Employees' Stock Incentive Plans and Management Incentive Plans 3 (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Apr. 28, 2013	Apr. 29, 2012	Apr. 27, 2011
Weighted average assumptions used to estimate the fair value of stock options
Dividend yield	3.70%	3.70%	3.90%
Expected volatility	19.40%	20.90%	20.50%
Expected term (years)	7 years	5 years	5 years 6 months
Risk-free interest rate	1.00%	1.00%	1.70%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning Balance, Number of Options	8,608	9,768	12,921
Options granted, Number of Options	1,540	1,649	1,733
Options exercised, Number of Options	(3,504)	(2,798)	(4,813)
Options cancelled/forfeited and returned to the plan, Number of Options	(110)	(11)	(73)
Ending Balance, Number of Options	6,534	8,608	9,768
Options vested and exercisable, Number of Options	2,573	4,418	5,744
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Beginning of Period, Weighted Average Exercise Price	$ 45.69	$ 42.38	$ 39.36
Options granted, Weighted Average Exercise Price	$ 55.72	$ 52.19	$ 46.42
Options exercised, Weighted Average Exercise Price	$ 42.35	$ 37.99	$ 35.73
Options cancelled/forfeited and returned to the plan, Weighted Average Exercise Price	$ 50.67	$ 38.38	$ 42.81
End of Period, Weighted Average Exercise Price	$ 49.76	$ 45.69	$ 42.38
Options vested and exercisable, Weighted Average Exercise Price	$ 48.01	$ 43.90	$ 40.65
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value [Roll Forward]
Beginning of Period, Aggregate Intrinsic Value	$ 393,290	$ 413,944	$ 508,611
Options granted, Aggregate Intrinsic Value	85,828	86,068	80,460
Options exercised, Aggregate Intrinsic Value	(148,376)	(106,287)	(171,980)
Options cancelled/forfeited and returned to the plan, Aggregate Intrinsic Value	(5,616)	(435)	(3,147)
Options vested and exercisable, Aggregate Intrinsic Value	123,502	193,942	233,507
End of Period, Aggregate Intrinsic Value	$ 325,126	$ 393,290	$ 413,944