Document and Entity Information - USD ($) $ in Billions | 12 Months Ended | | |
Dec. 29, 2023 | Feb. 16, 2024 | Jun. 30, 2023 |
Cover [Abstract] | | | |
Document Type | 10-K/A | | |
Amendment Flag | true | | |
Amendment Description | Pursuant to Rule 12b-15 under the Securities Exchange Act of 1934, as amended, this Amendment contains new certifications pursuant to Section 302 of the Sarbanes-Oxley Act of 2002, which are attached hereto. | | |
Document Period End Date | Dec. 29, 2023 | | |
Document Fiscal Year Focus | 2023 | | |
Document Fiscal Period Focus | FY | | |
Entity Registrant Name | EXPONENT, INC. | | |
Entity Central Index Key | 0000851520 | | |
Current Fiscal Year End Date | --12-29 | | |
Entity Well-known Seasoned Issuer | Yes | | |
Entity Voluntary Filers | No | | |
Entity Current Reporting Status | Yes | | |
Entity Filer Category | Large Accelerated Filer | | |
Entity Public Float | | | $ 3.4 |
Trading Symbol | EXPO | | |
Entity Common Stock, Shares Outstanding | | 50,563,193 | |
Entity Shell Company | false | | |
Entity Emerging Growth Company | false | | |
Entity Small Business | false | | |
Entity File Number | 0-18655 | | |
Entity Incorporation, State or Country Code | DE | | |
Entity Tax Identification Number | 77-0218904 | | |
Entity Address, Address Line One | 149 Commonwealth Drive | | |
Entity Address, City or Town | Menlo Park | | |
Entity Address, State or Province | CA | | |
Entity Address, Postal Zip Code | 94025 | | |
City Area Code | 650 | | |
Local Phone Number | 326-9400 | | |
Document Annual Report | true | | |
Document Transition Report | false | | |
ICFR Auditor Attestation Flag | true | | |
Entity Interactive Data Current | Yes | | |
Title of each class | Common Stock, par value $0.001 per share | | |
Name of each exchange on which registered | NASDAQ | | |
Auditor Firm ID | 185 | | |
Auditor Name | KPMG, LLP | | |
Auditor Location | San Francisco, California | | |
Document Financial Statement Error Correction [Flag] | false | | |
Documents Incorporated by Reference | Portions of the registrant’s Definitive Proxy Statement for the registrant’s 2023 Annual Meeting of Stockholders to be held on June 6, 2024 are incorporated by reference into Part III of this Annual Report on Form 10-K. | | |