XML 37 R23.htm IDEA: XBRL DOCUMENT v3.19.1
Note 3 - Valuation and Qualifying Accounts (Tables)
 12 Months Ended
Mar. 31, 2019
Notes Tables  
Valuation and Qualifying Accounts [Table Text Block]
   
Year Ended March 31,
  
   
2019
   
2018
   
2017
 
                         
Allowance for doubtful accounts:
                        
Balance at beginning of period
   $
35
     $
27
     $
13
  
Provision for doubtful accounts
    
85
      
112
      
421
  
Write-off of uncollectible accounts receivable
    
(81
 )    
(104
 )    
(407
 )
                         
Balance at end of year
   $
39
     $
35
     $
27