Capital Stock - Schedule of Ordinary Shares Reserved for Future Issuance under EIP and ESPP (Detail)	Jan. 31, 2015	Jan. 31, 2014
Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved	5,055,845	5,699,530
Employee stock purchase plan awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved	667,990	456,410

Aggregate number of common shares reserved for future issuance.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.29)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant