Earnings per Share - Basic and Diluted Weighted Average Common Shares Used in Earnings Per Share Calculation (Detail) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Earnings Per Share [Abstract]
Basic weighted average common shares outstanding	12,476	12,767	12,631	12,766
Stock options	194	359	267	390
Unvested restricted stock	21	19	27	24
Total weighted average common share equivalents	215	378	294	414
Diluted weighted average common shares outstanding	12,691	13,145	12,925	13,180