Fair value, after offset of derivative asset, of financial liability or 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, elected not to be and before offset against a right to receive collateral under a master netting arrangement. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=d3e41678-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-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

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=51825145&loc=SL20226006-175313

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=51825145&loc=SL20226008-175313

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

Derivative Financial Instruments (Details) - USD ($) $ in Thousands	Apr. 30, 2017	Jan. 31, 2017	Apr. 30, 2016
Designated as Hedging Instrument
Fair value and presentation of derivatives
Asset Derivatives	$ 5
Liability Derivatives	156		$ 191
Designated as Hedging Instrument \| Foreign Exchange Contract \| Other Current Assets
Fair value and presentation of derivatives
Asset Derivatives	5
Designated as Hedging Instrument \| Foreign Exchange Contract \| Accrued Liabilities
Fair value and presentation of derivatives
Liability Derivatives	156		191
Not Designated as Hedging Instrument
Fair value and presentation of derivatives
Asset Derivatives	200	$ 145	719
Liability Derivatives	6	211	8
Not Designated as Hedging Instrument \| Foreign Exchange Contract \| Other Current Assets
Fair value and presentation of derivatives
Asset Derivatives	200	145	719
Not Designated as Hedging Instrument \| Foreign Exchange Contract \| Accrued Liabilities
Fair value and presentation of derivatives
Liability Derivatives	$ 6	$ 211	$ 8