Amount of cash and cash equivalents restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(2))
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
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Name:	us-gaap_RestrictedCashAndCashEquivalents
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES - Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Oct. 31, 2018	Apr. 30, 2018	Oct. 31, 2017	Apr. 30, 2017
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	$ 12,777	$ 11,891		$ 0
Restricted cash	5,085	4,225	3,782
Total cash, cash equivalents and restricted cash	17,862	$ 16,116	46,246	56,800
Previously Reported [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents			$ 42,464	28,819
Total cash, cash equivalents and restricted cash				$ 0
Escrow Deposits [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	$ 5,100