Long-Term Debt (Components Of Long-Term Debt) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended		12 Months Ended		12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2014 Senior Notes, 5.500%, Due November 2022	Oct. 25, 2012 Senior Notes, 5.500%, Due November 2022	Apr. 30, 2014 Senior Notes, 7.875%, Due January 2013	Apr. 30, 2014 Senior Notes, 5.125%, Due October 2014	Apr. 30, 2013 Senior Notes, 5.125%, Due October 2014
Debt Instrument [Line Items]
Senior Notes	$ 497,612	$ 497,330				$ 399,882	$ 399,648
Capital lease obligation, due over the next 9 years	8,980	9,702
Total long term debt	906,474	906,680		500,000
Less: Current portion	(400,637)	(722)
Long-term debt	$ 505,837	$ 905,958
Senior Notes, interest rate			5.50%		7.875%	5.125%
Senior Notes, maturity date	Jun. 01, 2012				Jan. 15, 2013	Oct. 30, 2014