v2.4.0.8
Stock options (Non-vested and Exercisable stock options) (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified
9 Months Ended 12 Months Ended
Oct. 31, 2014
Jan. 31, 2014
Non-vested stock options, Number of shares    
Beginning balance 2,812  
Granted 1,946  
Vesting (2,216)  
Forfeited/expired (164)  
Ending balance 2,378 2,812
Non-vested stock options, Weighted average grant date fair value (usd per share)    
Beginning balance $ 0.26  
Granted $ 5.25  
Vested $ 0.22  
Forfeited/expired $ 3.61  
Ending balance $ 4.15 $ 0.26
Exercisable stock options    
Number of shares, Beginning balance 3,557  
Number of shares, Vesting 2,216  
Number of shares, Exercised (1,793)  
Number of shares, Forfeited/expired (5)  
Number of shares, Ending balance 3,975 3,557
Weighted average exercise price, Beginning balance (usd per share) $ 1.30  
Weighted average exercise price, Vesting (usd per share) $ 1.25  
Weighted average exercise price, Exercised (usd per share) $ 1.3370  
Weighted average exercise price, Forfeited/expired (usd per share) $ 2.25  
Weighted average exercise price, Ending balance (usd per share) $ 0.80 $ 1.30
Weighted average contractual term (in years) 5 years 6 months 32 days 5 years 0 months 11 days
Aggregate intrinsic value $ 77,916 $ 9,835
Vested and expected to vest    
Number of shares 4,772  
Weighted- average exercise price (usd per share) $ 2.01  
Weighted- average contractual term (in years) 6 years 1 month 30 days  
Aggregate intrinsic value $ 87,742