Stock options Options additional text (Details) (USD $)	12 Months Ended
	Jan. 31, 2013	Jan. 31, 2012
Initial options available to issue under the 2004 Plan	250,000
increase number of shares that may be issued	2.00%
Initial number of options to grant under plan	100,000
increase number of shares that may be issued Directors Plan	0.35%
number of options given a Director upon hire	10,000
minimum number of shares granted Directors each year	1,000
vesting period for stock options	P4Y
Current Fiscal Year End Date	--01-31
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized	$ 1,000,000
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition		2 years 5 months 24 days
Share-based Compensation	$ 484,000	$ 621,000
Maturity period for stock option fromI isuance date	P10Y
Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 3.31	$ 3.84