| Document and Entity Information | Jan. 28, 2024 |
| Cover [Abstract] | |
| Document Type | 8-K/A |
| Amendment Flag | true |
| Document Period End Date | Jan. 28, 2024 |
| Entity Registrant Name | McGRATH RENTCORP |
| Entity Incorporation State Country Code | CA |
| Entity File Number | 0-13292 |
| Entity Tax Identification Number | 94-2579843 |
| Entity Address Address Line 1 | 5700 Las Positas Road |
| Entity Address City Or Town | Livermore |
| Entity Address State Or Province | CA |
| Entity Address Postal Zip Code | 94551-7800 |
| City Area Code | 925 |
| Local Phone Number | 606-9200 |
| Written Communications | true |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock |
| Trading Symbol | MGRC |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000752714 |
| Amendment Description | This Amendment No. 1 on Form 8-K/A (this “Amendment”) amends the Current Report on Form 8-K filed by McGrath RentCorp, a California corporation (the “Company”) on January 29, 2024, in which the Company reported its entry into an Agreement and Plan of Merger (the “Merger Agreement”), with WillScot Mobile Mini Holdings Corp., a Delaware corporation (the “Parent”), Brunello Merger Sub I, Inc., a Delaware corporation and a direct wholly owned subsidiary of Parent (“Merger Sub I”), and Brunello Merger Sub II, LLC, a Delaware limited liability company and direct wholly owned subsidiary of Parent (“Merger Sub II”). This Amendment is being filed to file a copy of the Merger Agreement that was referenced in the Form 8-K as “to be filed by amendment” as well as to furnish a copy of the letter from the Chief Executive Officer of the Company to employees regarding the transactions contemplated in the Merger Agreement. The disclosure previously provided is not changed. |
