SCHEDULE II – VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands	12 Months Ended
Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2015
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning Balance	$ 2,362	$ 3,992	$ 2,324
Additions	2,762	3,121	4,120
Deductions	(3,864)	(4,751)	(2,452)
Ending Balance	1,260	2,362	3,992
Valuation Allowance of Deferred Tax Assets [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning Balance	73,806	66,448	52,734
Additions	4,752	7,358	13,714
Deductions	0	0	0
Ending Balance	$ 78,558	$ 73,806	$ 66,448

Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SX 210.12-09)
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

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Amount of increase in the allowances and reserves, which consist of the valuation and qualifying accounts that are either netted against the cost of an asset or that reflect a liability established to represent expected future costs, from charges to costs and expenses.

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Total of the deductions in a given period to allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs, representing receivables written off as uncollectible and portions of the reserves utilized, respectively.

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