| Cover | Nov. 19, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Nov. 22, 2021 |
| Entity Registrant Name | MANNATECH, INCORPORATED |
| Entity Address, City or Town | Flower Mound, |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 75028 |
| Local Phone Number | 471-7400 |
| City Area Code | (972) |
| Entity Incorporation, State or Country Code | TX |
| Entity File Number | 000-24657 |
| Entity Tax Identification Number | 75-2508900 |
| Entity Address, Address Line One | 1410 Lakeside Parkway, Suite 200 |
| 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 | MTEX |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Amendment Flag | false |
| Entity Central Index Key | 0001056358 |
