Financial Instruments And Fair Value (Summary Of Financial Assets And Liabilities Measured At Fair Value On A Recurring Basis By Balance Sheet Grouping) (Details) (USD $) In Millions	Jul. 29, 2011
Cash equivalents	$ 1,645.9
Short-term investments	2,170.9
Other current assets	5.3
Total	3,899.3
Other non-current assets	20.9
Other current liabilities	4.2
Long-Term Investments [Member]
Total	56.3
Fair Value, Inputs, Level 1 [Member] | Long-Term Investments [Member]
Total	0
Fair Value, Inputs, Level 2 [Member] | Long-Term Investments [Member]
Total	0
Fair Value, Inputs, Level 3 [Member] | Long-Term Investments [Member]
Total	56.3
Fair Value, Inputs, Level 1 [Member]
Cash equivalents	1,524.7
Short-term investments	0
Other current assets	3.7
Total	1,548.3
Other non-current assets	19.9
Other current liabilities	0
Fair Value, Inputs, Level 2 [Member]
Cash equivalents	121.2
Short-term investments	2,170.9
Other current assets	1.6
Total	2,293.7
Other non-current assets	0
Other current liabilities	4.2
Fair Value, Inputs, Level 3 [Member]
Cash equivalents	0
Short-term investments	0
Other current assets	0
Total	57.3
Other non-current assets	1.0
Other current liabilities	$ 0