Note 8 - Federal, State and Local Income Taxes (Details Textual)	4 Months Ended	9 Months Ended	12 Months Ended
Apr. 30, 2018	Jan. 31, 2018	Jan. 31, 2017	Apr. 30, 2019	Apr. 30, 2018
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		30.33%	35.00%
Effective Income Tax Rate Reconciliation, Percent		(34.69%)	33.48%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent		(65.87%)
Scenario, Forecast [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%			21.00%	30.33%

Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the income tax rates.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I)
-URI http://asc.fasb.org/extlink&oid=34349781&loc=d3e330036-122817

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319

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