Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt (Details)

v3.19.3.a.u2
Long-Term Debt (Details)
$ in Thousands
9 Months Ended 12 Months Ended
Dec. 31, 2020
Oct. 30, 2017
CAD ($)
Oct. 30, 2017
USD ($)
Sep. 30, 2020
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Mar. 31, 2019
USD ($)
Apr. 01, 2018
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 $5,432 and $6,271 as of September 30, 2019 and March 31, 2019, respectively         171,382,000   197,729,000  
Debt issuance costs, net         5,432,000   6,271,000  
Repayments of long-term debt         46,279,000 $ 20,307,000    
Maximum leverage ratio to secure additional borrowing   4.0 4.0          
Outstanding borrowings         3,080,000   11,225,000  
Loans Payable                
Debt Instrument [Line Items]                
Debt Instrument, face amount             5,905,000  
Revolving credit facility                
Debt Instrument [Line Items]                
Outstanding borrowings         3,080,000   11,225,000  
Capacity available under credit facility         52,758,000      
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   2.25% 2.25%          
Revolving credit facility | London Interbank Offered Rate (LIBOR) | Line of Credit                
Debt Instrument [Line Items]                
Basis spread on variable rate   3.25% 3.25%          
Revolving credit facility | Canadian Base Rate [Member] | Line of Credit                
Debt Instrument [Line Items]                
Basis spread on variable rate   2.25% 2.25%          
Revolving credit facility | CDOR | Line of Credit                
Debt Instrument [Line Items]                
Basis spread on variable rate   3.25% 3.25%          
Variable Rate Term Loan due October 2024 | Loans Payable                
Debt Instrument [Line Items]                
Variable Rate Term Loans         173,882,000   200,229,000  
Debt issuance costs, net         $ 5,432,000   $ 6,271,000  
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  
Additional borrowing capacity     $ 30,000,000          
Maximum leverage ratio         3.5      
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   2.75% 2.75%          
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)         4.67%