Pension and Other Postretirement Benefit Plans 2 (Details) (USD $) In Thousands, unless otherwise specified	Apr. 28, 2013	Apr. 29, 2012
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Other non-current assets	$ 287,467	$ 399,868
Other accrued liabilities	(32,271)	(15,943)
Other non-current liabilities	(147,619)	(173,438)
Net asset/(liabilities) recognized	107,577	210,487
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Other non-current assets	0	0
Other accrued liabilities	(16,998)	(17,565)
Other non-current liabilities	(240,319)	(231,452)
Net asset/(liabilities) recognized	$ (257,317)	$ (249,017)