Incentive Stock Rights - Additional Information (Detail) (USD $)	3 Months Ended				6 Months Ended
	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2012	Jul. 31, 2010	Jul. 31, 2013	Jun. 24, 2010
Disclosure Incentive Stock Rights Additional Information [Abstract]
Incentive stock purchase right adoption date				Jun. 24, 2010
Dividend distribution of rights declared for each outstanding share of common stock						1
Dividends payable, date of record	Jun. 10, 2013	Mar. 22, 2013		Jul. 06, 2010
Incentive stock purchase right amendment date	Jun. 28, 2013		Dec. 23, 2011
Class of warrant or right issuable with each new share of common stock	1				1
Number of shares called by rights	0.0001				0.0001
Incentive stock purchase price	$ 90				$ 90
Percentage of common stock acquired to initiate exercise of incentive stock rights, minimum					15.00%
Percentage of common stock acquired to initiate exercise of incentive stock rights, certain investors					20.00%
Percent of incentive stock right exercise price for value of the entity's common stock received upon exercise of incentive stock right					200.00%
Percent of incentive stock right exercise price for value of acquiring company's common stock received upon exercise of incentive stock right					200.00%
Date on which rights expire					Jun. 30, 2015
Rights redemption price	$ 0.001