Note I - Stock-based Compensation (Tables)

9 Months Ended

Jan. 31, 2017

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		August 10, 2026
Shares available for grant at January 31, 2017		286,000

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

	Nine Months Ended January 31,
	2017			2016
Expected term (years)		5.5			5.5
Risk-free interest rate		1.28	%		1.58	%
Volatility		36	%		34	%
Dividend yield		-			-

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

	Nine Months Ended January 31,
(Dollars in thousands)	2017		2016
Options exercised		169,500		30,750
Cash received from option exercises	$	1,675	$	400
Intrinsic value of options exercised	$	4,374	$	943