Pension and Postretirement Benefits (Details 1) (USD $) In Millions, unless otherwise specified	May 27, 2012	Sep. 08, 2011	May 29, 2011
Amounts Recognized in Accumulated Other Comprehensive (Income) Loss (Pre-tax)
Actuarial net loss	$ (27.6)
Weighted-Average Actuarial Assumptions Used to Determine Benefit Obligations At May 27, 2012 and May 29, 2011
Discount rate		4.30%	4.90%
Projected benefit obligation, accumulated benefit obligation, and fair value of plan in excess of plan assets
Projected benefit obligation	3,159.7		2,505.6
Accumulated benefit obligation	3,057.2		2,436.1
Fair value of plan assets	2,594.1		2,153.4
Pension Benefits [Member]
Funded status and Amounts recognized in Balance Sheets
Funded status	(561.7)		(337.5)
Amounts Recognized in Consolidated Balance Sheets
Other assets	3.9		14.7
Other accrued liabilities	(8.8)		(8.7)
Other noncurrent liabilities	(556.8)		(343.5)
Net amount recognized	(561.7)		(337.5)
Amounts Recognized in Accumulated Other Comprehensive (Income) Loss (Pre-tax)
Actuarial net loss	332.0		205.9
Net prior service cost (benefit)	17.9		15.7
Total	349.9		221.6
Weighted-Average Actuarial Assumptions Used to Determine Benefit Obligations At May 27, 2012 and May 29, 2011
Discount rate	4.50%		5.30%
Long-term rate of compensation increase	4.25%		4.25%
Other Benefits [Member]
Funded status and Amounts recognized in Balance Sheets
Funded status	(282.6)		(322.5)
Amounts Recognized in Consolidated Balance Sheets
Other accrued liabilities	(26.8)		(27.5)
Other noncurrent liabilities	(255.8)		(295.0)
Net amount recognized	(282.6)		(322.5)
Amounts Recognized in Accumulated Other Comprehensive (Income) Loss (Pre-tax)
Actuarial net loss	80.5		75.6
Net prior service cost (benefit)	(39.3)		(12.2)
Total	$ 41.2		$ 63.4
Weighted-Average Actuarial Assumptions Used to Determine Benefit Obligations At May 27, 2012 and May 29, 2011
Discount rate	3.90%		4.90%