Nature of Business and Basis of Presentation - Consolidated Statements of Operations Comprehensive Income (Loss) and Balance Sheet (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2013	Jul. 31, 2012	Jan. 31, 2013
Stock-based compensation expense	$ 657	$ 2,004	$ 1,770	$ 3,032
Loss from operations	535	(7,509)	(1,281)	(8,680)
Net loss	(215)	(5,998)	(2,200)	(25,575)
Comprehensive loss	125	(2,461)	(2,897)	(20,416)
Basic and diluted net loss per share		$ (0.18)		$ (0.78)
Additional paid-in capital	218,628		218,628		216,359
Accumulated loss	(14,858)		(14,858)		(12,658)
As Previously Reported [Member]
Stock-based compensation expense		1,300		2,328
Loss from operations		(6,805)		(7,976)
Net loss		(5,294)		(24,871)
Comprehensive loss		(1,757)		(19,712)
Basic and diluted net loss per share		$ (0.16)		$ (0.76)
Additional paid-in capital					214,531
Accumulated loss					(10,830)
Adjustment [Member]
Stock-based compensation expense		704		704
Loss from operations		(704)		(704)
Net loss		(704)		(704)
Comprehensive loss		(704)		(704)
Basic and diluted net loss per share		$ (0.02)		$ (0.02)
Additional paid-in capital					1,828
Accumulated loss					$ (1,828)