CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - UNAUDITED (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jul. 31, 2012	Jul. 31, 2011
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - UNAUDITED [Abstract]
Net Income	$ 36,117	$ 50,796
Other Comprehensive Income /(Loss):
Foreign currency translation adjustment	(40,997)	(3,881)
Unamortized retirement costs, net of tax	3,626	701
Unrealized loss on interest rate swaps, net of tax	(380)	(122)
Total Other Comprehensive Loss	(37,751)	(3,302)
Comprehensive Income/(Loss)	$ (1,634)	$ 47,494