Pension and Other Postretirement Benefit Plans 2 (Details) (USD $) In Thousands, unless otherwise specified	Apr. 29, 2012	Apr. 27, 2011
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Other non-current assets	$ 399,868	$ 644,598
Other accrued liabilities	(15,943)	(31,589)
Other non-current liabilities	(173,438)	(116,444)
Net asset/(liabilities) recognized	210,487	496,565
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Other non-current assets	0	0
Other accrued liabilities	(17,565)	(18,259)
Other non-current liabilities	(231,452)	(216,172)
Net asset/(liabilities) recognized	$ (249,017)	$ (234,431)