Income Taxes - Summary of the activity related to the gross unrecognized tax benefits (excluding interest and penalties) (Details) - USD ($) $ in Thousands	12 Months Ended
Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2015
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Gross unrecognized tax benefits at beginning of year	$ 2,327	$ 2,307	$ 4,660
Increases in tax positions related to the current year	279	395	909
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions	(193)	0	0
Decreases as a result of a lapse in applicable statute of limitations	(303)	(375)	(393)
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities	0	0	(2,869)
Gross unrecognized tax benefits at end of year	$ 2,110	$ 2,327	$ 2,307

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount of unrecognized tax benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=65882285&loc=SL6600010-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Unrecognized Tax Benefit
-URI http://asc.fasb.org/extlink&oid=6527854

+ Details

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- Definition

Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

+ References

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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- Definition

Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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- Definition

Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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