Financial Instruments And Fair Value (Quantitative Information About Level 3 Fair Value Measurements) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Apr. 27, 2012
Fair Value Inputs, Assets, Quantitative Information [Line Items]
ARS, Fair Value	4,827.9
Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
ARS, Fair Value	51.0
Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Time-to-economic maturity	6 years 4 months 24 days
Minimum [Member] | Market Comparable Securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate	4.70%
Minimum [Member] | Discounted Cash Flow [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Liquidity risk premium, market credit spread and other factors	1.80%
Coupon rate	1.20%
Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Time-to-economic maturity	16 years 1 month 6 days
Maximum [Member] | Market Comparable Securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate	12.60%
Maximum [Member] | Discounted Cash Flow [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Liquidity risk premium, market credit spread and other factors	3.20%
Coupon rate	3.20%
Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Time-to-economic maturity	10 years 2 months 12 days
Weighted Average [Member] | Market Comparable Securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate	8.60%
Weighted Average [Member] | Discounted Cash Flow [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Liquidity risk premium, market credit spread and other factors	2.20%
Coupon rate	1.80%
Auction Rate Securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
ARS, Fair Value	51.0