| Cover | Sep. 28, 2020 |
| Cover [Abstract] | |
| Entity Central Index Key | 0000007039 |
| Amendment Flag | false |
| Document Type | 8-K |
| Document Period End Date | Apr. 16, 2021 |
| Entity Registrant Name | Trecora Resources |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 1-33926 |
| Entity Tax Identification Number | 75-1256622 |
| Entity Address, Address Line One | 1650 Hwy 6 South |
| Entity Address, Address Line Two | Suite 190 |
| Entity Address, City or Town | Sugar Land |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 77478 |
| City Area Code | (281) |
| Local Phone Number | 980-5522 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $0.10 per share |
| Trading Symbol | TREC |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
