Summary of Significant Accounting Policies (Details) (USD $)	12 Months Ended
	Jan. 27, 2013	Jan. 29, 2012	Jan. 30, 2011	Jan. 31, 2010
Accounting Policies [Abstract]
Excess Tax Benefit Related To StockBasedCompensation	$ 459,100,000
Deferred Tax Assets, Valuation Allowance	224,774,000	212,285,000
Advertising Expense	9,200,000	8,400,000	9,500,000
Foreign Currency Transaction Gain (Loss), Realized	(1,500,000)	1,600,000	(2,400,000)
Asset Retirement Obligation	10,600,000	10,200,000
Summary of cash equivalents and marketable securities:
Amortized Cost	3,286,436,000	2,864,755,000
Cash and cash equivalents	732,786,000	667,876,000	665,361,000	447,221,000
Percentage of accounts receivable from significant customers	0.40
Money Market Funds
Summary of cash equivalents and marketable securities:
Amortized Cost	$ 195,790,000	$ 290,732,000
Customer A (AR)
Summary of cash equivalents and marketable securities:
Percentage of accounts receivable from significant customers	0.20	0.20