Earnings per Share - Basic and Diluted Weighted Average Common Shares Used in Earnings Per Share Calculation (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2016	Oct. 31, 2015
Earnings Per Share [Abstract]
Basic weighted average common shares outstanding	12,075	12,051	12,068	12,035
Stock options	8		6	17
Unvested restricted stock	37	54	46	42
Total weighted average common share equivalents	45	54	52	59
Diluted weighted average common shares outstanding	12,120	12,105	12,120	12,094