Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Name:	us-gaap_Revenues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Geographic Information (Details) $ in Thousands	3 Months Ended
Geographic Information (Details) $ in Thousands	Apr. 30, 2016 USD ($) customer	Apr. 30, 2015 USD ($)	Jan. 31, 2016 customer
Revenues by geographic region
Revenue	$ 185,952	$ 125,665
United States
Revenues by geographic region
Revenue	137,805	95,187
International
Revenues by geographic region
Revenue	$ 48,147	$ 30,478
Accounts receivable \| Customer concentration risk
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration Risk, Number of Customers \| customer	2		2