STOCK-BASED COMPENSATION - Summary of Activity under Company's Stock Option Plans (Details 2) - $ / shares	9 Months Ended		12 Months Ended
	Oct. 31, 2015	Oct. 31, 2014	Jan. 31, 2015	Jan. 31, 2014
STOCK-BASED COMPENSATION
Shares, Outstanding, Beginning balance	876,350	916,150	916,150
Shares, Granted	240,000	220,500
Shares, Exercised	(96,450)	(243,300)
Shares, Forfeited	(6,000)
Shares, Outstanding, Ending balance	1,013,900	893,350	876,350	916,150
Shares, Exercisable	668,900	597,850
Weighted Average Exercise Price, Outstanding, Beginning balance	$ 22.34	$ 17.36	$ 17.36
Weighted Average Exercise Price, Granted	35.76	28.84
Weighted Average Exercise Price, Exercised	17.31	15.96
Weighted Average Exercise Price, Forfeited	17.33
Weighted Average Exercise Price, Outstanding, Ending balance	26.03	20.57	$ 22.34	$ 17.36
Weighted Average Exercise Price, Exercisable	$ 21.92	$ 16.73
Weighted Average Remaining Term, Outstanding	6 years 11 months 23 days	6 years 6 months 7 days	7 years 29 days	6 years 15 days
Weighted Average Remaining Term, Exercisable	6 years 4 months 2 days	5 years 9 months 7 days
Weighted Average Fair Value, Outstanding	$ 6.82	$ 5.87	$ 6.01	$ 5.58
Weighted Average Fair Value, Exercisable	$ 5.81	$ 5.58