Pension and Other Postretirement Benefit Plans 1 (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Apr. 28, 2013	Apr. 29, 2012	Apr. 27, 2011
Change in Plan Assets:
Fair value of plan assets at the beginning of the year	$ 3,140,834
Employer contribution	69,400
Fair value of plan assets at the end of the year	3,379,143
Pension Plans, Defined Benefit [Member]
Change in Benefit Obligation:
Benefit obligation at the beginning of the year	2,930,347	2,765,316
Service cost	31,580	33,719	32,329
Interest cost	132,110	139,525	142,133
Participants’ contributions	2,294	2,281
Amendments	(145)	3,396
Actuarial loss	428,881	196,606
Settlement	(11,971)	(1,854)
Benefits paid	(157,672)	(152,342)
Exchange/other	(83,858)	(56,300)
Benefit obligation at the end of the year	3,271,566	2,930,347	2,765,316
Change in Plan Assets:
Fair value of plan assets at the beginning of the year	3,140,834	3,261,881
Actual return on plan assets	429,011	84,004
Settlement	(11,971)	(1,854)
Employer contribution	69,388	23,469
Participants’ contributions	2,294	2,281
Benefits paid	(157,672)	(152,342)
Exchange/other	(92,741)	(76,605)
Fair value of plan assets at the end of the year	3,379,143	3,140,834	3,261,881
Funded status	107,577	210,487
Other Postretirement Benefit Plans, Defined Benefit [Member]
Change in Benefit Obligation:
Benefit obligation at the beginning of the year	249,017	234,431
Service cost	6,486	5,967	6,311
Interest cost	9,923	11,457	12,712
Participants’ contributions	659	712
Amendments	0	735
Actuarial loss	9,153	17,278
Settlement	0	0
Benefits paid	(15,760)	(19,574)
Exchange/other	(2,161)	(1,989)
Benefit obligation at the end of the year	257,317	249,017	234,431
Change in Plan Assets:
Fair value of plan assets at the beginning of the year	0	0
Actual return on plan assets	0	0
Settlement	0	0
Employer contribution	15,101	18,862
Participants’ contributions	659	712
Benefits paid	(15,760)	(19,574)
Exchange/other	0	0
Fair value of plan assets at the end of the year	0	0	0
Funded status	$ (257,317)	$ (249,017)