Shareholders' Equity - Additional Information (Detail) (USD $)	12 Months Ended
	Jan. 31, 2014 Plan	Jan. 31, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for future grant	296,396
Number of stock award plans	3
Term period	10 years
Award vesting percent	20.00%
Vesting period	5 years
Purchase term	3 years
Purchase amount	$ 5,000,000
Maximum amount transferable under Stock transfer Agreement	5,000,000
Stock transfer agreement termination date	Feb. 09, 2019
Stock transfer agreement termination period after death of key man	4 years
Stock transfer agreement amount	10,000,000
Annual dividend declared per share		$ 0.02
Special dividend declared per share		$ 0.35
2006 Incentive Stock Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for future grant	500,000
2010 Incentive Stock Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for future grant	500,000
2012 Outside Directors Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for future grant	50,000
2012 Stock Grant Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for future grant	20,180
Annual Issued Grant	$ 10,000