Treasury Stock and Repurchase Program (Detail Textuals) (USD $)	12 Months Ended				1 Months Ended
	Apr. 30, 2013		Apr. 30, 2012	Apr. 30, 2011	Sep. 19, 2012 September 2012 Share Repurchase Program	Jan. 20, 2011 January 2011 Share Repurchase Program	Jan. 31, 2012 Former Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Authorized repurchase amount of common stock					$ 3,000,000	$ 3,200,000
Number of treasury shares	19,953	[1]	78,500	6,719			85,219
Total average cost	$ 182,000	[1]	$ 946,000	$ 90,000			$ 1,036,000

[1] Were acquired during the new repurchase program authorized in September 2012.