Quarterly report pursuant to Section 13 or 15(d)

DEBT - Narrative (Details)

v3.8.0.1
DEBT - Narrative (Details)
3 Months Ended 6 Months Ended
Sep. 30, 2017
USD ($)
Dec. 31, 2012
USD ($)
$ / shares
Sep. 30, 2017
USD ($)
Sep. 30, 2016
USD ($)
Mar. 31, 2017
USD ($)
Debt Instrument [Line Items]          
Aggregate principal amount $ 130,615,000   $ 130,615,000    
Cash repayments     6,000,000 $ 0  
Outstanding letters of credit 70,631,000   70,631,000   $ 65,028,000
Credit agreement | Letter of credit          
Debt Instrument [Line Items]          
Outstanding letters of credit 1,000,000   1,000,000    
4.50% convertible subordinated notes          
Debt Instrument [Line Items]          
Aggregate principal amount $ 57,090,000 $ 70,000,000 $ 57,090,000    
Stated interest rate 4.50% 4.50% 4.50%    
Conversion ratio   75.896      
Conversion ratio applied per principal amount   $ 1,000      
Conversion price (usd per share) | $ / shares   $ 13.20      
Aggregate principal amount $ 6,000,000.0        
Cash repayments 6,000,000        
Loss on debt extinguishment $ 100,000        
Quarterly repayment of original principal balance (percent) 1.25%   1.25%    
Revolving Credit Agreement with PNC          
Debt Instrument [Line Items]          
Aggregate principal amount $ 23,525,000   $ 23,525,000    
Commitment fee percentage on unused capacity (percent)     0.375%    
Revolving Credit Agreement with PNC | Federal funds rate          
Debt Instrument [Line Items]          
Variable interest rate     0.50%    
Revolving Credit Agreement with PNC | One month LIBOR          
Debt Instrument [Line Items]          
Variable interest rate     1.00%    
Revolving Credit Agreement with PNC | One Month LIBOR margin | Minimum          
Debt Instrument [Line Items]          
Variable interest rate     1.50%    
Revolving Credit Agreement with PNC | One Month LIBOR margin | Maximum          
Debt Instrument [Line Items]          
Variable interest rate     2.50%    
Revolving Credit Agreement with PNC | Credit agreement          
Debt Instrument [Line Items]          
Available uncommitted accordion     $ 20,000,000    
Excess availability under revolving credit agreement 19,800,000   19,800,000    
Revolving Credit Agreement with PNC | Credit agreement | Revolving credit agreement          
Debt Instrument [Line Items]          
Aggregate principal amount 23,525,000   23,525,000   $ 18,500,000
Borrowing capacity $ 80,000,000   $ 80,000,000    
Line of credit at an interest rate 5.39%   5.39%    
Term loan agreement          
Debt Instrument [Line Items]          
Aggregate principal amount $ 50,000,000   $ 50,000,000    
DDTL 20,000,000   $ 20,000,000    
Interest rate during the period (percent)     8.74%    
Term loan agreement | Federal funds rate          
Debt Instrument [Line Items]          
Variable interest rate     0.50%    
Term loan agreement | One month LIBOR          
Debt Instrument [Line Items]          
Variable interest rate     1.00%    
Term loan agreement | Base rate          
Debt Instrument [Line Items]          
Variable interest rate     3.00%    
Term loan agreement | Prime rate quoted by the Wall Street Journal | Minimum          
Debt Instrument [Line Items]          
Variable interest rate     6.00%    
Term loan agreement | Prime rate quoted by the Wall Street Journal | Maximum          
Debt Instrument [Line Items]          
Variable interest rate     7.25%    
Term loan agreement | LIBOR rate plus senior net leverage ratio | Minimum          
Debt Instrument [Line Items]          
Variable interest rate     7.00%    
Term loan agreement | LIBOR rate plus senior net leverage ratio | Maximum          
Debt Instrument [Line Items]          
Variable interest rate     8.25%    
Term loan agreement | Secured secured term loan          
Debt Instrument [Line Items]          
Aggregate principal amount $ 50,000,000   $ 50,000,000