Loss Per Share and Stockholders' Equity (Details) (USD $)	3 Months Ended		12 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Apr. 30, 2013
Earnings Per Share [Abstract]
Net loss from continuing operations attributable to shareholders	$ (113,270,000)	$ (105,650,000)
Net loss allocated to participating securities	(62,000)	(73,000)
Net loss from continuing operations attributable to common shareholders	(113,332,000)	(105,723,000)
Basic weighted average common shares (in shares)	273,080,000	277,155,000
Potential dilutive shares (in shares)	0	0
Weighted Average Number of Shares Outstanding, Basic and Diluted	273,080,000	277,155,000
Basic (in usd per share)	$ (0.42)	$ (0.38)
Narrative Details [Abstract]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	6,300,000	9,200,000
Shares repurchased and retired (in shares)			21,300,000
Share repurchase and retired, value			315,000,000
Shares repurchased during the period, (in shares)	200,000	100,000
Shares repurchased during the period, Value	4,200,000	1,600,000
Shares issued during period (in shares)	1,400,000	300,000
Nonvested units granted	800,000
Stock-based compensation	4,600,000	2,400,000
Unrecognized compensation costs, options	2,700,000
Unrecognized compensation costs, nonvested shares and units	$ 39,200,000