Basis of Presentation, Business and Summary of Significant Accounting Policies - Revision of Condensed Consolidated Statement of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Apr. 30, 2016
Effect of the revision
Net income	$ 9,163	$ 3,011	$ 12,564
Adjustments to reconcile net income to net cash used in operating activities
Deferred income tax expense	(3,222)	(4,091)
Cash used in operating activities	$ (30,620)	(18,411)
As previously reported
Effect of the revision
Net income		2,786
Adjustments to reconcile net income to net cash used in operating activities
Deferred income tax expense		(3,866)
Cash used in operating activities		(18,411)
Correction to statutory tax rate used in purchase accounting for April 1, 2014 Acquisition | Adjustment
Effect of the revision
Net income		225
Adjustments to reconcile net income to net cash used in operating activities
Deferred income tax expense		$ (225)