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, unless otherwise specified	Apr. 27, 2012
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	$ 900.0
Short-term investments	3,848.7
Other current assets	9.0
Other non-current assets	70.2
Total	4,827.9
Other current liabilities	2.6
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	724.8
Short-term investments	234.3
Other current assets	6.3
Other non-current assets	19.2
Total	984.6
Other current liabilities	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	175.2
Short-term investments	3,614.4
Other current assets	2.7
Other non-current assets	0
Total	3,792.3
Other current liabilities	2.6
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	0
Short-term investments	0
Other current assets	0
Other non-current assets	51.0
Total	51.0
Other current liabilities	$ 0