Amount of valuation allowance of deferred tax asset attributable to deductible temporary differences and carryforwards, classified as noncurrent.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=84176650&loc=d3e31917-109318

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=84176650&loc=d3e31928-109318

Name:	us-gaap_DeferredTaxAssetsValuationAllowanceNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Income Taxes (Details Textual) - USD ($) $ in Millions	12 Months Ended
Income Taxes (Details Textual) - USD ($) $ in Millions	Jan. 31, 2019	Jan. 31, 2018	Apr. 30, 2018
Income Taxes [Line Items]
Deferred Tax Assets, Valuation Allowance, Noncurrent		$ 2.2	$ 2.2
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		33.81%
Scenario, Plan [Member]
Income Taxes [Line Items]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Maximum [Member]
Income Taxes [Line Items]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		35.00%