Employees' Stock Incentive Plans and Management Incentive Plans 5 (Details) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	12 Months Ended
	Apr. 29, 2012	Apr. 27, 2011	Apr. 28, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted, Number of Options	1,649	1,733	1,768
Options granted, Weighted Grant Date Fair Value, Beginning Balance	$ 5.80	$ 5.36	$ 4.71
Nonvested Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested options, Number of Options, Beginning Balance	4,024
Options granted, Number of Options	1,649
Options vested, Number of Options	(1,483)
Unvested options, Number of Options, Ending Balance	4,190
Unvested options, Weighted Grant Date Fair Value, Beginning Balance	$ 5.27
Options granted, Weighted Grant Date Fair Value, Beginning Balance	$ 5.80
Options vested, Weighted Grant Date Fair Value	$ 5.41
Unvested options, Weighted Grant Date Fair Value, Ending Balance	$ 5.43
Unrecognized compensation costs	$ 6.4	$ 7.7
Weighted average period of recognition for unrecognized compensation costs	1.5