v3.8.0.1

Fair Value of Financial Assets and Liabilities - Summary of Cash and Cash Equivalents (Details) - USD ($) $ in Thousands | Oct. 31, 2017 | Apr. 30, 2017
--- | --- | ---
Cash and Cash Equivalents [Line Items] |  |
Total cash and cash equivalents | $ 51,988 | $ 52,494
Demand deposit accounts |  |
Cash and Cash Equivalents [Line Items] |  |
Total cash and cash equivalents | 50,211 | 46,164
Money market funds |  |
Cash and Cash Equivalents [Line Items] |  |
Total cash and cash equivalents | 178 | 3,532
Commercial paper |  |
Cash and Cash Equivalents [Line Items] |  |
Total cash and cash equivalents | 1,399 | 2,798
US government agencies debt securities |  |
Cash and Cash Equivalents [Line Items] |  |
Total cash and cash equivalents | $ 200 | $ 0

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- Definition Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash -URI http://asc.fasb.org/extlink&oid=6506951 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash Equivalents -URI http://asc.fasb.org/extlink&oid=6507016 + Details
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