Note 3 - Fair Value of Financial Instruments (Tables)

12 Months Ended

Mar. 31, 2022

Notes Tables

Investments Classified by Contractual Maturity Date [Table Text Block]

Total		<1 Year		1–3 Years		3–5 Years
$	51,910,887	$	27,596,676	$	24,314,211	$	-

Fair Value, Assets Measured on Recurring Basis [Table Text Block]

	As of March 31, 2022						As of March 31, 2021
	Level 1		Level 2		Total		Level 1		Level 2		Total
Money market funds	$	6,756,993	$	-	$	6,756,993	$	10,143,196	$	-	$	10,143,196
Corporate bonds		-		45,153,894		45,153,894		-		54,717,626		54,717,626
Total	$	6,756,993	$	45,153,894	$	51,910,887	$	10,143,196	$	54,717,626	$	64,860,822

Schedule of Available-for-Sale Securities Reconciliation [Table Text Block]

	As of March 31, 2022									As of March 31, 2021
	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses			Estimated Fair Value		Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses			Estimated Fair Value
Money market funds	$	6,756,993	$	-	$	-		$	6,756,993	$	10,143,196	$	-	$	-		$	10,143,196
Corporate bonds		45,561,114		230,085		(637,305	)		45,153,894		53,308,105		1,570,195		(160,674	)		54,717,626
Total	$	52,318,107	$	230,085	$	(637,305	)	$	51,910,887	$	63,451,301	$	1,570,195	$	(160,674	)	$	64,860,822

Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block]

	Less Than 12 Months					12 Months or Greater					Total
	Estimated Fair Value		Gross Unrealized Holding Losses			Estimated Fair Value		Gross Unrealized Holding Losses			Estimated Fair Value		Gross Unrealized Holding Losses
As of March 31, 2022
Corporate bonds	$	6,306,750	$	(23,727	)	$	9,738,338	$	(613,578	)	$	16,045,088	$	(637,305	)
Total	$	6,306,750	$	(23,727	)	$	9,738,338	$	(613,578	)	$	16,045,088	$	(637,305	)
As of March 31, 2021
Corporate bonds	$	10,322,539	$	(160,674	)	$	-	$	-		$	10,322,539	$	(160,674	)
Total	$	10,322,539	$	(160,674	)	$	-	$	-		$	10,322,539	$	(160,674	)