Quarterly report pursuant to Section 13 or 15(d)

Restructuring and other charges (income) - Narrative (Details)

v3.20.4
Restructuring and other charges (income) - Narrative (Details)
3 Months Ended 9 Months Ended
Dec. 15, 2020
USD ($)
Dec. 15, 2020
ZAR (R)
Dec. 31, 2020
USD ($)
positions
Dec. 31, 2020
USD ($)
positions
Dec. 31, 2019
USD ($)
Mar. 31, 2020
USD ($)
Restructuring Cost and Reserve [Line Items]            
Number of positions eliminated | positions     66 262    
Severance costs     $ 997,000 $ 5,858,000    
Lease abandonment charges     144,000 191,000    
Sale of stock, consideration received on transaction $ 167,000 R 2,500        
Loss on disposition of business       (2,045,000) $ 0  
Accumulated other comprehensive loss     (35,388,000) $ (35,388,000)   $ (63,894,000)
Thermon South Africa Proprieary Limited            
Restructuring Cost and Reserve [Line Items]            
Sale of stock, percentage of ownership before transaction 100.00% 100.00%        
Loss on disposition of business $ 2,214,000          
Accumulated other comprehensive loss $ 828,000          
Canada            
Restructuring Cost and Reserve [Line Items]            
Lease abandonment charges     $ 429,000