Quarterly report pursuant to Section 13 or 15(d)

Customer Concentrations and Accounts Receivable (Details)

v3.8.0.1
Customer Concentrations and Accounts Receivable (Details) - USD ($)
3 Months Ended 9 Months Ended 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2017
Dec. 31, 2016
Mar. 31, 2017
Customer Concentrations and Accounts Receivable          
Provision for doubtful accounts receivable $ (700,000) $ 12,000 $ (771,000) $ (1,384,000)  
Accounts receivable     1,697,000 1,747,000  
Deferred revenue     181,000 $ 212,000  
BPC Engineering          
Customer Concentrations and Accounts Receivable          
Provision for doubtful accounts receivable     8,100,000    
Accounts receivable     $ 1,800,000    
Sales | Customer concentrations | E-Finity          
Customer Concentrations and Accounts Receivable          
Concentration percentage 29.00%   19.00%    
Sales | Customer concentrations | CAL          
Customer Concentrations and Accounts Receivable          
Concentration percentage 14.00%        
Sales | Customer concentrations | BPC Engineering          
Customer Concentrations and Accounts Receivable          
Concentration percentage   16.00%   12.00%  
Sales | Customer concentrations | Horizon Power Systems          
Customer Concentrations and Accounts Receivable          
Concentration percentage   16.00% 10.00% 10.00%  
Net accounts receivable | Credit concentration | E-Finity          
Customer Concentrations and Accounts Receivable          
Concentration percentage     42.00%   29.00%
Net accounts receivable | Credit concentration | CAL          
Customer Concentrations and Accounts Receivable          
Concentration percentage     15.00%    
Net accounts receivable | Credit concentration | DTC          
Customer Concentrations and Accounts Receivable          
Concentration percentage         12.00%
Net accounts receivable | Credit concentration | Reliable Secure Power Systems          
Customer Concentrations and Accounts Receivable          
Concentration percentage         10.00%