Document and Entity Information	12 Months Ended
Document and Entity Information	Jan. 03, 2025
Cover [Abstract]
Document Type	DEF 14A
Amendment Flag	false
Entity Registrant Name	Exponent, Inc.
Entity Central Index Key	0000851520

Pay vs Performance Disclosure - USD ($)

12 Months Ended

Jan. 03, 2025

Dec. 29, 2023

Dec. 30, 2022

Dec. 31, 2021

Jan. 01, 2021

Pay vs Performance Disclosure

Pay vs Performance Disclosure, Table

PAY VERSUS PERFORMANCE DISCLOSURE

The following table provides information on compensation for the principal executive officer (“PEO”), the average compensation for the other Named Executive Officers (“Non-PEO NEOs”) and certain measures of the Company’s financial performance for the last five fiscal years ended January 3, 2025:


									Value of Initial Fixed $100 Investment Based on:
Year	Summary Compensation Table Total for PEO ($)(1)		Compensation Actually Paid to PEO ($)(1)		Average Summary Compensation Table Total for Non-PEO NEOs ($)(1)		Average Compensation Actually Paid to Non-PEO NEOs ($)(1)		Total Shareholder Return (2)		Peer Group Total Shareholder Return (3)		Net Income ($ '000) (4)		EBITDA ($ '000) (5)
2024		3,495,068		3,468,736		1,908,925		1,922,398		133		166		109,002		147,058
2023		3,558,964		2,829,817		1,885,140		1,683,408		130		144		100,339		137,662
2022		3,589,062		2,322,702		1,626,994		1,245,805		145		124		102,330		137,217
2021		3,022,417		5,151,590		1,500,913		2,165,705		169		142		101,202		132,258
2020		2,674,793		4,300,765		1,362,236		1,938,548		129		114		82,552		102,102

(1)

Dr. Corrigan was the PEO in 2024, 2023, 2022, 2021 and 2020. Mr. Schlenker, Dr. Rakow Dr. Reitman and Dr. Sala were the non-PEO NEOs in 2024. Mr. Schlenker, Dr. Guyer, Dr. Rakow and Dr. Reitman were the non-PEO NEOs in 2023. Mr. Schlenker, Dr. Murray, Dr. Reitman and Dr. Pye were the non-PEO NEOs in 2022. Mr. Schlenker, Dr. Murray, Dr. Reitman and Dr. Doyle were the non-PEO NEOs in 2021. Mr. Schlenker, Dr. Murray, Dr. Reitman and Dr. James were the non-PEO NEOs in 2020.The value of the “compensation actually paid” to our PEO and Non-PEO NEOs reflect the following adjustments from the Summary Compensation Table:


Compensation Actually Paid Adjustment Summary	Principal Executive Officer ($)(PEO)			Non PEO Named Executive Officers ($)(NEO) (average)
	2024			2024
Summary Compensation Table (SCT) Total		3,495,068			1,908,925
Stock and option award values reported in the SCT		(1,640,626	)		(773,438	)
The year-end fair value of any outstanding and unvested stock awards granted during the year		539,061			370,666
The year-end fair value of any outstanding and unvested option awards granted during the year		859,803			143,300
The change in fair value as of the vesting date (from the end of the prior year) of any stock awards that vest during the year		(57,396	)		(26,649	)
The change in fair value as of the vesting date (from the end of the prior year) of any option awards that vest during the year		(140,548	)		(23,425	)
The change in year-end fair value (from the end of the prior year) of any outstanding and unvested stock awards granted in prior years		14,270			6,443
The change in year-end fair value (from the end of the prior year) of any outstanding and unvested option awards granted in prior years		(80,904	)		(13,484	)
'The dollar value of stock awards that were both granted and vested during the year		480,008			330,060
The dollar value of any dividends or other earnings paid on stock or option awards during the year (prior to vesting) that are not otherwise reflected		—			—
Compensation Actually Paid		3,468,736			1,922,398

(2)

Amounts represent the cumulative Total Shareholder Return ("TSR") for Exponent calculated and presented as the dollar value of an investment of $100 made on January 3, 2020, assuming dividend reinvestment.

(3)

Amounts represent the cumulative TSR for the S&P 400 Mid Cap Index as "Peer Group" calculated and presented as the dollar value of an investment of $100 made on January 3, 2020, assuming dividend reinvestment.

(4)

Net Income is calculated in accordance with generally accepted accounting principles.

(5)

EBITDA is our company-selected measure and is defined as net income before income taxes, interest income, depreciation and amortization.

Company Selected Measure Name

EBITDA

Named Executive Officers, Footnote

Peer Group Issuers, Footnote

PEO Total Compensation Amount

$ 3,495,068

$ 3,558,964

$ 3,589,062

$ 3,022,417

$ 2,674,793

PEO Actually Paid Compensation Amount

$ 3,468,736

2,829,817

2,322,702

5,151,590

4,300,765

Adjustment To PEO Compensation, Footnote


Compensation Actually Paid Adjustment Summary	Principal Executive Officer ($)(PEO)			Non PEO Named Executive Officers ($)(NEO) (average)
	2024			2024
Summary Compensation Table (SCT) Total		3,495,068			1,908,925
Stock and option award values reported in the SCT		(1,640,626	)		(773,438	)
The year-end fair value of any outstanding and unvested stock awards granted during the year		539,061			370,666
The year-end fair value of any outstanding and unvested option awards granted during the year		859,803			143,300
The change in fair value as of the vesting date (from the end of the prior year) of any stock awards that vest during the year		(57,396	)		(26,649	)
The change in fair value as of the vesting date (from the end of the prior year) of any option awards that vest during the year		(140,548	)		(23,425	)
The change in year-end fair value (from the end of the prior year) of any outstanding and unvested stock awards granted in prior years		14,270			6,443
The change in year-end fair value (from the end of the prior year) of any outstanding and unvested option awards granted in prior years		(80,904	)		(13,484	)
'The dollar value of stock awards that were both granted and vested during the year		480,008			330,060
The dollar value of any dividends or other earnings paid on stock or option awards during the year (prior to vesting) that are not otherwise reflected		—			—
Compensation Actually Paid		3,468,736			1,922,398

Non-PEO NEO Average Total Compensation Amount

$ 1,908,925

1,885,140

1,626,994

1,500,913

1,362,236

Non-PEO NEO Average Compensation Actually Paid Amount

$ 1,922,398

1,683,408

1,245,805

2,165,705

1,938,548

Adjustment to Non-PEO NEO Compensation Footnote


Compensation Actually Paid Adjustment Summary	Principal Executive Officer ($)(PEO)			Non PEO Named Executive Officers ($)(NEO) (average)
	2024			2024
Summary Compensation Table (SCT) Total		3,495,068			1,908,925
Stock and option award values reported in the SCT		(1,640,626	)		(773,438	)
The year-end fair value of any outstanding and unvested stock awards granted during the year		539,061			370,666
The year-end fair value of any outstanding and unvested option awards granted during the year		859,803			143,300
The change in fair value as of the vesting date (from the end of the prior year) of any stock awards that vest during the year		(57,396	)		(26,649	)
The change in fair value as of the vesting date (from the end of the prior year) of any option awards that vest during the year		(140,548	)		(23,425	)
The change in year-end fair value (from the end of the prior year) of any outstanding and unvested stock awards granted in prior years		14,270			6,443
The change in year-end fair value (from the end of the prior year) of any outstanding and unvested option awards granted in prior years		(80,904	)		(13,484	)
'The dollar value of stock awards that were both granted and vested during the year		480,008			330,060
The dollar value of any dividends or other earnings paid on stock or option awards during the year (prior to vesting) that are not otherwise reflected		—			—
Compensation Actually Paid		3,468,736			1,922,398

Compensation Actually Paid vs. Net Income

Compensation Actually Paid vs. Company Selected Measure

Total Shareholder Return Vs Peer Group

Tabular List, Table

Performance Measures. The following table lists the most important financial performance measures used to link CAP to the PEO and Non-PEO NEOs for the fiscal year ended January 3, 2025:

       EBITDA

      

       Revenues before reimbursement growth

      

       EBITDA margin

      

Total Shareholder Return Amount

$ 133

130

145

169

129

Peer Group Total Shareholder Return Amount

166

144

124

142

114

Net Income (Loss)

$ 109,002,000

$ 100,339,000

$ 102,330,000

$ 101,202,000

$ 82,552,000

Company Selected Measure Amount

147,058,000

137,662,000

137,217,000

132,258,000

102,102,000

PEO Name

Dr. Corrigan

Measure:: 1

Pay vs Performance Disclosure

Name

EBITDA

Non-GAAP Measure Description

EBITDA is our company-selected measure and is defined as net income before income taxes, interest income, depreciation and amortization.

Measure:: 2

Pay vs Performance Disclosure

Name

Revenues before reimbursement growth

Measure:: 3

Pay vs Performance Disclosure

Name

EBITDA margin

PEO | Stock and option award values reported in the SCT [Member]

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

$ (1,640,626)

PEO | Year-end Fair Value Of Any Outstanding And Unvested Stock Awards Granted During The Year [Member]

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

539,061

PEO | Year-end Fair Value Of Any Outstanding And Unvested Option Awards Granted During The Year [Member]

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

859,803

PEO | Change In Fair Value As Of The Vesting Date (From The End Of The Prior Year) Of Any Stock Awards That Vest During The Year [Member]

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

(57,396)

PEO | Change In Fair Value As Of The Vesting Date (From The End Of The Prior Year) Of Any Option Awards That Vest During The Year [Member]

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

(140,548)

PEO | Change In Year-end Fair Value (From The End Of The Prior Year) Of Any Outstanding And Unvested Stock Awards Granted In Prior Years [Member]

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

14,270

PEO | Change In Year-end Fair Value (From The End Of The Prior Year) Of Any Outstanding And Unvested Option Awards Granted In Prior Years [Member]

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

(80,904)

PEO | Dollar Value Of Stock Awards That Were Both Granted And Vested During The Year [Member]

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

480,008

Non-PEO NEO | Stock and option award values reported in the SCT [Member]

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

(773,438)

Non-PEO NEO | Year-end Fair Value Of Any Outstanding And Unvested Stock Awards Granted During The Year [Member]

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

370,666

Non-PEO NEO | Year-end Fair Value Of Any Outstanding And Unvested Option Awards Granted During The Year [Member]

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

143,300

Non-PEO NEO | Change In Fair Value As Of The Vesting Date (From The End Of The Prior Year) Of Any Stock Awards That Vest During The Year [Member]

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

(26,649)

Non-PEO NEO | Change In Fair Value As Of The Vesting Date (From The End Of The Prior Year) Of Any Option Awards That Vest During The Year [Member]

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

(23,425)

Non-PEO NEO | Change In Year-end Fair Value (From The End Of The Prior Year) Of Any Outstanding And Unvested Stock Awards Granted In Prior Years [Member]

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

6,443

Non-PEO NEO | Change In Year-end Fair Value (From The End Of The Prior Year) Of Any Outstanding And Unvested Option Awards Granted In Prior Years [Member]

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

(13,484)

Non-PEO NEO | Dollar Value Of Stock Awards That Were Both Granted And Vested During The Year [Member]

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

$ 330,060

Award Timing Disclosure	12 Months Ended
Award Timing Disclosure	Jan. 03, 2025
Award Timing Disclosures [Line Items]
Award Timing MNPI Disclosure	The Committee approves equity awards granted to our named executive officers on or before the grant date. The Committee does not take material nonpublic information into account when determining the timing and terms of such awards. We have not timed the disclosure of material nonpublic information for the purpose of affecting the value of executive compensation. In 2024, we did not award any stock options to our named executive officers during any period beginning four business days before the filing of a periodic report on Form 10-Q or Form 10-K or the filing or furnishing of a current report on Form 8-K disclosing material non-public information and ending one business day after the filing or furnishing of such report with the SEC.
Award Timing MNPI Considered	false
MNPI Disclosure Timed for Compensation Value	false

Insider Trading Policies and Procedures	12 Months Ended
Insider Trading Policies and Procedures	Jan. 03, 2025
Insider Trading Policies and Procedures [Line Items]
Insider Trading Policies and Procedures Adopted	true