Goodwill and Intangible Assets - Future Amortization Expense For Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Apr. 27, 2014		Jan. 26, 2014
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Remainder of fiscal year 2015	$ 20,188
Fiscal year 2016	26,437
Fiscal year 2017	26,091
Fiscal year 2018	25,049
Fiscal year 2019	21,507
Thereafter	10,933
Net carrying amount	130,205		136,944
Developed Technology [Member]
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Remainder of fiscal year 2015	15,689
Fiscal year 2016	20,919
Fiscal year 2017	20,919
Fiscal year 2018	20,919
Fiscal year 2019	17,507
Thereafter	10,385
Net carrying amount	106,338		111,568
Customer Relationships [Member]
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Remainder of fiscal year 2015	3,112
Fiscal year 2016	4,149
Fiscal year 2017	4,149
Fiscal year 2018	4,130
Fiscal year 2019	4,000
Thereafter	548
Net carrying amount	20,088		21,125
Technology Licenses [Member]
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Remainder of fiscal year 2015	919
Fiscal year 2016	1,226
Fiscal year 2017	1,023
Fiscal year 2018	0
Fiscal year 2019	0
Thereafter	0
Net carrying amount	3,168	[1]	3,475	[1]
Other Intangible Assets [Member]
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Remainder of fiscal year 2015	468
Fiscal year 2016	143
Fiscal year 2017	0
Fiscal year 2018	0
Fiscal year 2019	0
Thereafter	0
Net carrying amount	$ 611		$ 776

[1] Technology licenses relate to licensing agreements entered into by the Company that are used in research and development activities and have alternative future uses. Amortization expense related to technology licenses is reported as “Product development and engineering” in the unaudited consolidated condensed statements of income.