Annual report pursuant to Section 13 and 15(d)

Document and Entity Information

v3.21.1
Document and Entity Information - USD ($)
 12 Months Ended
Mar. 31, 2021
May 26, 2021
Sep. 30, 2020
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Mar. 31, 2021    
Document Transition Report false    
Entity File Number 001-35159    
Entity Registrant Name THERMON GROUP HOLDINGS, INC.    
Entity Incorporation, State or Country Code DE    
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    
Title of 12(b) Security Common Stock, $0.001 par value per share    
Trading Symbol THR    
Security Exchange Name NYSE    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Shell Company false    
ICFR Auditor Attestation Flag true    
Entity Public Float     $ 367,767,182
Entity Common Stock, Shares Outstanding   33,245,749  
Documents Incorporated by Reference As permitted by General Instruction G of Form 10-K, certain portions, as expressly described in this report, of the registrant's Definitive Proxy Statement for the 2021 Annual Meeting of Stockholders to be filed with the SEC are incorporated by reference into Part III of this Annual Report on Form 10-K.    
Entity Central Index Key 0001489096    
Current Fiscal Year End Date --03-31    
Document Fiscal Year Focus 2021    
Document Fiscal Period Focus FY    
Amendment Flag false