Stock Based Compensation Equity Incentive Plans (Details) (USD $)	12 Months Ended
	Jan. 29, 2012	Jan. 30, 2011	Jan. 31, 2010	Jan. 25, 2009
2007 Equity Incentive Plan [Abstract]
Number Of Shares Authorized Under 2007 Plan Prior To Stock Splits	101,845,177
Number Of Shares Authorized Under 2007 Plan After Stock Splits	152,767,766
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	22,425,952	33,736,488	44,016,042	29,500,759
Change in vesting period	changed the vesting schedule for stock options and RSUs granted to employees from a three year period to a four year period
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	four
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Date	six or ten
PortalPlayer, Inc. 1999 Stock Option Plan [Abstract]
Exchange Ratio For Acquired Entity Outstanding Stock Options Rights For Those Of Acquiring Entity	by multiplying the number of shares of PortalPlayer common stock underlying such option by 0.3601
Stock Option Exercise Price Ratio For Assumed Stock Options Rights For Those Of Acquiring Entity	he exercise price per share for each assumed option was similarly adjusted by dividing the exercise price by 0.3601
Incentive Stock Options Minimum Grant Price Percentage Of Common Stock Market Price	1
NonStatutory Stock Options Minimum Grant Price Percentage Of Common Stock Market Price	0.85
1998 Employee Stock Purchase Plan [Abstract]
Number Of Years 1998 Employee Stock Purchase Plan Shares Reserved Automatically Increase Each Fiscal Year End	10
Percentage Of Outstanding Shares Used To Automatically Increase Shares Reserved For Issuance Under 1998 Employee Stock Purchase Plan	2.00%
NumberOfSharesAuthorizedUnder1998EmployeeStockPurchasePlanPriorToStockSplits	52,000,000
NumberOfSharesAuthorizedUnder1998EmployeeStockPurchasePlanAfterStockSplits	78,000,000
MaximumOfferingPeriodUnder1998EmployeeStockPurchasePlan	27
CurrentOfferingPeriodUnder1998EmployeeStockPurchasePlan	24
NumberOfMonthsInPurchasePeriodsInCurrentOfferingPeriodUnder1998EmployeeStockPurchasePlan	6
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	5,800,000	6,700,000	5,900,000
GrantDateFairValuePerShareInPeriodGrantsToEmployees	5.47	4.06	4.60
CommonStockPurchasePricePercentageOfCommonStockMarketPrice	85.00%
Stock Issued During Period, Shares, New Issues	51,792,571
Share-based Compensation Arrangement by Share-based Payment Award, Per Share Weighted Average Price of Shares Purchased	$ 8.18	$ 6.59	$ 6.76
Equity Awards, Available For Grant Under Equity Incentive Plans [Abstract]
Total Shares granted during the period (options and RSUs)	(13,767,554)	(12,923,659)	(15,374,295)
ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedInPeriodTotalFairValue	$ 49,500,000	$ 60,700,000	$ 37,000,000
Total Shares forfeited (Options and RSUs)	2,457,018	2,644,105	1,357,528
Stock Options [Abstract]
Options, Forfeitures in Period	(1,588,207)	(1,878,447)	(1,175,541)
Stock Options Cancelled Related To Stock Option Purchase			(28,532,050)
Options, Exercises in Period, Total Intrinsic Value	105,300,000	139,100,000	140,300,000
Options, Forfeitures in Period, Weighted Average Exercise Price	$ 14.78	$ 12.56	$ 12.90
Options, Outstanding, Number	33,328,976	44,001,458	58,348,422	97,454,280
Options, Outstanding, Weighted Average Exercise Price	$ 14.44	$ 12.88	$ 11.30	$ 13.83
Options, Outstanding, Weighted Average Remaining Contractual Term	4.15
Options, Outstanding, Intrinsic Value	79,174,063,000
Retricteds stock units, nonvested, Number	13,637,803	10,611,914	7,488,512
Stock Options granted (in shares)	6,430,778	5,818,966	7,701,396
Options, Exercises in Period, Weighted Average Exercise Price	$ 16.18	$ 13.79	$ 11.50
Options, Exercises in Period	(15,515,053)	(18,287,483)	(17,099,663)
Options, Grants in Period, Weighted Average Exercise Price	$ 10.70	$ 8.16	$ 5.74
Options, Exercisable, Number	21,434,294
Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Remaining Contractual Term	2.28
Options, Exercisable, Weighted Average Exercise Price	$ 13.80
Options, Exercisable, Intrinsic Value	66,073,341,000
Options, Vested and Expected to Vest, Outstanding, Number	31,451,419
Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price	$ 14.38
Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term	3.95
Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value	77,103,721,000
EntityClosingStockPrice	14.91
OustandingOptionsInMoney	18,900,000
ExercisableOptionsInMoney	13,300,000
Restricted Stock Units [Abstract]
Restricted stock units, Vested in Period, Weighted Average Grant Date Fair Value	$ 12.02	$ 11.74	$ 12.40
Restricted stock units granted (in shares)	7,336,776	7,104,693	7,672,899
Restricted stock units, Nonvested, Weighted Average Grant Date Fair Value	$ 15.10	$ 13.23	$ 12.28
Weighted average grant date fair value of restricted stock units granted	$ 16.31	$ 13.61	$ 12.26
Restricted stock units, Forfeited in Period	(868,811)	(765,658)	(181,987)
Restricted stock units, Forfeited in Period, Weighted Average Grant Date Fair Value	$ 14.72	$ 13.76	$ 11.37
Restricted stock units, Vested in Period	(3,442,076)	(3,215,633)	(2,400)
Aggregate Intrinsic value of RSUs vested and expected to vest	$ 11,017,627
Restricted stock units Vested and Expected To Vest Weighted Average Grant Date Fair Value	15.10
Restricted Stock Units (RSUs) [Member]
2007 Equity Incentive Plan [Abstract]
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
2007 Equity Incentive Plan [Abstract]
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
Employee Stock Purchase Plan
2007 Equity Incentive Plan [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	26,207,429
Portal Player 1999 Stock Option Plan [Member]
2007 Equity Incentive Plan [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights	25% on the first anniversary of the grant date of the option, and an additional 1/48th of the shares upon completion of each succeeding full month of continuous employment thereafter.
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Date	ten