Note I - Stock-based Compensation (Tables)

3 Months Ended

Jul. 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 1, 2029
Shares available for grant at July 31, 2019		273,500

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

	Three Months Ended July 31,
	2019			2018
Expected term (years)		5.5			5.5
Risk-free interest rate		2.28	%		2.78	%
Volatility		39	%		36	%
Dividend yield		-			-

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

	Three Months Ended July 31,
(Dollars in thousands)	2019		2018
Options exercised		21,500		162,250
Cash received from option exercises	$	80	$	3,259
Intrinsic value of options exercised	$	1,284	$	5,508