| Document And Entity Information | Oct. 07, 2021 |
| Document Information [Line Items] | |
| Entity, Registrant Name | inTEST Corporation |
| Document, Type | 8-K |
| Document, Period End Date | Oct. 7, 2021 |
| Entity, Incorporation, State or Country Code | DE |
| Entity, File Number | 1-36117 |
| Entity, Tax Identification Number | 22-2370659 |
| Entity, Address, Address Line One | 804 East Gate Drive, Suite 200 |
| Entity, Address, City or Town | Mt. Laurel |
| Entity, Address, State or Province | NJ |
| Entity, Address, Postal Zip Code | 08054 |
| City Area Code | 856 |
| Local Phone Number | 505-8800 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | INTT |
| Security Exchange Name | NYSEAMER |
| Entity, Emerging Growth Company | false |
| Amendment Flag | false |
| Entity, Central Index Key | 0001036262 |
