Summary of Significant Accounting Policies (Details) (USD $)	12 Months Ended
	Jan. 29, 2012	Jan. 30, 2011	Jan. 31, 2010	Jan. 25, 2009
Summary of cash equivalents and marketable securities:
Amortized Cost	$ 2,864,755,000	$ 2,165,536,000
Advertising Expense	8,400,000	9,500,000	16,300,000
Cash and cash equivalents	667,876,000	665,361,000	447,221,000	417,688,000
Foreign Currency Transaction Gain (Loss), Realized	1,600,000	(2,400,000)	(900,000)
Excess Tax Benefit Related To StockBasedCompensation	526,000,000
Asset Retirement Obligation	10,200,000	9,700,000
Deferred Tax Assets, Valuation Allowance	(212,285,000)	(148,016,000)
Money Market Funds [Member]
Summary of cash equivalents and marketable securities:
Amortized Cost	$ 290,732,000	$ 132,586,000
Customer A (AR) [Member]
Summary of cash equivalents and marketable securities:
Percentage of accounts receivable from significant customers (in hundredths)	0.20	0.11