Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Total
Balance (in shares) at Apr. 30, 2015	10,000,000		(190,504)
Balance at Apr. 30, 2015	$ 1,000	$ 991	$ (2,244)	$ 34,587	$ 105	$ 34,439
Net income				7,291		7,291
Change in unrealized gains on securities, net of taxes					20	$ 20
Purchase of treasury stock (in shares)			(52,907)			(52,907)	[1]
Purchase of treasury stock			$ (796)			$ (796)	[1]
Dividends declared				(6,354)		(6,354)
Balance (in shares) at Apr. 30, 2016	10,000,000		(243,411)
Balance at Apr. 30, 2016	$ 1,000	991	$ (3,040)	35,524	125	34,600
Net income				10,367		10,367
Change in unrealized gains on securities, net of taxes					333	$ 333
Purchase of treasury stock (in shares)			(44,924)			(44,924)	[1]
Purchase of treasury stock			$ (741)			$ (741)	[1]
Dividends declared				(6,705)		(6,705)
Balance (in shares) at Apr. 30, 2017	10,000,000		(288,335)
Balance at Apr. 30, 2017	$ 1,000	991	$ (3,781)	39,186	458	37,854
Net income				14,738		14,738
Change in unrealized gains on securities, net of taxes					325	$ 325
Purchase of treasury stock (in shares)			(20,045)			(20,045)	[1]
Purchase of treasury stock			$ (354)			$ (354)	[1]
Dividends declared				(9,022)		(9,022)
Balance (in shares) at Apr. 30, 2018	10,000,000		(308,380)
Balance at Apr. 30, 2018	$ 1,000	$ 991	$ (4,135)	$ 44,902	$ 783	$ 43,541

[1] Were acquired during the $3 million repurchase program authorized in September 2012.