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. 28, 2013	Apr. 29, 2012	Apr. 27, 2011
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Unvested options at April 29, 2012	4,190
Options granted, Number of Options	1,540	1,649	1,733
Options vested, number of options	(1,662)
Options forfeited, number of options	(107)
Unvested options at April 28, 2013	3,961	4,190
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Unvested options, Weighted Grant Date Fair Value, Beginning Balance	$ 5.43
Options granted, Weighted Grant Date Fair Value, Beginning Balance	$ 5.79
Options vested, Weighted Grant Date Fair Value	$ 5.39
Options forfeited, Weighted Average Grant Date Fair Value	$ 5.61
Unvested options, Weighted Grant Date Fair Value, Ending Balance	$ 5.59	$ 5.43
Unrecognized compensation costs	$ 4.6	$ 6.4
Weighted average period of recognition for unrecognized compensation costs	1 year 6 months