Retirement Benefits and Postemployment Benefits (Schedule of one percentage point change in the health care trend rate) (Details) $ in Millions	12 Months Ended
May 27, 2018 USD ($)
Defined Benefit Plan Effect Of One Percentage Point Change In Assumed Health Care Cost Trend Rates [Abstract]
Effect of one percentage point increase on the aggregate of the service and interest cost components next year	$ 1.9
Effect of one percentage point increase on the other postretirement accumulated benefit obligation as of current year end	47.8
Effect of one percentage point decrease on the aggregate of the service and interest cost components next year	(1.8)
Effect of one percentage point decrease on the other postretirement accumulated benefit obligation as of current year end	$ (44.5)

No definition available.

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- Definition

Amount of decrease in accumulated postretirement benefit obligation from one-percentage-point decrease in assumed health care cost trend rate.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (m)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

+ Details

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- Definition

Amount of decrease in service and interest cost components of net periodic postretirement benefit cost from one-percentage-point decrease in assumed health care cost trend rate.

+ References

+ Details

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- Definition

Amount of increase in accumulated postretirement benefit obligation from one-percentage-point increase in assumed health care cost trend rate.

+ References

+ Details

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- Definition

Amount of increase in service and interest cost components of net periodic postretirement benefit cost from one-percentage-point increase in assumed health care cost trend rate.

+ References

+ Details

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