| 7. Stock-Based Compensation (Details-Stock-based compensation) - USD ($) | 3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
| Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2018 | Dec. 31, 2017 | |
| Total stock-based compensation | $ 402,000 | $ 665,000 | $ 1,275,000 | $ 1,530,000 | 
| Cost of revenues [Member] | ||||
| Total stock-based compensation | 24,000 | 43,000 | 89,000 | 136,000 | 
| Research and development [Member] | ||||
| Total stock-based compensation | 26,000 | 38,000 | 87,000 | 128,000 | 
| Selling, general and administrative [Member] | ||||
| Total stock-based compensation | $ 352,000 | $ 584,000 | $ 1,099,000 | $ 1,266,000 | 
| X | ||||||||||
| 
- Definition Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
 | 
| X | ||||||||||
| 
- Details 
 | 
| X | ||||||||||
| 
- Details 
 | 
| X | ||||||||||
| 
- Details 
 |