Investments (Detail Textuals) (USD $)	3 Months Ended				9 Months Ended				12 Months Ended
	Jan. 31, 2013		Jan. 31, 2012		Jan. 31, 2013		Jan. 31, 2012		Apr. 30, 2012
Schedule of Trading Securities and Other Trading Assets [Line Items]
Aggregate cost of equity securities available for sale	$ 4,950,000				$ 4,950,000				$ 3,749,000
Fair Value	5,152,000				5,152,000				3,881,000
Other comprehensive income (loss), available-for-sale securities adjustment, before tax, portion attributable to parent					70,000		21,000
Accumulated other comprehensive income, net of tax	131,000				131,000				85,000
Deferred taxes on unrealized gains on securities					71,000				46,000
Proceeds from maturities and sales of government debt securities							11,196,000
Realized loss on sales of fixed income securities		[1]	(18,000)	[1]		[1]	(22,000)	[1]
Equity Securities
Schedule of Trading Securities and Other Trading Assets [Line Items]
Aggregate cost of equity securities available for sale	4,950,000				4,950,000				3,749,000
Fair Value	5,152,000				5,152,000				3,881,000
Other comprehensive income unrealized holding gain loss on securities arising during period tax (expense) benefit					70,000		12,000
Deferred taxes on unrealized gains on securities					24,000		4,000
Government Debt Securities (Fixed Income Securities)
Schedule of Trading Securities and Other Trading Assets [Line Items]
Other comprehensive income unrealized holding gain loss on securities arising during period tax (expense) benefit							9,000
Deferred taxes on unrealized gains on securities							4,000
Proceeds from maturities and sales of government debt securities							11,196,000
Realized loss on sales of fixed income securities							$ (22,000)

[1] This amount was reclassified from Accumulated Other Comprehensive Income in the Consolidated Condensed Balance Sheets to the Consolidated Condensed Statements of Income.