Intangible Assets (Schedule Of Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jul. 31, 2011 years	Jan. 30, 2011 years
Intangible assets, gross excluding goodwill	$ 90,400	$ 90,400
Accumulated Amortization	(19,782)	(15,577)
Net Book Value	70,618	74,823
In-process Research And Development [Member]
Infinite intangible assets, gross carrying amount	12,370	12,370
Accumulated Amortization
Net Book Value	12,370	12,370
Core Technologies [Member]
Estimated Useful Life, minimum (in years)	2	2
Estimated Useful Life, maximum (in years)	10	10
Finite lived intangible, gross carrying amount	65,900	65,900
Accumulated Amortization	(17,532)	(14,006)
Net Book Value	48,368	51,894
Customer Relationships [Member]
Estimated Useful Life, minimum (in years)	8	8
Estimated Useful Life, maximum (in years)	10	10
Finite lived intangible, gross carrying amount	12,130	12,130
Accumulated Amortization	(2,250)	(1,571)
Net Book Value	$ 9,880	$ 10,559