Note 4 - Supplementary Cash Flows Information - Supplementary Cash Flow Elements (Details) - USD ($) $ in Thousands	3 Months Ended
Jul. 31, 2019	Jul. 31, 2018	Apr. 30, 2019
Cash and cash equivalents	$ 3,718	$ 4,992	$ 6,493
Restricted cash	469	469
Total cash, cash equivalents, and restricted cash shown in the Consolidated Condensed Statement of Cash Flows	4,187	5,461
State and local income tax payments	49	102
Federal income tax payments to the Parent

Amount of cash and cash equivalents, and cash and cash equivalents restricted to withdrawal or usage; including, but not limited to, disposal group and discontinued operations. 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.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
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