Loss Per Share And Stockholders' Equity (Computation Of Basic And Diluted Loss Per Share From Continuing Operations) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Jul. 31, 2012	Jul. 31, 2011
Loss Per Share And Stockholders' Equity [Abstract]
Net loss from continuing operations attributable to shareholders	$ (105,650)	$ (119,155)
Amounts allocated to participating securities (nonvested shares)	(73)	(114)
Net loss from continuing operations attributable to common shareholders	$ (105,723)	$ (119,269)
Basic weighted average common shares	277,155	305,491
Potential dilutive shares
Dilutive weighted average common shares	277,155	305,491
Basic	$ (0.38)	$ (0.39)
Diluted	$ (0.38)	$ (0.39)