Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended					6 Months Ended		12 Months Ended
	Oct. 31, 2022	Jul. 31, 2022		Oct. 31, 2021	Jul. 31, 2021	Oct. 31, 2022	Oct. 31, 2021	Apr. 30, 2022	Apr. 30, 2021
Cash flows from operating activities:
Net loss	$ (2,314)	$ (3,117)		$ 497	$ (1,575)	$ (5,431)	$ (1,078)
Non-cash charges to earnings						1,209	1,765
Net changes in operating assets and liabilities						3,756	974
Net cash (used in) provided by operating activities			[1]			(466)	1,661	$ 4,036	$ 12,157
Cash flows from investing activities:
Proceeds on redemption of marketable securities						1,137	1,427
Purchase of marketable securities						(1,383)	(1,164)
Purchase of property, plant, and equipment, and other assets						(729)	(1,108)
Net cash used in investing activities						(975)	(845)
Net (decrease) increase in cash and cash equivalents						(1,441)	816
Cash and cash equivalents at beginning of period		$ 11,561			$ 9,807	11,561	9,807	9,807
Cash and cash equivalents at end of period	$ 10,120			$ 10,623		10,120	10,623	$ 11,561	$ 9,807
Supplemental disclosures of cash flow information:
Interest						36	40
Income Taxes						0	15
Income Taxes						$ 176	$ 0

[1] No effect on the Company's quarterly report for the period ended July 31, 2022 as the Statement of Cash Flows are condensed