Marketable Securities (Tables)

12 Months Ended

Apr. 30, 2022

Investments, Debt and Equity Securities [Abstract]

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

The cost, gross unrealized gains, gross unrealized losses and fair market value of available-for-sale securities at April 30, 2022 and 2021, respectively, were as follows (in thousands):

	April 30, 2022
	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Market Value
Fixed income securities	$	10,403	$	23	$	(462	)	$	9,964

	April 30, 2021
	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Market Value
Fixed income securities	$	10,022	$	393	$	(102	)	$	10,313

Unrealized Gain (Loss) on Investments [Table Text Block]

The following table presents the fair value and unrealized losses, aggregated by investment type and length of time that individual securities have been in a continuous unrealized loss position (in thousands):

	Less than 12 months					12 Months or more					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
April 30, 2022
Fixed Income Securities	$	2,349	$	(146	)	$	5,573	$	(316	)	$	7,922	$	(462	)
April 30, 2021
Fixed Income Securities	$	1,793	$	(52	)	$	614	$	(50	)	$	2,407	$	(102	)

Realized Gain (Loss) on Investments [Table Text Block]

Proceeds from the sale or redemption of available-for-sale securities and the resulting gross realized gains and losses included in the determination of net income (loss) for the years ended April 30, 2022 and 2021, respectively, were as follows (in thousands):

	For the years ended April 30,
	2022		2021
Proceeds	$	2,089	$	2,498
Gross realized gains	$	6	$	28
Gross realized losses	$	-	$	-

Fair Value, by Balance Sheet Grouping [Table Text Block]

Maturities of fixed income securities classified as available-for-sale at April 30, 2022 were as follows (at cost, in thousands):

Current	$	3,025
Due after one year through five years		5,694
Due after five years		1,684
	$	10,403