Note 4 - Fair Value Measurements - Fair Values of the Derivative Instrument (Details) - Fair Value, Inputs, Level 2 [Member] - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Apr. 30, 2019	Jan. 31, 2019
Derivative instrument:
Fair value of derivative instrument	$ 45	$ 136
Fair value of derivative instrument	45	136
Interest Rate Swap [Member] \| Other Noncurrent Assets [Member]
Derivative instrument:
Fair value of derivative instrument	45
Fair value of derivative instrument	$ 45
Interest Rate Swap [Member] \| Other Noncurrent Liabilities [Member]
Derivative instrument:
Fair value of derivative instrument		136
Fair value of derivative instrument		$ 136

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13433-108611

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

Name:	us-gaap_DerivativeAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant