Retirement Benefits and Postemployment Benefits (Schedule of assumed health care trend costs) (Details)	12 Months Ended
May 25, 2014	May 26, 2013
Defined Benefit Plan Assumed Health Care Cost Trend Rates [Abstract]
Health care cost trend rate for next year		8.00%
Rate to which the cost trend rate is assumed to decline (ultimate rate)	5.00%	5.20%
Under Age 65 [Member]
Defined Benefit Plan Assumed Health Care Cost Trend Rates [Abstract]
Health care cost trend rate for next year	6.50%
Over Age 65 [Member]
Defined Benefit Plan Assumed Health Care Cost Trend Rates [Abstract]
Health care cost trend rate for next year	7.30%

The assumed health care cost trend rate for the next year used to measure the expected cost of benefits covered by the plan (gross eligible charges). This is based upon the annual rate of change in the cost of health care benefits currently provided by the postretirement benefit plan, due to factors other than changes in the composition of the plan population by age and dependency status.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (l)

-URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Health Care Cost Trend Rate

-URI http://asc.fasb.org/extlink&oid=6514820

Name:	us-gaap_DefinedBenefitPlanHealthCareCostTrendRateAssumedForNextFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration