Investments (Detail Textuals) (USD $)	12 Months Ended
	Apr. 30, 2013		Apr. 30, 2012		Apr. 30, 2011
Schedule of Available-for-sale Securities [Line Items]
Aggregate cost of equity securities available for sale	$ 6,295,000		$ 3,749,000
Fair value of equity securities	6,682,000		3,881,000
Other comprehensive income (loss), available-for-sale securities adjustment, before tax, portion attributable to parent	255,000		35,000		100,000
Proceeds from maturities and sales of government debt securities			11,196,000		38,021,000
Realized loss on sales of fixed income securities		[1]	(11,000)	[1]	(63,000)	[1]
Accumulated other comprehensive income, net of tax	251,000		85,000
Equity Securities
Schedule of Available-for-sale Securities [Line Items]
Aggregate cost of equity securities available for sale	6,295,000		3,749,000
Fair value of equity securities	6,682,000		3,881,000
Increase in gross unrealized gains on equity securities	255,000		24,000		106,000
Deferred taxes on unrealized gains on securities	89,000		9,000		37,000
Proceeds from maturities and sales of government debt securities			89,000
Realized loss on sales of fixed income securities	11,000
Government Debt Securities (Fixed Income Securities)
Schedule of Available-for-sale Securities [Line Items]
Deferred taxes on unrealized gains on securities	136,000		46,000
Proceeds from maturities and sales of government debt securities			11,196,000		38,021,000
Realized loss on sales of fixed income securities			22,000		68,000
Accumulated other comprehensive income, net of tax	387,000		131,000
Interest income recorded net of bond premium amortization					$ 14,000

[1] These amounts were reclassified from Accumulated Other Comprehensive Income in the Consolidated Balance Sheets to the Consolidated Statements of Income.