Borrowings (Schedule Of Borrowings) (Details) (USD $) In Thousands, unless otherwise specified				6 Months Ended			6 Months Ended			6 Months Ended
	Oct. 31, 2012	Apr. 30, 2012	Oct. 31, 2011	Oct. 31, 2012 Senior Notes, 7.875% Due January 2013 [Member]	Apr. 30, 2012 Senior Notes, 7.875% Due January 2013 [Member]	Oct. 31, 2011 Senior Notes, 7.875% Due January 2013 [Member]	Oct. 31, 2012 Senior Notes, 5.125%, Due October 2014 [Member]	Apr. 30, 2012 Senior Notes, 5.125%, Due October 2014 [Member]	Oct. 31, 2011 Senior Notes, 5.125%, Due October 2014 [Member]	Oct. 31, 2012 Senior Notes, 5.500%, Due November 2022 [Member]	Oct. 25, 2012 Senior Notes, 5.500%, Due November 2022 [Member]	Oct. 31, 2012 Other [Member]	Apr. 30, 2012 Other [Member]	Oct. 31, 2011 Other [Member]
Debt Instrument [Line Items]
Commercial paper outstanding			$ 39,990
Debt, Long-term and Short-term, Combined Amount, Total	1,506,803	1,040,549	1,039,931	599,975	599,913	599,851	399,530	399,412	399,294	497,190		10,108	41,224	40,786
Less: Current portion	(600,678)	(631,434)	(30,735)
Long-term debt	$ 906,125	$ 409,115	$ 1,009,196								$ 500,000
Long-term note, interest rate				7.875%			5.125%			5.50%
Senior notes, maturity date				Jan. 01, 2013			Oct. 01, 2014			Nov. 01, 2022