Loss Per Share and Stockholders' Equity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Apr. 30, 2015	Apr. 30, 2014
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss)	$ (6,789)	$ 3,334
Gross losses arising during the period	(10,990)	(728)
Income taxes	(875)	(460)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(10,115)	(268)
Gross amount reclassified	0	0
Income taxes	0	0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax	0	0
Change in foreign currency translation adjustments	(8,755)	455
Accumulated Other Comprehensive Income (Loss)	(15,544)	3,789
Unrealized Gain (Loss) on AFS Securities
Accumulated Other Comprehensive Income (Loss)	8,529	1,843
Gross amount reclassified	230	941
Tax effect of reclassification adjustment for gains included in income	89	367
Reclassification adjustment for gains included in income	141	574
Net other comprehensive loss	(1,219)	(149)
Accumulated Other Comprehensive Income (Loss)	7,310	1,694
Accumulated other comprehensive income (loss)	(8,234)	5,483	$ 1,740	$ 5,177
Other Comprehensive Income (Loss), Net of Tax	(9,974)	306
Net loss from continuing operations attributable to shareholders	(96,505)	(108,851)
Amounts allocated to participating securities	(102)	(89)
Net loss from continuing operations attributable to common shareholders	$ (96,607)	$ (108,940)
Basic weighted average common shares (in shares)	275,765	274,575
Potential dilutive shares (in shares)	0	0
Weighted Average Number of Shares Outstanding, Diluted	275,765	274,575
Basic (in usd per share)	$ (0.35)	$ (0.40)
Narrative Details [Abstract]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	5,000	5,500
Shares repurchased during the period, (in shares)	600	300
Shares repurchased during the period, Value	$ 17,800	$ 9,400
Shares issued during period (in shares)	1,600	1,100
Nonvested units granted	900
Stock-based compensation	$ 6,000	$ 7,500
Unrecognized compensation costs, options	100
Unrecognized compensation costs, nonvested shares and units	50,200
Accumulated Translation Adjustment [Member]
Foreign Currency Translation Adjustments
Gross losses arising during the period	(8,755)	455
Income taxes	0	0
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(8,755)	455
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Foreign Currency Translation Adjustments
Gross losses arising during the period	(2,235)	(1,183)
Income taxes	(875)	(460)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	$ (1,360)	$ (723)