Shareholders' Equity - Additional Information (Detail)	12 Months Ended
	Jan. 31, 2018 quarter $ / shares shares	Jan. 31, 2017 $ / shares shares	Jan. 31, 2016 $ / shares shares	Apr. 30, 2013 shares
Statement Of Shareholders Equity [Line Items]
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares outstanding	532,000	343,000
Preferred stock, par value (in usd per share) | $ / shares	$ 1.00	$ 1.00
Number of quarterly periods to obtain voting rights | quarter	6
Common stock, shares authorized	20,000,000	20,000,000
Common stock, shares issued	14,019,000	14,019,000
Number of shares authorized to repurchase				1,000,000
Number of shares of common stock repurchased			852,100
Average price of shares repurchased (in usd per share) | $ / shares			$ 11.41
Shares surrendered in exchange for payment of taxes	359	718	580
Average fair value of shares (in usd per share) | $ / shares	$ 4.79	$ 3.76	$ 4.86
Series A Preferred Stock
Statement Of Shareholders Equity [Line Items]
Preferred stock, shares outstanding	532,000	343,000
Preferred stock, dividend rate	9.00%
Preferred stock, par value (in usd per share) | $ / shares	$ 1.00
Preferred stock, liquidation preference per share (in usd per share) | $ / shares	25.00
Preferred stock, dividend rate (in usd per share) | $ / shares	2.25
Preferred stock, redemption price (in usd per share) | $ / shares	$ 25.00
Preferred stock, redemption period	120 days
Period of time for listing	180 days