Amount of Shares of Common Stock Reserved (Detail)	3 Months Ended
	Apr. 30, 2013	Jan. 31, 2013
Stock Option Outstanding [Line Items]
Common stock issued and outstanding	34,843,441
Warrants	3,011,000	2,936,000
Stock options outstanding	5,832,000	5,300,000
Equity incentive plan, shares available for future grant	3,810,333
Conversion of Notes	60,986,818
Conversion of 10% Notes
Stock Option Outstanding [Line Items]
Common stock issued and outstanding	10,883,761
Warrants	0
Stock options outstanding	0
Conversion of Notes	0
Conversion of 8% Notes
Stock Option Outstanding [Line Items]
Common stock issued and outstanding	600,000
Warrants	0
Stock options outstanding	0
Conversion of Notes	0
Conversion of 9% Notes
Stock Option Outstanding [Line Items]
Common stock issued and outstanding	2,006,283
Warrants	0
Stock options outstanding	0
Conversion of Notes	0