of these certain financial assets and liabilities was determined using the following inputs at January 3, 2025 (in thousands): Fair Value Measurements at Reporting Date Using Total Quoted Significant Significant Assets Money market securities (1) $ 57,549 $ 57,549 $ — $ — Fixed income trading securities held in (2) 42,291 42,291 — — Equity trading securities held in deferred (2) 85,546 85,546 — — Total $ 185,386 $ 185,386 $ — $ — Liabilities Deferred compensation plan (3) 127,622 127,622 — — Total $ 127,622 $ 127,622 $ — $ — (1) Included in cash and cash equivalents on the Company’s consolidated balance sheet. (2) Included in prepaid expenses and other current assets and deferred compensation plan assets on the Company’s consolidated balance sheet. (3) Included in accounts payable and accrued liabilities and deferred compensation plan liabilities on the Company’s consolidated balance sheet. The fair value of these certain financial assets and liabilities was determined using the following inputs at December 29, 2023 (in thousands): Fair Value Measurements at Reporting Date Using Total Quoted Significant Significant Assets Money market securities (1) $ 54,686 $ 54,686 $ — $ — Fixed income trading securities held in (2) 36,788 36,788 — — Equity trading securities held in deferred (2) 78,399 78,399 — — Total $ 169,873 $ 169,873 $ — $ — Liabilities Deferred compensation plan (3) 116,564 116,564 — — Total $ 116,564 $ 116,564 $ — $ — (1) Included in cash and cash equivalents on the Company’s consolidated balance sheet. (2) Included in prepaid expenses and other current assets and deferred compensation plan assets on the Company’s consolidated balance sheet. (3) Included in accounts payable and accrued liabilities and deferred compensation plan liabilities on the Company’s consolidated balance sheet. Fixed income and equity trading securities as of January 3, 2025 and December 29, 2023 represent mutual funds held in the Company’s deferred compensation plan. See Note 11 for additional information about the Company’s deferred compensation plan. The following financial instruments are not measured at fair value on the Company's consolidated balance sheet at January 3, 2025, but require disclosure of their fair values: accounts receivable, other assets and accounts payable. The estimated fair value of such instruments at January 3, 2025 approximates their carrying value as reported on the consolidated balance sheet. There were no other-than-temporary impairments or credit losses related to available-for-sale securities during 2024, 2023 and 2022.

Property, Equipment and Leaseho

Property, Equipment and Leasehold Improvements	12 Months Ended
	Jan. 03, 2025
Property, Plant and Equipment [Abstract]
Property, Equipment and Leasehold Improvements	Note 5: Property, Equipment and Leasehold Improvements Fiscal Years (In thousands) 2024 2023 Property: Land $ 18,339 $ 18,339 Buildings 70,416 69,698 Construction in progress 219 1,114 Equipment: Machinery and equipment 57,041 54,008 Office furniture and equipment 13,749 12,411 Leasehold improvements 25,445 23,759 185,209 179,329 Less accumulated depreciation and amortization 112,202 104,011 Property, equipment and leasehold improvements, net $ 73,007 $ 75,318 Depreciation and amortization for 2024, 2023 and 2022 was $ 9,689,000 , $ 8,916,000 and $ 7,079,000 , respectively.

Other Significant Balance Sheet

Other Significant Balance Sheet Components	12 Months Ended
	Jan. 03, 2025
Significant Balance Sheet Components [Abstract]
Other Significant Balance Sheet Components	Note 6: Other Significant Balance Sheet Components Account receivable, net Fiscal Years (In thousands) 2024 2023 Billed accounts receivable $ 117,503 $ 128,052 Unbilled accounts receivable 50,045 44,589 Allowance for contract losses and doubtful accounts ( 6,141 ) ( 5,281 ) Total accounts receivable, net $ 161,407 $ 167,360 Accounts payable and accrued liabilities Fiscal Years (In thousands) 2024 2023 Accounts payable $ 5,272 $ 4,489 Accrued liabilities 16,864 17,636 Total accounts payable and other accrued liabilities $ 22,136 $ 22,125 Accrued payroll and employee benefits Fiscal Years (In thousands) 2024 2023 Accrued bonuses payable $ 76,844 $ 68,415 Accrued 401(k) contributions 10,807 11,138 Accrued vacation 14,433 13,492 Deferred compensation plan 14,976 13,166 Other accrued payroll and employee benefits 2,225 5,562 Total accrued payroll and employee benefits $ 119,285 $ 111,773 Other accrued payroll and employee benefits consist primarily of accrued wages, payroll taxes and disability insurance programs. A portion of accrued bonuses payable will be settled by issuing fully vested restricted stock units. See Note 9 and Note 16 for additional information.

Income Taxes

Income Taxes	12 Months Ended
	Jan. 03, 2025
Income Tax Disclosure [Abstract]
Income Taxes	Note 7: Income Taxes Income before income taxes includes income from foreign operations of $ 13,135,000 , $ 10,353,000 and $ 10,646,000 for 2024, 2023 and 2022, respectively. Total income tax expense for 2024, 2023 and 2022 consisted of the following: Fiscal Years (In thousands) 2024 2023 2022 Current Federal $ 28,237 $ 23,193 $ 24,411 Foreign 3,041 2,254 1,973 State 10,393 10,025 10,883 41,671 35,472 37,267 Deferred Federal ( 2,665 ) ( 775 ) ( 4,910 ) State ( 638 ) 860 ( 2,453 ) ( 3,303 ) 85 ( 7,363 ) Total $ 38,368 $ 35,557 $ 29,904 The Company’s effective tax rate differs from the statutory federal tax rate of 21 % as shown in the following schedule: Fiscal Years (In thousands) 2024 2023 2022 Tax at federal statutory rate $ 30,948 $ 28,538 $ 27,769 State taxes, net of federal benefit 7,699 8,587 6,726 Non-deductible officer compensation 1,787 870 1,160 Non-deductible expenses 427 456 52 Non-deductible stock-based compensation 14 12 12 Excess tax benefit from equity incentive plans ( 2,239 ) ( 2,844 ) ( 4,533 ) Difference between statutory rate and foreign effective tax rate ( 194 ) ( 264 ) ( 693 ) Other ( 74 ) 202 ( 589 ) Tax expense $ 38,368 $ 35,557 $ 29,904 Effective tax rate 26.0 % 26.2 % 22.6 % The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities at January 3, 2025 and December 29, 2023 are presented in the following schedule: Fiscal Years (In thousands) 2024 2023 Deferred tax assets: Accrued liabilities and allowances $ 22,831 $ 21,235 Deferred compensation plan 43,222 40,280 Operating leases 22,782 7,853 Total deferred tax assets $ 88,835 $ 69,368 Deferred tax liabilities: State taxes $ ( 2,310 ) $ ( 2,255 ) Deductible goodwill ( 2,065 ) ( 2,071 ) Operating leases ( 22,782 ) ( 7,853 ) Unrealized gain of deferred compensation plan assets ( 3,319 ) ( 1,652 ) Property, equipment and leasehold improvements ( 1,232 ) ( 1,695 ) Other — ( 18 ) Total deferred tax liabilities ( 31,708 ) ( 15,544 ) Net deferred tax assets $ 57,127 $ 53,824 Management believes it is more likely than not that the results of future operations will generate sufficient taxable income to realize the net deferred tax assets. The Company is entitled to a deduction for federal and state tax purposes with respect to employees’ stock award activity. The net reduction in taxes otherwise payable arising from that deduction has been recorded as an income tax benefit. For 2024, 2023 and 2022, the net reduction in tax payable arising from employees’ stock award activity was $ 2,793,000 , $ 3,620,000 and $ 5,829,000 , respectively. The Company and its subsidiaries file income tax returns in the United States federal jurisdiction, California and various other state and foreign jurisdictions. The Company is no longer subject to United States federal income tax examination for years prior to 2021. The Company is no longer subject to California franchise tax examinations for years prior to 2020. With few exceptions, the Company is no longer subject to state and local or non-United States income tax examination by tax authorities for years prior to 2020. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands): Balance at December 30, 2022 $ 2,047 Additions based on tax positions related to the current year 571 Reductions due to lapse of statute of limitations ( 473 ) Balance at December 29, 2023 $ 2,145 Additions based on tax positions related to the current year 651 Reductions due to lapse of statute of limitations ( 369 ) Balance at January 3, 2025 $ 2,427 Unrecognized tax benefits are included in other liabilities in the accompanying consolidated balance sheets. To the extent these unrecognized tax benefits are ultimately recognized, they will impact the effective tax rate by $ 1,918,000 in a future period. There are no uncertain tax positions whose resolution in the next 12 months is expected to materially affect operating results.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Jan. 03, 2025
Stockholders' Equity Note [Abstract]
Stockholders' Equity	Note 8: Stockholders’ Equity Preferred Stock The Company has authorized 2,000,000 shares of undesignated preferred stock with a par value of $ 0.001 per share. None of the preferred shares were issued and outstanding at January 3, 2025 and December 29, 2023. Dividends The Company declared and paid cash dividends per share of common stock during the periods presented as follows: Fiscal Year 2024 Dividends Amount Per Share (in thousands) First Quarter $ 0.280 $ 14,159 Second Quarter $ 0.280 14,193 Third Quarter $ 0.280 14,212 Fourth Quarter $ 0.280 14,226 $ 56,790 Fiscal Year 2023 Dividends Amount Per Share (in thousands) First Quarter $ 0.260 $ 13,169 Second Quarter $ 0.260 13,217 Third Quarter $ 0.260 13,177 Fourth Quarter $ 0.260 13,148 $ 52,711 Treasury Stock Net losses related to the re-issuance of treasury stock to settle restricted stock unit and stock option awards of $ 720,000 , $ 1,009,000 and $ 1,392,000 were recorded as a reduction to retained earnings during 2024, 2023 and 2022, respectively. Repurchase of Common Stock The Company repurchased 74,000 shares of its common stock for $ 5,710,000 during 2024. The Company repurchased 288,000 shares of its common stock for $ 24,208,000 during 2023. The Company repurchased 1,756,000 shares of its common stock for $ 155,856,000 during 2022. On February 1, 2024, the Board of Directors authorized $ 61,600,000 for the repurchase of the Company’s common stock. On February 22, 2022, the Board of Directors authorized $ 150,000,000 for the repurchase of the Company’s common stock. These repurchase programs have no expiration dates. As of January 3, 2025, the Company had remaining authorization under its stock repurchase plan of $ 94,290,000 to repurchase shares of common stock.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Jan. 03, 2025
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Note 9: Stock-Based Compensation On May 29, 2008, the Company’s stockholders approved the 2008 Equity Incentive Plan and the 2008 Employee Stock Purchase Plan (“ESPP”). The 2008 Equity Incentive Plan and ESPP were previously adopted by the Company’s Board of Directors on April 8, 2008, subject to stockholder approval. The 2008 Equity Incentive Plan allows for the award of stock options, stock awards (including stock units, stock grants and stock appreciation rights or other similar equity awards) and cash awards to officers, employees, consultants and non-employee members of the Board of Directors. The total number of shares reserved for issuance under the 2008 Equity Incentive Plan was 13,336,300 shares of common stock, subject to adjustment resulting from a stock split or the payment of a stock dividend or any other increase or decrease in the number of issued shares of the Company’s stock effected without receipt of consideration by the Company. As of January 3, 2025, 2,313,565 shares were available for grant under the 2008 Equity Incentive Plan. The ESPP allows for officers and employees to purchase common stock through payroll deductions of up to 15 % of a participant’s eligible compensation. Shares of common stock are purchased under the ESPP at 95 % of the fair market value of the Company’s common stock on each purchase date. Subject to adjustment resulting from a stock split or the payment of a stock dividend or any other increase or decrease in the number of issued shares of the Company’s stock effected without receipt of consideration by the Company, the total number of shares reserved for issuance under the ESPP was 1,200,000 shares of common stock. As of January 3, 2025, 275,324 shares were available for grant. Weighted average purchase prices for shares sold under the ESPP plan in 2024, 2023 and 2022 were $ 88.70 , $ 87.12 and $ 91.17 , respectively. Restricted Stock Units The Company grants restricted stock units to employees and outside directors. These restricted stock unit grants are designed to attract and retain employees, and to better align employee interests with those of the Company’s stockholders. For a select group of employees, up to 40 % of their annual bonus is settled with fully vested restricted stock unit awards. Under these fully vested restricted stock unit awards, the holder of each award has the right to receive one share of the Company’s common stock for each fully vested restricted stock unit four years from the date of grant. Each individual who received a fully vested restricted stock unit award is granted a matching number of unvested restricted stock unit awards. These unvested restricted stock unit awards cliff vest four years from the date of grant, at which time the holder of each award will have the right to receive one share of the Company’s common stock for each restricted stock unit award, provided the holder of each award has met certain employment conditions. In the case of retirement at 59 ½ years or older, all unvested restricted stock unit awards will continue to vest provided the holder of each award performs all consulting work through the Company and does not become an employee for a past or present client, beneficial party or competitor of the Company. All restricted stock units granted have dividend equivalent rights (“DER”), which entitle holders of restricted stock units to the same dividend value per share as holders of common stock. DER are subject to the same vesting and other terms and conditions as the corresponding unvested restricted stock units. DER are accumulated and paid when the underlying shares vest and are forfeited if the underlying shares are forfeited. The value of these restricted stock unit awards is determined based on the market price of the Company’s common stock on the date of grant. The value of fully vested restricted stock unit awards issued is recorded as a reduction to accrued bonuses. The portion of bonus expense that the Company expects to settle with fully vested restricted stock unit awards is recorded as stock-based compensation during the period the bonus is earned. For 2024, 2023 and 2022, the Company recorded stock-based compensation expense associated with accrued bonus awards of $ 12,182,000 , $ 10,445,000 and $ 10,365,000 , respectively. The Company recorded stock-based compensation expense associated with the unvested restricted stock unit awards of $ 9,634,000 , $ 8,831,000 and $ 9,164,000 during 2024, 2023 and 2022, respectively. The total fair value of restricted stock unit awards vested during 2024, 2023 and 2022 was $ 21,286,000 , $ 25,277,000 and $ 29,875,000 , respectively. The weighted-average grant date fair values of restricted stock unit awards granted during 2024, 2023 and 2022 were $ 79.59 , $ 99.47 and $ 94.24 , respectively. The number of unvested restricted stock unit awards outstanding as of January 3, 2025 is as follows (1) : Number Weighted- Weighted- Aggregate (2) Balance at December 29, 2023 418,708 $ 88.78 Awards granted 284,912 79.59 Awards vested ( 266,859 ) 74.70 Awards forfeited ( 23,465 ) 90.72 Balance at January 3, 2025 413,296 $ 91.43 1.9 $ 36,746 (1) Does not include employee stock purchase plans or stock option plans. (2) The intrinsic value is calculated as the market value as of the end of the fiscal period. As reported by the NASDAQ Global Select Market, the market value as of January 3, 2025 was $ 88.91 . Stock Options The Company currently grants stock options under the 2008 Equity Incentive Plan. Options are granted for terms of 10 years and generally vest ratably over a four-year period from the grant date. In the case of retirement at 59 ½ years or older, all unvested stock options will continue to vest provided the holder of each option does all consulting work through the Company and does not become an employee for a past or present client, beneficial party, or competitor of the Company. The Company grants options at exercise prices equal to the fair value of the Company’s common stock on the date of grant. All stock options have DER, which entitle holders of stock options to the same dividend value per share as holders of common stock. DER are subject to the same vesting terms as the corresponding stock options. DER are accumulated and paid in cash when the underlying stock options vest and are forfeited if the underlying stock options do not vest. During 2024, 2023 and 2022, the Company recorded stock-based compensation expense of $ 1,423,000 , $ 1,081,000 and $ 835,000 , respectively, associated with stock options. Option activity is as follows (1) : Number Weighted- Weighted- Aggregate Exercisable at December 29, 2023 463,235 $ 51.86 Options granted 40,000 75.87 Options forfeited and expired — — Options exercised ( 124,206 ) 31.37 Balance at January 3, 2025 379,029 $ 61.11 4.80 $ 11,267 Exercisable at January 3, 2025 289,446 $ 52.79 3.76 $ 10,726 (1) Does not include restricted stock or employee stock purchase plans. The total intrinsic value of options exercised during 2024, 2023 and 2022 was $ 8,410,000 , $ 742,000 and $ 0 , respectively. The aggregate intrinsic value in the table above represents the total pre-tax intrinsic value (the difference between the Company’s closing stock price on the last trading day of the fiscal year ended January 3, 2025, and the exercise price, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their options on January 3, 2025. This amount changes based on the fair-value of the Company’s stock. The Company uses the Black-Scholes option-pricing model to determine the fair value of options granted. The determination of the fair value of stock-based payment awards on the date of grant using an option-pricing model is affected by the Company’s stock price as well as assumptions regarding a number of complex and subjective variables. These variables include expected stock price volatility over the term of the award, actual and projected employee stock option exercise behaviors, the risk-free interest rate and expected dividends. The Company used historical exercise and post-vesting forfeiture and expiration data to estimate the expected term of options granted. The historical volatility of the Company’s common stock over a period of time equal to the expected term of the options granted was used to estimate expected volatility. The risk-free interest rate used in the option-pricing model was based on United States Treasury zero coupon issues with remaining terms similar to the expected term on the options. The dividend yield assumption considers the expectation of continued declaration of dividends, offset by option holders’ DER. All stock-based payment awards are recognized on a straight-line basis over the requisite service periods of the awards. The assumptions used to value option grants for 2024, 2023 and 2022 are as follows: Stock Option Plan Fiscal Years 2024 2023 2022 Expected term (in years) 5.7 5.8 5.6 Risk-free interest rate 4.26 % 3.99 % 1.90 % Volatility 30 % 29 % 28 % Dividend yield 0 % 0 % 0 % The weighted-average grant date fair value of options granted during 2024, 2023 and 2022 were $ 28.36 , $ 38.29 and $ 26.64 , respectively. The amount of stock-based compensation expense and the related income tax benefit recognized in the Company’s consolidated statements of income for 2024, 2023 and 2022 is as follows: Fiscal Years (In thousands) 2024 2023 2022 Compensation and related expenses: Restricted stock units $ 21,086 $ 18,542 $ 18,810 Stock option grants 1,423 1,081 835 Sub-total 22,509 19,623 19,645 General and administrative expenses: Restricted stock units 730 734 719 Sub-total 730 734 719 Total stock-based compensation expense $ 23,239 $ 20,357 $ 20,364 Income tax benefit $ 2,793 $ 3,620 $ 5,829 As of January 3, 2025, there was $ 12,984,000 of unrecognized compensation cost, expected to be recognized over a weighted average period of 2.5 years, related to unvested restricted stock unit awards and $ 1,253,000 of unrecognized compensation cost, expected to be recognized over a weighted average period of 2.1 years, related to unvested stock options.

Retirement Plans

Retirement Plans	12 Months Ended
	Jan. 03, 2025
Pension and Other Postretirement Benefits Cost (Reversal of Cost) [Abstract]
Retirement Plans	Note 10: Retirement Plans The Company provides a defined contribution retirement plan for its employees whereby the Company contributes to each eligible employee’s account 7 % of the employee’s eligible salary. The employee does not need to make a contribution to the plan to be eligible for the Company’s 7 % contribution. To be eligible under the plan, an employee must be at least 21 years of age and be either a full-time or part-time salaried employee. The 7 % Company contribution will vest 20 % per year for the first five years of employment and then immediately thereafter. These contributions are made to the 401(k) plan up to the statutory maximum. Any portion of the 7 % contribution in excess of the statutory maximum is made to the Company’s nonqualified deferred compensation plan. The Company’s expenses related to this plan were $ 11,704,000 , $ 11,867,000 and $ 10,166,000 in 2024, 2023 and 2022, respectively.

Deferred Compensation Plans

Deferred Compensation Plans	12 Months Ended
	Jan. 03, 2025
Deferred Compensation Arrangements [Abstract]
Deferred Compensation Plans	Note 11: Deferred Compensation Plans The Company maintains nonqualified deferred compensation plans for the benefit of a select group of highly compensated employees. Under these plans, participants may elect to defer up to 100 % of their compensation. Company assets that are earmarked to pay benefits under the plans are held in a rabbi trust and are subject to the claims of the Company’s creditors. As of January 3, 2025 and December 29, 2023, invested amounts under the plans totaled $ 127,837,000 and $ 115,187,000 , respectively. These assets are classified as trading securities and are recorded at fair market value with changes recorded as adjustments to miscellaneous income, net. As of January 3, 2025 and December 29, 2023, vested amounts due under the plans totaled $ 127,622,000 and $ 116,564,000 , respectively. Changes in the liability are recorded as adjustments to compensation and related expense. During 2024, 2023 and 2022, the Company recognized compensation expense of $ 14,928,000 , $ 14,315,000 and ($ 14,187,000 ), respectively, as a result of changes in the market value of the trust assets with the same amount being recorded as other income, net.

Leases

Leases	12 Months Ended
	Jan. 03, 2025
Leases [Abstract]
Leases	Note 12: Leases The Company determines if an arrangement is a lease at the inception of the arrangement. Operating leases are included in operating lease right-of-use (“ROU”) assets, current operating lease liabilities, and long-term operating lease liabilities in the Company’s consolidated balance sheet. The Company does not have any finance leases as of January 3, 2025. ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate, based on the information available at commencement date, in determining the present value of lease payments. The operating lease ROU asset also includes any lease payments made and excludes lease incentives. The Company’s lease terms include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term. The amortization of operating lease ROU assets and the change in operating lease liabilities is disclosed as a single line item in the consolidated statements of cash flows. The Company leases office, laboratory, and storage space in 13 states and the District of Columbia, as well as in China, Hong Kong, Singapore, Switzerland and the United Kingdom. Leases for these office, laboratory, and storage facilities have terms generally ranging between one and 10 years. Some of these leases include options to extend or terminate the lease, none of which are currently included in the lease term as the Company has determined that exercise of these options is not reasonably certain. The Company has a Test and Engineering Center on 147 acres of land in Phoenix, Arizona. The Company leases this land from the state of Arizona under a 30 -year lease agreement that expires in January of 2028 and has options to renew for two 15-year periods. On June 19, 2024, the Company entered into an agreement with the State of Arizona to extend this lease for 15 years beginning on January 17, 2028. The Company is currently obligated to make payments under the lease of $ 1,009,000 per year, which obligation will continue at that level until January 16, 2028. Beginning on January 17, 2028, the Company’s payments under the lease will increase to approximately $ 6,183,000 per year for the 15-year extension term with adjustments to the annual rent payment in 2033 and 2038 based on the consumer price index. As a result of this extension, the Company added an additional right-of-use asset in exchange for an operating lease liability of $ 48,683,000 during the second quarter of 2024. As of January 3, 2025, the Company has determined that the exercise of the second renewal option is not reasonably certain and thus that extension is not included in the lease term. The Company’s equipment leases are included in the ROU asset and liability balances, but are not material. The components of lease expense included in other operating expenses on the consolidated statements of income were as follows: Fiscal Year Fiscal Year Fiscal Year (In thousands) 2024 2023 2022 Operating lease cost $ 11,061 $ 7,732 $ 7,050 Variable lease cost 1,425 1,635 1,263 Short-term lease cost 1,345 1,174 651 Supplemental cash flow information related to operating leases was as follows: Fiscal Year Fiscal Year Fiscal Year (In thousands) 2024 2023 2022 Cash paid for amounts included in the measurement of operating lease liabilities $ 7,559 $ 7,249 $ 6,564 Supplemental balance sheet information related to operating leases was as follows: Fiscal Year Fiscal Year Fiscal Year 2024 2023 2022 Weighted Average Remaining Lease Term 13.7 years 6.1 years 4.1 years Weighted Average Discount Rate 6.3 % 5.1 % 4.3 % Maturities of operating lease liabilities as of January 3, 2025: Operating (In thousands) Leases 2025 8,001 2026 7,756 2027 6,633 2028 9,666 2029 9,390 Thereafter 89,052 Total lease payments $ 130,498 Less imputed interest 49,021 Total lease liability $ 81,477

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Jan. 03, 2025
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 13: Commitments and Contingencies The Company is a party to various legal actions from time to time and may be contingently liable in connection with claims and contracts arising in the normal course of business, the outcome of which the Company believes, after consultation with legal counsel, will not have a material adverse effect on its financial condition, results of operations or liquidity. However, due to the risks and uncertainties inherent in legal proceedings, actual results could differ from current expected results. All legal costs associated with litigation are expensed as incurred.

Miscellaneous Income, Net

Miscellaneous Income, Net	12 Months Ended
	Jan. 03, 2025
Other Income and Expenses [Abstract]
Miscellaneous Income, Net	Note 14: Miscellaneous Income, Net Miscellaneous income, net, consisted of the following: Fiscal Years (In thousands) 2024 2023 2022 Rental income $ 2,853 $ 3,371 $ 2,938 Gain (loss) on deferred compensation investments 14,928 14,315 ( 14,187 ) Gain (loss) on foreign exchange ( 14 ) ( 259 ) 522 Other 45 ( 3 ) 23 Total $ 17,812 $ 17,424 $ ( 10,704 )

Industry and Client Credit Risk

Industry and Client Credit Risk	12 Months Ended
	Jan. 03, 2025
Risks and Uncertainties [Abstract]
Industry and Client Credit Risk	Note 15: Industry and Client Credit Risk The Company serves clients in various segments of the economy. During 2024, the Company provided services representing approxima tely 24 %, 19 %, 16 % and 10 % of r evenues to clients in the consumer products industry, energy and utilities industries, the transportation industry and the chemical industry, respectively. No single client comprised more than 10 % of the Company’s revenues during 2024 or 2023. One client comprised 15 % of the Company’s revenues during 2022.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	12 Months Ended
	Jan. 03, 2025
Supplemental Cash Flow Information [Abstract]
Supplemental Cash Flow Information	Note 16: Supplemental Cash Flow Information The following is supplemental disclosure of cash flow information: Fiscal Years (In thousands) 2024 2023 2022 Cash paid during the year: Income taxes $ 39,723 $ 38,944 $ 40,121 Non-cash investing and financing activities: Vested stock unit awards granted to settle accrued bonus 10,846 10,496 10,200 Right-of-use asset obtained in exchange for operating 58,032 15,749 9,476 Leasehold improvements obtained in exchange for right-of-use asset - 3,219 - Accrual for capital expenditures 575 137 1,017

Segment Reporting

Segment Reporting	12 Months Ended
	Jan. 03, 2025
Segment Reporting [Abstract]
Segment Reporting	Note 17: Segment Reporting The Company has two reportable operating segments based on two primary areas of service. The Engineering and Other Scientific segment is a broad service group providing technical consulting in different practices primarily in engineering. The Environmental and Health segment provides services in the area of environmental, epidemiology and health risk analysis. This segment provides a wide range of consulting services relating to environmental hazards and risks and the impact on both human health and the environment. Segment information is presented for selected data from the statements of income and statements of cash flows for 2024, 2023 and 2022. Segment information for selected data from the balance sheets is presented for the fiscal years ended January 3, 2025 and December 29, 2023. The Company’s CEO, the chief operating decision maker, does not review total assets in her evaluation of segment performance and capital allocation. Revenues Fiscal Years (In thousands) 2024 2023 2022 Engineering and Other Scientific $ 469,544 $ 446,888 $ 427,796 Environmental and Health 88,970 89,878 85,497 Total revenues $ 558,514 $ 536,766 $ 513,293 Compensation and related expenses Fiscal Years (In thousands) 2024 2023 2022 Engineering and Other Scientific $ 223,395 $ 215,650 $ 195,243 Environmental and Health 47,600 48,619 47,288 Total segment compensation and related expenses 270,995 264,269 242,531 Corporate compensation and related expenses 59,016 55,617 21,704 Total compensation and related expenses $ 330,011 $ 319,886 $ 264,235 Certain expenses are excluded from the Company’s measure of segment compensation and related expenses. These include the deferred compensation expense/benefit due to changes in value of assets associated with the Company’s deferred compensation plan; stock-based compensation associated with restricted stock unit and stock option awards, and the compensation costs associated with the Company’s human resources, finance, information technology, corporate, and business development groups. Operating Income Fiscal Years (In thousands) 2024 2023 2022 Engineering and Other Scientific $ 164,883 $ 153,918 $ 152,679 Environmental and Health 29,995 28,432 27,340 Total segment operating income 194,878 182,350 180,019 Corporate operating expense ( 75,321 ) ( 71,028 ) ( 39,177 ) Total operating income $ 119,557 $ 111,322 $ 140,842 Certain operating expenses are excluded from the Company's measure of segment operating income. These expenses include the costs associated with the Company’s human resources, finance, information technology, corporate, and business development groups; the deferred compensation expense/benefit due to the change in value of assets associated with the Company’s deferred compensation plan; stock-based compensation associated with restricted stock unit and stock option awards; and the change in the Company’s allowance for contract losses and doubtful accounts. Capital Expenditures Fiscal Years (In thousands) 2024 2023 2022 Engineering and Other Scientific $ 3,257 $ 3,895 $ 4,661 Environmental and Health 77 170 174 Total segment capital expenditures 3,334 4,065 4,835 Corporate capital expenditures 4,043 14,630 7,812 Total capital expenditures $ 7,377 $ 18,695 $ 12,647 Certain capital expenditures associated with the Company's corporate cost centers and the related depreciation are excluded from the Company's segment information. Depreciation and Amortization Fiscal Years (In thousands) 2024 2023 2022 Engineering and Other Scientific $ 6,833 $ 6,087 $ 4,489 Environmental and Health 206 213 171 Total segment depreciation and amortization 7,039 6,300 4,660 Corporate depreciation and amortization 2,650 2,616 2,419 Total depreciation and amortization $ 9,689 $ 8,916 $ 7,079 Information regarding the Company’s operations in different geographical areas: Property, Equipment and Leasehold Improvements, net Fiscal Years (In thousands) 2024 2023 United States $ 72,418 $ 74,668 Foreign Countries 589 650 Total $ 73,007 $ 75,318 Revenues (1) Fiscal Years (In thousands) 2024 2023 2022 United States $ 493,067 $ 470,078 $ 450,445 Foreign Countries 65,447 66,688 62,848 Total $ 558,514 $ 536,766 $ 513,293 (1) Geographic revenues are allocated based on the location of the client. Below is a breakdown of goodwill, reported by segment as of January 3, 2025 and December 29, 2023: (In thousands) Environmental Engineering Total Goodwill $ 8,099 $ 508 $ 8,607 There were no changes in the carrying amount of goodwill for 2024, 2023 and 2022. There were no goodwill impairments or gains or losses on disposals for any portion of the Company’s reporting units during 2024, 2023, and 2022.

Subsequent Events

Subsequent Events	12 Months Ended
	Jan. 03, 2025
Subsequent Events [Abstract]
Subsequent Events	Note 18: Subsequent Events On February 6, 2025 , the Company announced that its Board of Directors had declared a quarterly cash dividend of $ 0.30 per share to be paid on March 21, 2025 to all common stockholders of record as of March 7, 2025 .

Schedule II Valuation and Quali

Schedule II Valuation and Qualifying Accounts	12 Months Ended
	Jan. 03, 2025
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Valuation and Qualifying Accounts	Sched ule II Valuation and Qualifying Accounts Additions Deletions (1) (In thousands) Balance at Provision Provision Accounts Balance Year Ended January 3, 2025 Allowance for bad debt $ 1,162 $ 993 $ — $ ( 804 ) $ 1,351 Allowance for contract losses $ 4,119 $ — $ 3,457 $ ( 2,786 ) $ 4,790 Year Ended December 29, 2023 Allowance for bad debt $ 1,239 $ 856 $ — $ ( 933 ) $ 1,162 Allowance for contract losses $ 4,954 $ — $ 2,368 $ ( 3,203 ) $ 4,119 Year Ended December 30, 2022 Allowance for bad debt $ 973 $ 455 $ — $ ( 189 ) $ 1,239 Allowance for contract losses $ 3,450 $ — $ 2,626 $ ( 1,122 ) $ 4,954 (1) Balance includes currency translation adjustments. Recoveries of accounts receivable previously written off were $ 74,000 , $ 181,000 and $ 11,000 for 2024, 2023 and 2022, respectively. Schedules other than above have been omitted since they are either not required, not applicable, or the information is otherwise included in the Annual Report on Form 10-K.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Jan. 03, 2025
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation Exponent, Inc. together with its subsidiaries (collectively referred to as the “Company”) is a science and engineering consulting firm that provides solutions to complex problems. The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. The Company operates on a 52-53 week fiscal year with each year ending on the Friday closest to December 31 st . Fiscal period 2024 included 53 weeks of activity and ended on January 3, 2025. Fiscal period 2023 included 52 weeks of activity and ended on December 29, 2023. Fiscal period 2022 included 52 weeks of activity and ended on December 30, 2022. Fiscal period 2025 is 52 weeks and will end on January 2, 2026.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the period. Estimates are used for, but not limited to, revenue recognition, allowance for contract losses and doubtful accounts, stock-based compensation, income taxes, goodwill, the useful life of property, equipment and leasehold improvements, and operating lease liabilities. Actual results could differ from those estimates.
Foreign Currency Translation	Foreign Currency Translation The Company translates the assets and liabilities of foreign subsidiaries, whose functional currency is the local currency, at exchange rates in effect at the balance sheet date. Revenues and expenses are translated at the average rates of exchange prevailing during the year. The adjustment resulting from translating the financial statements of such foreign subsidiaries is included in accumulated other comprehensive income/(loss), which is reflected as a separate component of stockholders’ equity.
Cash Equivalents	Cash Equivalents Cash equivalents consist of highly liquid investments such as money market mutual funds, commercial paper and debt securities with original remaining maturities of three months or less from the date of purchase.
Allowances for Contract Losses and Doubtful Accounts	Allowances for Contract Losses and Doubtful Accounts The Company maintains allowances for estimated losses resulting from the inability of customers to meet their financial obligations or for disputes that affect the Company’s ability to fully collect amounts due. In circumstances where the Company is aware of a specific customer’s inability to meet its financial obligations or is aware of a dispute with a specific customer, a specific allowance is recorded to reduce the net recognized receivable to the amount the Company reasonably believes will be collected. For all other customers the Company recognizes allowances for doubtful accounts based upon historical write-offs, customer concentration, customer creditworthiness, current and forecasts of future economic conditions, aging of amounts due and changes in customer payment terms.
Property, Equipment and Leasehold Improvements	Property, Equipment and Leasehold Improvements Property, equipment and leasehold improvements are stated at cost less accumulated depreciation and amortization. Depreciation and amortization are recognized using the straight-line method. Buildings are depreciated over their estimated useful lives ranging from 30 to 40 years. Equipment is depreciated over its estimated useful life, which generally ranges from 3 to 7 years. Leasehold improvements are amortized over the shorter of their estimated useful lives, generally 7 years, or the term of the related lease.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company evaluates long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of the assets to future undiscounted cash flows to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured as the amount by which the carrying amount of the assets exceeds the fair value of the assets. The Company has not recognized impairment losses on any long-lived assets in 2024, 2023 or 2022.
Goodwill	Goodwill The Company assesses the impairment of goodwill annually and whenever events or changes in circumstances indicate that the carrying amount may be impaired. The Company’s annual goodwill impairment review is completed during the fourth quarter of each year. The Company evaluates goodwill for each reporting unit for impairment by assessing qualitative factors to determine whether it is necessary to perform a quantitative goodwill impairment test. The Company considers events and circumstances, including but not limited to, macroeconomic conditions, industry and market considerations, cost factors, overall financial performance, changes in management or key personnel, changes in strategy, changes in customers, a change in the composition or carrying amount of a reporting unit’s net assets and changes in the price of its common stock. If, after assessing the totality of events or circumstances, the Company determines that it is more likely than not that the fair value of a reporting unit is greater than its carrying amount, then the quantitative goodwill impairment test is not performed. The Company completed its annual assessment for all reporting units with goodwill for 2024 and determined, after assessing the totality of the qualitative factors, that it is more likely than not that the fair value of each reporting unit is greater than its respective carrying amount. Accordingly, there was no indication of impairment of goodwill for any of the Company’s reporting units and the quantitative goodwill impairment test was not performed. The Company did not recognize any goodwill impairment losses in 2024, 2023 or 2022.
Deferred Revenues	Deferred Revenues Deferred revenues represent amounts billed to clients in advance of services provided.
Income Taxes	Income Taxes Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the expected tax consequences of temporary differences between the tax basis and the financial reporting basis of assets and liabilities. Deferred tax assets and liabilities are measured using the enacted tax rates and laws in effect when the differences are expected to reverse. The effect on deferred tax assets and liabilities from changes in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance is recorded for deferred tax assets if it is more likely than not that some portion or all of the deferred tax assets will not be realized. An uncertain tax position is recognized if it is determined that it is more likely than not to be sustained upon examination. The tax position is measured as the largest amount of benefit that is greater than 50% likely of being realized upon ultimate settlement. The Company’s policy is to recognize interest and penalties related to unrecognized tax benefits as income tax expense. Accrued interest and penalties are insignificant at January 3, 2025 and December 29, 2023.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Financial instruments consist of cash and cash equivalents, short-term investments, accounts receivable, other assets and accounts payable. Cash, cash equivalents and short-term investments are recorded at fair value. The carrying amount of the Company’s accounts receivable, other assets and accounts payable approximates their fair values due to their short maturities.
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation is measured at the grant date based on the fair value of the award and is recognized as expense on a straight-line basis over the requisite service period of the entire award. The Company accounts for forfeitures of stock-based awards when they occur.
Net Income Per Share	Net Income Per Share Basic per share amounts are computed using the weighted-average number of common shares outstanding during the period. Diluted per share amounts are computed using the weighted-average number of common shares outstanding and potentially dilutive securities, using the treasury stock method if their effect would be dilutive. The following schedule reconciles the denominators of the Company’s calculation for basic and diluted net income per share: Fiscal Years (In thousands) 2024 2023 2022 Shares used in basic per share computation 51,129 51,152 51,727 Effect of dilutive common stock options outstanding 166 188 204 Effect of unvested restricted stock units outstanding 274 295 349 Shares used in diluted per share computation 51,569 51,635 52,280 Common stock options to purchase 30,000 shares were excluded from the diluted per share calculation for 2024 due to their anti-dilutive effect. Common stock options to purchase 59,459 shares were excluded from the diluted per share calculation for 2023 due to their anti-dilutive effect. There were no equity awards excluded from the diluted per share calculation for 2022.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements On November 27, 2023, the Financial Accounting Standards Board (the "FASB") issued Accounting Standards Update ("ASU") 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures . This standard improves reportable segment disclosures by adding and enhancing interim disclosure requirements, clarifying circumstances in which entities can disclose multiple segment measures of profit or loss, providing new segment disclosure requirements for entities with a single reportable segment, and adding the disclosure of significant segment expenses that are regularly provided to the chief operating decision maker within each reported measure of segment profit and loss. This standard is effective for all entities that are subject to Topic 280, Segment Reporting for annual periods beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. The Company has included all required disclosures within its Form 10-K for the year ended December 31, 2024. See Note 17 for further information on segment disclosures.
Recently Accounting Pronouncements Not Yet Adopted	Recent Accounting Pronouncements Not Yet Adopted In November 2024, the FASB issued ASU 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (subtopic 220-40) , which requires disclosure of disaggregation of certain relevant expenses included in the statements of operations on an annual and interim basis. ASU 2024-03 will be effective for our annual periods beginning January 1, 2027 and interim periods beginning January 1, 2028. The amendments must be applied retrospectively, and early adoption is permitted. The Company is currently evaluating the effects of adoption on our consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Jan. 03, 2025
Accounting Policies [Abstract]
Reconciles Shares to Calculate Basic and Diluted Net Income Per Share	The following schedule reconciles the denominators of the Company’s calculation for basic and diluted net income per share: Fiscal Years (In thousands) 2024 2023 2022 Shares used in basic per share computation 51,129 51,152 51,727 Effect of dilutive common stock options outstanding 166 188 204 Effect of unvested restricted stock units outstanding 274 295 349 Shares used in diluted per share computation 51,569 51,635 52,280

Revenue Recognition (Tables)

Revenue Recognition (Tables)	12 Months Ended
	Jan. 03, 2025
Revenue from Contract with Customer [Abstract]
Summary of Percent of Revenues	The following table discloses the percent of the Company’s revenue generated from time and materials contracts: Fiscal Years 2024 2023 2022 Engineering & Other Scientific 64 % 63 % 63 % Environmental and Health 15 % 15 % 16 % Total time and materials revenues 79 % 78 % 79 % The following table discloses the percent of the Company’s revenue generated from fixed price contracts: Fiscal Years 2024 2023 2022 Engineering & Other Scientific 20 % 20 % 20 % Environmental and Health 1 % 2 % 1 % Total fixed price revenues 21 % 22 % 21 %

Cash and cash equivalents (Tabl

Cash and cash equivalents (Tables)	12 Months Ended
	Jan. 03, 2025
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	Cash and cash equivalents consisted of the following as of January 3, 2025: Estimated (In thousands) Amortized Unrealized Unrealized Fair Classified as current assets: Cash $ 201,352 $ — $ — $ 201,352 Cash equivalents: Money market securities 57,549 — — 57,549 Total cash equivalents 57,549 — — 57,549 Total cash and cash equivalents 258,901 — — 258,901 Cash and cash equivalents consisted of the following as of December 29, 2023: Estimated (In thousands) Amortized Unrealized Unrealized Fair Classified as current assets: Cash $ 132,464 $ — $ — $ 132,464 Cash equivalents: Money market securities 54,686 — — 54,686 Total cash equivalents 54,686 — — 54,686 Total cash and cash equivalents 187,150 — — 187,150

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Jan. 03, 2025
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	The fair value of these certain financial assets and liabilities was determined using the following inputs at January 3, 2025 (in thousands): Fair Value Measurements at Reporting Date Using Total Quoted Significant Significant Assets Money market securities (1) $ 57,549 $ 57,549 $ — $ — Fixed income trading securities held in (2) 42,291 42,291 — — Equity trading securities held in deferred (2) 85,546 85,546 — — Total $ 185,386 $ 185,386 $ — $ — Liabilities Deferred compensation plan (3) 127,622 127,622 — — Total $ 127,622 $ 127,622 $ — $ — (1) Included in cash and cash equivalents on the Company’s consolidated balance sheet. (2) Included in prepaid expenses and other current assets and deferred compensation plan assets on the Company’s consolidated balance sheet. (3) Included in accounts payable and accrued liabilities and deferred compensation plan liabilities on the Company’s consolidated balance sheet. The fair value of these certain financial assets and liabilities was determined using the following inputs at December 29, 2023 (in thousands): Fair Value Measurements at Reporting Date Using Total Quoted Significant Significant Assets Money market securities (1) $ 54,686 $ 54,686 $ — $ — Fixed income trading securities held in (2) 36,788 36,788 — — Equity trading securities held in deferred (2) 78,399 78,399 — — Total $ 169,873 $ 169,873 $ — $ — Liabilities Deferred compensation plan (3) 116,564 116,564 — — Total $ 116,564 $ 116,564 $ — $ — (1) Included in cash and cash equivalents on the Company’s consolidated balance sheet. (2) Included in prepaid expenses and other current assets and deferred compensation plan assets on the Company’s consolidated balance sheet. Included in accounts payable and accrued liabilities and deferred compensation plan liabilities on the Company’s consolidated balance sheet.

Property, Equipment and Lease_2

Property, Equipment and Leasehold Improvements (Tables)	12 Months Ended
	Jan. 03, 2025
Property, Plant and Equipment [Abstract]
Property, Equipment and Leasehold Improvements	Fiscal Years (In thousands) 2024 2023 Property: Land $ 18,339 $ 18,339 Buildings 70,416 69,698 Construction in progress 219 1,114 Equipment: Machinery and equipment 57,041 54,008 Office furniture and equipment 13,749 12,411 Leasehold improvements 25,445 23,759 185,209 179,329 Less accumulated depreciation and amortization 112,202 104,011 Property, equipment and leasehold improvements, net $ 73,007 $ 75,318

Other Significant Balance She_2

Other Significant Balance Sheet Components (Tables)	12 Months Ended
	Jan. 03, 2025
Significant Balance Sheet Components [Abstract]
Account receivable, net	Account receivable, net Fiscal Years (In thousands) 2024 2023 Billed accounts receivable $ 117,503 $ 128,052 Unbilled accounts receivable 50,045 44,589 Allowance for contract losses and doubtful accounts ( 6,141 ) ( 5,281 ) Total accounts receivable, net $ 161,407 $ 167,360
Accounts payable and accrued liabilities	Accounts payable and accrued liabilities Fiscal Years (In thousands) 2024 2023 Accounts payable $ 5,272 $ 4,489 Accrued liabilities 16,864 17,636 Total accounts payable and other accrued liabilities $ 22,136 $ 22,125
Accrued payroll and employee benefits	Accrued payroll and employee benefits Fiscal Years (In thousands) 2024 2023 Accrued bonuses payable $ 76,844 $ 68,415 Accrued 401(k) contributions 10,807 11,138 Accrued vacation 14,433 13,492 Deferred compensation plan 14,976 13,166 Other accrued payroll and employee benefits 2,225 5,562 Total accrued payroll and employee benefits $ 119,285 $ 111,773

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Jan. 03, 2025
Income Tax Disclosure [Abstract]
Total Income Tax Expense	Total income tax expense for 2024, 2023 and 2022 consisted of the following: Fiscal Years (In thousands) 2024 2023 2022 Current Federal $ 28,237 $ 23,193 $ 24,411 Foreign 3,041 2,254 1,973 State 10,393 10,025 10,883 41,671 35,472 37,267 Deferred Federal ( 2,665 ) ( 775 ) ( 4,910 ) State ( 638 ) 860 ( 2,453 ) ( 3,303 ) 85 ( 7,363 ) Total $ 38,368 $ 35,557 $ 29,904
Company's Effective Tax Rate Differs From Statutory Federal Tax Rate	The Company’s effective tax rate differs from the statutory federal tax rate of 21 % as shown in the following schedule: Fiscal Years (In thousands) 2024 2023 2022 Tax at federal statutory rate $ 30,948 $ 28,538 $ 27,769 State taxes, net of federal benefit 7,699 8,587 6,726 Non-deductible officer compensation 1,787 870 1,160 Non-deductible expenses 427 456 52 Non-deductible stock-based compensation 14 12 12 Excess tax benefit from equity incentive plans ( 2,239 ) ( 2,844 ) ( 4,533 ) Difference between statutory rate and foreign effective tax rate ( 194 ) ( 264 ) ( 693 ) Other ( 74 ) 202 ( 589 ) Tax expense $ 38,368 $ 35,557 $ 29,904 Effective tax rate 26.0 % 26.2 % 22.6 %
Significant Portions of Deferred Tax Assets and Deferred Tax Liabilities	The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities at January 3, 2025 and December 29, 2023 are presented in the following schedule: Fiscal Years (In thousands) 2024 2023 Deferred tax assets: Accrued liabilities and allowances $ 22,831 $ 21,235 Deferred compensation plan 43,222 40,280 Operating leases 22,782 7,853 Total deferred tax assets $ 88,835 $ 69,368 Deferred tax liabilities: State taxes $ ( 2,310 ) $ ( 2,255 ) Deductible goodwill ( 2,065 ) ( 2,071 ) Operating leases ( 22,782 ) ( 7,853 ) Unrealized gain of deferred compensation plan assets ( 3,319 ) ( 1,652 ) Property, equipment and leasehold improvements ( 1,232 ) ( 1,695 ) Other — ( 18 ) Total deferred tax liabilities ( 31,708 ) ( 15,544 ) Net deferred tax assets $ 57,127 $ 53,824
Reconciliation of The Beginning and Ending Amount of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands): Balance at December 30, 2022 $ 2,047 Additions based on tax positions related to the current year 571 Reductions due to lapse of statute of limitations ( 473 ) Balance at December 29, 2023 $ 2,145 Additions based on tax positions related to the current year 651 Reductions due to lapse of statute of limitations ( 369 ) Balance at January 3, 2025 $ 2,427

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Jan. 03, 2025
Stockholders' Equity Note [Abstract]
Cash Dividends Per Common Share	The Company declared and paid cash dividends per share of common stock during the periods presented as follows: Fiscal Year 2024 Dividends Amount Per Share (in thousands) First Quarter $ 0.280 $ 14,159 Second Quarter $ 0.280 14,193 Third Quarter $ 0.280 14,212 Fourth Quarter $ 0.280 14,226 $ 56,790 Fiscal Year 2023 Dividends Amount Per Share (in thousands) First Quarter $ 0.260 $ 13,169 Second Quarter $ 0.260 13,217 Third Quarter $ 0.260 13,177 Fourth Quarter $ 0.260 13,148 $ 52,711

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Jan. 03, 2025
Share-Based Payment Arrangement [Abstract]
Share-Based Compensation, Restricted Stock Units Award Activity	The number of unvested restricted stock unit awards outstanding as of January 3, 2025 is as follows (1) : Number Weighted- Weighted- Aggregate (2) Balance at December 29, 2023 418,708 $ 88.78 Awards granted 284,912 79.59 Awards vested ( 266,859 ) 74.70 Awards forfeited ( 23,465 ) 90.72 Balance at January 3, 2025 413,296 $ 91.43 1.9 $ 36,746 (1) Does not include employee stock purchase plans or stock option plans. (2) The intrinsic value is calculated as the market value as of the end of the fiscal period. As reported by the NASDAQ Global Select Market, the market value as of January 3, 2025 was $ 88.91 .
Stock Option Activity	Option activity is as follows (1) : Number Weighted- Weighted- Aggregate Exercisable at December 29, 2023 463,235 $ 51.86 Options granted 40,000 75.87 Options forfeited and expired — — Options exercised ( 124,206 ) 31.37 Balance at January 3, 2025 379,029 $ 61.11 4.80 $ 11,267 Exercisable at January 3, 2025 289,446 $ 52.79 3.76 $ 10,726 (1) Does not include restricted stock or employee stock purchase plans.
The Assumptions Used to Value Option Grants	The assumptions used to value option grants for 2024, 2023 and 2022 are as follows: Stock Option Plan Fiscal Years 2024 2023 2022 Expected term (in years) 5.7 5.8 5.6 Risk-free interest rate 4.26 % 3.99 % 1.90 % Volatility 30 % 29 % 28 % Dividend yield 0 % 0 % 0 %
Stock-Based Compensation Expense Recognized in Consolidated Statements of Income	The amount of stock-based compensation expense and the related income tax benefit recognized in the Company’s consolidated statements of income for 2024, 2023 and 2022 is as follows: Fiscal Years (In thousands) 2024 2023 2022 Compensation and related expenses: Restricted stock units $ 21,086 $ 18,542 $ 18,810 Stock option grants 1,423 1,081 835 Sub-total 22,509 19,623 19,645 General and administrative expenses: Restricted stock units 730 734 719 Sub-total 730 734 719 Total stock-based compensation expense $ 23,239 $ 20,357 $ 20,364 Income tax benefit $ 2,793 $ 3,620 $ 5,829

Leases (Tables)

Leases (Tables)	12 Months Ended
	Jan. 03, 2025
Leases [Abstract]
Lease, Cost	The components of lease expense included in other operating expenses on the consolidated statements of income were as follows: Fiscal Year Fiscal Year Fiscal Year (In thousands) 2024 2023 2022 Operating lease cost $ 11,061 $ 7,732 $ 7,050 Variable lease cost 1,425 1,635 1,263 Short-term lease cost 1,345 1,174 651
Supplemental Cash Flow Information Related to Operating Lease	Supplemental cash flow information related to operating leases was as follows: Fiscal Year Fiscal Year Fiscal Year (In thousands) 2024 2023 2022 Cash paid for amounts included in the measurement of operating lease liabilities $ 7,559 $ 7,249 $ 6,564
Supplemental Balance Sheet Information Related to Operating Lease	Supplemental balance sheet information related to operating leases was as follows: Fiscal Year Fiscal Year Fiscal Year 2024 2023 2022 Weighted Average Remaining Lease Term 13.7 years 6.1 years 4.1 years Weighted Average Discount Rate 6.3 % 5.1 % 4.3 %
Maturities of Lease Liabilities	Maturities of operating lease liabilities as of January 3, 2025: Operating (In thousands) Leases 2025 8,001 2026 7,756 2027 6,633 2028 9,666 2029 9,390 Thereafter 89,052 Total lease payments $ 130,498 Less imputed interest 49,021 Total lease liability $ 81,477

Miscellaneous Income, Net (Tabl

Miscellaneous Income, Net (Tables)	12 Months Ended
	Jan. 03, 2025
Other Income and Expenses [Abstract]
Miscellaneous income, net	Miscellaneous income, net, consisted of the following: Fiscal Years (In thousands) 2024 2023 2022 Rental income $ 2,853 $ 3,371 $ 2,938 Gain (loss) on deferred compensation investments 14,928 14,315 ( 14,187 ) Gain (loss) on foreign exchange ( 14 ) ( 259 ) 522 Other 45 ( 3 ) 23 Total $ 17,812 $ 17,424 $ ( 10,704 )

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Tables)	12 Months Ended
	Jan. 03, 2025
Supplemental Cash Flow Information [Abstract]
Supplemental Disclosure of Cash Flow Information	The following is supplemental disclosure of cash flow information: Fiscal Years (In thousands) 2024 2023 2022 Cash paid during the year: Income taxes $ 39,723 $ 38,944 $ 40,121 Non-cash investing and financing activities: Vested stock unit awards granted to settle accrued bonus 10,846 10,496 10,200 Right-of-use asset obtained in exchange for operating 58,032 15,749 9,476 Leasehold improvements obtained in exchange for right-of-use asset - 3,219 - Accrual for capital expenditures 575 137 1,017

Segment Reporting (Tables)

Segment Reporting (Tables)	12 Months Ended
	Jan. 03, 2025
Segment Reporting [Abstract]
Segment Reporting Information, by Segment	Segment information is presented for selected data from the statements of income and statements of cash flows for 2024, 2023 and 2022. Segment information for selected data from the balance sheets is presented for the fiscal years ended January 3, 2025 and December 29, 2023. The Company’s CEO, the chief operating decision maker, does not review total assets in her evaluation of segment performance and capital allocation. Revenues Fiscal Years (In thousands) 2024 2023 2022 Engineering and Other Scientific $ 469,544 $ 446,888 $ 427,796 Environmental and Health 88,970 89,878 85,497 Total revenues $ 558,514 $ 536,766 $ 513,293 Compensation and related expenses Fiscal Years (In thousands) 2024 2023 2022 Engineering and Other Scientific $ 223,395 $ 215,650 $ 195,243 Environmental and Health 47,600 48,619 47,288 Total segment compensation and related expenses 270,995 264,269 242,531 Corporate compensation and related expenses 59,016 55,617 21,704 Total compensation and related expenses $ 330,011 $ 319,886 $ 264,235 Certain expenses are excluded from the Company’s measure of segment compensation and related expenses. These include the deferred compensation expense/benefit due to changes in value of assets associated with the Company’s deferred compensation plan; stock-based compensation associated with restricted stock unit and stock option awards, and the compensation costs associated with the Company’s human resources, finance, information technology, corporate, and business development groups. Operating Income Fiscal Years (In thousands) 2024 2023 2022 Engineering and Other Scientific $ 164,883 $ 153,918 $ 152,679 Environmental and Health 29,995 28,432 27,340 Total segment operating income 194,878 182,350 180,019 Corporate operating expense ( 75,321 ) ( 71,028 ) ( 39,177 ) Total operating income $ 119,557 $ 111,322 $ 140,842 Capital Expenditures Fiscal Years (In thousands) 2024 2023 2022 Engineering and Other Scientific $ 3,257 $ 3,895 $ 4,661 Environmental and Health 77 170 174 Total segment capital expenditures 3,334 4,065 4,835 Corporate capital expenditures 4,043 14,630 7,812 Total capital expenditures $ 7,377 $ 18,695 $ 12,647 Certain capital expenditures associated with the Company's corporate cost centers and the related depreciation are excluded from the Company's segment information. Depreciation and Amortization Fiscal Years (In thousands) 2024 2023 2022 Engineering and Other Scientific $ 6,833 $ 6,087 $ 4,489 Environmental and Health 206 213 171 Total segment depreciation and amortization 7,039 6,300 4,660 Corporate depreciation and amortization 2,650 2,616 2,419 Total depreciation and amortization $ 9,689 $ 8,916 $ 7,079
Operations In Different Geographical Areas	Information regarding the Company’s operations in different geographical areas: Property, Equipment and Leasehold Improvements, net Fiscal Years (In thousands) 2024 2023 United States $ 72,418 $ 74,668 Foreign Countries 589 650 Total $ 73,007 $ 75,318 Revenues (1) Fiscal Years (In thousands) 2024 2023 2022 United States $ 493,067 $ 470,078 $ 450,445 Foreign Countries 65,447 66,688 62,848 Total $ 558,514 $ 536,766 $ 513,293 (1) Geographic revenues are allocated based on the location of the client.
Schedule of Goodwill	Below is a breakdown of goodwill, reported by segment as of January 3, 2025 and December 29, 2023: (In thousands) Environmental Engineering Total Goodwill $ 8,099 $ 508 $ 8,607

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Jan. 03, 2025 Segment shares	Dec. 29, 2023 shares	Dec. 30, 2022 shares
Summary Of Significant Accounting Policies [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | shares	30,000	59,459	0
Number of reportable segment | Segment	1
Buildings | Minimum
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life	30 years
Buildings | Maximum
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life	40 years
Equipment | Minimum
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life	3 years
Equipment | Maximum
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life	7 years
Leasehold Improvements
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life	7 years

Reconciles the Denominators of

Reconciles the Denominators of the Company's Calculation for Basic and Diluted Net Income per Share (Detail) - shares shares in Thousands	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Schedule Of Earnings Per Share Basic and Diluted [Line Items]
Shares used in basic per share computation	51,129	51,152	51,727
Shares used in diluted per share computation	51,569	51,635	52,280
Employee Stock Option
Schedule Of Earnings Per Share Basic and Diluted [Line Items]
Effect of dilutive stock outstanding	166	188	204
Restricted Stock Units (RSUs)
Schedule Of Earnings Per Share Basic and Diluted [Line Items]
Effect of dilutive stock outstanding	274	295	349

Revenue Recognition - Summary o

Revenue Recognition - Summary of Revenues (Detail) - Sales Revenue, Net [Member] - Revenue from Rights Concentration Risk [Member]	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Time And Materials Contracts [Member]
Disaggregation Of Revenue [Line Items]
Concentration Risk, Percentage	79%	78%	79%
Time And Materials Contracts [Member] | Engineering and Other Scientific [Member]
Disaggregation Of Revenue [Line Items]
Concentration Risk, Percentage	64%	63%	63%
Time And Materials Contracts [Member] | Environmental and Health [Member]
Disaggregation Of Revenue [Line Items]
Concentration Risk, Percentage	15%	15%	16%
Fixed Price Contracts [Member]
Disaggregation Of Revenue [Line Items]
Concentration Risk, Percentage	21%	22%	21%
Fixed Price Contracts [Member] | Engineering and Other Scientific [Member]
Disaggregation Of Revenue [Line Items]
Concentration Risk, Percentage	20%	20%	20%
Fixed Price Contracts [Member] | Environmental and Health [Member]
Disaggregation Of Revenue [Line Items]
Concentration Risk, Percentage	1%	2%	1%

Revenue Recognition - Additiona

Revenue Recognition - Additional Information (Detail) - USD ($)	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Revenue Recognition [Abstract]
Deferred Revenue, Revenue Recognized	$ 14,173,000	$ 14,463,000	$ 15,384,000
Subcontractor Fees Not Included In Revenues	$ 10,970,000	$ 12,268,000	$ 28,754,000

Cash and cash equivalents (Deta

Cash and cash equivalents (Detail) - USD ($) $ in Thousands	Jan. 03, 2025	Dec. 29, 2023
Cash
Fair Value Measurements [Line Items]
Amortized Cost	$ 201,352	$ 132,464
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	201,352	132,464
Money market securities
Fair Value Measurements [Line Items]
Amortized Cost	57,549	54,686
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	57,549	54,686
Total cash equivalents
Fair Value Measurements [Line Items]
Amortized Cost	57,549	54,686
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	57,549	54,686
Total cash and cash equivalents
Fair Value Measurements [Line Items]
Amortized Cost	258,901	187,150
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	$ 258,901	$ 187,150

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($)	Jan. 03, 2025		Dec. 29, 2023
Assets
Trading securities held in deferred compensation plan	$ 127,837,000		$ 115,187,000
Total	185,386,000		169,873,000
Liabilities
Deferred compensation plan	127,622,000	[1]	116,564,000	[2]
Total	127,622,000		116,564,000
Money market securities
Assets
Money market securities	57,549,000	[3]	54,686,000	[4]
Fixed income securities
Assets
Trading securities held in deferred compensation plan	42,291,000	[5]	36,788,000	[6]
Equity securities
Assets
Trading securities held in deferred compensation plan	85,546,000	[5]	78,399,000	[6]
Fair Value, Inputs, Level 1
Assets
Total	185,386,000		169,873,000
Liabilities
Deferred compensation plan	127,622,000	[1]	116,564,000	[2]
Total	127,622,000		116,564,000
Fair Value, Inputs, Level 1 | Money market securities
Assets
Money market securities	57,549,000	[3]	54,686,000	[4]
Fair Value, Inputs, Level 1 | Fixed income securities
Assets
Trading securities held in deferred compensation plan	42,291,000	[5]	36,788,000	[6]
Fair Value, Inputs, Level 1 | Equity securities
Assets
Trading securities held in deferred compensation plan	85,546,000	[5]	78,399,000	[6]
Fair Value, Inputs, Level 2
Assets
Total	0		0
Liabilities
Deferred compensation plan	0	[1]	0	[2]
Total	0		0
Fair Value, Inputs, Level 2 | Money market securities
Assets
Money market securities	0	[3]	0	[4]
Fair Value, Inputs, Level 2 | Fixed income securities
Assets
Trading securities held in deferred compensation plan	0	[5]	0	[6]
Fair Value, Inputs, Level 2 | Equity securities
Assets
Trading securities held in deferred compensation plan	0	[5]	0	[6]
Fair Value, Inputs, Level 3
Assets
Total	0		0
Liabilities
Deferred compensation plan	0	[1]	0	[2]
Total	0		0
Fair Value, Inputs, Level 3 | Money market securities
Assets
Money market securities	0	[3]	0	[4]
Fair Value, Inputs, Level 3 | Fixed income securities
Assets
Trading securities held in deferred compensation plan	0	[5]	0	[6]
Fair Value, Inputs, Level 3 | Equity securities
Assets
Trading securities held in deferred compensation plan	$ 0	[5]	$ 0	[6]
[1] Included in accounts payable and accrued liabilities and deferred compensation plan liabilities on the Company’s consolidated balance sheet. Included in accounts payable and accrued liabilities and deferred compensation plan liabilities on the Company’s consolidated balance sheet. Included in cash and cash equivalents on the Company’s consolidated balance sheet. Included in cash and cash equivalents on the Company’s consolidated balance sheet. Included in prepaid expenses and other current assets and deferred compensation plan assets on the Company’s consolidated balance sheet. Included in prepaid expenses and other current assets and deferred compensation plan assets on the Company’s consolidated balance sheet.

Property, Equipment and Lease_3

Property, Equipment and Leasehold Improvements (Detail) - USD ($) $ in Thousands	Jan. 03, 2025	Dec. 29, 2023
Property:
Land	$ 18,339	$ 18,339
Buildings	70,416	69,698
Construction in progress	219	1,114
Equipment:
Machinery and equipment	57,041	54,008
Office furniture and equipment	13,749	12,411
Leasehold improvements	25,445	23,759
Property, Plant and Equipment, Gross, Total	185,209	179,329
Less accumulated depreciation and amortization	112,202	104,011
Property, equipment and leasehold improvements, net	$ 73,007	$ 75,318

Property, Equipment and Lease_4

Property, Equipment and Leasehold Improvements - Additional Information (Detail) - USD ($)	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Property, Plant and Equipment [Abstract]
Depreciation and amortization of property, equipment and leasehold improvements	$ 9,689,000	$ 8,916,000	$ 7,079,000

Accounts Receivable, Net (Detai

Accounts Receivable, Net (Detail) - USD ($) $ in Thousands	Jan. 03, 2025	Dec. 29, 2023
Accounts Notes And Loans Receivable [Line Items]
Allowance for contract losses and doubtful accounts	$ (6,141)	$ (5,281)
Total accounts receivable, net	161,407	167,360
Billed accounts receivable
Accounts Notes And Loans Receivable [Line Items]
Accounts Receivable	117,503	128,052
Unbilled accounts receivable
Accounts Notes And Loans Receivable [Line Items]
Accounts Receivable	$ 50,045	$ 44,589

Accounts Payable and Accrued Li

Accounts Payable and Accrued Liabilities (Detail) - USD ($) $ in Thousands	Jan. 03, 2025	Dec. 29, 2023
Accounts Payable and Accrued Liabilities [Abstract]
Accounts payable	$ 5,272	$ 4,489
Accrued liabilities	16,864	17,636
Total accounts payable and other accrued liabilities	$ 22,136	$ 22,125

Accrued Payroll and Employee Be

Accrued Payroll and Employee Benefits (Detail) - USD ($) $ in Thousands	Jan. 03, 2025	Dec. 29, 2023
Employee-related Liabilities, Current [Abstract]
Accrued bonuses payable	$ 76,844	$ 68,415
Accrued 401(k) contributions	10,807	11,138
Accrued vacation	14,433	13,492
Deferred compensation plan	14,976	13,166
Other accrued payroll and employee benefits	2,225	5,562
Total accrued payroll and employee benefits	$ 119,285	$ 111,773

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Income Tax Disclosure [Abstract]
Income (Loss) from Continuing Operations before Income Taxes, Foreign	$ 13,135,000	$ 10,353,000	$ 10,646,000
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21%	21%	21%
Total Excess Tax Benefit From Share Based Compensation	$ 2,793,000	$ 3,620,000	$ 5,829,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	1,918,000
Unrecognized Liability For Uncertain Tax Positions For Next Twelve Months	$ 0

Total Income Tax Expense (Detai

Total Income Tax Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Current
Federal	$ 28,237	$ 23,193	$ 24,411
Foreign	3,041	2,254	1,973
State	10,393	10,025	10,883
Current Income Tax Expense	41,671	35,472	37,267
Deferred
Federal	(2,665)	(775)	(4,910)
State	(638)	860	(2,453)
Deferred Income Tax Expense	(3,303)	85	(7,363)
Total	$ 38,368	$ 35,557	$ 29,904

Company's Effective Tax Rate Di

Company's Effective Tax Rate Differs From Statutory Federal Tax Rate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Income Tax Disclosure [Abstract]
Tax at federal statutory rate	$ 30,948	$ 28,538	$ 27,769
State taxes, net of federal benefit	7,699	8,587	6,726
Non-deductible officer compensation	1,787	870	1,160
Non-deductible expenses	427	456	52
Non-deductible stock-based compensation	14	12	12
Excess tax benefit from equity incentive plans	(2,239)	(2,844)	(4,533)
Difference between statutory rate and foreign effective tax rate	(194)	(264)	(693)
Other	(74)	202	(589)
Total	$ 38,368	$ 35,557	$ 29,904
Effective tax rate	26%	26.20%	22.60%

Significant Portions of Deferre

Significant Portions of Deferred Tax Assets and Deferred Tax Liabilities (Detail) - USD ($) $ in Thousands	Jan. 03, 2025	Dec. 29, 2023
Deferred tax assets:
Accrued liabilities and allowances	$ 22,831	$ 21,235
Deferred compensation plan	43,222	40,280
Operating leases	22,782	7,853
Total deferred tax assets	88,835	69,368
Deferred tax liabilities:
State taxes	(2,310)	(2,255)
Deductible goodwill	(2,065)	(2,071)
Operating leases	(22,782)	(7,853)
Unrealized gain of deferred compensation plan assets	(3,319)	(1,652)
Property, equipment and leasehold improvements	(1,232)	(1,695)
Other		(18)
Total deferred tax liabilities	(31,708)	(15,544)
Net deferred tax assets	$ 57,127	$ 53,824

Reconciliation of The Beginning

Reconciliation of The Beginning and Ending Amount of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023
Schedule Of Unrecognized Tax Benefits [Abstract]
Balance	$ 2,145	$ 2,047
Additions based on tax positions related to the current year	651	571
Reductions due to lapse of statute of limitations	(369)	(473)
Balance	$ 2,427	$ 2,145

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($)	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022	Feb. 01, 2024	Feb. 22, 2022
Stockholders' Equity Note [Abstract]
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, par or stated value per share	$ 0.001	$ 0.001
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Net losses related to the re-issuance of treasury stock	$ 720,000	$ 1,009,000	$ 1,392,000
Purchase of treasury shares (in shares)	74,000	288,000	1,756,000
Purchase of treasury shares	$ 5,710,000	$ 24,208,000	$ 155,856,000
Stock repurchase program, authorized amount				$ 61,600,000	$ 150,000,000
Stock repurchase program, remaining authorized repurchase amount	$ 94,290,000

Stockholders' Equity (Detail)

Stockholders' Equity (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 03, 2025	Sep. 27, 2024	Jun. 28, 2024	Mar. 29, 2024	Dec. 29, 2023	Sep. 29, 2023	Jun. 30, 2023	Mar. 31, 2023	Jan. 03, 2025	Dec. 29, 2023
Stockholders' Equity Note [Abstract]
Dividends Per Share	$ 0.28	$ 0.28	$ 0.28	$ 0.28	$ 0.26	$ 0.26	$ 0.26	$ 0.26
Amount	$ 14,226	$ 14,212	$ 14,193	$ 14,159	$ 13,148	$ 13,177	$ 13,217	$ 13,169	$ 56,790	$ 52,711

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($)		12 Months Ended
		Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value		$ 21,286,000	$ 25,277,000	$ 29,875,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value		$ 79.59	$ 99.47	$ 94.24
Share Based Compensation Arrangement By Share Based Payment Award Options Expiration Term		10 years
Total intrinsic value of options exercised		$ 8,410,000	$ 742,000	$ 0
Weighted average fair value of options granted		$ 28.36	$ 38.29	$ 26.64
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of annual bonus settled with fully vested restricted stock unit awards		40%
2008 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total number of shares reserved for issuance		13,336,300
Number of Shares Available for Grant		2,313,565
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total number of shares reserved for issuance		1,200,000
Number of Shares Available for Grant		275,324
Weighted average purchase price		$ 88.7	$ 87.12	$ 91.17
Purchase Price Of Common Stock As a Percentage of Fair Market Value		95%
Employee Stock Purchase Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum Percentage Of Payroll Deductions Related To Purchase Of Common Stock		15%
Vested Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation, holding period		4 years
Stock based compensation expense		$ 12,182,000	$ 10,445,000	$ 10,365,000
Unvested Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation, vesting period		4 years
Stock based compensation expense		$ 9,634,000	8,831,000	9,164,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]	$ 79.59
Unrecognized compensation cost		$ 12,984,000
Weighted average period of recognized term		2 years 6 months
Unvested Restricted Stock | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recipient age to expense award on grant date		59 years 6 months
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation, vesting period		4 years
Stock based compensation expense		$ 1,423,000	$ 1,081,000	$ 835,000
Unrecognized compensation cost		$ 1,253,000
Weighted average period of recognized term		2 years 1 month 6 days
Unvested Stock Options | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recipient age to expense award on grant date		59 years 6 months
[1] Does not include employee stock purchase plans or stock option plans.

Number of Unvested Restricted S

Number of Unvested Restricted Stock Unit Awards Outstanding (Detail) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant date fair value, awards granted		$ 79.59	$ 99.47	$ 94.24
Unvested Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares outstanding, awards balance	[1]	418,708
Number of shares outstanding, awards granted	[1]	284,912
Number of shares outstanding, awards vested	[1]	(266,859)
Number of shares outstanding, awards forfeited	[1]	(23,465)
Balance at January 3, 2025	[1]	413,296	418,708
Weighted-average grant date fair value, awards balance	[1]	$ 88.78
Weighted-average grant date fair value, awards granted	[1]	79.59
Weighted-average grant date fair value, awards vested	[1]	74.7
Weighted-average grant date fair value, awards forfeited	[1]	90.72
Weighted-average grant date fair value, awards balance	[1]	$ 91.43	$ 88.78
Weighted average remaining contractual term, Balance	[1]	1 year 10 months 24 days
Aggregate intrinsic value, Balance	[1],[2]	$ 36,746
[1] Does not include employee stock purchase plans or stock option plans. The intrinsic value is calculated as the market value as of the end of the fiscal period. As reported by the NASDAQ Global Select Market, the market value as of January 3, 2025 was $ 88.91 .

Number of Unvested Restricted_2

Number of Unvested Restricted Stock Unit Awards Outstanding (Parenthetical) (Detail)	Jan. 03, 2025 $ / shares
Unvested Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instrument Other than Option, Nonvested, Intrinsic Value	$ 88.91

Option Activity (Detail)

Option Activity (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Jan. 03, 2025 USD ($) $ / shares shares	[1]
Share-Based Payment Arrangement [Abstract]
Number of shares outstanding, Options Balance | shares	463,235
Number of shares outstanding, Options Granted | shares	40,000
Number of shares outstanding, Options forfeited and expired | shares	0
Exercise of stock options (in shares) | shares	(124,206)
Number of shares outstanding, Options Balance | shares	379,029
Number of shares outstanding, Exercisable | shares	289,446
Weighted-average exercise price, Options Balance | $ / shares	$ 51.86
Weighted-average exercise price, Options Granted | $ / shares	75.87
Weighted-average exercise price, Options forfeited and expired | $ / shares	0
Weighted-average exercise price, Options Exercised | $ / shares	31.37
Weighted-average exercise price, Options Balance | $ / shares	61.11
Weighted-average exercise price, Exercisable | $ / shares	$ 52.79
Weighted average remaining contractual term, Balance	4 years 9 months 18 days
Weighted average remaining contractual term, Exercisable	3 years 9 months 3 days
Aggregate intrinsic value, Balance | $	$ 11,267
Aggregate intrinsic value, Exercisable | $	$ 10,726
[1] Does not include restricted stock or employee stock purchase plans.

Assumptions Used to Value Optio

Assumptions Used to Value Option Grants (Detail) - Employee Stock Option	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	5 years 8 months 12 days	5 years 9 months 18 days	5 years 7 months 6 days
Risk-free interest rate	4.26%	3.99%	1.90%
Volatility	30%	29%	28%
Dividend yield	0%	0%	0%

Stock-Based Compensation Expens

Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 23,239	$ 20,357	$ 20,364
Income tax benefit	2,793	3,620	5,829
Compensation and Related Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	22,509	19,623	19,645
Compensation and Related Expenses [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	21,086	18,542	18,810
Compensation and Related Expenses [Member] | Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	1,423	1,081	835
General and Administrative Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	730	734	719
General and Administrative Expenses [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 730	$ 734	$ 719

Retirement Plans - Additional I

Retirement Plans - Additional Information (Detail) - USD ($)	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Retirement Benefits [Abstract]
Defined Contribution Plan Employer Contribution Percentage Of Eligible Wages	7%
Defined Contribution Plan Employer Contribution Annual Vesting Percentage	20%
Defined Contribution Plan Employer Contribution Annual Vesting Period	5 years
Pension and Other Postretirement Benefits Cost (Reversal of Cost)	$ 11,704,000	$ 11,867,000	$ 10,166,000

Deferred Compensation Plans - A

Deferred Compensation Plans - Additional Information (Detail) - USD ($)	12 Months Ended
	Jan. 03, 2025		Dec. 29, 2023		Dec. 30, 2022
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Trading securities held in deferred compensation plan	$ 127,837,000		$ 115,187,000
Deferred compensation plan	127,622,000	[1]	116,564,000	[2]
Change in market value of trust assets	$ 14,928,000		$ 14,315,000		$ (14,187,000)
Maximum
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Percentage of compensation deferred	100%
[1] Included in accounts payable and accrued liabilities and deferred compensation plan liabilities on the Company’s consolidated balance sheet. Included in accounts payable and accrued liabilities and deferred compensation plan liabilities on the Company’s consolidated balance sheet.

Leases - Additional Information

Leases - Additional Information (Detail)		3 Months Ended	12 Months Ended
	Jun. 19, 2024 USD ($)	Jun. 28, 2024 USD ($)	Jan. 03, 2025 USD ($) a State Option	Dec. 29, 2023 USD ($)	Dec. 30, 2022 USD ($)
Lessee Lease Description [Line Items]
Lease payment obligation per year			$ 130,498,000
Additional right-of-use asset in exchange for operating lease liability			$ 58,032,000	$ 15,749,000	$ 9,476,000
Office, Laboratory, and Storage Space [Member]
Lessee Lease Description [Line Items]
Number of States in which Entity Has Lease Arrangements | State			13
Office, Laboratory, and Storage Space [Member] | Minimum
Lessee Lease Description [Line Items]
Lessee, Operating Lease, Term of Contract			1 year
Office, Laboratory, and Storage Space [Member] | Maximum
Lessee Lease Description [Line Items]
Lessee, Operating Lease, Term of Contract			10 years
Phoenix Arizona [Member]
Lessee Lease Description [Line Items]
Lessee, Operating Lease, Term of Contract			30 years
Area of Land | a			147
Number of Options to Renew Lease | Option			2
Lessee, Operating Lease, Option to Extend			The Company leases this land from the state of Arizona under a 30-year lease agreement that expires in January of 2028 and has options to renew for two 15-year periods.
Lessee, Operating Lease, Existence of Option to Extend [true false]			true
Lessee, Operating Lease, Renewal Term	15 years		15 years
Annual rent payment adjustment year one	2033
Annual rent payment adjustment year two	2038
Additional right-of-use asset in exchange for operating lease liability		$ 48,683,000
Phoenix Arizona [Member] | Lease Period Until January 16, 2028 [Member]
Lessee Lease Description [Line Items]
Lease payment obligation per year	$ 1,009,000
Phoenix Arizona [Member] | Lease Period After January 16, 2028 [Member]
Lessee Lease Description [Line Items]
Lease payment obligation per year	$ 6,183,000

Components of Lease Expense (De

Components of Lease Expense (Detail) - Other Operating Income (Expense) [Member] - USD ($) $ in Thousands	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Operating lease cost	$ 11,061	$ 7,732	$ 7,050
Variable lease cost	1,425	1,635	1,263
Short-term lease cost	$ 1,345	$ 1,174	$ 651

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information Related to Operating Leases (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Leases [Abstract]
Cash paid for amounts included in the measurement of operating lease liabilities	$ 7,559	$ 7,249	$ 6,564

Supplemental Balance Sheet Info

Supplemental Balance Sheet Information Related to Operating Leases (Detail)	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Leases [Abstract]
Weighted Average Remaining Lease Term	13 years 8 months 12 days	6 years 1 month 6 days	4 years 1 month 6 days
Weighted Average Discount Rate	6.30%	5.10%	4.30%

Maturities of Lease Liabilities

Maturities of Lease Liabilities (Detail) $ in Thousands	Jan. 03, 2025 USD ($)
Leases [Abstract]
2025	$ 8,001
2026	7,756
2027	6,633
2028	9,666
2029	9,390
Thereafter	89,052
Total lease payments	130,498
Less imputed interest	49,021
Total lease liability	$ 81,477

Miscellaneous Income, Net (Deta

Miscellaneous Income, Net (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Other Income and Expenses [Abstract]
Rental income	$ 2,853	$ 3,371	$ 2,938
Gain (loss) on deferred compensation investments	14,928	14,315	(14,187)
Gain (loss) on foreign exchange	(14)	(259)	522
Other	45	(3)	23
Total	$ 17,812	$ 17,424	$ (10,704)

Industry and Client Credit Ri_2

Industry and Client Credit Risk - Additional Information (Detail) - Sales Revenue, Net [Member] - Client	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Revenue from Rights Concentration Risk [Member] | Single Client
Concentration Risk [Line Items]
Fiscal Years	10%	10%	15%
Number of clients comprised more than 10% of revenue or accounts receivable	0	0	1
Consumer Products [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Fiscal Years	24%
Energy and Utilities [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Fiscal Years	19%
Transportation Industry [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Fiscal Years	16%
Chemical Industry [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Fiscal Years	10%

Supplemental Disclosure of Cash

Supplemental Disclosure of Cash Flow Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Cash paid during the year:
Income taxes	$ 39,723	$ 38,944	$ 40,121
Non-cash investing and financing activities:
Vested stock unit awards granted to settle accrued bonus	10,846	10,496	10,200
Right-of-use asset obtained in exchange for operating lease obligation	58,032	15,749	9,476
Leasehold improvements obtained in exchange for right-of-use asset	0	3,219	0
Accrual for capital expenditures	$ 575	$ 137	$ 1,017

Segment Reporting - Additional

Segment Reporting - Additional Information (Detail)	12 Months Ended
	Jan. 03, 2025 USD ($) Segment	Dec. 29, 2023 USD ($)	Dec. 30, 2022 USD ($)
Segment Reporting [Abstract]
Number of reportable operating segments | Segment	2
Changes in the carrying amount of goodwill	$ 0	$ 0	$ 0
Goodwill impairments or gains or losses on disposals	$ 0	$ 0	$ 0

Segment Information (Detail)

Segment Information (Detail) - USD ($)	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Segment Reporting Information [Line Items]
Revenues	$ 558,514,000	$ 536,766,000	$ 513,293,000
Compensation and related expenses	330,011,000	319,886,000	264,235,000
Operating Income	119,557,000	111,322,000	140,842,000
Capital Expenditures	7,377,000	18,695,000	12,647,000
Depreciation and Amortization	9,689,000	8,916,000	7,079,000
Operating segments
Segment Reporting Information [Line Items]
Compensation and related expenses	270,995,000	264,269,000	242,531,000
Operating Income	194,878,000	182,350,000	180,019,000
Capital Expenditures	3,334,000	4,065,000	4,835,000
Depreciation and Amortization	7,039,000	6,300,000	4,660,000
Corporate
Segment Reporting Information [Line Items]
Compensation and related expenses	59,016,000	55,617,000	21,704,000
Operating Income	(75,321,000)	(71,028,000)	(39,177,000)
Capital Expenditures	4,043,000	14,630,000	7,812,000
Depreciation and Amortization	2,650,000	2,616,000	2,419,000
Engineering and Other Scientific | Operating segments
Segment Reporting Information [Line Items]
Revenues	469,544,000	446,888,000	427,796,000
Compensation and related expenses	223,395,000	215,650,000	195,243,000
Operating Income	164,883,000	153,918,000	152,679,000
Capital Expenditures	3,257,000	3,895,000	4,661,000
Depreciation and Amortization	6,833,000	6,087,000	4,489,000
Environmental and Health | Operating segments
Segment Reporting Information [Line Items]
Revenues	88,970,000	89,878,000	85,497,000
Compensation and related expenses	47,600,000	48,619,000	47,288,000
Operating Income	29,995,000	28,432,000	27,340,000
Capital Expenditures	77,000	170,000	174,000
Depreciation and Amortization	$ 206,000	$ 213,000	$ 171,000

Operations in Different Geograp

Operations in Different Geographic Areas (Detail) - USD ($) $ in Thousands		12 Months Ended
		Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Operations in Different Geographic Areas [Line Items]
Property, equipment and leasehold improvements, net		$ 73,007	$ 75,318
Revenues	[1]	558,514	536,766	$ 513,293
United States
Operations in Different Geographic Areas [Line Items]
Property, equipment and leasehold improvements, net		72,418	74,668
Revenues	[1]	493,067	470,078	450,445
Foreign Countries
Operations in Different Geographic Areas [Line Items]
Property, equipment and leasehold improvements, net		589	650
Revenues	[1]	$ 65,447	$ 66,688	$ 62,848
[1] Geographic revenues are allocated based on the location of the client.

Goodwill Reported By segment (D

Goodwill Reported By segment (Detail) - USD ($) $ in Thousands	Jan. 03, 2025	Dec. 29, 2023
Goodwill Reported By Segment [Line Items]
Goodwill	$ 8,607	$ 8,607
Environmental and Health
Goodwill Reported By Segment [Line Items]
Goodwill	8,099	8,099
Engineering and Other Scientific
Goodwill Reported By Segment [Line Items]
Goodwill	$ 508	$ 508

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - $ / shares		12 Months Ended
	Feb. 06, 2025	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Subsequent Event [Line Items]
Cash dividends declared per common share (in dollars per share)		$ 1.12	$ 1.04	$ 0.96
O 2025 Q1 Dividends | Subsequent Event
Subsequent Event [Line Items]
Cash dividends declared per common share (in dollars per share)	$ 0.3
Dividends Payable, Date Declared	Feb. 06, 2025
Dividends Payable, Date of Record	Mar. 07, 2025
Dividends Payable, Date to be Paid	Mar. 21, 2025

Valuation and Qualifying Accoun

Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands		12 Months Ended
		Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Allowance For Bad Debt [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year		$ 1,162	$ 1,239	$ 973
Provision Charged to Expense		993	856	455
Provision Charged to Revenues		0	0	0
Accounts Written-off Net of Recoveries	[1]	(804)	(933)	(189)
Balance at End of Year		1,351	1,162	1,239
Allowance For Contract Losses [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year		4,119	4,954	3,450
Provision Charged to Expense		0	0	0
Provision Charged to Revenues		3,457	2,368	2,626
Accounts Written-off Net of Recoveries	[1]	(2,786)	(3,203)	(1,122)
Balance at End of Year		$ 4,790	$ 4,119	$ 4,954
[1] Balance includes currency translation adjustments.

Valuation And Qualifying Acco_2

Valuation And Qualifying Accounts - Additional Information (Detail) - USD ($)	12 Months Ended
	Jan. 03, 2025	Dec. 29, 2023	Dec. 30, 2022
Trade Accounts Receivable [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Written-off Net of Recoveries	$ 74,000	$ 181,000	$ 11,000