Condensed Consolidated Statements Of Operations (Parenthetical) (USD $)	3 Months Ended				6 Months Ended
	Oct. 31, 2011		Oct. 31, 2010		Oct. 31, 2011		Oct. 31, 2010
Diluted	$ 0.11	[1]	$ 0.06	[1]	$ 0.20	[1]	$ 0.11	[1]
Class A
Diluted	$ 0.11		$ 0.06		$ 0.20		$ 0.11
Class B
Diluted	$ 0.11		$ 0.06		$ 0.20		$ 0.11

[1] Basic per share amounts are the same for Class A and Class B shares. Diluted per share amounts for Class A shares are shown above. Diluted earnings per share for Class B shares under the two-class method are $0.11 and $0.06 for the three months ended October 31, 2011 and 2010 and $0.20 and $0.11 for the six months ended October 31, 2011 and 2010, respectively. See Note D to the Condensed Consolidated Financial Statements.