Employees' Stock Incentive Plans and Management Incentive Plans 3 (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Apr. 29, 2012	Apr. 27, 2011	Apr. 28, 2010
Employees Stock Incentive Plans And Management Incentive Plans (Textuals) [Abstract]
Weighted average fair value per share of the options granted	$ 5.80	$ 5.36	$ 4.71
Weighted average assumptions used to estimate the fair value of stock options
Dividend yield	3.70%	3.90%	4.30%
Expected volatility	20.90%	20.50%	20.20%
Expected term (years)	5.0	5.5	5.5
Risk-free interest rate	1.00%	1.70%	2.70%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning Balance, Number of Options	9,768	12,921	14,100
Options granted, Number of Options	1,649	1,733	1,768
Options exercised, Number of Options	(2,798)	(4,813)	(2,921)
Options cancelled/forfeited and returned to the plan, Number of Options	(11)	(73)	(26)
Ending Balance, Number of Options	8,608	9,768	12,921
Options vested and exercisable, Number of Options	4,418	5,744	9,300
Beginning of Period, Weighted Average Exercise Price	$ 42.38	$ 39.36	$ 38.59
Options granted, Weighted Average Exercise Price	$ 52.19	$ 46.42	$ 39.12
Options exercised, Weighted Average Exercise Price	$ 37.99	$ 35.73	$ 35.46
Options cancelled/forfeited and returned to the plan, Weighted Average Exercise Price	$ 38.38	$ 42.81	$ 40.44
End of Period, Weighted Average Exercise Price	$ 45.69	$ 42.38	$ 39.36
Options vested and exercisable, Weighted Average Exercise Price	$ 43.90	$ 40.65	$ 37.59
Beginning of Period, Aggregate Intrinsic Value	$ 413,944	$ 508,611	$ 544,071
Options granted, Aggregate Intrinsic Value	86,068	80,460	69,166
Options exercised, Aggregate Intrinsic Value	(106,287)	(171,980)	(103,558)
Options cancelled/forfeited and returned to the plan, Aggregate Intrinsic Value	(435)	(3,147)	(1,068)
Options vested and exercisable, Aggregate Intrinsic Value	193,942	233,507	349,600
End of Period, Aggregate Intrinsic Value	$ 393,290	$ 413,944	$ 508,611