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		6 Months Ended
	Oct. 31, 2012	Oct. 31, 2011	Oct. 31, 2012	Oct. 31, 2011
Loss Per Share And Stockholders' Equity [Abstract]
Net loss from continuing operations attributable to shareholders	$ (101,199)	$ (123,013)	$ (206,849)	$ (242,168)
Amounts allocated to participating securities (nonvested shares)	64	62	137	176
Net loss from continuing operations attributable to common shareholders	$ (101,263)	$ (123,075)	$ (206,986)	$ (242,344)
Basic weighted average common shares	271,145	299,895	274,150	302,693
Potential dilutive shares
Dilutive weighted average common shares	271,145	299,895	274,150	302,693
Basic	$ (0.37)	$ (0.41)	$ (0.76)	$ (0.80)
Diluted	$ (0.37)	$ (0.41)	$ (0.76)	$ (0.80)