| Note 8 - Stock-based Compensation (Tables)
 | 12 Months Ended | 
| Mar. 29, 2020 | 
|---|
| Notes Tables |  | 
| Share-based Payment Arrangement, Option, Activity [Table Text Block] |   |  |  |  |  |   |  |  |  |  |  |  |  |   |  |  |  |  |  |   |   |   |  |  |  |  |   |   |   |   |  |  |  |  |  |  |  |  |  |  |  |  |  |   |  |  |  |  |  |  |  |  |  |  |  |  |  |   |  |  |  |  |  |  |  |  |  |  |  |  |  |   | Outstanding at Beginning of Period |  | $ | 7.45 |  |  |  | 457,500 |  |  | $ | 7.93 |  |  |  | 395,000 |  |   | Granted |  |  | 4.76 |  |  |  | 125,000 |  |  |  | 5.90 |  |  |  | 110,000 |  |   | Exercised |  |  | 6.20 |  |  |  | (10,000 | ) |  |  | - |  |  |  | - |  |   | Forfeited |  |  | 7.07 |  |  |  | (55,000 | ) |  |  | 7.83 |  |  |  | (47,500 | ) |   | Outstanding at End of Period |  |  | 6.86 |  |  |  | 517,500 |  |  |  | 7.45 |  |  |  | 457,500 |  |   | Exercisable at End of Period |  |  | 7.74 |  |  |  | 347,500 |  |  |  | 8.03 |  |  |  | 292,500 |  |  | 
| Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] |   |  |  |  |  |   |  |  |  |  |  |  |  |   | Number of options issued |  |  | 125,000 |  |  |  | 110,000 |  |   | Grant date |  |   | June 13, 2019 |  |  |   | June 13, 2018 |  |   | Dividend yield |  |  | 6.72 | % |  |  | 5.42 | % |   | Expected volatility |  |  | 25.00 | % |  |  | 25.00 | % |   | Risk free interest rate |  |  | 1.81 | % |  |  | 2.78 | % |   | Contractual term (years) |  |  | 10.00 |  |  |  | 10.00 |  |   | Expected term (years) |  |  | 4.00 |  |  |  | 4.00 |  |   | Forfeiture rate |  |  | 5.00 | % |  |  | 5.00 | % |   | Exercise price (grant-date closing price) per option |  | $ | 4.76 |  |  | $ | 5.90 |  |   | Fair value per option |  | $ | 0.39 |  |  | $ | 0.49 |  |  | 
| Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] |   |  |  | Fiscal Year Ended March 29, 2020 |  |   |  |  |  |  |  |  |  |  |   |   |   |   |  |  |  |  |  |  |  |  |  |  |   | Options Granted in Fiscal Year |  |  |  |  |  |  |  |  |  |   | 2018 |  | $ | 5 |  |  | $ | 1 |  |  | $ | 6 |  |   | 2019 |  |  | 10 |  |  |  | 8 |  |  |  | 18 |  |   | 2020 |  |  | 7 |  |  |  | 11 |  |  |  | 18 |  |   |  |  |  |  |  |  |  |  |  |  |  |  |  |   | Total stock option compensation |  | $ | 22 |  |  | $ | 20 |  |  | $ | 42 |  |   |  |  | Fiscal Year Ended March 31, 2019 |  |   |  |  |  |  |  |  |  |  |   |   |   |   |  |  |  |  |  |  |  |  |  |  |   | Options Granted in Fiscal Year |  |  |  |  |  |  |  |  |  |   | 2017 |  | $ | 6 |  |  | $ | 4 |  |  | $ | 10 |  |   | 2018 |  |  | 17 |  |  |  | 26 |  |  |  | 43 |  |   | 2019 |  |  | 7 |  |  |  | 13 |  |  |  | 20 |  |   |  |  |  |  |  |  |  |  |  |  |  |  |  |   | Total stock option compensation |  | $ | 30 |  |  | $ | 43 |  |  | $ | 73 |  |  | 
| Share-based Payment Arrangement, Option, Exercise Price Range [Table Text Block] |   |  |   |   |   |  |   |   |   |  |   |   |   |  |  |  |  |   |   |   |  |  |  |   |  |  |  |   |  |   |  |   |  |  |  |  |  |  |  |   |  |   |  |  |  |   |  |  |  |   |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |   |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |   |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |   | $4.00 | - | 4.99 |  |  |  | 130,000 |  |  |  | 8.90 |  |  | $ | 4.76 |  |  |  | 5,000 |  |  | $ | 4.81 |  |   | $5.00 | - | 5.99 |  |  |  | 105,000 |  |  |  | 7.06 |  |  | $ | 5.81 |  |  |  | 60,000 |  |  | $ | 5.74 |  |   | $6.00 | - | 6.99 |  |  |  | 25,000 |  |  |  | 4.11 |  |  | $ | 6.21 |  |  |  | 25,000 |  |  | $ | 6.21 |  |   | $7.00 | - | 7.99 |  |  |  | 132,500 |  |  |  | 6.02 |  |  | $ | 7.81 |  |  |  | 132,500 |  |  | $ | 7.81 |  |   | $8.00 | - | 8.99 |  |  |  | 55,000 |  |  |  | 5.20 |  |  | $ | 8.38 |  |  |  | 55,000 |  |  | $ | 8.38 |  |   | $9.00 | - | 9.99 |  |  |  | 70,000 |  |  |  | 6.19 |  |  | $ | 9.60 |  |  |  | 70,000 |  |  | $ | 9.60 |  |   |  |   |   |  |  |  | 517,500 |  |  |  | 6.80 |  |  | $ | 6.86 |  |  |  | 347,500 |  |  | $ | 7.74 |  |  | 
| Share-based Payment Arrangement, Nonemployee Director Award Plan, Activity [Table Text Block] |   |  |  |  |  |  |  |  |  |  |   |  |  |  |  |  |  |  |  |  |   |  |  | 46,512 |  |  | $ | 5.16 |  |  |  |  |   |  |  | 28,000 |  |  |  | 5.43 |  |  |  |  |   |  |  | 28,000 |  |  |  | 5.50 |  |  |  |  |   |  |  | 28,000 |  |  |  | 10.08 |  |  |  |  |  | 
| Schedule of Nonvested Share Activity [Table Text Block] |   |  |  | Fiscal Year Ended March 29, 2020 |  |   |  |  |   |   |   |  |  |  |  |  |  |   | Stock Granted in Fiscal Year |  |  |  |  |  |  |  |  |  |   | 2018 |  | $ | - |  |  | $ | 26 |  |  | $ | 26 |  |   | 2019 |  |  | 73 |  |  |  | 76 |  |  |  | 149 |  |   | 2020 |  |  | - |  |  |  | 80 |  |  |  | 80 |  |   |  |  |  |  |  |  |  |  |  |  |  |  |  |   | Total stock grant compensation |  | $ | 73 |  |  | $ | 182 |  |  | $ | 255 |  |   |  |  | Fiscal Year Ended March 31, 2019 |  |   |  |  |   |   |   |  |  |  |  |  |  |   | Stock Granted in Fiscal Year |  |  |  |  |  |  |  |  |  |   | 2017 |  | $ | - |  |  | $ | 47 |  |  | $ | 47 |  |   | 2018 |  |  | 116 |  |  |  | 77 |  |  |  | 193 |  |   | 2019 |  |  | 13 |  |  |  | 51 |  |  |  | 64 |  |   |  |  |  |  |  |  |  |  |  |  |  |  |  |   | Total stock grant compensation |  | $ | 129 |  |  | $ | 175 |  |  | $ | 304 |  |  | 
| Performance Shares [Member] |  | 
| Notes Tables |  | 
| Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block] |   |  |  |   |   |   |  | 
Vesting of shares during the  fiscal years  ended |  |   |  |  |   |   |   |  |  |  |  |  |  |   |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |   |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |   | 2017 |  |  | 41,205 |  |  |  | - |  |  | $ | - |  |  | $ | - |  |  |  | 20,601 |  |  | $ | 122,000 |  |  | $ | 39,000 |  |   | 2018 |  |  | 42,250 |  |  |  | 21,125 |  |  |  | 109,000 |  |  |  | 17,000 |  |  |  | 21,125 |  |  |  | 124,000 |  |  |  | 56,000 |  |   |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |   |  |  |  |  |  |  | 21,125 |  |  | $ | 109,000 |  |  | $ | 17,000 |  |  |  | 41,726 |  |  | $ | 246,000 |  |  | $ | 95,000 |  |  |