Note I - Stock-based Compensation (Tables)

9 Months Ended

Jan. 31, 2021

Notes Tables

Stock Option Plan Comparison [Table Text Block]

	Restated Option Plan
Minimum exercise price as a percentage of fair market value at date of grant		100%
Last expiration date for outstanding options	May 1, 2030
Shares available for grant at January 31, 2021		245,000

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	Nine Months Ended January 31,
	2021			2020
Expected term (years)		5.5			5.5
Risk-free interest rate		0.36	%		1.75	%
Volatility		50	%		39	%
Dividend yield		-			-

Schedule of Share-based Compensation, Stock Options, Exercises [Table Text Block]

	Nine Months Ended January 31,
(Dollars in thousands)	2021		2020
Options exercised		107,000		112,250
Cash received from option exercises	$	4,731	$	2,849
Intrinsic value of options exercised	$	4,868	$	6,861