| Note 14 – Changes in Accumulated Other Comprehensive Loss: The changes in accumulated other comprehensive loss by component for fiscal 2021 and fiscal 2020 are:   
|   |   | Pension and Other Postretirement Benefit Items |   |   | Foreign Currency Items |   |   | Total |   |  
| Balance at April 1, 2019 |   | $ | (8,947 | ) |   | $ | 114 |   |   | $ | (8,833 | ) |  
| Other comprehensive loss before reclassifications |   |   | (1,296 | ) |   |   | (198 | ) |   |   | (1,494 | ) |  
| Amounts reclassified from accumulated other   comprehensive loss |   |   | 771 |   |   |   | — |   |   |   | 771 |   |  
| Net current-period other comprehensive loss |   |   | (525 | ) |   |   | (198 | ) |   |   | (723 | ) |  
| Balance at March 31, 2020 |   |   | (9,472 | ) |   |   | (84 | ) |   |   | (9,556 | ) |  
| Other comprehensive income before reclassifications |   |   | 946 |   |   |   | 385 |   |   |   | 1,331 |   |  
| Amounts reclassified from accumulated other   comprehensive loss |   |   | 828 |   |   |   | — |   |   |   | 828 |   |  
| Net current-period other comprehensive income |   |   | 1,774 |   |   |   | 385 |   |   |   | 2,159 |   |  
| Balance at March 31, 2021 |   | $ | (7,698 | ) |   | $ | 301 |   |   | $ | (7,397 | ) |          The reclassifications out of accumulated other comprehensive loss by component are as follows: Year ended March 31, 2021   
| Details about Accumulated Other Comprehensive Loss Components |   | Amounts Reclassified from Accumulated Other Comprehensive Loss |   |   |   | Affected Line Item in the Consolidated Statements of Operations |  
| Pension and other postretirement benefit items: |   |   |   |   |   |   |   |  
| Amortization of unrecognized prior service    benefit |   | $ | — |   |   |   |   |  
| Amortization of actuarial loss |   |   | (1,066 | ) | (1) |   |   |  
|   |   |   | (1,066 | ) |   |   | Income before provision for income taxes |  
|   |   |   | (238 | ) |   |   | Provision for income taxes |  
|   |   | $ | (828 | ) |   |   | Net income |    Year ended March 31, 2020   
| Details about Accumulated Other Comprehensive Loss Components |   | Amounts Reclassified from Accumulated Other Comprehensive Loss |   |   |   | Affected Line Item in the Consolidated Statements of Operations |  
| Pension and other postretirement benefit items: |   |   |   |   |   |   |   |  
| Amortization of unrecognized prior service    benefit |   | $ | — |   |   |   |   |  
| Amortization of actuarial loss |   |   | (997 | ) | (1) |   |   |  
|   |   |   | (997 | ) |   |   | Income before provision for income taxes |  
|   |   |   | (226 | ) |   |   | Provision for income taxes |  
|   |   | $ | (771 | ) |   |   | Net income |    
| (1) | These accumulated other comprehensive loss components are included within the computation of net periodic pension and other postretirement benefit costs.  See Note 12. |  |