Goodwill and Intangible Assets - Schedule Of Indefinite-Lived Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Jul. 28, 2013	Jan. 27, 2013
Indefinite-lived Intangible Assets by Major Class [Line Items]
Gross carrying amount	$ 29,870	$ 34,870
Accumulated impairment loss	(5,770)	(3,170)
Net carrying amount	24,100	31,700
In-Process Research And Development [Member]
Indefinite-lived Intangible Assets by Major Class [Line Items]
Gross carrying amount	29,870	34,870
Accumulated impairment loss	(5,770)	(3,170)
Net carrying amount	$ 24,100	$ 31,700