Summary of Significant Accounting Policies - Stock Based Compensation Section 2 (Details) - Stock Options - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Oct. 31, 2015	Jan. 31, 2015
Shares
Outstanding at the beginning of the period (in shares)	1,185,767
Granted (in shares)	335,000
Exercised (in shares)	(261,097)
Expired/forfeited (in shares)	(146,667)
Outstanding at the end of the period (in shares)	1,113,003	1,185,767
Vested and Exercisable at the end of the period (in shares)	570,828
Weighted Average Price
Outstanding at the beginning of the period (in dollars per share)	$ 15.89
Granted (in dollars per share)	22.79
Exercised (in dollars per share)	17.06
Canceled/forfeited (in dollars per share)	17.33
Outstanding at the end of the period (in dollars per share)	17.50	$ 15.89
Vested and Exercisable at the end of the period (in dollars per share)	$ 15.38
Weighted Average Remaining Contractual Term (in years)
Outstanding	4 years 3 months 22 days	3 years 5 months 27 days
Vested and Exercisable at the end of the period	3 years
Aggregate Intrinsic Value
Outstanding at the beginning of the period (in dollars)	$ 2,910
Outstanding at the end of the period (in dollars)	2,075	$ 2,910
Vested and Exercisable at the end of the period (in dollars)	1,443
Unrecognized stock-based compensation
Unrecognized stock-based compensation expense (in dollars)	$ 2,346
Weighted average period for recognition of unrecognized stock-based compensation expense	2 years 3 months 15 days
Total fair value of vested options (in dollars)	$ 677