Investments (Detail Textuals) (USD $)	3 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Apr. 30, 2014
Schedule of Available-for-sale Securities [Line Items]
Aggregate cost of equity securities available for sale	$ 8,847,000		$ 8,847,000
Fair value of equity securities	9,095,000		9,226,000
Increase (decreases) in gross unrealized gains on equity securities classified as available-for-sale	(131,000)	(4,000)
Equity Securities
Schedule of Available-for-sale Securities [Line Items]
Increase (decreases) in gross unrealized gains on equity securities classified as available-for-sale	(131,000)	(4,000)
Deferred taxes on unrealized gains on securities	46,000	1,000
Accumulated other comprehensive income, net of tax	248,000		379,000
Deferred taxes on accumulated other comprehensive income	$ 87,000		$ 133,000