1. THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - PP&E (Details) $ in Thousands	12 Months Ended
	Mar. 31, 2020 USD ($) segment	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)
Property and equipment, net:
Impairment losses on long-lived equipment	$ 0	$ 0	$ 0
Inventories
Minimum months to determine excess inventory	12 months
Inventory write-downs	$ 343	1,195	1,561
Segments
Number of operating segments | segment	1
Accounting for stock-based compensation
Expected life	5 years
Dividend yield (as a percent)	0.00%
Comprehensive income (loss)	$ (10,229)	268	$ (4,595)
Income taxes
Valuation allowance	$ 9,389	$ 6,700
Minimum
Property and equipment, net:
Useful life, intangible assets	5 years
Maximum
Property and equipment, net:
Useful life, intangible assets	15 years
Software | Minimum
Property and equipment, net:
Useful life, property and equipment	3 years
Software | Maximum
Property and equipment, net:
Useful life, property and equipment	5 years
Computer and other equipment | Minimum
Property and equipment, net:
Useful life, property and equipment	5 years
Computer and other equipment | Maximum
Property and equipment, net:
Useful life, property and equipment	10 years
Building and building improvements | Minimum
Property and equipment, net:
Useful life, property and equipment	10 years
Building and building improvements | Maximum
Property and equipment, net:
Useful life, property and equipment	25 years
Furniture and fixtures
Property and equipment, net:
Useful life, property and equipment	7 years