Annual report pursuant to Section 13 and 15(d)

Commitments and Contingencies (Details)

v3.20.1
Commitments and Contingencies (Details) - USD ($)
12 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]      
Operating Leases, Rent Expense $ 3,900    
Totaled arrangements under letter of credit guarantees and performance bonds securing performance obligations 10,416,000    
Guarantee obligations secured by cash deposits 2,769,000    
Guarantee obligations represented by a reduction of the available amount of the company's short term and long term revolving lines of credit 3,988,000    
Cash deposits pledged as collateral on performance bonds and letters of credit 2,769,000 $ 2,439,000  
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]      
Service fee expense 2,679,000 3,809,000 $ 3,439,000
Purchase Obligation, Fiscal Year Maturity [Abstract]      
2020 1,007,000    
2021 93,000    
Purchase Obligation 1,100,000    
Changes in the product liability      
Balance at beginning of period 365,000 300,000 300,000
Provision for warranties issued 160,000 300,000 281,000
Settlements (48,000) (235,000) (281,000)
Balance at end of period $ 477,000 $ 365,000 $ 300,000