Consolidated Condensed Statements of Comprehensive Income (unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2013	Jan. 31, 2012
Statement Of Other Comprehensive Income [Abstract]
Net income	$ 1,747	$ 1,844	$ 5,095	$ 5,835
Other comprehensive income, net of tax:
Change in unrealized gains on securities, net of taxes	19	43	46	13
Other comprehensive income	19	43	46	13
Comprehensive income	$ 1,766	$ 1,887	$ 5,141	$ 5,848