Exponent (EXPO) 10-Q 2 Nov 18 2018 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 28, 2018	Oct. 26, 2018
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 28, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Entity Registrant Name	EXPONENT INC
Entity Central Index Key	851,520
Current Fiscal Year End Date	--12-28
Entity Filer Category	Large Accelerated Filer
Trading Symbol	EXPO
Entity Common Stock, Shares Outstanding		52,012,151
Entity Emerging Growth Company	false
Entity Small Business	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 28, 2018	Dec. 29, 2017
Current assets:
Cash and cash equivalents	$ 120,977	$ 124,794
Short-term investments	81,373	71,604
Accounts receivable, net of allowance for contract losses and doubtful accounts of $3,912 and $3,526 at September 28, 2018 and December 29, 2017, respectively	122,911	110,100
Prepaid expenses and other assets	11,243	9,011
Total current assets	336,504	315,509
Property, equipment and leasehold improvements, net	43,969	35,014
Goodwill	8,607	8,607
Deferred income taxes	32,966	30,437
Deferred compensation plan assets	57,432	48,676
Other assets	1,415	1,346
Total assets	480,893	439,589
Current liabilities:
Accounts payable and accrued liabilities	13,221	14,741
Accrued payroll and employee benefits	66,060	70,064
Deferred revenues	8,864	8,302
Total current liabilities	88,145	93,107
Other liabilities	2,911	3,326
Deferred compensation	57,998	52,776
Deferred rent	1,205	1,292
Total liabilities	150,259	150,501
Stockholders' equity:
Common stock, $0.001 par value; 120,000 shares authorized; 65,707 shares issued at September 28, 2018 and December 29, 2017	66	66
Additional paid-in capital	225,454	210,230
Accumulated other comprehensive income (loss)
Investment securities, available-for-sale	(288)	(236)
Foreign currency translation adjustments	(2,726)	(1,793)
Accumulated other comprehensive income (loss)	(3,014)	(2,029)
Retained earnings	332,907	303,990
Treasury stock, at cost; 13,655 and 14,169 shares held at September 28, 2018 and December 29, 2017, respectively	(224,779)	(223,169)
Total stockholders' equity	330,634	289,088
Total liabilities and stockholders' equity	$ 480,893	$ 439,589

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Sep. 28, 2018	Dec. 29, 2017
Accounts receivable, net of allowance for contract losses and doubtful accounts	$ 3,912	$ 3,526
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	120,000	120,000
Common stock, shares issued	65,707	65,707
Treasury stock, shares	13,655	14,169

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2018	Sep. 29, 2017	Sep. 28, 2018	Sep. 29, 2017
Revenues:
Revenues before reimbursements	$ 88,714	$ 82,359	$ 269,370	$ 246,946
Reimbursements	6,588	5,196	18,010	12,571
Revenues	95,302	87,555	287,380	259,517
Operating expenses:
Compensation and related expenses	55,639	51,493	168,676	157,447
Other operating expenses	7,826	7,500	22,857	21,966
Reimbursable expenses	6,588	5,196	18,010	12,571
General and administrative expenses	4,655	4,061	13,167	13,277
Total operating expenses	74,708	68,250	222,710	205,261
Operating income	20,594	19,305	64,670	54,256
Other income, net:
Interest income, net	740	372	1,813	872
Miscellaneous income, net	2,655	2,353	4,875	6,660
Total other income, net	3,395	2,725	6,688	7,532
Income before income taxes	23,989	22,030	71,358	61,788
Income taxes	6,536	7,387	15,140	16,778
Net income	$ 17,453	$ 14,643	$ 56,218	$ 45,010
Net income per share:
Basic	$ 0.33	$ 0.28	$ 1.06	$ 0.85
Diluted	$ 0.32	$ 0.27	$ 1.04	$ 0.83
Shares used in per share computations:
Basic	53,032	52,740	52,928	52,724
Diluted	54,302	53,926	54,181	53,952
Cash dividends declared per common share	$ 0.130	$ 0.105	$ 0.390	$ 0.315

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2018	Sep. 29, 2017	Sep. 28, 2018	Sep. 29, 2017
Net income	$ 17,453	$ 14,643	$ 56,218	$ 45,010
Other comprehensive income (loss):
Foreign currency translation adjustments, net of tax	(304)	456	(933)	1,046
Unrealized (losses) gains on available-for- sale investment securities arising during the period, net of tax	(31)	13	(52)	17
Comprehensive income	$ 17,118	$ 15,112	$ 55,233	$ 46,073

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 28, 2018	Sep. 29, 2017
Cash flows from operating activities:
Net income	$ 56,218	$ 45,010
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of property, equipment and leasehold improvements	4,710	4,762
Amortization of premiums and accretion of discounts on short-term investments	(51)	0
Deferred rent	(87)	(314)
Provision for contract losses and doubtful accounts	1,359	1,657
Stock-based compensation	13,605	12,728
Deferred income tax provision	(2,510)	(421)
Changes in operating assets and liabilities:
Accounts receivable	(14,170)	(39,051)
Prepaid expenses and other assets	(8,999)	1,049
Accounts payable and accrued liabilities	(3,609)	3,950
Accrued payroll and employee benefits	(202)	(2,558)
Deferred revenues	562	152
Net cash provided by operating activities	46,826	26,964
Cash flows from investing activities:
Capital expenditures	(12,170)	(3,354)
Purchase of short-term investments	(37,788)	(20,997)
Maturity of short-term investments	28,000	4,000
Net cash used in investing activities	(21,958)	(20,351)
Cash flows from financing activities:
Payroll taxes for restricted stock units	(8,839)	(9,520)
Repurchase of common stock	0	(8,431)
Exercise of share-based payment awards	1,065	1,733
Dividends and dividend equivalents rights	(20,497)	(16,419)
Net cash used in financing activities	(28,271)	(32,637)
Effect of foreign currency exchange rates on cash and cash equivalents	(414)	866
Net decrease in cash and cash equivalents	(3,817)	(25,158)
Cash and cash equivalents at beginning of period	124,794	114,967
Cash and cash equivalents at end of period	$ 120,977	$ 89,809

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 28, 2018
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 28, 2018 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, 2017, which was filed with the U.S. Securities and Exchange Commission on February 23, 2018. The unaudited condensed consolidated financial statements include the accounts of Exponent, Inc. and its subsidiaries, which are all wholly owned. All intercompany accounts and transactions have been eliminated in consolidation. Stock Split. On May 31, 2018 , the Company’s stockholders approved an amendment to the Company’s certificate of incorporation to (i) increase the number of authorized shares of common stock to 120,000,000 and (ii) effect a two-for-one stock split. As a result of the stock split, each shareholder of record at the close of business on May 31 , 2018 , received one additional share of common stock for each share of common stock owned by such shareholder. Restricted stock unit awards and stock option awards have also been adjusted to reflect the two-for-one stock split. For periods prior to the stock split, all share and per share data in the Company’s condensed consolidated financial statements and related notes have been retroactively adjusted to reflect the stock split. Dividend. The Company declared and paid cash dividends per common share during the periods presented as follows: Fiscal Year 2018 Dividends Amount Per Share (in thousands) First Quarter $ 0.13 $ 6,700 Second Quarter 0.13 6,764 Third Quarter 0.13 6,765 Total $ 0.39 $ 20,229 Fiscal Year 2017 Dividends Amount Per Share (in thousands) First Quarter $ 0.105 $ 5,374 Second Quarter 0.105 5,424 Third Quarter 0.105 5,424 Fourth Quarter 0.105 5,416 Total $ 0.420 $ 21,638 On October 18, 2018, the Company’s Board of Directors announced a cash dividend of $0.13 per share of the Company’s common stock, payable December 21, 2018 to stockholders of record as of December 7, 2018. The Company expects to continue paying quarterly dividends in the future, subject to declaration by the Company’s Board of Directors. 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. Recently Adopted Accounting Pronouncements . On May 28, 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers , which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The ASU replaced most existing revenue recognition guidance in U.S. generally accepted accounting principles (“GAAP”). The Company adopted the ASU as of the beginning of its first quarter of fiscal 2018 using the modified retrospective transition method. Under the modified retrospective transition method, the cumulative effect of applying the ASU is recognized at the date of initial application. The cumulative effect of adopting the ASU was not material and thus no cumulative effect adjustment was recorded. The Company’s analysis of its contracts under the ASU supports the recognition of revenue over time, which is consistent with the Company’s revenue recognition model prior to the adoption of the ASU. Recent Accounting Pronouncements Not Yet Effective . On February 25, 2016, the FASB issued ASU No. 2016-02, Leases , which requires lessees to recognize most leases on their balance sheet. The new standard will be effective for the Company on the first day of fiscal 2019 (December 29, 2018). Early adoption is permitted. The standard requires use of the modified retrospective transition method, with elective relief, which requires application of the guidance for all periods presented. The Company is evaluating the effect that ASU No. 2016-02 will have on its consolidated financial statements and related disclosures. The standard will require the Company to record a right of use asset and a lease liability that will materially gross up its balance sheet.

Revenue Recognition

Revenue Recognition	9 Months Ended
	Sep. 28, 2018
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 the 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. During the third quarter of fiscal 2018, the Company recognized revenue of $ 76,337,000 associated with time and materials contracts. These revenues represent 80 % of the Company’s consolidated revenues and include revenues of $ 59,582,000 for the Company’s Engineering and Other Scientific segment and $ 16,755,000 for the Company’s Environmental and Health segment. During the first nine months of fiscal 2018 , the Company recognized revenue of $ 239,473,000 associated with time and materials contracts. These revenues represent 83 % of the Company’s consolidated revenues and include revenues of $ 186,486,000 for the Company’s Engineering and Other Scientific segment and $ 52,987,000 for the Company’s Environmental and Health segment. The Company’s time and materials contracts are terminable and subject to postponement or delay at any time by our clients, and as such, the performance obligations for all of the Company’s time and materials contracts 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 and the following additional considerations:  the Company considers labor hours at standard rates and expenses to be incurred when pricing its contracts;  the Company generally does not incur set up costs on its contracts;  the Company does not believe that there are reliable milestones to measure progress towards completion;  the customer is required to pay the Company for time at standard rates plus materials incurred to date if the contract is terminated early;  the Company’s contracts do not include award fees or bonuses;  the Company does not include revenue for unpriced change orders until the customer agrees with the changes;  historically the Company has not had significant accounts receivable write-offs or cost overruns; and  its contracts are typically progress billed on a monthly basis. During the third quarter of fiscal 2018 the Company recognized revenue of $18,965,000 associated with fixed-price contracts. These revenues represent 20% of the Company’s consolidated revenues and include revenues of $18,315,000 for the Company’s Engineering and Other Scientific segment and $650,000 for the Company’s Environmental and Health segment. During the first nine months of fiscal 2018 the Company recognized revenue of $47,907,000 associated with fixed-price contracts. These revenues represent 17% of the Company’s consolidated revenues and include revenues of $45,494,000 for the Company’s Engineering and Other Scientific segment and $2,413,000 for the Company’s Environmental and Health segment. The Company’s fixed-price contracts are terminable and subject to postponement or delay at any time by our clients, and as such, the performance obligations for all of the Company’s fixed-price contracts have an original expected duration of one year or less. Deferred revenues represent amounts billed to clients in advance of services provided. During the third quarter of fiscal 2018 $4,163,000 of revenues were recognized that were included in the deferred revenue balance at June 29, 2018. During the first nine months of fiscal 2018 $5,332,000 of revenues were recognized that were included in the deferred revenue balance at December 29, 2017. 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 were $4.7 million during the third quarter of fiscal 2018. The total amount of subcontractor fees not included in revenues because the Company was acting as an agent were $21.9 million during the first nine months of fiscal 2018.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 28, 2018
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 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 were no transfers between fair value measurement levels during the three and nine months ended September 28, 2018 and September 29, 2017. 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 28, 2018: Fair Value Measurements at Reporting Date Using (In thousands) Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Money market securities (1) $ 605 $ 605 $ - $ - Fixed income available- for-sale securities (2) 81,373 - 81,373 - Fixed income trading securities held in deferred compensation plan (3) 17,835 17,835 - - Equity trading securities held in deferred compensation plan (3) 45,435 45,435 - - Total $ 145,248 $ 63,875 $ 81,373 $ - Liabilities Deferred compensation plan (4) 65,036 65,036 - - Total $ 65,036 $ 65,036 $ - $ - (1) Included in cash and cash equivalents on the Company’s unaudited condensed consolidated balance sheet. (2) Included in short-term investments on the Company’s unaudited condensed consolidated balance sheet. (3) Included in prepaid expenses and other assets and deferred compensation plan assets on the Company’s unaudited condensed consolidated balance sheet. (4) Included in accrued payroll and employee benefits and deferred compensation 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, 2017: Fair Value Measurements at Reporting Date Using (In thousands) Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Money market securities (1) $ 9,742 $ 9,742 $ - $ - Fixed income available- for-sale securities (2) 71,604 - 71,604 - Fixed income trading securities held in deferred compensation plan (3) 13,686 13,686 - - Equity trading securities held in deferred compensation plan (3) 39,664 39,664 - - Total $ 134,696 $ 63,092 $ 71,604 $ - Liabilities Deferred compensation plan (4) 59,050 59,050 - - Total $ 59,050 $ 59,050 $ - $ - (1) Included in cash and cash equivalents on the Company’s unaudited condensed consolidated balance sheet. (2) Included in short-term investments on the Company’s unaudited condensed consolidated balance sheet. (3) Included in prepaid expenses and other assets and deferred compensation plan assets on the Company’s unaudited condensed consolidated balance sheet. (4) Included in accrued payroll and employee benefits and deferred compensation on the Company’s unaudited condensed consolidated balance sheet. Fixed income available-for-sale securities as of September 28, 2018 and December 29, 2017 represent obligations of the United States Treasury and United States agencies. Fixed income and equity trading securities represent mutual funds held in the Company’s deferred compensation plan. See Note 7 for additional information about the Company’s deferred compensation plan. Cash, cash equivalents and short-term investments consisted of the following as of September 28, 2018: Gross Gross Amortized Unrealized Unrealized Estimated (In thousands) Cost Gains Losses Fair Value Classified as current assets: Cash $ 120,372 $ - $ - $ 120,372 Cash equivalents: Money market securities 605 - - 605 Total cash equivalents 605 - - 605 Total cash and cash equivalents 120,977 - - 120,977 Short-term investments: U.S. Treasury and agency securities 81,837 - (464 ) 81,373 Total short-term investments 81,837 - (464 ) 81,373 Total cash, cash equivalents and short-term investments $ 202,814 $ - $ (464 ) $ 202,350 Cash, cash equivalents and short-term investments consisted of the following as of December 29, 2017: Gross Gross Amortized Unrealized Unrealized Estimated (In thousands) Cost Gains Losses Fair Value Classified as current assets: Cash $ 115,052 $ - $ - $ 115,052 Cash equivalents: Money market securities 9,742 - - 9,742 Total cash equivalents 9,742 - - 9,742 Total cash and cash equivalents 124,794 - - 124,794 Short-term investments: U.S. Treasury and agency securities 71,997 - (393 ) 71,604 Total short-term investments 71,997 - (393 ) 71,604 Total cash, cash equivalents and short-term investments $ 196,791 $ - $ (393 ) $ 196,398 The following table summarizes the cost and estimated fair value of short-term fixed income securities classified as short-term investments based on stated effective maturities as of September 28, 2018: Amortized Estimated (In thousands) Cost Fair Value Due within one year $ 39,966 $ 39,796 Due between one and two years 41,871 41,577 Total $ 81,837 $ 81,373 At September 28, 2018 and December 29, 2017, 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 28, 2018 and December 29, 2017, but require disclosure of their fair values: accounts receivable, other assets and accounts payable. The estimated fair value of such instruments at September 28, 2018 and December 29, 2017 approximates their carrying value as reported on the Company’s unaudited condensed consolidated balance sheet. There were no other-than-temporary impairments or credit losses related to available-for-sale securities during the three and nine months ended September 28, 2018 and September 29, 2017.

Net Income Per Share

Net Income Per Share	9 Months Ended
	Sep. 28, 2018
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 common shares outstanding during the period. Diluted per share amounts are calculated using the weighted-average number of common shares outstanding during the period and, when dilutive, the weighted-average number of potential common shares 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 28, 2018 September 29, 2017 September 28, 2018 September 29, 2017 Shares used in basic per share computation 53,032 52,740 52,928 52,724 Effect of dilutive common stock options outstanding 441 294 391 278 Effect of dilutive restricted stock units outstanding 829 892 862 950 Shares used in diluted per share computation 54,302 53,926 54,181 53,952 There were no options excluded from the diluted per share calculations for the three and nine months ended September 28, 2018 and September 29, 2017.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 28, 2018
Share-based Compensation [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 continue to 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 $2,084,000 and $2,155,000 during the three months ended September 28, 2018 and September 29, 2017, respectively. For the nine months ended September 28, 2018 and September 29, 2017, the Company recorded stock-based compensation expense associated with accrued bonus awards of $6,484,000 and $6,284,000, 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 $1,372,000 and $1,294,000 during the three months ended September 28, 2018 and September 29, 2017, respectively. The Company recorded stock-based compensation expense associated with the unvested restricted stock unit awards of $6,340,000 and $5,788,000 during the nine months ended September 28, 2018 and September 29, 2017, 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 grants options at exercise prices equal to the fair value of the Company’s common stock on the date of grant. The Company recorded stock-based compensation expense associated with stock option grants of $116,000 and $92,000 during the three months ended September 28, 2018 and September 29, 2017, respectively. The Company recorded stock-based compensation expense associated with stock option grants of $781,000 and $656,000 during the nine months ended September 28, 2018 and September 29, 2017 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.

Treasury Stock

Treasury Stock	9 Months Ended
	Sep. 28, 2018
Equity [Abstract]
Treasury Stock	Note 6: Treasury Stock On October 21, 2015, the Company’s Board of Directors authorized the use of $35,000,000 for the repurchase of shares of the Company’s common stock. On October 19, 2016, the Company’s Board of Directors authorized an additional $35,000,000 for the repurchase of shares of the Company’s common stock. The Company did not repurchase any shares of its common stock during the nine months ended September 28, 2018. The Company repurchased 278,364 shares of its common stock for $8,431,000 during the nine months ended September 29, 2017. As of September 28, 2018, the Company had remaining authorization under its stock repurchase plans of $45,376,000 to repurchase shares of common stock. Net losses related to the re-issuance of treasury stock to settle restricted stock unit and stock option awards of $5,892,000 and $5,667,000 were recorded as a reduction to retained earnings during the nine months ended September 28, 2018 and September 29, 2017, respectively.

Deferred Compensation Plans

Deferred Compensation Plans	9 Months Ended
	Sep. 28, 2018
Deferred Compensation Arrangements [Abstract]
Deferred Compensation Plans	Note 7: 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 28, 2018 and December 29, 2017, the invested amounts under the plans totaled $63,270,000 and $53,350,000, respectively, and are recorded in prepaid expenses and other 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, net. As of September 28, 2018 and December 29, 2017, vested amounts due under the plans totaled $65,036,000 and $59,050,000, respectively, and are recorded within accrued payroll and employee benefits and deferred compensation on the Company’s unaudited condensed consolidated balance sheet. Changes in the liability are recorded as adjustments to compensation expense. During the three months ended September 28, 2018 and September 29, 2017, the Company recognized compensation expense of $1,840,000 and $1,699,000, respectively, 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 28, 2018 and September 29, 2017, the Company recognized compensation expense of $2,577,000 and $4,617,000, respectively, 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.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	9 Months Ended
	Sep. 28, 2018
Supplemental Cash Flow Information [Abstract]
Supplemental Cash Flow Information	Note 8: Supplemental Cash Flow Information The following is supplemental disclosure of cash flow information: Nine Months Ended (In thousands) September 28, 2018 September 29, 2017 Cash paid during period: Income taxes $ 19,721 $ 17,208 Non-cash investing and financing activities: Unrealized (loss) gain on short-term investments $ (52 ) $ 17 Vested stock unit awards issued to settle accrued bonuses $ 7,643 $ 6,910 Accrual for capital expenditures $ 1,643 $ 162

Accounts Receivable, Net

Accounts Receivable, Net	9 Months Ended
	Sep. 28, 2018
Receivables [Abstract]
Accounts Receivable, Net	Note 9: Accounts Receivable, Net At September 28, 2018 and December 29, 2017, accounts receivable, net, was comprised of the following: September 28, December 29, (In thousands) 2018 2017 Billed accounts receivable $ 83,939 $ 78,139 Unbilled accounts receivable 42,884 35,487 Allowance for contract losses and doubtful accounts (3,912 ) (3,526 ) Total accounts receivable, net $ 122,911 $ 110,100

Segment Reporting

Segment Reporting	9 Months Ended
	Sep. 28, 2018
Segment Reporting [Abstract]
Segment Reporting	Note 10: 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. 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 28, 2018 and September 29, 2017 follows: Revenues Three Months Ended Nine Months Ended (In thousands) September 28, 2018 September 29, 2017 September 28, 2018 September 29, 2017 Engineering and Other Scientific $ 77,853 $ 70,670 $ 231,980 $ 207,148 Environmental and Health 17,449 16,885 55,400 52,369 Total revenues $ 95,302 $ 87,555 $ 287,380 $ 259,517 Operating Income Three Months Ended Nine Months Ended (In thousands) September 28, 2018 September 29, 2017 September 28, 2018 September 29, 2017 Engineering and Other Scientific $ 25,784 $ 23,645 $ 77,499 $ 70,279 Environmental and Health 5,401 5,450 18,181 16,753 Total segment operating income 31,185 29,095 95,680 87,032 Corporate operating expense (10,591 ) (9,790 ) (31,010 ) (32,776 ) Total operating income $ 20,594 $ 19,305 $ 64,670 $ 54,256 Capital Expenditures Three Months Ended Nine Months Ended (In thousands) September 28, 2018 September 29, 2017 September 28, 2018 September 29, 2017 Engineering and Other Scientific $ 1,878 $ 662 $ 3,982 $ 2,464 Environmental and Health 43 64 141 170 Total segment capital expenditures 1,921 726 4,123 2,634 Corporate capital expenditures 2,795 102 9,542 720 Total capital expenditures $ 4,716 $ 828 $ 13,665 $ 3,354 Depreciation and Amortization Three Months Ended Nine Months Ended (In thousands) September 28, 2018 September 29, 2017 September 28, 2018 September 29, 2017 Engineering and Other Scientific $ 1,102 $ 1,103 $ 3,318 $ 3,381 Environmental and Health 44 47 124 132 Total segment depreciation and amortization 1,146 1,150 3,442 3,513 Corporate depreciation and amortization 415 417 1,268 1,249 Total depreciation and amortization $ 1,561 $ 1,567 $ 4,710 $ 4,762 One client comprised 12% of the Company’s revenues during the three months ended September 28, 2018. The same client comprised 14% of the Company’s revenues during the nine months ended September 28, 2018. No other single client comprised more than 10% of the Company’s revenues during the three and nine months ended September 28, 2018. One client comprised 17% of the Company’s revenues during the three months ended September 29, 2017. The same client comprised 14% of the Company’s revenues during the nine months ended September 29, 2017. No other single client comprised more than 10% of the Company’s revenues during the three and nine months ended September 29, 2017. The same client comprised 17% and 24% of the Company’s accounts receivable at September 28, 2018 and December 29, 2017, respectively. No other single client comprised more than 10% of the Company’s accounts receivable at September 28, 2018 and December 29, 2017.

Contingencies

Contingencies	9 Months Ended
	Sep. 28, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and 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.

Basis of Presentation (Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 28, 2018
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 28, 2018 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, 2017, which was filed with the U.S. Securities and Exchange Commission on February 23, 2018. The unaudited condensed consolidated financial statements include the accounts of Exponent, Inc. and its subsidiaries, which are all wholly owned. All intercompany accounts and transactions have been eliminated in consolidation.
Stock Split	Stock Split. On May 31, 2018 , the Company’s stockholders approved an amendment to the Company’s certificate of incorporation to (i) increase the number of authorized shares of common stock to 120,000,000 and (ii) effect a two-for-one stock split. As a result of the stock split, each shareholder of record at the close of business on May 31 , 2018 , received one additional share of common stock for each share of common stock owned by such shareholder. Restricted stock unit awards and stock option awards have also been adjusted to reflect the two-for-one stock split. For periods prior to the stock split, all share and per share data in the Company’s condensed consolidated financial statements and related notes have been retroactively adjusted to reflect the stock split.
Dividend	Dividend. The Company declared and paid cash dividends per common share during the periods presented as follows: Fiscal Year 2018 Dividends Amount Per Share (in thousands) First Quarter $ 0.13 $ 6,700 Second Quarter 0.13 6,764 Third Quarter 0.13 6,765 Total $ 0.39 $ 20,229 Fiscal Year 2017 Dividends Amount Per Share (in thousands) First Quarter $ 0.105 $ 5,374 Second Quarter 0.105 5,424 Third Quarter 0.105 5,424 Fourth Quarter 0.105 5,416 Total $ 0.420 $ 21,638 On October 18, 2018, the Company’s Board of Directors announced a cash dividend of $0.13 per share of the Company’s common stock, payable December 21, 2018 to stockholders of record as of December 7, 2018. The Company expects to continue paying quarterly dividends in the future, subject to declaration by the Company’s Board of Directors.
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. 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.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements . On May 28, 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers , which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The ASU replaced most existing revenue recognition guidance in U.S. generally accepted accounting principles (“GAAP”). The Company adopted the ASU as of the beginning of its first quarter of fiscal 2018 using the modified retrospective transition method. Under the modified retrospective transition method, the cumulative effect of applying the ASU is recognized at the date of initial application. The cumulative effect of adopting the ASU was not material and thus no cumulative effect adjustment was recorded. The Company’s analysis of its contracts under the ASU supports the recognition of revenue over time, which is consistent with the Company’s revenue recognition model prior to the adoption of the ASU. Recent Accounting Pronouncements Not Yet Effective . On February 25, 2016, the FASB issued ASU No. 2016-02, Leases , which requires lessees to recognize most leases on their balance sheet. The new standard will be effective for the Company on the first day of fiscal 2019 (December 29, 2018). Early adoption is permitted. The standard requires use of the modified retrospective transition method, with elective relief, which requires application of the guidance for all periods presented. The Company is evaluating the effect that ASU No. 2016-02 will have on its consolidated financial statements and related disclosures. The standard will require the Company to record a right of use asset and a lease liability that will materially gross up its balance sheet.

Basis of Presentation (Tables)

Basis of Presentation (Tables)	9 Months Ended
	Sep. 28, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Common Stock Dividends Declared Per Share	The Company declared and paid cash dividends per common share during the periods presented as follows: Fiscal Year 2018 Dividends Amount Per Share (in thousands) First Quarter $ 0.13 $ 6,700 Second Quarter 0.13 6,764 Third Quarter 0.13 6,765 Total $ 0.39 $ 20,229 Fiscal Year 2017 Dividends Amount Per Share (in thousands) First Quarter $ 0.105 $ 5,374 Second Quarter 0.105 5,424 Third Quarter 0.105 5,424 Fourth Quarter 0.105 5,416 Total $ 0.420 $ 21,638

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 28, 2018
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 28, 2018: Fair Value Measurements at Reporting Date Using (In thousands) Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Money market securities (1) $ 605 $ 605 $ - $ - Fixed income available- for-sale securities (2) 81,373 - 81,373 - Fixed income trading securities held in deferred compensation plan (3) 17,835 17,835 - - Equity trading securities held in deferred compensation plan (3) 45,435 45,435 - - Total $ 145,248 $ 63,875 $ 81,373 $ - Liabilities Deferred compensation plan (4) 65,036 65,036 - - Total $ 65,036 $ 65,036 $ - $ - (1) Included in cash and cash equivalents on the Company’s unaudited condensed consolidated balance sheet. (2) Included in short-term investments on the Company’s unaudited condensed consolidated balance sheet. (3) Included in prepaid expenses and other assets and deferred compensation plan assets on the Company’s unaudited condensed consolidated balance sheet. (4) Included in accrued payroll and employee benefits and deferred compensation 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, 2017: Fair Value Measurements at Reporting Date Using (In thousands) Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Money market securities (1) $ 9,742 $ 9,742 $ - $ - Fixed income available- for-sale securities (2) 71,604 - 71,604 - Fixed income trading securities held in deferred compensation plan (3) 13,686 13,686 - - Equity trading securities held in deferred compensation plan (3) 39,664 39,664 - - Total $ 134,696 $ 63,092 $ 71,604 $ - Liabilities Deferred compensation plan (4) 59,050 59,050 - - Total $ 59,050 $ 59,050 $ - $ - (1) Included in cash and cash equivalents on the Company’s unaudited condensed consolidated balance sheet. (2) Included in short-term investments on the Company’s unaudited condensed consolidated balance sheet. (3) Included in prepaid expenses and other assets and deferred compensation plan assets on the Company’s unaudited condensed consolidated balance sheet. (4) Included in accrued payroll and employee benefits and deferred compensation on the Company’s unaudited condensed consolidated balance sheet.
Cash, cash equivalents and short-term investments	Cash, cash equivalents and short-term investments consisted of the following as of September 28, 2018: Gross Gross Amortized Unrealized Unrealized Estimated (In thousands) Cost Gains Losses Fair Value Classified as current assets: Cash $ 120,372 $ - $ - $ 120,372 Cash equivalents: Money market securities 605 - - 605 Total cash equivalents 605 - - 605 Total cash and cash equivalents 120,977 - - 120,977 Short-term investments: U.S. Treasury and agency securities 81,837 - (464 ) 81,373 Total short-term investments 81,837 - (464 ) 81,373 Total cash, cash equivalents and short-term investments $ 202,814 $ - $ (464 ) $ 202,350 Cash, cash equivalents and short-term investments consisted of the following as of December 29, 2017: Gross Gross Amortized Unrealized Unrealized Estimated (In thousands) Cost Gains Losses Fair Value Classified as current assets: Cash $ 115,052 $ - $ - $ 115,052 Cash equivalents: Money market securities 9,742 - - 9,742 Total cash equivalents 9,742 - - 9,742 Total cash and cash equivalents 124,794 - - 124,794 Short-term investments: U.S. Treasury and agency securities 71,997 - (393 ) 71,604 Total short-term investments 71,997 - (393 ) 71,604 Total cash, cash equivalents and short-term investments $ 196,791 $ - $ (393 ) $ 196,398
Summary of Cost and Estimated Fair Value of Short Term Fixed Income Securities	The following table summarizes the cost and estimated fair value of short-term fixed income securities classified as short-term investments based on stated effective maturities as of September 28, 2018: Amortized Estimated (In thousands) Cost Fair Value Due within one year $ 39,966 $ 39,796 Due between one and two years 41,871 41,577 Total $ 81,837 $ 81,373

Net Income Per Share (Tables)

Net Income Per Share (Tables)	9 Months Ended
	Sep. 28, 2018
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 28, 2018 September 29, 2017 September 28, 2018 September 29, 2017 Shares used in basic per share computation 53,032 52,740 52,928 52,724 Effect of dilutive common stock options outstanding 441 294 391 278 Effect of dilutive restricted stock units outstanding 829 892 862 950 Shares used in diluted per share computation 54,302 53,926 54,181 53,952

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Tables)	9 Months Ended
	Sep. 28, 2018
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 28, 2018 September 29, 2017 Cash paid during period: Income taxes $ 19,721 $ 17,208 Non-cash investing and financing activities: Unrealized (loss) gain on short-term investments $ (52 ) $ 17 Vested stock unit awards issued to settle accrued bonuses $ 7,643 $ 6,910 Accrual for capital expenditures $ 1,643 $ 162

Accounts Receivable, Net (Table

Accounts Receivable, Net (Tables)	9 Months Ended
	Sep. 28, 2018
Receivables [Abstract]
Accounts Receivable, Net	At September 28, 2018 and December 29, 2017, accounts receivable, net, was comprised of the following: September 28, December 29, (In thousands) 2018 2017 Billed accounts receivable $ 83,939 $ 78,139 Unbilled accounts receivable 42,884 35,487 Allowance for contract losses and doubtful accounts (3,912 ) (3,526 ) Total accounts receivable, net $ 122,911 $ 110,100

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 28, 2018
Segment Reporting [Abstract]
Segment Reporting Information, by Segment	Segment information for the three and nine months ended September 28, 2018 and September 29, 2017 follows: Revenues Three Months Ended Nine Months Ended (In thousands) September 28, 2018 September 29, 2017 September 28, 2018 September 29, 2017 Engineering and Other Scientific $ 77,853 $ 70,670 $ 231,980 $ 207,148 Environmental and Health 17,449 16,885 55,400 52,369 Total revenues $ 95,302 $ 87,555 $ 287,380 $ 259,517 Operating Income Three Months Ended Nine Months Ended (In thousands) September 28, 2018 September 29, 2017 September 28, 2018 September 29, 2017 Engineering and Other Scientific $ 25,784 $ 23,645 $ 77,499 $ 70,279 Environmental and Health 5,401 5,450 18,181 16,753 Total segment operating income 31,185 29,095 95,680 87,032 Corporate operating expense (10,591 ) (9,790 ) (31,010 ) (32,776 ) Total operating income $ 20,594 $ 19,305 $ 64,670 $ 54,256 Capital Expenditures Three Months Ended Nine Months Ended (In thousands) September 28, 2018 September 29, 2017 September 28, 2018 September 29, 2017 Engineering and Other Scientific $ 1,878 $ 662 $ 3,982 $ 2,464 Environmental and Health 43 64 141 170 Total segment capital expenditures 1,921 726 4,123 2,634 Corporate capital expenditures 2,795 102 9,542 720 Total capital expenditures $ 4,716 $ 828 $ 13,665 $ 3,354 Depreciation and Amortization Three Months Ended Nine Months Ended (In thousands) September 28, 2018 September 29, 2017 September 28, 2018 September 29, 2017 Engineering and Other Scientific $ 1,102 $ 1,103 $ 3,318 $ 3,381 Environmental and Health 44 47 124 132 Total segment depreciation and amortization 1,146 1,150 3,442 3,513 Corporate depreciation and amortization 415 417 1,268 1,249 Total depreciation and amortization $ 1,561 $ 1,567 $ 4,710 $ 4,762

Basis of Presentation - Additio

Basis of Presentation - Additional Information (Detail) - $ / shares shares in Thousands	1 Months Ended
	Oct. 18, 2018	Sep. 28, 2018	May 31, 2018	Dec. 29, 2017
Class of Stock [Line Items]
Common Stock, Shares Authorized		120,000	120,000	120,000
Subsequent Event
Class of Stock [Line Items]
Common stock, dividends per share declared, subsequent event	$ 0.13
Dividends Payable, Date Declared	Oct. 18, 2018
Dividends Payable, Date to be Paid	Dec. 21, 2018
Dividends Payable, Date of Record	Dec. 7, 2018

Common Stock Dividends Declared

Common Stock Dividends Declared And Paid Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended							9 Months Ended	12 Months Ended
	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 29, 2017	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 28, 2018	Dec. 29, 2017
Class of Stock [Line Items]
Dividends Per Share	$ 0.13	$ 0.13	$ 0.13	$ 0.105	$ 0.105	$ 0.105	$ 0.105	$ 0.39	$ 0.420
Amount	$ 6,765	$ 6,764	$ 6,700	$ 5,416	$ 5,424	$ 5,424	$ 5,374	$ 20,229	$ 21,638

Revenue Recognition- Additional

Revenue Recognition- Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 28, 2018	Sep. 29, 2017	Sep. 28, 2018	Sep. 29, 2017
Revenues	$ 95,302,000	$ 87,555,000	$ 287,380,000	$ 259,517,000
Deferred Revenue, Revenue Recognized	4,163,000		5,332,000
Subcontractor Fees Not Included In Revenues	4,700,000		21,900,000
Engineering and Other Scientific [Member] | Time And Materials Contracts [Member]
Revenues	59,582,000		186,486,000
Engineering and Other Scientific [Member] | Fixed Price Contracts [Member]
Revenues	18,315,000		45,494,000
Environmental and Health [Member] | Time And Materials Contracts [Member]
Revenues	16,755,000		52,987,000
Environmental and Health [Member] | Fixed Price Contracts [Member]
Revenues	650,000		2,413,000
Sales Revenue, Net [Member] | Time And Materials Contracts [Member]
Revenues	$ 76,337,000		$ 239,473,000
Concentration Risk, Percentage	80.00%		83.00%
Sales Revenue, Net [Member] | Fixed Price Contracts [Member]
Revenues	$ 18,965,000		$ 47,907,000
Concentration Risk, Percentage	20.00%		17.00%

Assets and Liabilities Measured

Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands		Sep. 28, 2018	Dec. 29, 2017
Assets
Money market securities	[1]	$ 605	$ 9,742
Total		145,248	134,696
Liabilities
Deferred compensation plan	[2]	65,036	59,050
Total		65,036	59,050
Fixed income securities
Assets
Fixed income available-for-sale securities	[3]	81,373	71,604
Fixed income trading securities held in deferred compensation plan	[4]	17,835	13,686
Equity securities
Assets
Equity trading securities held in deferred compensation plan	[4]	45,435	39,664
Fair Value, Inputs, Level 1
Assets
Money market securities	[1]	605	9,742
Total		63,875	63,092
Liabilities
Deferred compensation plan	[2]	65,036	59,050
Total		65,036	59,050
Fair Value, Inputs, Level 1 | Fixed income securities
Assets
Fixed income available-for-sale securities	[3]	0	0
Fixed income trading securities held in deferred compensation plan	[4]	17,835	13,686
Fair Value, Inputs, Level 1 | Equity securities
Assets
Equity trading securities held in deferred compensation plan	[4]	45,435	39,664
Fair Value, Inputs, Level 2
Assets
Money market securities	[1]	0	0
Total		81,373	71,604
Liabilities
Deferred compensation plan	[2]	0	0
Total		0	0
Fair Value, Inputs, Level 2 | Fixed income securities
Assets
Fixed income available-for-sale securities	[3]	81,373	71,604
Fixed income trading securities held in deferred compensation plan	[4]	0	0
Fair Value, Inputs, Level 2 | Equity securities
Assets
Equity trading securities held in deferred compensation plan	[4]	0	0
Fair Value, Inputs, Level 3
Assets
Money market securities	[1]	0	0
Total		0	0
Liabilities
Deferred compensation plan	[2]	0	0
Total		0	0
Fair Value, Inputs, Level 3 | Fixed income securities
Assets
Fixed income available-for-sale securities	[3]	0	0
Fixed income trading securities held in deferred compensation plan	[4]	0	0
Fair Value, Inputs, Level 3 | Equity securities
Assets
Equity trading securities held in deferred compensation plan	[4]	$ 0	$ 0
[1]	Included in cash and cash equivalents on the Company’s unaudited condensed consolidated balance sheet.
[2]	Included in accrued payroll and employee benefits and deferred compensation on the Company’s unaudited condensed consolidated balance sheet.
[3]	Included in short-term investments on the Company’s unaudited condensed consolidated balance sheet.
[4]	Included in prepaid expenses and other assets and deferred compensation plan assets on the Company’s unaudited condensed consolidated balance sheet.

Cash, cash equivalents and shor

Cash, cash equivalents and short-term investments (Detail) - USD ($) $ in Thousands	Sep. 28, 2018	Dec. 29, 2017
Fair Value Measurements [Line Items]
Amortized Cost	$ 202,814	$ 196,791
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(464)	(393)
Estimated Fair Value	202,350	196,398
U.S. Treasury and agency securities
Fair Value Measurements [Line Items]
Amortized Cost	81,837	71,997
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(464)	(393)
Estimated Fair Value	81,373	71,604
Cash
Fair Value Measurements [Line Items]
Amortized Cost	120,372	115,052
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	120,372	115,052
Money market securities
Fair Value Measurements [Line Items]
Amortized Cost	605	9,742
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	605	9,742
Total cash equivalents
Fair Value Measurements [Line Items]
Amortized Cost	605	9,742
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	605	9,742
Total cash and cash equivalents
Fair Value Measurements [Line Items]
Amortized Cost	120,977	124,794
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	120,977	124,794
Total short-term investments
Fair Value Measurements [Line Items]
Amortized Cost	81,837	71,997
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(464)	(393)
Estimated Fair Value	$ 81,373	$ 71,604

Summarizes Cost And Estimated F

Summarizes Cost And Estimated Fair Value Of Short Term Fixed Income Securities (Detail) - USD ($) $ in Thousands	Sep. 28, 2018	Dec. 29, 2017
Fair Value Measurements [Line Items]
Due within one year, Amortized Cost	$ 39,966
Due between one and two years, Amortized Cost	41,871
Total Amortized Cost	81,837
Due within one year, Estimated Fair Value	39,796
Due between one and two years, Estimated Fair Value	41,577
Total Estimated Fair Value	$ 81,373	$ 71,604

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	3 Months Ended		9 Months Ended
	Sep. 28, 2018	Sep. 29, 2017	Sep. 28, 2018	Sep. 29, 2017
Schedule Of Earnings Per Share Basic and Diluted [Line Items]
Shares used in basic per share computation	53,032	52,740	52,928	52,724
Shares used in diluted per share computation	54,302	53,926	54,181	53,952
Employee Stock Option
Schedule Of Earnings Per Share Basic and Diluted [Line Items]
Effect of dilutive stock outstanding	441	294	391	278
Restricted Stock Units (RSUs)
Schedule Of Earnings Per Share Basic and Diluted [Line Items]
Effect of dilutive stock outstanding	829	892	862	950

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 28, 2018	Sep. 29, 2017	Sep. 28, 2018	Sep. 29, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Compensation Arrangement By Share Based Payment Award Options Expiration Term			10 years
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense	$ 116,000	$ 92,000	$ 781,000	$ 656,000
Vesting percentage of stock options granted per year			25.00%
Stock based compensation, vesting period			4 years
Vested Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense	2,084,000	2,155,000	$ 6,484,000	6,284,000
Stock based compensation, holding period			4 years
Vested Restricted Stock Awards | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of annual bonus settled with fully vested restricted stock unit awards			40.00%
Unvested Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense	$ 1,372,000	$ 1,294,000	$ 6,340,000	$ 5,788,000
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
Unvested Stock Options [Member] | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recipient age to expense award on grant date			59 years 6 months
Unvested Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation, vesting period			4 years

Treasury Stock - Additional Inf

Treasury Stock - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 28, 2018	Sep. 29, 2017	Oct. 19, 2016	Oct. 21, 2015
Equity, Class of Treasury Stock [Line Items]
Stock Repurchase Program, Authorized Amount			$ 35,000,000	$ 35,000,000
Purchase of treasury shares (in shares)		278,364
Repurchase of treasury shares		$ 8,431,000
Remaining authorized amount for repurchase of common stock	$ 45,376,000
Treasury stock reissued at lower than repurchase price	$ 5,892,000	$ 5,667,000

Deferred Compensation Plans - A

Deferred Compensation Plans - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 28, 2018	Sep. 29, 2017	Sep. 28, 2018	Sep. 29, 2017	Dec. 29, 2017
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Trading securities	$ 63,270,000		$ 63,270,000		$ 53,350,000
Deferred compensation plan vested amounts due	65,036,000		65,036,000		$ 59,050,000
Change in market value of trust assets	$ 1,840,000	$ 1,699,000	$ 2,577,000	$ 4,617,000
Maximum
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Percentage of compensation deferred			100.00%

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2018	Sep. 29, 2017	Sep. 28, 2018	Sep. 29, 2017
Cash paid during period:
Income taxes			$ 19,721	$ 17,208
Non-cash investing and financing activities:
Unrealized (loss) gain on short-term investments	$ (31)	$ 13	(52)	17
Vested stock unit awards issued to settle accrued bonuses			7,643	6,910
Accrual for capital expenditures			$ 1,643	$ 162

Accounts Receivable, Net (Detai

Accounts Receivable, Net (Detail) - USD ($) $ in Thousands	Sep. 28, 2018	Dec. 29, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for contract losses and doubtful accounts	$ (3,912)	$ (3,526)
Total accounts receivable, net	122,911	110,100
Billed accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable	83,939	78,139
Unbilled accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable	$ 42,884	$ 35,487

Segment Reporting - Additional

Segment Reporting - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 28, 2018	Sep. 29, 2017	Sep. 28, 2018	Sep. 29, 2017	Dec. 29, 2017
Segment Reporting Information [Line Items]
Percentage of Company's revenue	10.00%	10.00%	10.00%	10.00%
Sales Revenue, Net [Member] | Customer Concentration Risk [Member]
Segment Reporting Information [Line Items]
Concentration Risk, Percentage	12.00%	17.00%	14.00%	14.00%
Accounts Receivable [Member]
Segment Reporting Information [Line Items]
Percentage of account receivable	10.00%	10.00%	10.00%	10.00%	10.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member]
Segment Reporting Information [Line Items]
Percentage of account receivable	17.00%		17.00%		24.00%

Segment Information (Detail)

Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2018	Sep. 29, 2017	Sep. 28, 2018	Sep. 29, 2017
Segment Reporting Information [Line Items]
Revenues	$ 95,302	$ 87,555	$ 287,380	$ 259,517
Operating Income	20,594	19,305	64,670	54,256
Capital Expenditures	4,716	828	13,665	3,354
Depreciation and Amortization	1,561	1,567	4,710	4,762
Operating segments
Segment Reporting Information [Line Items]
Operating Income	31,185	29,095	95,680	87,032
Capital Expenditures	1,921	726	4,123	2,634
Depreciation and Amortization	1,146	1,150	3,442	3,513
Engineering and Other Scientific
Segment Reporting Information [Line Items]
Revenues	77,853	70,670	231,980	207,148
Operating Income	25,784	23,645	77,499	70,279
Capital Expenditures	1,878	662	3,982	2,464
Depreciation and Amortization	1,102	1,103	3,318	3,381
Environmental and Health
Segment Reporting Information [Line Items]
Revenues	17,449	16,885	55,400	52,369
Operating Income	5,401	5,450	18,181	16,753
Capital Expenditures	43	64	141	170
Depreciation and Amortization	44	47	124	132
Corporate
Segment Reporting Information [Line Items]
Operating Income	(10,591)	(9,790)	(31,010)	(32,776)
Capital Expenditures	2,795	102	9,542	720
Depreciation and Amortization	$ 415	$ 417	$ 1,268	$ 1,249