Stock-Based Compensation (Details 1) (USD $)	12 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2011	Jan. 31, 2010
Summary of stock options outstanding
Number of options outstanding	7,799,011	8,582,511	11,046,652	10,212,401
Weighted Average Remaining Contractual Life	5 years 9 months	6 years 11 months 16 days	7 years 2 months 16 days	8 years 7 months 24 days
Weighted Average Exercise Price on Options Outstanding	$ 2.72
Number Exercisable	4,435,976
Weighted Average Exercise Price on Options Exercisable	$ 3.02	$ 2.79	$ 2.79	$ 2.76
$1.25 [Member]
Summary of stock options outstanding
Exercise Price	$ 1.25
Number of options outstanding	872,810
Weighted Average Remaining Contractual Life	1 year 1 month 2 days
Weighted Average Exercise Price on Options Outstanding	$ 1.25
Number Exercisable	872,810
Weighted Average Exercise Price on Options Exercisable	$ 1.25
$3.00 [Member]
Summary of stock options outstanding
Exercise Price	$ 3.00
Number of options outstanding	3,237,844
Weighted Average Remaining Contractual Life	4 years 2 months 27 days
Weighted Average Exercise Price on Options Outstanding	$ 3.00
Number Exercisable	2,650,774
Weighted Average Exercise Price on Options Exercisable	$ 3.00
$3.08 [Member]
Summary of stock options outstanding
Exercise Price	$ 3.08
Number of options outstanding	554,999
Weighted Average Remaining Contractual Life	6 years 3 months 7 days
Weighted Average Exercise Price on Options Outstanding	$ 3.08
Number Exercisable	314,926
Weighted Average Exercise Price on Options Exercisable	$ 3.08
$3.19 [Member]
Summary of stock options outstanding
Exercise Price	$ 3.19
Number of options outstanding	425,000
Weighted Average Remaining Contractual Life	7 years 8 months 5 days
Weighted Average Exercise Price on Options Outstanding	$ 3.19
Number Exercisable	202,357
Weighted Average Exercise Price on Options Exercisable	$ 3.19
$3.48 [Member]
Summary of stock options outstanding
Exercise Price	$ 3.48
Number of options outstanding	1,268,500
Weighted Average Remaining Contractual Life	9 years 2 months 1 day
Weighted Average Exercise Price on Options Outstanding	$ 3.48
Number Exercisable	0
Weighted Average Exercise Price on Options Exercisable	$ 3.48
$3.54 [Member]
Summary of stock options outstanding
Exercise Price	$ 3.54
Number of options outstanding	438,192
Weighted Average Remaining Contractual Life	6 years 11 months 9 days
Weighted Average Exercise Price on Options Outstanding	$ 3.54
Number Exercisable	212,201
Weighted Average Exercise Price on Options Exercisable	$ 3.54
$3.58 [Member]
Summary of stock options outstanding
Exercise Price	$ 3.58
Number of options outstanding	226,666
Weighted Average Remaining Contractual Life	7 years 7 months 28 days
Weighted Average Exercise Price on Options Outstanding	$ 3.58
Number Exercisable	110,690
Weighted Average Exercise Price on Options Exercisable	$ 3.58
$3.72 [Member]
Summary of stock options outstanding
Exercise Price	$ 3.72
Number of options outstanding	775,000
Weighted Average Remaining Contractual Life	9 years 11 days
Weighted Average Exercise Price on Options Outstanding	$ 3.72
Number Exercisable	72,218
Weighted Average Exercise Price on Options Exercisable	$ 3.72