Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jul. 31, 2015	Apr. 30, 2015
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 1.00	$ 1.00
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	0	0
Common stock, no par value
Common stock, shares authorized	40,000,000	40,000,000
Common stock, shares issued	16,263,209	16,079,671
Common stock, shares outstanding	16,263,209	16,079,671