Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt (Details)

v3.5.0.2
Long-Term Debt (Details)
3 Months Ended 6 Months Ended
Sep. 30, 2016
USD ($)
Sep. 30, 2016
USD ($)
Sep. 30, 2015
USD ($)
Mar. 31, 2016
USD ($)
Apr. 30, 2013
USD ($)
Debt Instrument [Line Items]          
Less current portion $ (16,875,000) $ (16,875,000)   $ (13,500,000)  
Long-term debt, noncurrent 70,175,000 70,175,000   80,112,000  
Payments of Debt Issuance Costs   0 $ 341,000    
Debt issuance costs, net $ 700,000 $ 700,000   888,000  
Secured Debt          
Debt Instrument [Line Items]          
Debt Instrument, face amount         $ 135,000,000
Senior Notes          
Debt Instrument [Line Items]          
Debt Instrument, interest rate, stated percentage 2.5625% 2.5625%      
Loans Payable          
Debt Instrument [Line Items]          
Debt Instrument, face amount $ 5,905,000 $ 5,905,000      
Variable Rate Term Loan, due April 2019, net of deferred debt issuance costs of $700 and $888 as of September 30, 2016 and March 31, 2016, respectively $ 87,050,000 $ 87,050,000   93,612,000  
Debt Instrument, interest rate, stated percentage 2.5625% 2.5625%      
Revolving credit facility          
Debt Instrument [Line Items]          
Debt instrument, interest rate, decrease (percentage)   0.25%      
Line of credit facility, decrease in periodic payment (as a percentage) 0.05% 0.05%      
Annual commitment fee on unutilized commitments (as a percent) 0.30%        
Line of credit facility, commitment fee percentage 0.125%        
Outstanding borrowings $ 0 $ 0      
Capacity available under credit facility $ 59,022,000 $ 59,022,000      
Interest rate at period end (as a percent) 2.5625% 2.5625%      
London Interbank Offered Rate (LIBOR)          
Debt Instrument [Line Items]          
Interest rate in addition to LIBOR rate 1.00%        
Canadian Deposit Offer Rate          
Debt Instrument [Line Items]          
Interest rate in addition to LIBOR rate 1.00%        
Minimum | Base Rate          
Debt Instrument [Line Items]          
Interest rate in addition to LIBOR rate 0.50%        
Maximum          
Debt Instrument [Line Items]          
Maximum leverage ratio   2.75      
Maximum | Base Rate          
Debt Instrument [Line Items]          
Interest rate in addition to LIBOR rate 1.00%        
Through March 31, 2017 | Loans Payable          
Debt Instrument [Line Items]          
Repayments of Notes Payable   $ 1,125,000      
Last Two Years Of Loan | Loans Payable          
Debt Instrument [Line Items]          
Repayments of Notes Payable   $ 1,688,000      
Due in April 2019 | Loans Payable          
Debt Instrument [Line Items]          
Repayments of Notes Payable $ 40,500,000        
Interest Rate Swap | Revolving credit facility          
Debt Instrument [Line Items]          
Derivative, fixed interest rate 3.23% 3.23%      
Interest payments, percent hedged 100.00% 100.00%      
Revolving credit facility          
Debt Instrument [Line Items]          
Outstanding borrowings $ 0 $ 0   $ 0  
Revolving credit facility | Line of Credit          
Debt Instrument [Line Items]          
Debt Instrument, face amount         $ 60,000,000