Note 4 - Property, Plant and Equipment
 12 Months Ended
Mar. 31, 2017
Notes to Financial Statements  
Property, Plant and Equipment Disclosure [Text Block]
Note
4.
Property, Plant and Equipment
 
Property, plant and equipment consist of the following (in thousands):
 
 
 
March 31,
 
 
 
201
7
 
 
201
6
 
Land
   $
1,614
    $
1,614
 
Buildings
    
4,726
      
4,723
  
Manufacturing equipment
    
8,861
      
7,802
  
Computer equipment
    
4,143
      
2,649
  
Construction in progress
    
15,882
      
7,333
  
Other
    
1,220
      
685
  
     
36,446
      
24,806
  
Less accumulated depreciation
    
(10,444
 )    
(8,178
 )
    $
26,002
    $
16,628
 
 
Depreciation expense for the years ended
March 31, 2017,
2016
and
2015
was
$2,287,000,
$1,387,000
and
$981,000,
respectively.