Note I - Stock-based Compensation (Tables)

9 Months Ended

Jan. 31, 2019

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 8, 2028
Shares available for grant at January 31, 2019	298,500

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

	Nine Months Ended January 31,
	2019			2018
Expected term (years)		5.5			5.5
Risk-free interest rate		2.79	%		1.81	%
Volatility		36	%		36	%
Dividend yield		-			-

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

	Nine Months Ended January 31,
(Dollars in thousands)	2019		2018
Options exercised		224,500		133,000
Cash received from option exercises	$	4,373	$	1,311
Intrinsic value of options exercised	$	8,506	$	3,444