Goodwill and Intangible Assets - Schedule Of Finite-Lived Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Apr. 26, 2015		Jan. 25, 2015
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	181,048		$ 169,048
Accumulated amortization	(77,693)		(71,448)
Net carrying amount	103,355		97,600
Core Technologies [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	144,155		134,155
Accumulated amortization	(58,363)		(53,286)
Net carrying amount	85,792		80,869
Core Technologies [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful life	2 years
Core Technologies [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful life	10 years
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	30,030		28,030
Accumulated amortization	(12,546)		(11,480)
Net carrying amount	17,484		16,550
Customer Relationships [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful life	7 years
Customer Relationships [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful life	10 years
Technology Licenses [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	263	[1]	263	[1]
Accumulated amortization	(184)	[1]	(169)	[1]
Net carrying amount	79	[1]	94	[1]
Technology Licenses [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful life	5 years
Technology Licenses [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful life	10 years
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	6,600		6,600
Accumulated amortization	(6,600)		(6,513)
Net carrying amount	0		$ 87
Other Intangible Assets [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful life	1 year
Other Intangible Assets [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful life	5 years

[1] Technology licenses relate to end-license agreements for intellectual property that is used by the Company in research and development activities and also has alternative future uses. Amortization expense related to technology licenses is reported as “Product development and engineering” in the condensed consolidated statements of operations.