Basic and Diluted Earnings Per Share (Detail)	3 Months Ended		9 Months Ended
	Oct. 31, 2013	Oct. 31, 2012	Oct. 31, 2013	Oct. 31, 2012
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Incremental shares assumed issued on exercise of in the money	5,801,754	798,743	6,082,526	377,141
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Incremental shares assumed issued on exercise of in the money	4,373,687	0	4,547,125	0
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Incremental shares assumed issued on exercise of in the money	1,428,067	798,743	1,535,402	377,141