Stock Based Compensation Equity Incentive Plans (Details) (USD $)	12 Months Ended
	Jan. 26, 2014		Jan. 27, 2013		Jan. 29, 2012	Jan. 30, 2011
Amended and Restated 2007 Equity Incentive Plan
Increased number of shares by Amended 2007 Plan			25,000,000	[1]
Number of shares may be issued under the Restated 2007 Plan			177,767,766
Number of Shares Available for Grant under 2007 plan	24,722,435
Options expiration period	10
PortalPlayer, Inc. 1999 Stock Option Plan
Number of shares available for grant under PPI 1999 Plan	920
1998 and 2012 employee Stock Purchase Plan
Number Of Shares Authorized Under1998 ESPP			78,000,000
Stock Issued During Period, Shares, 1998 Plan, Prior to the effective date			54,567,667
Maximum number of shares subject to outstanding purchase rights granted under the 1998 Plan that would have returned to the 1998 Plan			15,000,000
Maximum shares available for future offerings under the 1998 Plan as of the effective date of the 2012 Plan			8,432,333
Maximum Aggregated Number of Shares under 2012 ESPP			55,432,333
Stock Issued During Period, Shares, Employee Stock Purchase Plans, after the effective date			2,687,698
Available but reserved shares for future issuance under 1998 Plan			183,000
Shares remaining in the 1998 ESPP moved to the 2012 ESPP			12,129,302
Shares issued during period under 1998 Plan	8,819
Number of shares under the 1998 Plan transferred into the share reserve for the 2012 Plan	174,181
Shares issued during period under 2012 Plan	6,115,403
Shares reserved for future issuance under 2012 Plan	46,620,413
Number of Month in Offering Period Under ESPP	24
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate			10.00%
ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRateBoardOfDirectorApproved			0.15
Stock Issued During Period, Shares, Employee Stock Purchase Plans	6,100,000		5,500,000		5,800,000
Share-based Compensation Arrangement by Share-based Payment Award, Per Share Weighted Average Price of Shares Purchased	$ 10.79		$ 10.83		$ 8.18
Grant Dat eFair Value Per Share In Period Grants to Employees	5.60		5.16		5.47
Equity Awards, Available For Grant Under Equity Incentive Plans
Equity Award, Number of Shares Available for Grant	24,733,190		36,899,876		22,425,952	33,736,488
Total Shares granted during the period (options and RSUs)	(16,905,398)		(15,254,977)		(13,767,554)
Total Shares forfeited (Options and RSUs)	4,738,712		4,728,901		2,457,018
Increased number of shares by Amended 2007 Plan			25,000,000	[1]
Stock Options
Options, Outstanding, Number	32,503,911		32,995,325		33,328,976	44,001,458
Stock Options granted (in shares)	6,148,672		7,119,319		6,430,778
Options, Exercises in Period	(3,058,530)		(3,646,680)		(15,515,053)
Options, Forfeitures in Period	(3,581,556)		(3,806,290)		(1,588,207)
Options, Outstanding, Weighted Average Exercise Price	$ 14.22		$ 14.66		$ 14.44	$ 12.88
Options, Grants in Period, Weighted Average Exercise Price	$ 14.30		$ 13.88		$ 16.18
Options, Exercises in Period, Weighted Average Exercise Price	$ 10.26		$ 8.66		$ 10.70
Options, Forfeitures in Period, Weighted Average Exercise Price	$ 21.85		$ 17.04		$ 14.78
Options, Exercisable, Number	19,866,375
Options, Exercisable, Weighted Average Exercise Price	$ 14.09
Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price	$ 14.21
Options, Outstanding, Weighted Average Remaining Contractual Term	5 years 6 months 0 days
Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Remaining Contractual Term	3 years 8 months 12 days
Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term	5 years 3 months 17 days
Options, Outstanding, Intrinsic Value	$ 67,868,413	[2]
Options, Exercisable, Intrinsic Value	49,516,264	[2]
Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value	64,921,492	[2]
Entity Closing Stock Price	15.56
Outstanding Options In Money	39,900,000
Exercisable Options In Money	12,300,000
Options, Exercises in Period, Total Intrinsic Value	14,400,000		21,100,000		105,300,000
Total fair value of Options, Vested in Period	$ 34,600,000		$ 40,300,000		$ 49,500,000
Restricted Stock Units
Retricteds stock units, nonvested, Number	18,852,288		15,159,227		13,637,803	10,611,914
Restricted stock units granted (in shares)	10,756,726		8,135,658		7,336,776
Restricted stock units, Vested in Period	(5,906,509)		(5,691,623)		(3,442,076)
Restricted stock units, Forfeited in Period	(1,157,156)		(922,611)		(868,811)
Restricted stock units, Nonvested, Weighted Average Grant Date Fair Value	$ 13.82		$ 14.46		$ 15.10	$ 13.23
Weighted average grant date fair value of RSUs granted	$ 13.46		$ 13.86		$ 16.31
Restricted stock units, Vested in Period, Weighted Average Grant Date Fair Value	$ 14.79		$ 15.02		$ 12.02
Restricted stock units, Forfeited in Period, Weighted Average Grant Date Fair Value	$ 13.86		$ 15.14		$ 14.72
Restricted stock units Vested and Expected To Vest Weighted Average Grant Date Fair Value	$ 13.82
Stock Options [Member]
Amended and Restated 2007 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years 0 months 0 days
Stock Options
Amended and Restated 2007 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights	25% vesting on the anniversary of the hire date in the case of new hires or the anniversary of the date of grant in the case of grants to existing employees and 6.25% vesting at the end of each quarterly period thereafter
Stock Options
Options, Vested and Expected to Vest, Outstanding, Number	30,498,779
Restricted Stock Units (RSUs)
Amended and Restated 2007 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years 0 months 0 days
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights	25% vesting on a pre-determined date that is close to the anniversary of the date of grant and 12.5% vesting semi-annually thereafter until fully vested
Stock Options
Options, Vested and Expected to Vest, Outstanding, Number	15,258,123

[1] Represents the shares that were approved at our 2012 Annual Meeting of Stockholders and re-approved at our 2013 Annual Meeting of Stockholders.

[2] The aggregate intrinsic value in the table above represents the total pre-tax intrinsic value for in-the-money options at January 26, 2014, based on the $15.56 closing stock price of our common stock on the NASDAQ Global Select Market on January 24, 2014, the last trading day of fiscal year 2014, which would have been received by the option holders had all in-the-money option holders exercised their options as of that date. The total number of in-the-money options outstanding and exercisable as of January 26, 2014 was 39.9 million shares and 12.3 million shares, respectively.