| 
           Note 6 - Stock-based Compensation (Detail) - Stock option compensation (USD $) 
        In Thousands, unless otherwise specified  | 
        6 Months Ended | |
|---|---|---|
| 
           Sep. 30, 2012 
         | 
        
           Oct. 02, 2011 
         | 
      |
| 
           Cost of Sales [Member] | Three-Month Period [Member] | Fiscal Year 2011 [Member] 
         | 
        ||
| Options Granted | $ 11 | |
| 
           Cost of Sales [Member] | Three-Month Period [Member] | Fiscal Year 2012 [Member] 
         | 
        ||
| Options Granted | 12 | 13 | 
| 
           Cost of Sales [Member] | Three-Month Period [Member] | Fiscal Year 2013 [Member] 
         | 
        ||
| Options Granted | 11 | |
| 
           Cost of Sales [Member] | Three-Month Period [Member] | Fiscal Year 2010 [Member] 
         | 
        ||
| Options Granted | 6 | |
| 
           Cost of Sales [Member] | Three-Month Period [Member] 
         | 
        ||
| Options Granted | 23 | 30 | 
| 
           Cost of Sales [Member] | Six-Month Period [Member] | Fiscal Year 2011 [Member] 
         | 
        ||
| Options Granted | 14 | 25 | 
| 
           Cost of Sales [Member] | Six-Month Period [Member] | Fiscal Year 2012 [Member] 
         | 
        ||
| Options Granted | 29 | 16 | 
| 
           Cost of Sales [Member] | Six-Month Period [Member] | Fiscal Year 2013 [Member] 
         | 
        ||
| Options Granted | 13 | |
| 
           Cost of Sales [Member] | Six-Month Period [Member] | Fiscal Year 2010 [Member] 
         | 
        ||
| Options Granted | 15 | |
| 
           Cost of Sales [Member] | Six-Month Period [Member] 
         | 
        ||
| Options Granted | 56 | 56 | 
| 
           Operating Expense [Member] | Three-Month Period [Member] | Fiscal Year 2011 [Member] 
         | 
        ||
| Options Granted | 11 | |
| 
           Operating Expense [Member] | Three-Month Period [Member] | Fiscal Year 2012 [Member] 
         | 
        ||
| Options Granted | 13 | 12 | 
| 
           Operating Expense [Member] | Three-Month Period [Member] | Fiscal Year 2013 [Member] 
         | 
        ||
| Options Granted | 12 | |
| 
           Operating Expense [Member] | Three-Month Period [Member] | Fiscal Year 2010 [Member] 
         | 
        ||
| Options Granted | 14 | |
| 
           Operating Expense [Member] | Three-Month Period [Member] 
         | 
        ||
| Options Granted | 25 | 37 | 
| 
           Operating Expense [Member] | Six-Month Period [Member] | Fiscal Year 2011 [Member] 
         | 
        ||
| Options Granted | 13 | 26 | 
| 
           Operating Expense [Member] | Six-Month Period [Member] | Fiscal Year 2012 [Member] 
         | 
        ||
| Options Granted | 29 | 15 | 
| 
           Operating Expense [Member] | Six-Month Period [Member] | Fiscal Year 2013 [Member] 
         | 
        ||
| Options Granted | 15 | |
| 
           Operating Expense [Member] | Six-Month Period [Member] | Fiscal Year 2010 [Member] 
         | 
        ||
| Options Granted | 33 | |
| 
           Operating Expense [Member] | Six-Month Period [Member] 
         | 
        ||
| Options Granted | 57 | 74 | 
| 
           Three-Month Period [Member] | Fiscal Year 2011 [Member] 
         | 
        ||
| Options Granted | 22 | |
| 
           Three-Month Period [Member] | Fiscal Year 2012 [Member] 
         | 
        ||
| Options Granted | 25 | 25 | 
| 
           Three-Month Period [Member] | Fiscal Year 2013 [Member] 
         | 
        ||
| Options Granted | 23 | |
| 
           Three-Month Period [Member] | Fiscal Year 2010 [Member] 
         | 
        ||
| Options Granted | 20 | |
| 
           Three-Month Period [Member] 
         | 
        ||
| Options Granted | 48 | 67 | 
| 
           Six-Month Period [Member] | Fiscal Year 2011 [Member] 
         | 
        ||
| Options Granted | 27 | 51 | 
| 
           Six-Month Period [Member] | Fiscal Year 2012 [Member] 
         | 
        ||
| Options Granted | 58 | 31 | 
| 
           Six-Month Period [Member] | Fiscal Year 2013 [Member] 
         | 
        ||
| Options Granted | 28 | |
| 
           Six-Month Period [Member] | Fiscal Year 2010 [Member] 
         | 
        ||
| Options Granted | 48 | |
| 
           Six-Month Period [Member] 
         | 
        ||
| Options Granted | $ 113 | $ 130 |