Condensed Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	AOCI Attributable to Parent [Member]	Total
Balance at Apr. 30, 2018	$ 9,164	$ 56,439	$ (65)	$ (1,361)	$ (915)	$ 63,262
Balance (in Shares) at Apr. 30, 2018	9,163,940			297,083
Opening BS adjustment for adoption of ASU 2014-09			484			484
Balance at May. 01, 2018	$ 9,164	56,439	419	$ (1,361)	(915)	63,746
Balance (in Shares) at May. 01, 2018	9,163,940			297,083
Balance at Apr. 30, 2018	$ 9,164	56,439	(65)	$ (1,361)	(915)	63,262
Balance (in Shares) at Apr. 30, 2018	9,163,940			297,083
Contribution of stock to 401(k) plan		50		$ 66		116
Contribution of stock to 401(k) plan (in Shares)				(14,339)
Stock-based compensation expense		121				121
Other comprehensive income, net of tax					(44)	(44)
Net income			31			31
Balance at Jul. 31, 2018	$ 9,164	56,610	450	$ (1,295)	(959)	63,970
Balance (in Shares) at Jul. 31, 2018	9,163,940			282,744
Balance at Apr. 30, 2018	$ 9,164	56,439	(65)	$ (1,361)	(915)	63,262
Balance (in Shares) at Apr. 30, 2018	9,163,940			297,083
Other comprehensive income, net of tax						(139)
Net income						153
Balance at Oct. 31, 2018	$ 9,164	56,710	572	$ (1,168)	(1,054)	64,224
Balance (in Shares) at Oct. 31, 2018	9,163,940			254,947
Balance at Jul. 31, 2018	$ 9,164	56,610	450	$ (1,295)	(959)	63,970
Balance (in Shares) at Jul. 31, 2018	9,163,940			282,744
Contribution of stock to 401(k) plan		58		$ 46		104
Contribution of stock to 401(k) plan (in Shares)				(10,089)
Stock-based compensation expense		123				123
Exercise of stock options and stock appreciation rights - net of shares tendered for exercise price		(81)		$ 81
Exercise of stock options and stock appreciation rights - net of shares tendered for exercise price (in Shares)				(17,708)
Other comprehensive income, net of tax					(95)	(95)
Net income			122			122
Balance at Oct. 31, 2018	$ 9,164	$ 56,710	$ 572	$ (1,168)	$ (1,054)	$ 64,224
Balance (in Shares) at Oct. 31, 2018	9,163,940			254,947