COMMON STOCK REPURCHASES - Additional Information (Details) $ / shares in Units, $ in Millions	3 Months Ended
	Apr. 30, 2015 USD ($) $ / shares shares
Equity, Class of Treasury Stock [Line Items]
Number of shares repurchased (in shares) | shares	700,003
Average price of shares repurchased (in usd per share) | $ / shares	$ 78.85
Additional paid-in capital
Equity, Class of Treasury Stock [Line Items]
Value of stock repurchased	$ 40.5
Retained earnings
Equity, Class of Treasury Stock [Line Items]
Value of stock repurchased	$ 14.0