Consolidated Statement of Stockholder's Equity (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Jul. 31, 2013
Cash dividends declared, per share	$ 0.10
Stock options exercised, shares	13,500
Stock options granted, shares	10,000
Treasury stock, shares	6,598
Additional Paid-in Capital [Member]
Stock options exercised, shares	13,500
Stock options granted, shares	10,000
Treasury Stock [Member]
Stock options exercised, shares	13,500
Treasury stock, shares	6,598
Retained Earnings [Member]
Cash dividends declared, per share	$ 0.10