Fair Value Measurements - Summary of Derivative Liability Activity (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended	3 Months Ended
	Oct. 27, 2012	Oct. 27, 2012	Oct. 27, 2012 Recurring Fair Value Measurements [Member] Derivative Liability [Member] Series B Preferred Stock [Member]	Jul. 28, 2012 Recurring Fair Value Measurements [Member] Derivative Liability [Member] Series B Preferred Stock [Member]	Apr. 28, 2012 Recurring Fair Value Measurements [Member] Derivative Liability [Member] Series B Preferred Stock [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Beginning balance			$ 21,962	$ 13,743	$ 20,076
(Gain) Loss on change in fair value	5,558	3,672	(5,558)	8,219	(6,333)
Ending balance			$ 16,404	$ 21,962	$ 13,743