| Cover Page Cover Page | May 27, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | May 27, 2021 |
| Entity Registrant Name | THERMON GROUP HOLDINGS, INC. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-35159 |
| Entity Tax Identification Number | 27-2228185 |
| Entity Address, Address Line One | 7171 Southwest Parkway |
| Entity Address, Address Line Two | Building 300, |
| Entity Address, Address Line Three | Suite 200 |
| Entity Address, City or Town | Austin |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 78735 |
| City Area Code | 512 |
| Local Phone Number | 690-0600 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.001 par value per share |
| Trading Symbol | THR |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001489096 |
| Amendment Flag | false |
