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, 2016	Jul. 31, 2015	Jul. 31, 2016	Jul. 31, 2015
Earnings Per Share [Abstract]
Basic weighted average common shares outstanding	12,070	12,037	12,065	12,028
Stock options			5	25
Unvested restricted stock	49	39	51	36
Total weighted average common share equivalents	49	39	56	61
Diluted weighted average common shares outstanding	12,119	12,076	12,121	12,089