Note 5 - Fair Value of Financial Instruments - Investment Securities With Unrealized Losses (Details) - USD ($)	Sep. 30, 2021	Mar. 31, 2021
Fair market value, less than 12 months	$ 10,306,776	$ 10,322,539
Gross unrealized losses, less than 12 months	(110,789)	(160,674)
Fair market value, 12 months or greater	0	0
Gross unrealized losses, 12 months or greater	0	0
Total fair market value	10,306,776	10,322,539
Total gross unrealized losses	(110,789)	(160,674)
Corporate Bond Securities [Member]
Fair market value, less than 12 months	10,306,776	10,322,539
Gross unrealized losses, less than 12 months	(110,789)	(160,674)
Fair market value, 12 months or greater	0	0
Gross unrealized losses, 12 months or greater	0	0
Total fair market value	10,306,776	10,322,539
Total gross unrealized losses	$ (110,789)	$ (160,674)

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 30
-Section 50
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-Publisher FASB
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Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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