8. Marketable Securities (Tables)

12 Months Ended

Apr. 30, 2019

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, 2019 and 2018, respectively, were as follows (in thousands):

	April 30, 2019
			Gross		Gross			Fair
			Unrealized		Unrealized			Market
	Cost		Gains		Losses			Value
Fixed income securities	$	8,152	$	71	$	(24	)	$	8,199

	April 30, 2018
			Gross		Gross			Fair
			Unrealized		Unrealized			Market
	Cost		Gains		Losses			Value
Fixed income securities	$	6,274	$	10	$	(135	)	$	6,149

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		Unrealized			Fair		Unrealized			Fair		Unrealized
	Value		Losses			Value		Losses			Value		Losses
April 30, 2019
Fixed income securities	$	995	$	(4	)	$	3,349	$	(20	)	$	4,344	$	(24	)
April 30, 2018
Fixed income securities	$	5,334	$	(135	)	$	-	$	-		$	5,334	$	(135	)

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 loss for the years ended April 30, 2019 and 2018, respectively, were as follows (in thousands):

	For the years ended April 30,
	2019		2018
Proceeds	$	1,812	$	6,477
Gross realized gains	$	3	$	1,317
Gross realized losses	$	-	$	(270	)

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

Maturities of fixed income securities classified as available-for-sale at April 30, 2019 were as follows (at cost, in thousands):

Current	$	998
Due after one year through five years		4,350
Due after five years through ten years		2,804
	$	8,152