Share Based Compensation - Outstanding stock options (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Jan. 31, 2016 USD ($) $ / shares shares
Number of options
Outstanding, beginning of period (in shares) | shares	1,015,275
Granted (in shares) | shares	289,600
Exercised (in shares) | shares	(50,000)
Forfeited (in shares) | shares	(72,400)
Expired (in shares) | shares	(256,525)
Outstanding, end of period (in shares) | shares	925,950
Weighted average exercise price
Outstanding, beginning of period (in usd per share) | $ / shares	$ 29.04
Granted (in usd per share) | $ / shares	20.09
Exercised (in usd per share) | $ / shares	15.49
Forfeited (in usd per share) | $ / shares	27.42
Expired (in usd per share) | $ / shares	24.18
Outstanding, end of period (in usd per share) | $ / shares	$ 28.44
Aggregate intrinsic value, Outstanding, end of period | $	$ 0
Weighted average remaining contractual term (years), Outstanding, end of period	2 years 5 months 22 days
Number of options, Outstanding exercisable, end of period | shares	453,425
Weighted average exercise price, Outstanding exercisable, end of period | $ / shares	$ 31.30
Aggregate intrinsic value, Outstanding exercisable, end of period | $	$ 0
Weighted average remaining contractual term (years), Outstanding exercisable, end of period	1 year 5 months 22 days