Annual report pursuant to Section 13 and 15(d)

Revolving Credit Facility (Details)

v3.8.0.1
Revolving Credit Facility (Details)
 12 Months Ended
Jun. 02, 2017
USD ($)
agreement
Jun. 10, 2015
USD ($)
item
Mar. 31, 2018
USD ($)
agreement
Mar. 31, 2017
USD ($)
Jun. 01, 2018
USD ($)
Jun. 30, 2015
USD ($)
Jun. 29, 2015
USD ($)
Revolving Credit Facility              
Restricted cash     $ 5,000,000 $ 5,514,000      
Outstanding borrowings     8,527,000 11,533,000      
Interest expense     606,000 536,000      
Amortization of deferred financing costs     $ 202,000 173,000      
Wells Fargo              
Revolving Credit Facility              
Number of credit and security agreements | agreement     2        
Bridge Bank              
Revolving Credit Facility              
Number of secured credit facilities | agreement 2            
Term of credit agreements 2 years            
Maximum borrowings as a percent of cash held 85.00%            
Restricted cash equivalents for credit facility     $ 5,000,000        
Bridge Bank | Prime Rate              
Revolving Credit Facility              
Variable base rate prime rate            
Interest margin on variable rate 1.50%            
Credit Facility | Wells Fargo              
Revolving Credit Facility              
Maximum borrowing capacity under facility     $ 20,000,000     $ 20,000,000 $ 15,000,000
Minimum cash balance       $ 9,800,000      
Number of noncompliance events waived | item   1          
Restricted cash   $ 5,000,000          
Variable base rate     Daily three month LIBOR        
Borrowing rate (as a percent)       4.90%      
Annual unused line fee (as a percent)     0.25%        
Interest rate with respect to letters of credit (as a percent)     1.50%        
Outstanding borrowings       $ 11,500,000      
Additional borrowing capacity under facility       6,800,000      
Interest expense     $ 200,000 500,000      
Amortization of deferred financing costs     $ 100,000 $ 200,000      
Credit Facility | Bridge Bank              
Revolving Credit Facility              
Maximum borrowing capacity under facility $ 12,000,000            
Borrowing rate (as a percent)     6.30%        
Outstanding borrowings     $ 8,500,000        
Interest expense     400,000        
Amortization of deferred financing costs     100,000        
Term of credit agreements 2 years            
Restricted cash equivalents for credit facility $ 5,000,000            
Origination fees     200,000        
Amount available for additional borrowing     $ 3,500,000        
Facility fee percentage     0.625%        
Cash collateral percentage     42.00%        
Credit Facility | Minimum | Wells Fargo              
Revolving Credit Facility              
Interest floor amount     $ 66,000        
Non-revolving capital expenditure line of credit | Wells Fargo              
Revolving Credit Facility              
Maximum borrowing capacity under facility     $ 500,000        
Letter Agreement | Bridge Bank | Subsequent event              
Revolving Credit Facility              
Maximum borrowing capacity under facility         $ 15,000,000    
Restricted cash         $ 6,000,000    
Interest rate (as a percent)         1.00%    
Facility fee percentage         0.50%    
Cash collateral percentage         40.00%    
Fee for early termination         $ 0    
Domestic Facility | Bridge Bank              
Revolving Credit Facility              
Maximum borrowings as a percent of cash held     85.00%