Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt (Details)

v3.20.2
Long-Term Debt (Details)
$ in Thousands
3 Months Ended 9 Months Ended
Dec. 31, 2020
Jun. 18, 2020
USD ($)
Oct. 30, 2017
USD ($)
Oct. 30, 2017
CAD ($)
Jun. 30, 2020
USD ($)
Jun. 30, 2019
USD ($)
Sep. 30, 2020
Mar. 31, 2020
USD ($)
Apr. 01, 2018
Mar. 31, 2017
USD ($)
Debt Instrument [Line Items]                    
Less current portion         $ (2,500,000)     $ (2,500,000)    
Long-term debt, net of current maturities and deferred debt issuance costs and debt discounts of $4,204 and $4,447 as of June 30, 2020 and March 31, 2020, respectively         168,671,000     169,053,000    
Debt issuance costs, net         4,204,000     4,447,000    
Repayments of long-term debt         34,294,000 $ 7,494,000        
Maximum leverage ratio to secure additional borrowing     4.0 4.0            
Outstanding borrowings         3,669,000     0    
Amount of excess cash   $ 20,000                
Loans Payable                    
Debt Instrument [Line Items]                    
Debt Instrument, face amount                   $ 5,905,000
Revolving credit facility                    
Debt Instrument [Line Items]                    
Outstanding borrowings         3,669,000          
Capacity available under credit facility         53,236,000          
Through March 31, 2019 | Loans Payable                    
Debt Instrument [Line Items]                    
Repayments of notes payable         $ 625          
Revolving credit facility | Line of Credit                    
Debt Instrument [Line Items]                    
Debt Instrument, face amount     $ 60,000,000              
Long-term Debt, Term     5 years              
Repayments of lines of credit     $ 6,000,000              
Liabilities incurred       $ 201,900            
Line of credit facility, commitment fee percentage     0.50% 0.50%            
Debt covenant, coverage ratio     1.25 1.25            
Revolving credit facility | Base Rate | Line of Credit                    
Debt Instrument [Line Items]                    
Basis spread on variable rate     22500.00% 22500.00%            
Revolving credit facility | London Interbank Offered Rate (LIBOR) | Line of Credit                    
Debt Instrument [Line Items]                    
Basis spread on variable rate     32500.00% 32500.00%            
Revolving credit facility | Canadian Base Rate [Member] | Line of Credit                    
Debt Instrument [Line Items]                    
Basis spread on variable rate     22500.00% 22500.00%            
Revolving credit facility | CDOR | Line of Credit                    
Debt Instrument [Line Items]                    
Basis spread on variable rate     32500.00% 32500.00%            
Variable Rate Term Loan due October 2024                    
Debt Instrument [Line Items]                    
Variable term loan, interest rate         4.75%          
Variable Rate Term Loan due October 2024 | Loans Payable                    
Debt Instrument [Line Items]                    
Variable Rate Term Loans         $ 171,171,000     171,553,000    
Debt issuance costs, net         $ 4,204,000     $ 4,447,000    
Variable Rate Senior Secured Term Loan B | Secured Debt                    
Debt Instrument [Line Items]                    
Debt Instrument, face amount     $ 250,000,000              
Long-term Debt, Term     7 years              
Variable interest rate floor     1.00%              
Quarterly amortization of debt, percent                 0.25%  
Repayment requirement, percentage of excess cash flow         50.00%          
Reduced repayment requirement, percentage of excess cash flow         25.00%          
Maximum leverage ratio requirement for reduced payment         4.0          
Minimum leverage ratio requirement for reduced payment         3.5          
Minimum repayment requirement percentage of excess cash flow         0.00%          
Maximum leverage ratio requirement for minimum repayment         3.5          
Maximum leverage ratio         3.5          
Additional borrowing capacity     $ 30,000,000              
Variable Rate Senior Secured Term Loan B | Secured Debt | Subsidiary Stock                    
Debt Instrument [Line Items]                    
Guarantor obligations, percentage     100.00% 100.00%            
Variable Rate Senior Secured Term Loan B | Secured Debt | Stock of First Tier Material Foreign Subsidiaries, US Borrower, and US Subsidiary                    
Debt Instrument [Line Items]                    
Guarantor obligations, percentage     65.00% 65.00%            
Variable Rate Senior Secured Term Loan B | Base Rate | Secured Debt                    
Debt Instrument [Line Items]                    
Basis spread on variable rate     27500.00% 27500.00%            
Variable Rate Senior Secured Term Loan B | London Interbank Offered Rate (LIBOR) | Secured Debt                    
Debt Instrument [Line Items]                    
Basis spread on variable rate     3.75% 3.75%            
Term Loan A due April 2019                    
Debt Instrument [Line Items]                    
Repayments of long-term debt     $ 70,875,000              
Thermon Heating Systems Inc.                    
Debt Instrument [Line Items]                    
Debt proceeds used as consideration for business acquisition     $ 164,900,000              
Scenario, Forecast | Revolving credit facility | Line of Credit                    
Debt Instrument [Line Items]                    
Maximum leverage ratio 3.75           4.5      
Canadian Borrower | Revolving credit facility                    
Debt Instrument [Line Items]                    
Interest rate at period end (as a percent)         3.95%