Consolidated Condensed Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2016	Jan. 31, 2015
Statement Of Other Comprehensive Income [Abstract]
Net income	$ 1,913	$ 2,177	$ 6,024	$ 6,195
Other comprehensive income (loss), net of tax:
Change in unrealized gains on securities, net of taxes	(127)	(16)	(153)	(33)
Other comprehensive income (loss)	(127)	(16)	(153)	(33)
Comprehensive income	$ 1,786	$ 2,161	$ 5,871	$ 6,162