Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 30, 2016	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2014
Operating Loss Carryforwards [Line Items]
Statutory federal tax rate									35.00%	35.00%	35.00%
Effective tax rate, change from prior year, percent									(1.80%)
Effective Income Tax Rate Reconciliation, Tax Contingency, State and Local, Percent									(4.30%)	0.00%	0.00%
Net loss from discontinued operations, net of tax benefits	$ (563)	$ (3,080)	$ (2,489)	$ (3,154)	$ (5,292)	$ (1,637)	$ 1,229	$ (7,381)	$ (9,286)	$ (13,081)	$ (24,940)
Tax benefits from discontinued operations									5,400	8,100	15,400
Valuation on deferred tax assets increase									(3,400)
Valuation allowance	21,515				24,937				$ 21,515	24,937
Document Fiscal Year Focus									2016
Unrecognized tax benefits that would impact effective tax rate	82,300				55,300				$ 82,300	55,300	73,700
Total gross interest and penalties accrued	22,300				$ 24,700				22,300	24,700	24,600
Settlement reducing uncertain tax benefits									450	$ 10,450	$ 23,993
State And Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Valuation allowance	$ 20,700								$ 20,700