Fair value ( Fair Value Assumptions) (Details) (Series D-3 redeemable convertible preferred stock derivative liability, Level 3, USD $)	12 Months Ended
Jan. 31, 2013	Jan. 31, 2014
Series D-3 redeemable convertible preferred stock derivative liability \| Level 3
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Market value of common stock on measurement date (per share)		$ 4.06
Projected exercise price ( usd per share)		$ 2.64
Risk-free interest rate	0.06%
Expected lives	180 days
Expected volatility	25.20%
Probability of liquidation event	0.00%

Fair Value Assumption, Probability of Liquidation

No definition available.

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- Details

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- Definition

Agreed upon price for the exchange of the underlying asset.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

+ Details

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- Definition

Period the instrument, asset or liability is expected to be outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

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- Definition

Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price.

+ References

+ Details

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- Definition

Risk-free interest rate assumption used in valuing an instrument.

+ References

+ Details

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- Definition

Price of a single share of a number of saleable stocks of a company.

+ References

No definition available.

+ Details

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