Earnings per Share - Basic and Diluted Weighted Average Common Shares Used in Earnings Per Share Calculation (Detail) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2015	Jul. 31, 2014
Earnings Per Share [Abstract]
Basic weighted average common shares outstanding	12,037	12,671	12,028	12,710
Stock options		293	25	305
Unvested restricted stock	39	22	36	29
Total weighted average common share equivalents	39	315	61	334
Diluted weighted average common shares outstanding	12,076	12,986	12,089	13,044