CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands	9 Months Ended
	Oct. 30, 2011	Oct. 31, 2010
Cash flows from operating activities:
Net income	$ 465,065	$ 81,495
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	152,310	140,596
Stock based compensation expense	100,918	74,985
Other	13,689	5,382
Deferred income taxes	14,242	(172)
Excess Tax benefit from stock based compensation	(52,703)	0
Changes in operating assets and liabilities
Accounts receivable	(8,834)	(24,567)
Inventories	39,748	(46,746)
Prepaid expenses and other current assets	35	3,798
Deposits and other assets	(2,992)	4,864
Accounts payable	9,218	(21,868)
Accrued liabilities and other long-term liabilities	(232,058)	23,357
Net cash provided by operating activities, net of effect of acquisition	498,638	241,124
Cash flows from investing activities:
Purchases of marketable securities	(1,324,350)	(1,193,323)
Proceeds from sales and maturities of marketable securities	953,808	931,099
Purchases of property and equipment and intangible assets	(93,553)	(76,547)
Acquisition of businesses, net of cash acquired	(348,884)	0
Other	(1,890)	(1,656)
Net cash used in investing activities	(814,869)	(340,427)
Cash flows from financing activities:
Proceeds from issuance of common stock under employee stock plans	176,490	104,131
Payments under capital lease obligations	(1,188)	(875)
Excess Tax benefit from Stock based compensation	52,703	0
Payment of notes payable assumed from acquisitions	(10,319)	0
Net cash provided by financing activities	217,686	103,256
Change in cash and cash equivalents	(98,545)	3,953
Cash and cash equivalents at beginning of period	665,361	447,221
Cash and cash equivalents at end of period	566,816	451,174
Supplemental disclosures of cash flow information:
Cash paid for income taxes, net	3,857	2,522
Cash paid for interest on capital lease obligations	2,254	2,359
Other non-cash activities:
Change in unrealized gains from marketable securities	(1,274)	497
Assets acquired by assuming related liabilities	$ 12,064	$ 67,785