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, 2020	Jul. 31, 2019	Jul. 31, 2020	Jul. 31, 2019
Earnings Per Share [Abstract]
Basic weighted average common shares outstanding	12,182	12,128	12,177	12,124
Stock options	3	96	1	64
Unvested restricted stock	10	2	5	2
Total weighted average common share equivalents	13	98	6	66
Diluted weighted average common shares outstanding	12,195	12,226	12,183	12,190