Investments (Detail Textuals) (USD $)	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Schedule of Available-for-sale Securities [Line Items]
Aggregate cost of equity securities available for sale	$ 8,847,000	$ 6,295,000
Fair value of equity securities	9,226,000	6,682,000
Realized loss on sales of fixed income securities			(11,000)
Increase (decrease) in gross unrealized gains on equity securities classified as available-for-sale	(8,000)	256,000	35,000
Proceeds from maturities and sales of government debt securities			11,196,000
Accumulated other comprehensive income, net of tax	246,000	251,000
Equity Securities
Schedule of Available-for-sale Securities [Line Items]
Aggregate cost of equity securities available for sale	8,847,000	6,295,000
Fair value of equity securities	9,226,000	6,682,000
Realized loss on sales of fixed income securities	36,000		11,000
Increase (decrease) in gross unrealized gains on equity securities classified as available-for-sale	(8,000)	256,000	24,000
Deferred taxes on unrealized gains on securities	3,000	90,000	9,000
Proceeds from maturities and sales of government debt securities			89,000
Government Debt Securities (Fixed Income Securities)
Schedule of Available-for-sale Securities [Line Items]
Realized loss on sales of fixed income securities			22,000
Deferred taxes on unrealized gains on securities	134,000	136,000
Proceeds from maturities and sales of government debt securities			11,196,000
Accumulated other comprehensive income, net of tax	$ 380,000	$ 387,000