Annual report pursuant to Section 13 and 15(d)

Organization and Summary of Significant Accounting Policies (Details)

v3.22.1
Organization and Summary of Significant Accounting Policies (Details)
 12 Months Ended
Mar. 31, 2022
USD ($)
Geographic_Region
segment
Mar. 31, 2021
USD ($)
Mar. 31, 2020
USD ($)
Business Acquisition [Line Items]      
Entity Wide Disclosure On Geographic Areas, Revenue From External Customers Attributed To Foreign Countries, Percentage 57.00% 65.00% 59.00%
Disclosure on Geographic Areas, Long-Lived Assets in Foreign Countries 62.00% 65.00%  
Number of reportable segments | segment 4    
Number of Countries in which Entity Operates | Geographic_Region 4    
Billed contracts receivable $ 5,352,000 $ 6,214,000  
Accounts receivable, allowance for doubtful accounts (in dollars) 2,177,000 2,074,000  
Goodwill impaired 0 0  
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Amortization of Deferred Charges 596,000 1,525,000 $ 1,885,000
Research and Development Expense 6,436,000 7,466,000 8,378,000
Inventories      
Business Acquisition [Line Items]      
Emergency Wage Subsidies 0 430,000  
Cost of Sales      
Business Acquisition [Line Items]      
Emergency Wage Subsidy 1,449,000 4,236,000  
Selling, General and Administrative Expenses      
Business Acquisition [Line Items]      
Emergency Wage Subsidy $ 504,000 2,176,000  
Buildings and improvements | Minimum      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Property, plant and equipment, estimated useful lives 10 years    
Buildings and improvements | Maximum      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Property, plant and equipment, estimated useful lives 30 years    
Machinery and equipment | Minimum      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Property, plant and equipment, estimated useful lives 3 years    
Machinery and equipment | Maximum      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Property, plant and equipment, estimated useful lives 25 years    
Office furniture and equipment | Minimum      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Property, plant and equipment, estimated useful lives 3 years    
Office furniture and equipment | Maximum      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Property, plant and equipment, estimated useful lives 10 years    
Internally developed software | Minimum      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Property, plant and equipment, estimated useful lives 5 years    
Internally developed software | Maximum      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Property, plant and equipment, estimated useful lives 7 years    
Allowance for Doubtful Accounts      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance, beginning of period $ 2,074,000 834,000 987,000
Additions to reserve 683,000 1,466,000 674,000
Write-off of uncollectible accounts (580,000) (226,000) (827,000)
Balance, end of period $ 2,177,000 $ 2,074,000 $ 834,000