Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Apr. 30, 2019	Apr. 30, 2018
Revenues	$ 49,509	$ 39,407
Cost of revenues	33,720	34,244
Gross profit	15,789	5,163
Selling and administrative expenses	12,100	10,608
Research and development expenses	6,506	6,950
Income (loss) from operations	(2,817)	(12,395)
Other income (expense):
Investment income	293	1,268
Interest expense	(83)	(79)
Other income/(expense), net	134	(69)
Loss before provision for income taxes	(2,473)	(11,275)
Provision for income taxes	56	11,176
Net loss from continuing operations	(2,529)	(22,451)
Loss from discontinued operations, net of tax	0	(967)
Loss on sale of discontinued operations	0	(359)
Total loss from discontinued operations	0	(1,326)
Net loss	$ (2,529)	$ (23,777)
Net loss per common share:
Basic and diluted loss from continuing operations (in Dollars per share)	$ (0.28)	$ (2.54)
Basic and diluted loss from discontinued operations (in Dollars per share)	0	(0.15)
Basic and diluted loss per share (in Dollars per share)	$ (0.28)	$ (2.69)
Weighted average number of shares outstanding:
Basic and diluted (in Shares)	8,916	8,841
Consolidated Statements of Comprehensive Loss
Net loss	$ (2,529)	$ (23,777)
Other comprehensive income (loss):
Foreign currency translation adjustment	790	(1,904)
Unrealized gain (loss) on marketable securities:
Change in market value of marketable securities before reclassification, net of tax of $(1) and ($360), respectively	173	(507)
Reclassification adjustment for realized gains included in net income, net of tax of $1 and $262, respectively	(2)	(785)
Total unrealized gain (loss) on marketable securities, net of tax	171	(1,292)
Total other comprehensive income (loss)	961	(3,196)
Comprehensive loss	$ (1,568)	$ (26,973)