Marketable Securities (Tables)

12 Months Ended

Apr. 30, 2021

Investments, Debt and Equity Securities [Abstract]

Available-for-sale Securities [Table Text Block]

The cost, gross unrealized gains, gross unrealized losses and fair market value of available-for-sale securities at April 30, 2021 and 2020, respectively, were as follows (in thousands):

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

	April 30, 2020
	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Market Value
Fixed income securities	$	10,081	$	495	$	(6	)	$	10,570

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, 2021
Fixed Income Securities	$	1,793	$	(52	)	$	614	$	(50	)	$	2,407	$	(102	)
April 30, 2020
Fixed Income Securities	$	380	$	(6	)	$	-	$	-		$	380	$	(6	)

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, 2021 and 2020, respectively, were as follows (in thousands):

	For the years ended April 30,
	2021		2020
Proceeds	$	2,498	$	3,539
Gross realized gains	$	28	$	-
Gross realized losses	$	-	$	(1	)

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

Maturities of fixed income securities classified as available-for-sale at April 30, 2021 were as follows (at cost, in thousands):

Current	$	3,490
Due after one year through five years		4,498
Due after five years		2,034
	$	10,022