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The performance conditions applicable to the award were determined to have been satisfied by the Issuer's Compensation Committee on March 28, 2022, resulting in the immediate vesting of the restricted stock units as to 1,316 shares of Common Stock."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes 3,800 shares of restricted stock that vest in one installment on March 8, 2023, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":25621,"source":{"system":"sec-edgar","filing":"0001415889-22-003479","document":"form4-03302022_020306.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000141588922003479/form4-03302022_020306.xml","form_type":"4"}},{"id":2326608,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, BUSINESS DEVELOPMENT"}}],"security":"Common Stock","published_at":"2022-03-17T23:26:47.000Z","date":"2022-03-15","kind":"sale","acquired":false,"shares":6825,"price":28.19,"value":192396.75,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares of Common Stock sold in the open market, the proceeds of which were used to pay the tax withholding obligations incurred upon the vesting of the performance-based restricted stock units on March 14, 2022."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes 3,800 shares of restricted stock that vest in one installment on March 8, 2023, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":24305,"source":{"system":"sec-edgar","filing":"0001415889-22-003151","document":"form4-03172022_040338.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000141588922003151/form4-03172022_040338.xml","form_type":"4"}},{"id":2326607,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, BUSINESS DEVELOPMENT"}}],"security":"Common Stock","published_at":"2022-03-17T23:26:47.000Z","date":"2022-03-15","kind":"sale","acquired":false,"shares":633,"price":26.44,"value":16736.52,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares of Common Stock sold in the open market, the proceeds of which were used to pay the tax withholding obligations incurred upon the vesting of the performance-based restricted stock units on March 14, 2022."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is the weighted average price. These shares were sold in multiple transactions at prices ranging from $26.43 to $27.10, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote"},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes 3,800 shares of restricted stock that vest in one installment on March 8, 2023, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":31130,"source":{"system":"sec-edgar","filing":"0001415889-22-003151","document":"form4-03172022_040338.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000141588922003151/form4-03172022_040338.xml","form_type":"4"}},{"id":2330377,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, BUSINESS DEVELOPMENT"}}],"security":"Common Stock","published_at":"2022-03-16T23:12:57.000Z","date":"2022-03-14","kind":"grant","acquired":true,"shares":12582,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents performance-based restricted stock units previously granted to the Reporting Person by the Issuer on March 9, 2021. The performance conditions applicable to the award were determined to have been satisfied by the Issuer's Compensation Committee on March 14, 2022, resulting in the immediate vesting of the restricted stock units as to 12,582 shares of Common Stock."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes 3,800 shares of restricted stock that vest in one installment on March 8, 2023, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":31763,"source":{"system":"sec-edgar","filing":"0001415889-22-003076","document":"form4-03162022_040344.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000141588922003076/form4-03162022_040344.xml","form_type":"4"}},{"id":2339469,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, BUSINESS DEVELOPMENT"}}],"security":"Common Stock","published_at":"2022-03-11T00:40:42.000Z","date":"2022-03-08","kind":"grant","acquired":true,"shares":3800,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares of restricted stock awarded to the Reporting Person by the Issuer on March 8, 2022, which vests in one installment on March 8, 2023, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes 302 shares of Common Stock purchased under the Amended and Restated Willdan Group, Inc. 2006 Employee Stock Purchase Plan on December 31, 2021."}],"balance_after":19181,"source":{"system":"sec-edgar","filing":"0001415889-22-002852","document":"form4-03102022_040328.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000141588922002852/form4-03102022_040328.xml","form_type":"4"}},{"id":2465516,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, BUSINESS DEVELOPMENT"}}],"security":"Stock Options (Right to Buy)","published_at":"2021-12-17T22:35:03.000Z","date":"2021-12-15","kind":"exercise","acquired":true,"shares":11000,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F4","text":"Stock options granted under the Willdan Group, Inc. 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The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (2) and footnote (3)."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes 242 shares of Common Stock purchased under the Amended and Restated Willdan Group, Inc. 2006 Employee Stock Purchase Plan on June 30, 2021."}],"balance_after":21027,"source":{"system":"sec-edgar","filing":"0001415889-21-006083","document":"form4-12172021_021250.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000141588921006083/form4-12172021_021250.xml","form_type":"4"}},{"id":2465513,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, BUSINESS DEVELOPMENT"}}],"security":"Common Stock","published_at":"2021-12-17T22:35:03.000Z","date":"2021-12-15","kind":"exercise","acquired":true,"shares":11000,"price":16.09,"value":176990.0,"ownership":{"direct":true},"footnotes":[{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes 242 shares of Common Stock purchased under the Amended and Restated Willdan Group, Inc. 2006 Employee Stock Purchase Plan on June 30, 2021."}],"balance_after":26079,"source":{"system":"sec-edgar","filing":"0001415889-21-006083","document":"form4-12172021_021250.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000141588921006083/form4-12172021_021250.xml","form_type":"4"}},{"id":2667816,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Common Stock","published_at":"2021-06-15T22:13:58.000Z","date":"2021-06-14","kind":"sale","acquired":false,"shares":2000,"price":40.36,"value":80720.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The price reported in Column 4 is the weighted average price. 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These shares were sold in multiple transactions at prices ranging from $39.82 to $40.74, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (2) through footnote (10)."}],"balance_after":23343,"source":{"system":"sec-edgar","filing":"0001179110-21-003826","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911021003826/edgar.xml","form_type":"4"}},{"id":2774288,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Stock Option (Right to Buy)","published_at":"2021-03-23T22:12:29.000Z","date":"2021-03-19","kind":"exercise","acquired":false,"shares":5000,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F14","text":"Stock options granted under the Willdan Group, Inc. 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These shares were sold in multiple transactions at prices ranging from $45.91 to $46.87, inclusive."}],"balance_after":20148,"source":{"system":"sec-edgar","filing":"0001179110-21-003739","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911021003739/edgar.xml","form_type":"4"}},{"id":2774276,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Common Stock","published_at":"2021-03-23T22:12:29.000Z","date":"2021-03-11","kind":"sale","acquired":false,"shares":224,"price":47.62,"value":10666.88,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares of Common Stock sold in the open market, the proceeds of which were used to pay the tax withholding obligations incurred upon the vesting of performance-based restricted stock units on March 10, 2021."},{"field":"price","element":"transactionPricePerShare","label":"F4","text":"The price reported in Column 4 is the weighted average price. 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These shares were sold in multiple transactions at prices ranging from $44.97 to $45.95, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (2) through footnote (11) and footnote (13)."}],"balance_after":20745,"source":{"system":"sec-edgar","filing":"0001179110-21-003739","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911021003739/edgar.xml","form_type":"4"}},{"id":2791368,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Common Stock","published_at":"2021-03-12T22:14:57.000Z","date":"2021-03-10","kind":"grant","acquired":true,"shares":4588,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents performance-based restricted stock units previously granted to the Reporting Person by the Issuer on March 2, 2020. The performance conditions applicable to the award were determined to have been satisfied by the Issuer's Compensation Committee on March 10, 2021, resulting in the immediate vesting of the restricted stock units as to 4,588 shares of Common Stock."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes 342 shares of Common Stock purchased under the Amended and Restated Willdan Group, Inc. 2006 Employee Stock Purchase Plan on December 31, 2020."}],"balance_after":20863,"source":{"system":"sec-edgar","filing":"0001179110-21-003369","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911021003369/edgar.xml","form_type":"4"}},{"id":2937478,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Stock Option (Right to Buy)","published_at":"2020-12-18T18:31:46.000Z","date":"2020-12-16","kind":"exercise","acquired":false,"shares":10000,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Stock options granted under the Willdan Group, Inc. Amended and Restated 2008 Performance Incentive Plan, which vested in three equal installments on each of May 5, 2017, May 5,2018 and May 5, 2019."}],"balance_after":5000,"derivative":{"exercise_price":10.81,"expiration_date":"2026-05-05","underlying":"Common Stock","underlying_shares":10000},"source":{"system":"sec-edgar","filing":"0001179110-20-012094","document":"edgar.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911020012094/edgar.xml","form_type":"4"}},{"id":2937477,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Common Stock","published_at":"2020-12-18T18:31:46.000Z","date":"2020-12-16","kind":"sale","acquired":false,"shares":10000,"price":39.84,"value":398400.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The price reported in Column 4 is weighted average price. These shares were sold in multiple transactions at prices ranging from $39.70-$40.17, inclusive. The reporting person undertakes to provide to Willdan Group, Inc., any security holder of Willdan Group, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above."}],"balance_after":15933,"source":{"system":"sec-edgar","filing":"0001179110-20-012094","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911020012094/edgar.xml","form_type":"4"}},{"id":2937476,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Common Stock","published_at":"2020-12-18T18:31:46.000Z","date":"2020-12-16","kind":"exercise","acquired":true,"shares":10000,"price":10.81,"value":108100.0,"ownership":{"direct":true},"balance_after":25933,"source":{"system":"sec-edgar","filing":"0001179110-20-012094","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911020012094/edgar.xml","form_type":"4"}},{"id":2994347,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Common Stock","published_at":"2020-11-03T20:07:00.000Z","date":"2020-10-31","kind":"tax_withholding","acquired":false,"shares":153,"price":26.17,"value":4004.01,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares of the Issuer's Common Stock withheld for tax withholding purposes in connection with the vesting of restricted stock on October 31, 2020, which restricted stock was granted on October 31, 2017."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes 265 shares of Common Stock purchased under the Amended and Restated Willdan Group, Inc. 2006 Employee Stock Purchase Plan on June 30, 2020."}],"balance_after":15933,"source":{"system":"sec-edgar","filing":"0001179110-20-010738","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911020010738/edgar.xml","form_type":"4"}},{"id":3102861,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Common Stock","published_at":"2020-06-22T22:49:50.000Z","date":"2020-06-19","kind":"sale","acquired":false,"shares":3764,"price":23.49,"value":88416.36,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares of Common Stock sold in the open market, the proceeds of which were used to pay the tax withholding obligations incurred upon the vesting of performance-based restricted stock units on June 10, 2020."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is the weighted average price. These shares were sold in multiple transactions at prices ranging from $23.18 to $24.01, inclusive. The reporting person undertakes to provide to Willdan Group, Inc., any security holder of Willdan Group, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes (i) 444 shares of restricted stock that vest on October 31, 2020."}],"balance_after":15821,"source":{"system":"sec-edgar","filing":"0001179110-20-007688","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911020007688/edgar.xml","form_type":"4"}},{"id":3111504,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Common Stock","published_at":"2020-06-12T19:58:14.000Z","date":"2020-06-10","kind":"grant","acquired":true,"shares":9816,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents performance-based restricted stock units previously granted to the Reporting Person by the Issuer on June 13, 2019. The performance conditions applicable to the award were determined to have been satisfied by the Issuer's Compensation Committee on June 10, 2020, resulting in the immediate vesting of the restricted stock units as to 9,816 shares of Common Stock."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes 444 shares of restricted stock that vest on October 31, 2020."}],"balance_after":19585,"source":{"system":"sec-edgar","filing":"0001179110-20-007250","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911020007250/edgar.xml","form_type":"4"}},{"id":3213155,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Common Stock","published_at":"2020-03-12T20:56:59.000Z","date":"2020-03-09","kind":"tax_withholding","acquired":false,"shares":157,"price":32.68,"value":5130.76,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F4","text":"Represents shares of the Issuer's Common Stock withheld for tax withholding purposes in connection with the vesting of restricted stock on March 8, 2020, which restricted stock was granted on March 8, 2017."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes (i) 444 shares of restricted stock that vest on October 31, 2020 and (ii) an aggregate of 272 shares of Common Stock purchased under the Amended and Restated Willdan Group, Inc. 2006 Employee Stock Purchase Plan, including 128 shares on June 30, 2019 and 144 shares on December 31, 2019."}],"balance_after":9769,"source":{"system":"sec-edgar","filing":"0001179110-20-003572","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911020003572/edgar.xml","form_type":"4"}},{"id":3213154,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Common Stock","published_at":"2020-03-12T20:56:59.000Z","date":"2020-03-06","kind":"tax_withholding","acquired":false,"shares":2545,"price":32.68,"value":83170.6,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F3","text":"Represents shares of the Issuer's Common Stock withheld for tax withholding purposes in connection with the vesting of the performance-based restricted stock units referenced in footnote (1)."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes (i) 444 shares of restricted stock that vest on October 31, 2020 and (ii) an aggregate of 272 shares of Common Stock purchased under the Amended and Restated Willdan Group, Inc. 2006 Employee Stock Purchase Plan, including 128 shares on June 30, 2019 and 144 shares on December 31, 2019."}],"balance_after":9926,"source":{"system":"sec-edgar","filing":"0001179110-20-003572","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911020003572/edgar.xml","form_type":"4"}},{"id":3213153,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Common Stock","published_at":"2020-03-12T20:56:59.000Z","date":"2020-03-02","kind":"grant","acquired":true,"shares":7010,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents performance-based restricted stock units previously granted to the Reporting Person by the Issuer on March 6, 2018. The performance conditions applicable to the award were determined to have been satisfied by the Issuer's Compensation Committee on March 2, 2020, resulting in the immediate vesting of the restricted stock units as to 7,010 shares of Common Stock."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes (i) 444 shares of restricted stock that vest on October 31, 2020 and (ii) an aggregate of 272 shares of Common Stock purchased under the Amended and Restated Willdan Group, Inc. 2006 Employee Stock Purchase Plan, including 128 shares on June 30, 2019 and 144 shares on December 31, 2019."}],"balance_after":12471,"source":{"system":"sec-edgar","filing":"0001179110-20-003572","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911020003572/edgar.xml","form_type":"4"}},{"id":3306186,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Common stock","published_at":"2020-01-21T16:20:41.000Z","date":"2019-10-31","kind":"tax_withholding","acquired":false,"shares":153,"price":30.3,"value":4635.9,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares of the Issuer's Common Stock withheld for tax withholding purposes in connection with the vesting of restricted stock on October 31, 2019, which restricted stock was granted on October 21, 2017."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes (i) 444 shares of restricted stock that vest on March 8, 2020, (ii) 444 shares of restricted stock that vest on October 31, 2020 and (iii) an aggregate of 1,164 shares of Common Stock purchased under the Amended and Restated Willdan Group, Inc. 2006 Employee Stock Purchase Plan, including 225 shares on December 31, 2016, 229 shares on June 30, 2017, 225 shares on December 31, 2017, 355 shares on June 30, 2018 and 130 shares on December 31, 2018."}],"balance_after":5189,"source":{"system":"sec-edgar","filing":"0001179110-20-000668","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911020000668/edgar.xml","form_type":"4"}},{"id":3494079,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Common Stock","published_at":"2019-06-11T21:56:22.000Z","date":"2019-06-10","kind":"sale","acquired":false,"shares":1779,"price":31.51,"value":56056.29,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is weighted average price. These shares were sold in multiple transactions at prices ranging from $31.50-$31.57, inclusive. The reporting person undertakes to provide to Willdan Group, Inc., any security holder of Willdan Group, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes (i) 444 shares of restricted stock that vest on March 8, 2020, (ii) 889 shares of restricted stock that vest in two substantially equal installments on each of October 31, 2019 and October 31, 2020 and (iii) an aggregate of 1,164 shares of Common Stock purchased under the Amended and Restated Willdan Group, Inc. 2006 Employee Stock Purchase Plan, including 225 shares on December 31, 2016, 229 shares on June 30, 2017, 225 shares on December 31, 2017, 355 shares on June 30, 2018 and 130 shares on December 31, 2018."}],"balance_after":5342,"source":{"system":"sec-edgar","filing":"0001179110-19-007517","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911019007517/edgar.xml","form_type":"4"}},{"id":3494078,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Common Stock","published_at":"2019-06-11T21:56:22.000Z","date":"2019-06-07","kind":"sale","acquired":false,"shares":1721,"price":31.97,"value":55020.37,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The price reported in Column 4 is weighted average price. These shares were sold in multiple transactions at prices ranging from $31.96-$31.975, inclusive. The reporting person undertakes to provide to Willdan Group, Inc., any security holder of Willdan Group, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes (i) 444 shares of restricted stock that vest on March 8, 2020, (ii) 889 shares of restricted stock that vest in two substantially equal installments on each of October 31, 2019 and October 31, 2020 and (iii) an aggregate of 1,164 shares of Common Stock purchased under the Amended and Restated Willdan Group, Inc. 2006 Employee Stock Purchase Plan, including 225 shares on December 31, 2016, 229 shares on June 30, 2017, 225 shares on December 31, 2017, 355 shares on June 30, 2018 and 130 shares on December 31, 2018."}],"balance_after":7121,"source":{"system":"sec-edgar","filing":"0001179110-19-007517","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911019007517/edgar.xml","form_type":"4"}},{"id":3536279,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Common Stock","published_at":"2019-05-07T20:47:27.000Z","date":"2019-03-08","kind":"tax_withholding","acquired":false,"shares":178,"price":36,"value":6408.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares of the Issuer's Common Stock withheld for tax withholding purposes in connection with the vesting of restricted stock on March 8, 2019, which restricted stock was granted on March 8, 2017."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes (i) 444 shares of restricted stock that vest on March 8, 2020 and (ii) 889 shares of restricted stock that vest in two substantially equal installments on each of October 31, 2019 and October 31, 2020."}],"balance_after":7678,"source":{"system":"sec-edgar","filing":"0001179110-19-005664","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911019005664/edgar.xml","form_type":"4"}},{"id":3578206,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Common Stock","published_at":"2019-03-26T21:22:24.000Z","date":"2019-03-06","kind":"tax_withholding","acquired":false,"shares":2530,"price":38.2,"value":96646.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F3","text":"Represents shares of the Issuer's Common Stock withheld for tax withholding purposes in connection with the vesting of the performance-based restricted stock units granted on March 6, 2018."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes (i) 444 shares of restricted stock that vest on March 8, 2020 and (ii) 889 shares of restricted stock that vest in two substantially equal installments on each of October 31, 2019 and October 31, 2020."}],"balance_after":7856,"source":{"system":"sec-edgar","filing":"0001179110-19-004311","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911019004311/edgar.xml","form_type":"4"}},{"id":3578205,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Common Stock","published_at":"2019-03-26T21:22:24.000Z","date":"2019-03-05","kind":"grant","acquired":true,"shares":7010,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares of the Issuer's Common Stock that vested subject to a time-based vesting restriction on March 6, 2019 under performance-based restricted stock units granted on March 6, 2018."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes (i) 444 shares of restricted stock that vest on March 8, 2020 and (ii) 889 shares of restricted stock that vest in two substantially equal installments on each of October 31, 2019 and October 31, 2020."}],"balance_after":10386,"source":{"system":"sec-edgar","filing":"0001179110-19-004311","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911019004311/edgar.xml","form_type":"4"}},{"id":3916767,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Stock Option (Right to Buy)","published_at":"2018-05-25T21:28:00.000Z","date":"2018-05-23","kind":"exercise","acquired":false,"shares":1000,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F3","text":"The option became exercisable in three substantially equal installments on each of March 26, 2013, March 26, 2014 and March 26, 2015."}],"balance_after":0,"derivative":{"exercise_price":3.84,"expiration_date":"2022-03-26","underlying":"Common Stock","underlying_shares":1000},"source":{"system":"sec-edgar","filing":"0001179110-18-007576","document":"edgar.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911018007576/edgar.xml","form_type":"4"}},{"id":3916766,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Common Stock","published_at":"2018-05-25T21:28:00.000Z","date":"2018-05-23","kind":"sale","acquired":false,"shares":4709,"price":27.18,"value":127990.62,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $26.99 - $27.27, inclusive. The reporting person undertakes to provide to Willdan Group, Inc., any security holder of Willdan Group, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes (i) 889 shares of restricted stock that vest in two substantially equal installments on each of March 8, 2019 and March 8, 2020 and (ii) 1,333 shares of restricted stock that vest in three substantially equal installments on each of October 31, 2018, October 31, 2019 and October 31, 2020."}],"balance_after":3376,"source":{"system":"sec-edgar","filing":"0001179110-18-007576","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911018007576/edgar.xml","form_type":"4"}},{"id":3916765,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":128625,"kind":"person","name":"WHITELAW PAUL MILTON","position":1,"cik":"0001733724","reported_name":"WHITELAW PAUL MILTON","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, Business Development"}}],"security":"Common Stock","published_at":"2018-05-25T21:28:00.000Z","date":"2018-05-23","kind":"exercise","acquired":true,"shares":1000,"price":3.84,"value":3840.0,"ownership":{"direct":true},"footnotes":[{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes (i) 889 shares of restricted stock that vest in two substantially equal installments on each of March 8, 2019 and March 8, 2020 and (ii) 1,333 shares of restricted stock that vest in three substantially equal installments on each of October 31, 2018, October 31, 2019 and October 31, 2020."}],"balance_after":8085,"source":{"system":"sec-edgar","filing":"0001179110-18-007576","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1370450/000117911018007576/edgar.xml","form_type":"4"}}]}