Annual report pursuant to Section 13 and 15(d)

Long-Term Debt (Details)

v3.7.0.1
Long-Term Debt (Details)
12 Months Ended
Jun. 11, 2014
Mar. 31, 2017
USD ($)
Mar. 31, 2016
USD ($)
Apr. 30, 2013
USD ($)
Debt Instrument [Line Items]        
Less current portion   $ (20,250,000) $ (13,500,000)  
Long-term debt, noncurrent   $ 60,226,000 80,112,000  
Debt Instrument, Interest Rate, Increase (Decrease)   (0.25%)    
Line of Credit Facility, Commitment Fee Percentage, Increase (Decrease) (0.05%)      
Debt instrument, maturity date   Apr. 30, 2019    
Debt issuance costs, net   $ 524,000 888,000  
Revolving Credit Facility [Member]        
Debt Instrument [Line Items]        
Maximum leverage ratio 2.75      
Annual commitment fee on unutilized commitments (as a percent)   0.30%    
Debt Instrument, Fee   .00125    
Capacity available under credit facility   $ 56,539,000    
Secured Debt [Member]        
Debt Instrument [Line Items]        
Debt instrument, face amount       $ 135,000,000,000
Loans Payable [Member]        
Debt Instrument [Line Items]        
Long-term debt   $ 80,476,000 $ 93,612,000  
Interest rate (as a percent)   2.81%    
Period One [Member] | Loans Payable [Member]        
Debt Instrument [Line Items]        
Repayments of Notes Payable   $ 1,125,000    
Period Two [Member] | Loans Payable [Member]        
Debt Instrument [Line Items]        
Repayments of Notes Payable   1,688,000    
Period Three [Member] | Loans Payable [Member]        
Debt Instrument [Line Items]        
Repayments of Notes Payable   $ 40,500,000    
Revolving Credit Facility [Member] | Line of Credit [Member]        
Debt Instrument [Line Items]        
Debt instrument, face amount       $ 60,000,000,000
Minimum [Member]        
Debt Instrument [Line Items]        
Derivative, Fixed Interest Rate   3.12%    
Maximum [Member]        
Debt Instrument [Line Items]        
Derivative, Fixed Interest Rate   3.81%    
Thermon Industries Inc [Member] | Revolving Credit Facility [Member]        
Debt Instrument [Line Items]        
Interest rate at period end (as a percent)   2.81%