Exponent (EXPO) 10-Q 1 Nov 24 2024 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 27, 2024	Oct. 25, 2024
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 27, 2024
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Entity Registrant Name	EXPONENT, INC.
Entity Central Index Key	0000851520
Current Fiscal Year End Date	--12-29
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Trading Symbol	EXPO
Entity Common Stock, Shares Outstanding		50,764,457
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	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 Quarterly Report	true
Document Transition Report	false
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

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 27, 2024	Dec. 29, 2023
Current assets:
Cash and cash equivalents	$ 219,708	$ 187,150
Accounts receivable, net of allowance for contract losses and doubtful accounts of $6,481 and $5,281 at September 27, 2024 and December 29, 2023, respectively	168,618	167,360
Prepaid expenses and other current assets	24,255	25,022
Total current assets	412,581	379,532
Property, equipment and leasehold improvements, net of accumulated depreciation and amortization of $110,828 and $104,011 at September 27, 2024 and December 29, 2023, respectively	72,862	75,318
Operating lease right-of-use assets	75,797	24,600
Goodwill	8,607	8,607
Deferred income taxes	54,345	53,824
Deferred compensation plan assets	113,225	101,169
Other assets	6,648	3,727
Total assets	744,065	646,777
Current liabilities:
Accounts payable and accrued liabilities	22,646	22,125
Accrued payroll and employee benefits	96,738	111,773
Deferred revenues	13,414	21,709
Operating lease liabilities	4,940	6,302
Total current liabilities	137,738	161,909
Other liabilities	4,604	3,426
Deferred compensation plan liabilities	115,527	103,398
Operating lease liabilities	75,922	21,959
Total liabilities	333,791	290,692
Stockholders’ equity:
Common stock, $0.001 par value; 120,000 shares authorized; 65,707 shares issued at September 27, 2024 and December 29, 2023	66	66
Additional paid-in capital	342,301	321,448
Accumulated other comprehensive loss
Foreign currency translation adjustments	(1,606)	(2,977)
Retained earnings	614,991	574,082
Treasury stock, at cost; 14,942 and 15,134 shares held at September 27, 2024 and December 29, 2023, respectively	(545,478)	(536,534)
Total stockholders’ equity	410,274	356,085
Total liabilities and stockholders’ equity	$ 744,065	$ 646,777

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 27, 2024	Dec. 29, 2023
Statement of Financial Position [Abstract]
Accounts receivable, net of allowance for contract losses and doubtful accounts	$ 6,481	$ 5,281
Property, equipment and leasehold improvements, net of accumulated depreciation and amortization	$ 110,828	$ 104,011
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	14,942,000	15,134,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2024	Sep. 29, 2023	Sep. 27, 2024	Sep. 29, 2023
Revenues:
Revenues before reimbursements	$ 125,085	$ 124,959	$ 394,726	$ 383,317
Reimbursements	11,194	8,377	27,022	30,549
Revenues	136,279	133,336	421,748	413,866
Operating expenses:
Compensation and related expenses	81,954	74,011	251,747	241,028
Other operating expenses	11,975	10,997	33,691	30,863
Reimbursable expenses	11,194	8,377	27,022	30,549
General and administrative expenses	5,309	6,018	16,984	18,498
Total operating expenses	110,432	99,403	329,444	320,938
Operating income	25,847	33,933	92,304	92,928
Other income, net:
Interest income, net	2,559	1,858	7,416	5,221
Miscellaneous income (expense), net	7,531	(1,774)	16,322	7,659
Total other income, net	10,090	84	23,738	12,880
Income before income taxes	35,937	34,017	116,042	105,808
Income taxes	9,893	9,479	30,629	26,398
Net income	$ 26,044	$ 24,538	$ 85,413	$ 79,410
Net income per share:
Basic (in dollars per share)	$ 0.51	$ 0.48	$ 1.67	$ 1.55
Diluted (in dollars per share)	$ 0.5	$ 0.48	$ 1.66	$ 1.54
Shares used in per share computations:
Basic (in shares)	51,177	51,203	51,098	51,197
Diluted (in shares)	51,622	51,645	51,527	51,680
Cash dividends declared per common share (in dollars per share)	$ 0.28	$ 0.26	$ 0.84	$ 0.78

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2024	Sep. 29, 2023	Sep. 27, 2024	Sep. 29, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 26,044	$ 24,538	$ 85,413	$ 79,410
Other comprehensive income (loss):
Foreign currency translation adjustments, net of tax	1,567	(515)	1,371	(188)
Comprehensive income	$ 27,611	$ 24,023	$ 86,784	$ 79,222

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ 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. 30, 2022	$ 320,752	$ 66	$ 301,002	$ (3,587)	$ 528,810	$ (505,539)
Balances (in shares) at Dec. 30, 2022		65,707				15,064
Employee stock purchase plan	1,143		1,015			$ 128
Employee stock purchase plan (in shares)						(12)
Amortization of unrecognized stock-based compensation	6,627		6,627
Foreign currency translation adjustments	327			327
Grant of restricted stock units to settle accrued bonus	10,497		10,497
Settlement of restricted stock units	(9,920)		(1,817)		(1,009)	$ (7,094)
Settlement of restricted stock units (in shares)						(186)
Exercise of stock options	100		22			$ 78
Exercise of stock options (in shares)						(8)
Dividends and dividend equivalent rights	(27,319)				(27,319)
Net income	54,872				54,872
Balance at Jun. 30, 2023	357,079	$ 66	317,346	(3,260)	555,354	$ (512,427)
Balances (in shares) at Jun. 30, 2023		65,707				14,858
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				15,064
Net income	79,410
Balance at Sep. 29, 2023	353,635	$ 66	320,152	(3,775)	566,518	$ (529,326)
Balances (in shares) at Sep. 29, 2023		65,707				15,040
Balance at Jun. 30, 2023	357,079	$ 66	317,346	(3,260)	555,354	$ (512,427)
Balances (in shares) at Jun. 30, 2023		65,707				14,858
Employee stock purchase plan	569		498			$ 71
Employee stock purchase plan (in shares)						(7)
Amortization of unrecognized stock-based compensation	2,308		2,308
Purchase of treasury stock	(16,970)					$ (16,970)
Purchase of treasury stock (in shares)						189
Foreign currency translation adjustments	(515)			(515)
Dividends and dividend equivalent rights	(13,374)				(13,374)
Net income	24,538				24,538
Balance at Sep. 29, 2023	353,635	$ 66	320,152	(3,775)	566,518	$ (529,326)
Balances (in shares) at Sep. 29, 2023		65,707				15,040
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				15,134
Employee stock purchase plan	958		842			$ 116
Employee stock purchase plan (in shares)						(12)
Amortization of unrecognized stock-based compensation	6,521		6,521
Purchase of treasury stock	(5,710)					$ (5,710)
Purchase of treasury stock (in shares)						74
Foreign currency translation adjustments	(196)			(196)
Grant of restricted stock units to settle accrued bonus	10,846		10,846
Settlement of restricted stock units	(6,796)		(1,875)		(720)	$ (4,201)
Settlement of restricted stock units (in shares)						(166)
Exercise of stock options	1,494		952			$ 542
Exercise of stock options (in shares)						(54)
Dividends and dividend equivalent rights	(29,358)				(29,358)
Net income	59,369				59,369
Balance at Jun. 28, 2024	393,213	$ 66	338,734	(3,173)	603,373	$ (545,787)
Balances (in shares) at Jun. 28, 2024		65,707				14,976
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				15,134
Net income	85,413
Balance at Sep. 27, 2024	410,274	$ 66	342,301	(1,606)	614,991	$ (545,478)
Balances (in shares) at Sep. 27, 2024		65,707				14,942
Balance at Jun. 28, 2024	393,213	$ 66	338,734	(3,173)	603,373	$ (545,787)
Balances (in shares) at Jun. 28, 2024		65,707				14,976
Employee stock purchase plan	457		413			$ 44
Employee stock purchase plan (in shares)						(4)
Amortization of unrecognized stock-based compensation	2,623		2,623
Foreign currency translation adjustments	1,567			1,567
Settlement of restricted stock units	(34)		(13)			$ (21)
Settlement of restricted stock units (in shares)						(1)
Exercise of stock options	830		544			$ 286
Exercise of stock options (in shares)						(29)
Dividends and dividend equivalent rights	(14,426)				(14,426)
Net income	26,044				26,044
Balance at Sep. 27, 2024	$ 410,274	$ 66	$ 342,301	$ (1,606)	$ 614,991	$ (545,478)
Balances (in shares) at Sep. 27, 2024		65,707				14,942

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 27, 2024	Sep. 29, 2023
Cash flows from operating activities:
Net income	$ 85,413	$ 79,410
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of property, equipment and leasehold improvements	7,199	6,535
Provision for contract losses and doubtful accounts	3,140	1,911
Stock-based compensation	18,382	17,177
Deferred income tax provision	(521)	(539)
Changes in operating assets and liabilities:
Accounts receivable	(4,398)	(13,551)
Prepaid expenses and other current assets	257	(5,886)
Change in operating leases	1,404	(451)
Accounts payable and accrued liabilities	1,502	(7,094)
Accrued payroll and employee benefits	(15,598)	(13,124)
Deferred revenues	(8,295)	(8,345)
Net cash provided by operating activities	88,485	56,043
Cash flows from investing activities:
Capital expenditures	(4,342)	(14,422)
Net cash used in investing activities	(4,342)	(14,422)
Cash flows from financing activities:
Payroll taxes for restricted stock units	(6,830)	(9,920)
Repurchase of common stock	(5,709)	(16,970)
Exercise of stock-based payment awards	3,739	1,812
Dividends and dividend equivalents rights	(43,988)	(40,894)
Net cash used in financing activities	(52,788)	(65,972)
Effect of foreign currency exchange rates on cash and cash equivalents	1,203	(8)
Net change in cash and cash equivalents	32,558	(24,359)
Cash and cash equivalents at beginning of period	187,150	161,458
Cash and cash equivalents at end of period	$ 219,708	$ 137,099

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		9 Months Ended
	Sep. 27, 2024	Sep. 29, 2023	Jun. 28, 2024	Jun. 30, 2023	Sep. 27, 2024	Sep. 29, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ 26,044	$ 24,538	$ 59,369	$ 54,872	$ 85,413	$ 79,410

Insider Trading Arrangements

Insider Trading Arrangements shares in Thousands	3 Months Ended
	Sep. 27, 2024 shares
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	Rule 10b5-1 Plans The following table summarizes the adoption by the Company’s directors and officers of trading plans intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) during the three months ended September 27, 2024: Name and Title Adoption Date Expiration Date Aggregate Number of Securities to be Sold Aggregate Number of Securities to be Purchased Paul Johnston , Director July 30, 2024 December 31, 2024 42,000 0 During the three months ended September 27, 2024, no pre-existing trading plans intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) were modified or terminated by the Company’s directors and officers, and no other written trading arrangements that are not intended to qualify for the Rule 10b5-1(c) affirmative defense were adopted, modified, or terminated by the Company’s directors and officers.
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
Paul Johnston
Trading Arrangements, by Individual
Name	Paul Johnston
Title	Director
Rule 10b5-1 Arrangement Adopted	true
Non-Rule 10b5-1 Arrangement Adopted	false
Adoption Date	July 30, 2024
Expiration Date	December 31, 2024
Arrangement Duration	154 days
Aggregate Available	42,000

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 27, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Note 1: Basis of Presentation Exponent, Inc. (referred to as the “Company” or “Exponent”) is an engineering and scientific consulting firm that provides solutions to complex problems. The Company operates on a 52-53 week fiscal year ending on the Friday closest to the last day of December. The accompanying unaudited condensed consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America for interim financial information, the instructions to Form 10-Q and Article 10 of Regulation S-X promulgated by the U.S. Securities and Exchange Commission. Accordingly, they do not contain all the information and notes required by accounting principles generally accepted in the United States of America for complete financial statements. In the opinion of management, all adjustments which are necessary for the fair presentation of the condensed consolidated financial statements have been included and all such adjustments are of a normal and recurring nature. The operating results for the three and nine months ended September 27, 2024 are not necessarily representative of the results of future quarterly or annual periods. The following information should be read in conjunction with the audited consolidated financial statements and accompanying notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 29, 2023, which was filed with the U.S. Securities and Exchange Commission on February 23, 2024 and amended on April 17, 2024. The unaudited condensed consolidated financial statements include the accounts of Exponent and its subsidiaries, which are all wholly owned. All intercompany accounts and transactions have been eliminated in consolidation. 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. Items subject to such estimates and assumptions include accounting for revenue recognition and estimating the allowance for contract losses and doubtful accounts. Actual results could differ from those estimates.

Revenue Recognition

Revenue Recognition	9 Months Ended
	Sep. 27, 2024
Revenue Recognition [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 that 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) then the entity may recognize revenue in the amount to which the entity has a right to invoice. The following table discloses the percentage of the Company’s revenue generated from time and materials contracts: Three Months Ended Nine Months Ended September 27, September 29, September 27, September 29, Engineering & Other Scientific 63 % 61 % 63 % 63 % Environmental and Health 15 % 15 % 16 % 15 % Total time and materials revenues 78 % 76 % 79 % 78 % 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 percentage of the Company’s revenue generated from fixed price contracts: Three Months Ended Nine Months Ended September 27, September 29, September 27, September 29, Engineering & Other Scientific 21 % 23 % 20 % 20 % Environmental and Health 1 % 1 % 1 % 2 % Total fixed price revenues 22 % 24 % 21 % 22 % Deferred revenues represent amounts billed to clients in advance of services provided. During the third quarter of 2024 , $ 3,666,000 of revenues were recognized that were included in the deferred revenue balance at June 28, 2024. During the first nine months of 20 24, $ 12,974,000 of revenues were recognized that were included in the deferred revenue balance at December 29, 2023. 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 mark-up on 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 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 wer e $ 2,689,000 and $ 2,379,000 during the third quarter of 2024 and 2023, respectively, an d $ 9,222,000 and $ 10,727,000 during the first nine months of 2024 and 2023, respectively.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 27, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 3: Fair Value Measurements The Company measures certain financial assets and liabilities at fair value on a recurring basis, including money market securities, trading fixed income and equity securities held in its deferred compensation plan and the liability associated with its deferred compensation plan. There were no transfers between fair value measurement levels during the three and nine months ended September 27, 2024 and September 29, 2023. 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 September 27, 2024: Fair Value Measurements at Reporting Date Using (In thousands) Total Quoted Prices in Significant Other Significant Assets Money market securities (1) $ 56,869 $ 56,869 $ - $ - Fixed income trading securities held in deferred (2) 38,935 38,935 - - Equity trading securities held in deferred compensation (2) 87,859 87,859 - - Total $ 183,663 $ 183,663 $ - $ - Liabilities Deferred compensation plan (3) 127,722 127,722 - - Total $ 127,722 $ 127,722 $ - $ - (1) Included in cash and cash equivalents on the Company’s unaudited condensed consolidated balance sheet. (2) Included in prepaid expenses and other current assets and deferred compensation plan assets on the Company’s unaudited condensed consolidated balance sheet. (3) Included in accrued payroll and employee benefits and deferred compensation plan liabilities on the Company’s unaudited condensed consolidated balance sheet. The fair value of these certain financial assets and liabilities was determined using the following inputs at December 29, 2023: Fair Value Measurements at Reporting Date Using (In thousands) Total Quoted Prices in Significant Other Significant Assets Money market securities (1) $ 54,686 $ 54,686 $ - $ - Fixed income trading securities held in deferred (2) 36,788 36,788 - - Equity trading securities held in deferred compensation (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 unaudited condensed consolidated balance sheet. (2) Included in prepaid expenses and other current assets and deferred compensation plan assets on the Company’s unaudited condensed consolidated balance sheet. (3) Included in accrued payroll and employee benefits and deferred compensation plan liabilities on the Company’s unaudited condensed consolidated balance sheet. Money market securities as of September 27, 2024 and December 29, 2023 represent obligations of the United States Treasury. Fixed income and equity trading securities represent mutual funds held in the Company’s deferred compensation plan. See Note 6 for additional information about the Company’s deferred compensation plan. Cash and cash equivalents consisted of the following as of September 27, 2024: Gross Gross Amortized Unrealized Unrealized Estimated (In thousands) Cost Gains Losses Fair Value Classified as current assets: Cash $ 162,839 $ - $ - $ 162,839 Cash equivalents: Money market securities 56,869 - - 56,869 Total cash equivalents 56,869 - - 56,869 Total cash and cash equivalents 219,708 - - 219,708 Cash and cash equivalents consisted of the following as of December 29, 2023: Amortized Unrealized Unrealized Estimated (In thousands) Cost Gains Losses Fair Value 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 At September 27, 2024 and December 29, 2023, the Company did not have any assets or liabilities valued using significant unobservable inputs. The following financial instruments are not measured at fair value on the Company's unaudited condensed consolidated balance sheet at September 27, 2024 and December 29, 2023, but require disclosure of their fair values: accounts receivable, other assets and accounts payable. The estimated fair value of such instruments at September 27, 2024 and December 29, 2023 approximates their carrying value as reported on the Company’s unaudited condensed consolidated balance sheet.

Net Income Per Share

Net Income Per Share	9 Months Ended
	Sep. 27, 2024
Earnings Per Share [Abstract]
Net Income Per Share	Note 4: Net Income Per Share Basic per share amounts are computed using the weighted-average number of shares of common stock outstanding during the period. Diluted per share amounts are calculated using the weighted-average number of shares of common stock outstanding during the period and, when dilutive, the weighted-average number of potential shares of common stock from the issuance of common stock to satisfy outstanding restricted stock units and the exercise of outstanding options to purchase common stock using the treasury stock method. The following schedule reconciles the shares used to calculate basic and diluted net income per share: Three Months Ended Nine Months Ended (In thousands) September 27, September 29, September 27, September 29, Shares used in basic per share computation 51,177 51,203 51,098 51,197 Effect of dilutive common stock options 175 183 172 195 Effect of dilutive restricted stock units 270 259 257 288 Shares used in diluted per share 51,622 51,645 51,527 51,680 Common stock options to purchase 30,000 and 63,333 shares were excluded from the diluted per share calculation for the three months ended September 27, 2024 and September 29, 2023, respectively, due to their anti-dilutive effect. Common stock options to purchase 63,333 and 24,835 shares were excluded from the diluted per share calculation for the nine months ended September 27, 2024 and September 29, 2023, respectively, due to their anti-dilutive effect.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 27, 2024
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Note 5: Stock-Based Compensation Restricted Stock Units 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 receives a fully vested restricted stock unit award is also granted a matching number of unvested restricted stock unit awards. Unvested restricted stock unit awards are also granted for select new hires and promotions. These unvested restricted stock unit awards generally 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 59½ years or older, all unvested restricted stock unit awards will vest, provided that the holder of each award 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 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. The Company recorded stock-based compensation expense associated with accrued bonus awards of $ 2,842,000 and $ 2,583,000 during the three months ended September 27, 2024 and September 29, 2023, respectively. For the nine months ended September 27, 2024 and September 29, 2023, the Company recorded stock-based compensation expense associated with accrued bonus awards of $ 9,238,000 and $ 8,242,000 , respectively. The value of the unvested restricted stock unit awards granted is recognized on a straight-line basis over the shorter of the four-year vesting period or the period between the grant date and the date the award recipient turns 59½ . If the award recipient is 59½ years or older on the date of grant, the value of the entire award is expensed upon grant. The Company recorded stock-based compensation expense associated with the unvested restricted stock unit awards of $ 2,255,000 and $ 2,038,000 during the three months ended September 27, 2024 and September 29, 2023, respectively. The Company recorded stock-based compensation expense associated with the unvested restricted stock unit awards of $ 8,089,000 and $ 8,124,000 during the nine months ended September 27, 2024 and September 29, 2023, respectively. Stock Options Stock options are granted for terms of ten years and generally vest 25 % per year over a four-year period from the grant date. Unvested stock option awards will continue to vest in the case of retirement at 59½ years or older, provided that the holder of each award 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 value of the unvested stock option awards granted is recognized on a straight-line basis over the shorter of the four-year vesting period or the period between the grant date and the date the award recipient turns 59½ . If the award recipient is 59½ years or older on the date of grant, the value of the entire award is expensed upon grant. The Company recorded stock-based compensation expense associated with stock option grants o f $ 368,000 and $ 270,000 during the three months ended September 27, 2024 and September 29, 2023, respectively. The Company recorded stock-based compensation expense associated with stock option grants of $ 1,055,000 and $ 811,000 during the nine months ended September 27, 2024 and September 29, 2023, respectively. 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 option 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, forfeiture, and post-vesting 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 of the options. The dividend yield assumption considers the expectation of continued declaration of dividends, offset by option holders’ dividend equivalent rights. The Company accounts for forfeitures of stock-based awards when they occur. All stock-based payment awards are recognized on a straight-line basis over the requisite service periods of the awards.

Deferred Compensation Plans

Deferred Compensation Plans	9 Months Ended
	Sep. 27, 2024
Deferred Compensation Arrangements [Abstract]
Deferred Compensation Plans	Note 6: 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 September 27, 2024 and December 29, 2023, the invested amounts under the plans totaled $ 126,794,000 and $ 115,187,000 , respectively, and are recorded in prepaid expenses and other current assets and deferred compensation plan assets on the Company’s unaudited condensed consolidated balance sheet. These assets are classified as trading securities and are recorded at fair value with changes recorded as adjustments to miscellaneous income (loss), net. As of September 27, 2024 and December 29, 2023, vested amounts due under the plans totaled $ 127,722,000 and $ 116,564,000 , respectively, and are recorded within accrued payroll and employee benefits and deferred compensation plan liabilities on the Company’s unaudited condensed consolidated balance sheets. Changes in the liability are recorded as adjustments to compensation expense. During the three months ended September 27, 2024, the Company recognized additional compensation expense of $ 7,157,000 as a result of changes in the market value of the trust assets with the same amount being recorded as gain in miscellaneous income (loss), net. During the three months ended September 29, 2023, the Company recognized a reduction in compensation expense of $ 2,769,000 as a result of changes in the market value of the trust assets with the same amount being recorded as a loss in miscellaneous income (loss), net. During the nine months ended September 27, 2024, the Company recognized additional compensation expense of $ 14,299,000 as a result of changes in the market value of the trust assets with the same amount being recorded as income in miscellaneous income, net. During the nine months ended September 29, 2023, the Company recognized additional compensation expense of $ 5,271,000 as a result of changes in the market value of the trust assets with the same amount being recorded as income in miscellaneous income (loss), net.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	9 Months Ended
	Sep. 27, 2024
Supplemental Cash Flow Information [Abstract]
Supplemental Cash Flow Information	Note 7: Supplemental Cash Flow Information The following is supplemental disclosure of cash flow information: Nine Months Ended (In thousands) September 27, September 29, Cash paid during period: Income taxes $ 29,060 $ 27,753 Non-cash investing and financing activities: Vested stock unit awards issued to settle accrued bonuses 10,846 10,497 Right-of-use asset obtained in exchange for operating lease obligations 56,714 13,803 Leasehold improvements obtained in exchange for right-of-use asset - 3,219 Accrual for capital expenditures as of period end 537 618

Accounts Receivable, Net

Accounts Receivable, Net	9 Months Ended
	Sep. 27, 2024
Receivables [Abstract]
Accounts Receivable, Net	Note 8: Accounts Receivable, Net At September 27, 2024 and December 29, 2023, accounts receivable, net, was comprised of the following: September 27, December 29, (In thousands) 2024 2023 Billed accounts receivable $ 117,746 $ 128,052 Unbilled accounts receivable 57,353 44,589 Allowance for contract losses and doubtful accounts ( 6,481 ) ( 5,281 ) Total accounts receivable, net $ 168,618 $ 167,360 The Company maintains allowances for estimated losses over the remaining contractual life of its receivables 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 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 economic conditions, aging of amounts due and future expectations. A reconciliation of the beginning and ending amount of the allowance for contract losses and doubtful accounts is as follows (in thousands): Balance at December 29, 2023 $ 5,281 Provision for contract losses and doubtful accounts 3,140 Write-offs ( 1,940 ) Balance at September 27, 2024 $ 6,481

Segment Reporting

Segment Reporting	9 Months Ended
	Sep. 27, 2024
Segment Reporting [Abstract]
Segment Reporting	Note 9: 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 areas 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. Our Chief Executive Officer, the chief operating decision maker, reviews revenues and operating income for each of our reportable segments, but does not review total assets in evaluating segment performance and capital allocation. Segment information for the three and nine months ended September 27, 2024 and September 29, 2023 follows: Revenues Three Months Ended Nine Months Ended (In thousands) September 27, September 29, September 27, September 29, Engineering and Other Scientific $ 115,244 $ 110,857 $ 355,193 $ 344,552 Environmental and Health 21,035 22,479 66,555 69,314 Total revenues $ 136,279 $ 133,336 $ 421,748 $ 413,866 Operating Income Three Months Ended Nine Months Ended (In thousands) September 27, September 29, September 27, September 29, Engineering and Other Scientific $ 40,292 $ 38,734 $ 132,687 $ 121,064 Environmental and Health 7,547 7,475 23,042 22,550 Total segment operating income 47,839 46,209 155,729 143,614 Corporate operating expense ( 21,992 ) ( 12,276 ) ( 63,425 ) ( 50,686 ) Total operating income $ 25,847 $ 33,933 $ 92,304 $ 92,928 Certain operating expenses are excluded from the Company’s measure of segment operating income. These expenses include costs associated with its human resources, finance, information technology, and business development groups; the deferred compensation expense/benefit due to the change in value of assets associated with its deferred compensation plan; stock-based compensation associated with restricted stock unit and stock option awards; and the change in its allowance for contract losses and doubtful accounts. Capital Expenditures Three Months Ended Nine Months Ended (In thousands) September 27, September 29, September 27, September 29, Engineering and Other Scientific $ 887 $ 541 $ 1,769 $ 3,210 Environmental and Health - 25 74 139 Total segment capital expenditures 887 566 1,843 3,349 Corporate capital expenditures 1,339 1,248 2,899 13,893 Total capital expenditures $ 2,226 $ 1,814 $ 4,742 $ 17,242 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 Three Months Ended Nine Months Ended (In thousands) September 27, September 29, September 27, September 29, Engineering and Other Scientific $ 1,735 $ 1,750 $ 5,128 $ 4,428 Environmental and Health 50 53 154 155 Total segment depreciation and 1,785 1,803 5,282 4,583 Corporate depreciation and amortization 604 558 1,917 1,952 Total depreciation and amortization $ 2,389 $ 2,361 $ 7,199 $ 6,535 No single client comprised more tha n 10 % of the Company’s revenues during the three and nine months ended September 27, 2024. No single client comprised more than 10 % of the Company’s revenues during the three and nine months ended September 29, 2023.

Leases

Leases	9 Months Ended
	Sep. 27, 2024
Leases [Abstract]
Leases	Note 10: 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 condensed consolidated balance sheet. The Company does not have any finance leases as of September 27, 2024. 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 may 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 condensed 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 ten 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 fifteen-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 September 27, 2024, 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 Company leases excess space in its Silicon Valley and Natick facilities. Rental income of $ 742,000 and $ 882,000 was included in other income for the three months ended September 27, 2024 and September 29, 2023, respectively. Rental income of $ 2,511,000 and $ 2,491,000 was included in other income for the nine months ended September 27, 2024 and September 29, 2023, respectively. The components of lease expense included in other operating expenses on the condensed consolidated statements of income were as follows: Three Months Ended Nine Months Ended (In thousands) September 27, September 29, September 27, September 29, Operating lease cost $ 3,251 $ 2,094 $ 7,758 $ 5,659 Variable lease cost 352 378 1,100 1,251 Short-term lease cost 378 256 1,028 937 Supplemental cash flow information related to operating leases was as follows: Three Months Ended Nine Months Ended (In thousands) September 27, 2024 September 29, 2023 September 27, 2024 September 29, 2023 Cash paid for amounts included in the $ 1,654 $ 1,715 $ 6,002 $ 5,516 Supplemental balance sheet information related to operating leases was as follows: September 27, September 29, 2023 Weighted Average Remaining Lease Term 14.0 years 6.4 years Weighted Average Discount Rate 6.2 % 5.1 % Maturities of operating lease liabilities as of September 27, 2024: Operating (In thousands) Leases 2024 (excluding the nine months ended September 27, 2024) $ 1,538 2025 7,803 2026 7,460 2027 6,183 2028 9,645 Thereafter 98,461 Total lease payments 131,090 Less imputed interest ( 50,228 ) Total lease liability $ 80,862

Contingencies

Contingencies	9 Months Ended
	Sep. 27, 2024
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Note 11: 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.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 27, 2024
Subsequent Events [Abstract]
Subsequent Events	Note 12: Subsequent Events On Octobe r 24 , 2024 , the Company’s Board of Directors announced a cash dividend of $ 0.28 per share of the Company’s common stock, payab le December 20, 2024 , to stockholders of record as of December 6, 2 024 .

Basis of Presentation (Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 27, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation Exponent, Inc. (referred to as the “Company” or “Exponent”) is an engineering and scientific consulting firm that provides solutions to complex problems. The Company operates on a 52-53 week fiscal year ending on the Friday closest to the last day of December. The accompanying unaudited condensed consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America for interim financial information, the instructions to Form 10-Q and Article 10 of Regulation S-X promulgated by the U.S. Securities and Exchange Commission. Accordingly, they do not contain all the information and notes required by accounting principles generally accepted in the United States of America for complete financial statements. In the opinion of management, all adjustments which are necessary for the fair presentation of the condensed consolidated financial statements have been included and all such adjustments are of a normal and recurring nature. The operating results for the three and nine months ended September 27, 2024 are not necessarily representative of the results of future quarterly or annual periods. The following information should be read in conjunction with the audited consolidated financial statements and accompanying notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 29, 2023, which was filed with the U.S. Securities and Exchange Commission on February 23, 2024 and amended on April 17, 2024. The unaudited condensed consolidated financial statements include the accounts of Exponent and its subsidiaries, which are all wholly owned. All intercompany accounts and transactions have been eliminated in consolidation.
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. Items subject to such estimates and assumptions include accounting for revenue recognition and estimating the allowance for contract losses and doubtful accounts. Actual results could differ from those estimates.

Revenue Recognition (Tables)

Revenue Recognition (Tables)	9 Months Ended
	Sep. 27, 2024
Revenue Recognition [Abstract]
Summary of Percent of Revenues	The following table discloses the percentage of the Company’s revenue generated from time and materials contracts: Three Months Ended Nine Months Ended September 27, September 29, September 27, September 29, Engineering & Other Scientific 63 % 61 % 63 % 63 % Environmental and Health 15 % 15 % 16 % 15 % Total time and materials revenues 78 % 76 % 79 % 78 % The following table discloses the percentage of the Company’s revenue generated from fixed price contracts: Three Months Ended Nine Months Ended September 27, September 29, September 27, September 29, Engineering & Other Scientific 21 % 23 % 20 % 20 % Environmental and Health 1 % 1 % 1 % 2 % Total fixed price revenues 22 % 24 % 21 % 22 %

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 27, 2024
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 September 27, 2024: Fair Value Measurements at Reporting Date Using (In thousands) Total Quoted Prices in Significant Other Significant Assets Money market securities (1) $ 56,869 $ 56,869 $ - $ - Fixed income trading securities held in deferred (2) 38,935 38,935 - - Equity trading securities held in deferred compensation (2) 87,859 87,859 - - Total $ 183,663 $ 183,663 $ - $ - Liabilities Deferred compensation plan (3) 127,722 127,722 - - Total $ 127,722 $ 127,722 $ - $ - (1) Included in cash and cash equivalents on the Company’s unaudited condensed consolidated balance sheet. (2) Included in prepaid expenses and other current assets and deferred compensation plan assets on the Company’s unaudited condensed consolidated balance sheet. (3) Included in accrued payroll and employee benefits and deferred compensation plan liabilities on the Company’s unaudited condensed consolidated balance sheet. The fair value of these certain financial assets and liabilities was determined using the following inputs at December 29, 2023: Fair Value Measurements at Reporting Date Using (In thousands) Total Quoted Prices in Significant Other Significant Assets Money market securities (1) $ 54,686 $ 54,686 $ - $ - Fixed income trading securities held in deferred (2) 36,788 36,788 - - Equity trading securities held in deferred compensation (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 unaudited condensed consolidated balance sheet. (2) Included in prepaid expenses and other current assets and deferred compensation plan assets on the Company’s unaudited condensed consolidated balance sheet. Included in accrued payroll and employee benefits and deferred compensation plan liabilities on the Company’s unaudited condensed consolidated balance sheet.
Cash and Cash Equivalents	Cash and cash equivalents consisted of the following as of September 27, 2024: Gross Gross Amortized Unrealized Unrealized Estimated (In thousands) Cost Gains Losses Fair Value Classified as current assets: Cash $ 162,839 $ - $ - $ 162,839 Cash equivalents: Money market securities 56,869 - - 56,869 Total cash equivalents 56,869 - - 56,869 Total cash and cash equivalents 219,708 - - 219,708 Cash and cash equivalents consisted of the following as of December 29, 2023: Amortized Unrealized Unrealized Estimated (In thousands) Cost Gains Losses Fair Value 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

Net Income Per Share (Tables)

Net Income Per Share (Tables)	9 Months Ended
	Sep. 27, 2024
Earnings Per Share [Abstract]
Reconciles Shares to Calculate Basic and Diluted Net Income Per Share	The following schedule reconciles the shares used to calculate basic and diluted net income per share: Three Months Ended Nine Months Ended (In thousands) September 27, September 29, September 27, September 29, Shares used in basic per share computation 51,177 51,203 51,098 51,197 Effect of dilutive common stock options 175 183 172 195 Effect of dilutive restricted stock units 270 259 257 288 Shares used in diluted per share 51,622 51,645 51,527 51,680

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Tables)	9 Months Ended
	Sep. 27, 2024
Supplemental Cash Flow Information [Abstract]
Supplemental Disclosure of Cash Flow Information	The following is supplemental disclosure of cash flow information: Nine Months Ended (In thousands) September 27, September 29, Cash paid during period: Income taxes $ 29,060 $ 27,753 Non-cash investing and financing activities: Vested stock unit awards issued to settle accrued bonuses 10,846 10,497 Right-of-use asset obtained in exchange for operating lease obligations 56,714 13,803 Leasehold improvements obtained in exchange for right-of-use asset - 3,219 Accrual for capital expenditures as of period end 537 618

Accounts Receivable, Net (Table

Accounts Receivable, Net (Tables)	9 Months Ended
	Sep. 27, 2024
Receivables [Abstract]
Accounts Receivable, Net	At September 27, 2024 and December 29, 2023, accounts receivable, net, was comprised of the following: September 27, December 29, (In thousands) 2024 2023 Billed accounts receivable $ 117,746 $ 128,052 Unbilled accounts receivable 57,353 44,589 Allowance for contract losses and doubtful accounts ( 6,481 ) ( 5,281 ) Total accounts receivable, net $ 168,618 $ 167,360
Reconciliation of Beginning and Ending Amount of Allowance for Contract Losses and Doubtful Accounts	A reconciliation of the beginning and ending amount of the allowance for contract losses and doubtful accounts is as follows (in thousands): Balance at December 29, 2023 $ 5,281 Provision for contract losses and doubtful accounts 3,140 Write-offs ( 1,940 ) Balance at September 27, 2024 $ 6,481

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 27, 2024
Segment Reporting [Abstract]
Segment Reporting Information, by Segment	Segment information for the three and nine months ended September 27, 2024 and September 29, 2023 follows: Revenues Three Months Ended Nine Months Ended (In thousands) September 27, September 29, September 27, September 29, Engineering and Other Scientific $ 115,244 $ 110,857 $ 355,193 $ 344,552 Environmental and Health 21,035 22,479 66,555 69,314 Total revenues $ 136,279 $ 133,336 $ 421,748 $ 413,866 Operating Income Three Months Ended Nine Months Ended (In thousands) September 27, September 29, September 27, September 29, Engineering and Other Scientific $ 40,292 $ 38,734 $ 132,687 $ 121,064 Environmental and Health 7,547 7,475 23,042 22,550 Total segment operating income 47,839 46,209 155,729 143,614 Corporate operating expense ( 21,992 ) ( 12,276 ) ( 63,425 ) ( 50,686 ) Total operating income $ 25,847 $ 33,933 $ 92,304 $ 92,928 Capital Expenditures Three Months Ended Nine Months Ended (In thousands) September 27, September 29, September 27, September 29, Engineering and Other Scientific $ 887 $ 541 $ 1,769 $ 3,210 Environmental and Health - 25 74 139 Total segment capital expenditures 887 566 1,843 3,349 Corporate capital expenditures 1,339 1,248 2,899 13,893 Total capital expenditures $ 2,226 $ 1,814 $ 4,742 $ 17,242 Depreciation and Amortization Three Months Ended Nine Months Ended (In thousands) September 27, September 29, September 27, September 29, Engineering and Other Scientific $ 1,735 $ 1,750 $ 5,128 $ 4,428 Environmental and Health 50 53 154 155 Total segment depreciation and 1,785 1,803 5,282 4,583 Corporate depreciation and amortization 604 558 1,917 1,952 Total depreciation and amortization $ 2,389 $ 2,361 $ 7,199 $ 6,535

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 27, 2024
Leases [Abstract]
Lease, Cost	The components of lease expense included in other operating expenses on the condensed consolidated statements of income were as follows: Three Months Ended Nine Months Ended (In thousands) September 27, September 29, September 27, September 29, Operating lease cost $ 3,251 $ 2,094 $ 7,758 $ 5,659 Variable lease cost 352 378 1,100 1,251 Short-term lease cost 378 256 1,028 937
Supplemental Cash Flow Information Related to Operating Lease	Supplemental cash flow information related to operating leases was as follows: Three Months Ended Nine Months Ended (In thousands) September 27, 2024 September 29, 2023 September 27, 2024 September 29, 2023 Cash paid for amounts included in the $ 1,654 $ 1,715 $ 6,002 $ 5,516
Supplemental Balance Sheet Information Related to Operating Lease	Supplemental balance sheet information related to operating leases was as follows: September 27, September 29, 2023 Weighted Average Remaining Lease Term 14.0 years 6.4 years Weighted Average Discount Rate 6.2 % 5.1 %
Maturities of Lease Liabilities	Maturities of operating lease liabilities as of September 27, 2024: Operating (In thousands) Leases 2024 (excluding the nine months ended September 27, 2024) $ 1,538 2025 7,803 2026 7,460 2027 6,183 2028 9,645 Thereafter 98,461 Total lease payments 131,090 Less imputed interest ( 50,228 ) Total lease liability $ 80,862

Revenue Recognition - Summary o

Revenue Recognition - Summary of Revenues (Detail) - Sales Revenue, Net [Member] - Revenue from Rights Concentration Risk [Member]	3 Months Ended		9 Months Ended
	Sep. 27, 2024	Sep. 29, 2023	Sep. 27, 2024	Sep. 29, 2023
Time And Materials Contracts [Member]
Disaggregation Of Revenue [Line Items]
Concentration Risk, Percentage	78%	76%	79%	78%
Time And Materials Contracts [Member] | Engineering and Other Scientific [Member]
Disaggregation Of Revenue [Line Items]
Concentration Risk, Percentage	63%	61%	63%	63%
Time And Materials Contracts [Member] | Environmental and Health [Member]
Disaggregation Of Revenue [Line Items]
Concentration Risk, Percentage	15%	15%	16%	15%
Fixed Price Contracts [Member]
Disaggregation Of Revenue [Line Items]
Concentration Risk, Percentage	22%	24%	21%	22%
Fixed Price Contracts [Member] | Engineering and Other Scientific [Member]
Disaggregation Of Revenue [Line Items]
Concentration Risk, Percentage	21%	23%	20%	20%
Fixed Price Contracts [Member] | Environmental and Health [Member]
Disaggregation Of Revenue [Line Items]
Concentration Risk, Percentage	1%	1%	1%	2%

Revenue Recognition - Additiona

Revenue Recognition - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 27, 2024	Sep. 29, 2023	Sep. 27, 2024	Sep. 29, 2023
Revenue Recognition [Abstract]
Deferred Revenue, Revenue Recognized	$ 3,666,000		$ 12,974,000
Subcontractor Fees Not Included In Revenues	$ 2,689,000	$ 2,379,000	$ 9,222,000	$ 10,727,000

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($)	Sep. 27, 2024		Dec. 29, 2023
Assets
Trading securities held in deferred compensation plan	$ 126,794,000		$ 115,187,000
Total	183,663,000		169,873,000
Liabilities
Deferred compensation plan	127,722,000	[1]	116,564,000	[2]
Total	127,722,000		116,564,000
Money market securities
Assets
Money market securities	56,869,000	[3]	54,686,000	[4]
Fixed income securities
Assets
Trading securities held in deferred compensation plan	38,935,000	[5]	36,788,000	[6]
Equity securities
Assets
Trading securities held in deferred compensation plan	87,859,000	[5]	78,399,000	[6]
Fair Value, Inputs, Level 1
Assets
Total	183,663,000		169,873,000
Liabilities
Deferred compensation plan	127,722,000	[1]	116,564,000	[2]
Total	127,722,000		116,564,000
Fair Value, Inputs, Level 1 | Money market securities
Assets
Money market securities	56,869,000	[3]	54,686,000	[4]
Fair Value, Inputs, Level 1 | Fixed income securities
Assets
Trading securities held in deferred compensation plan	38,935,000	[5]	36,788,000	[6]
Fair Value, Inputs, Level 1 | Equity securities
Assets
Trading securities held in deferred compensation plan	87,859,000	[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 accrued payroll and employee benefits and deferred compensation plan liabilities on the Company’s unaudited condensed consolidated balance sheet. Included in accrued payroll and employee benefits and deferred compensation plan liabilities on the Company’s unaudited condensed consolidated balance sheet. Included in cash and cash equivalents on the Company’s unaudited condensed consolidated balance sheet. Included in cash and cash equivalents on the Company’s unaudited condensed consolidated balance sheet. Included in prepaid expenses and other current assets and deferred compensation plan assets on the Company’s unaudited condensed consolidated balance sheet. Included in prepaid expenses and other current assets and deferred compensation plan assets on the Company’s unaudited condensed consolidated balance sheet.

Fair Value Measurements - Cash

Fair Value Measurements - Cash and Cash Equivalents (Detail) - USD ($) $ in Thousands	Sep. 27, 2024	Dec. 29, 2023
Cash
Fair Value Measurements [Line Items]
Amortized Cost	$ 162,839	$ 132,464
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	162,839	132,464
Money market securities
Fair Value Measurements [Line Items]
Amortized Cost	56,869	54,686
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	56,869	54,686
Total cash equivalents
Fair Value Measurements [Line Items]
Amortized Cost	56,869	54,686
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	56,869	54,686
Total cash and cash equivalents
Fair Value Measurements [Line Items]
Amortized Cost	219,708	187,150
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	$ 219,708	$ 187,150

Net Income Per Share - Reconcil

Net Income Per Share - Reconciles the Denominators of the Company's Calculation for Basic and Diluted Net Income per Share (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2024	Sep. 29, 2023	Sep. 27, 2024	Sep. 29, 2023
Schedule Of Earnings Per Share Basic and Diluted [Line Items]
Shares used in basic per share computation	51,177	51,203	51,098	51,197
Shares used in diluted per share computation	51,622	51,645	51,527	51,680
Employee Stock Option
Schedule Of Earnings Per Share Basic and Diluted [Line Items]
Effect of dilutive stock outstanding	175	183	172	195
Restricted Stock Units (RSUs)
Schedule Of Earnings Per Share Basic and Diluted [Line Items]
Effect of dilutive stock outstanding	270	259	257	288

Net Income Per Share - Addition

Net Income Per Share - Additional Information (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 27, 2024	Sep. 29, 2023	Sep. 27, 2024	Sep. 29, 2023
Earnings Per Share [Abstract]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	30,000	63,333	63,333	24,835

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 27, 2024	Sep. 29, 2023	Sep. 27, 2024	Sep. 29, 2023
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%
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	$ 2,842,000	$ 2,583,000	$ 9,238,000	$ 8,242,000
Unvested Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation, vesting period			4 years
Unvested Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense	2,255,000	2,038,000	$ 8,089,000	8,124,000
Unvested Restricted Stock Awards | 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	$ 368,000	$ 270,000	$ 1,055,000	$ 811,000
Share Based Compensation Arrangement By Share Based Payment Award Options Expiration Term			10 years
Vesting percentage of stock options granted per year			25%
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	59 years 6 months

Deferred Compensation Plans - A

Deferred Compensation Plans - Additional Information (Detail) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 27, 2024		Sep. 29, 2023	Sep. 27, 2024		Sep. 29, 2023	Dec. 29, 2023
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Trading securities held in deferred compensation plan	$ 126,794,000			$ 126,794,000			$ 115,187,000
Deferred compensation plan	127,722,000	[1]		127,722,000	[1]		$ 116,564,000	[2]
Change in market value of trust assets	$ 7,157,000		$ (2,769,000)	$ 14,299,000		$ 5,271,000
Maximum
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Percentage of compensation deferred				100%
[1] Included in accrued payroll and employee benefits and deferred compensation plan liabilities on the Company’s unaudited condensed consolidated balance sheet. Included in accrued payroll and employee benefits and deferred compensation plan liabilities on the Company’s unaudited condensed consolidated balance sheet.

Supplemental Disclosure of Cash

Supplemental Disclosure of Cash Flow Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 27, 2024	Sep. 29, 2023
Cash paid during period:
Income taxes	$ 29,060	$ 27,753
Non-cash investing and financing activities:
Vested stock unit awards issued to settle accrued bonuses	10,846	10,497
Right-of-use asset obtained in exchange for operating lease obligations	56,714	13,803
Leasehold improvements obtained in exchange for right-of-use asset	0	3,219
Accrual for capital expenditures as of period end	$ 537	$ 618

Accounts Receivable, Net (Detai

Accounts Receivable, Net (Detail) - USD ($) $ in Thousands	Sep. 27, 2024	Dec. 29, 2023
Accounts Notes And Loans Receivable [Line Items]
Allowance for contract losses and doubtful accounts	$ (6,481)	$ (5,281)
Total accounts receivable, net	168,618	167,360
Billed accounts receivable
Accounts Notes And Loans Receivable [Line Items]
Accounts Receivable	117,746	128,052
Unbilled accounts receivable
Accounts Notes And Loans Receivable [Line Items]
Accounts Receivable	$ 57,353	$ 44,589

Accounts Receivable, Net - Reco

Accounts Receivable, Net - Reconciliation of Beginning and Ending Amount of Allowance for Contract Losses and Doubtful Accounts (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 27, 2024	Sep. 29, 2023
Receivables [Abstract]
Balance at December 30, 2022	$ 5,281
Provision for contract losses and doubtful accounts	3,140	$ 1,911
Write-offs	(1,940)
Balance at September 29, 2023	$ 6,481

Segment Information (Detail)

Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2024	Sep. 29, 2023	Sep. 27, 2024	Sep. 29, 2023
Segment Reporting Information [Line Items]
Revenues	$ 136,279	$ 133,336	$ 421,748	$ 413,866
Operating Income	25,847	33,933	92,304	92,928
Capital Expenditure	2,226	1,814	4,742	17,242
Depreciation and Amortization	2,389	2,361	7,199	6,535
Operating segments
Segment Reporting Information [Line Items]
Operating Income	47,839	46,209	155,729	143,614
Capital Expenditure	887	566	1,843	3,349
Depreciation and Amortization	1,785	1,803	5,282	4,583
Corporate
Segment Reporting Information [Line Items]
Operating Income	(21,992)	(12,276)	(63,425)	(50,686)
Capital Expenditure	1,339	1,248	2,899	13,893
Depreciation and Amortization	604	558	1,917	1,952
Engineering and Other Scientific | Operating segments
Segment Reporting Information [Line Items]
Revenues	115,244	110,857	355,193	344,552
Operating Income	40,292	38,734	132,687	121,064
Capital Expenditure	887	541	1,769	3,210
Depreciation and Amortization	1,735	1,750	5,128	4,428
Environmental and Health | Operating segments
Segment Reporting Information [Line Items]
Revenues	21,035	22,479	66,555	69,314
Operating Income	7,547	7,475	23,042	22,550
Capital Expenditure	0	25	74	139
Depreciation and Amortization	$ 50	$ 53	$ 154	$ 155

Segment Reporting - Additional

Segment Reporting - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 27, 2024 Client	Sep. 29, 2023 Client	Sep. 27, 2024 Segment Client	Sep. 29, 2023 Client
Segment Reporting Information [Line Items]
Number of reportable operating segments | Segment			2
Sales Revenue, Net [Member] | Revenue from Rights Concentration Risk [Member] | Single Client [Member]
Segment Reporting Information [Line Items]
Number of clients comprised more than 10% of revenue or accounts receivable | Client	0	0	0	0
Concentration Risk, Percentage	10%	10%	10%	10%

Leases - Additional Information

Leases - Additional Information (Detail)		3 Months Ended			9 Months Ended
	Jun. 19, 2024 USD ($)	Sep. 27, 2024 USD ($) a Option State	Jun. 28, 2024 USD ($)	Sep. 29, 2023 USD ($)	Sep. 27, 2024 USD ($) a Option State	Sep. 29, 2023 USD ($)
Lessee Lease Description [Line Items]
Lease payment obligation per year		$ 131,090,000			$ 131,090,000
Additional right-of-use asset in exchange for operating lease liability					56,714,000	$ 13,803,000
Other Income [Member]
Lessee Lease Description [Line Items]
Rental Income		$ 742,000		$ 882,000	$ 2,511,000	$ 2,491,000
Office, Laboratory, and Storage Space [Member]
Lessee Lease Description [Line Items]
Number of States in which Entity Has Lease Arrangements | State		13			13
Office, Laboratory, and Storage Space [Member] | Minimum
Lessee Lease Description [Line Items]
Lessee, Operating Lease, Term of Contract		1 year			1 year
Office, Laboratory, and Storage Space [Member] | Maximum
Lessee Lease Description [Line Items]
Lessee, Operating Lease, Term of Contract		10 years			10 years
Phoenix Arizona [Member]
Lessee Lease Description [Line Items]
Lessee, Operating Lease, Term of Contract		30 years			30 years
Area of Land | a		147			147
Number of Options to Renew Lease | Option		2			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 fifteen-year periods.
Lessee, Operating Lease, Existence of Option to Extend [true false]					true
Lessee, Operating Lease, Renewal Term	15 years	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	3 Months Ended		9 Months Ended
	Sep. 27, 2024	Sep. 29, 2023	Sep. 27, 2024	Sep. 29, 2023
Operating lease cost	$ 3,251	$ 2,094	$ 7,758	$ 5,659
Variable lease cost	352	378	1,100	1,251
Short-term lease cost	$ 378	$ 256	$ 1,028	$ 937

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information Related to Operating Leases (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2024	Sep. 29, 2023	Sep. 27, 2024	Sep. 29, 2023
Leases [Abstract]
Cash paid for amounts included in the measurement of operating lease liabilities	$ 1,654	$ 1,715	$ 6,002	$ 5,516

Supplemental Balance Sheet Info

Supplemental Balance Sheet Information Related to Operating Leases (Detail)	Sep. 27, 2024	Sep. 29, 2023
Leases [Abstract]
Weighted Average Remaining Lease Term	14 years	6 years 4 months 24 days
Weighted Average Discount Rate	6.20%	5.10%

Maturities of Lease Liabilities

Maturities of Lease Liabilities (Detail) $ in Thousands	Sep. 27, 2024 USD ($)
Leases [Abstract]
2024 (excluding the nine months ended September 27, 2024)	$ 1,538
2025	7,803
2026	7,460
2027	6,183
2028	9,645
Thereafter	98,461
Total lease payments	131,090
Less imputed interest	(50,228)
Total lease liability	$ 80,862

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - $ / shares		3 Months Ended		9 Months Ended
	Oct. 24, 2024	Sep. 27, 2024	Sep. 29, 2023	Sep. 27, 2024	Sep. 29, 2023
Subsequent Event [Line Items]
Cash dividends declared per common share (in dollars per share)		$ 0.28	$ 0.26	$ 0.84	$ 0.78
Subsequent Event
Subsequent Event [Line Items]
Cash dividends declared per common share (in dollars per share)	$ 0.28
Subsequent Event | Q4 Dividends
Subsequent Event [Line Items]
Dividends Payable, Date Declared	Oct. 24, 2024
Dividends Payable, Date to be Paid	Dec. 20, 2024
Dividends Payable, Date of Record	Dec. 06, 2024