Business Segment and Geographic Information (Schedule of operating segment results) (Details) - USD ($) $ in Millions	3 Months Ended
Aug. 26, 2018	Aug. 27, 2017
Segment Reporting Information [Line Items]
Net sales	$ 4,094.0	$ 3,769.2
Operating profit	601.5	605.3
Restructuring, impairment, and other exit costs (recoveries)	(1.4)	5.2
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	4,094.0	3,769.2
Operating profit	706.4	664.1
Unallocated Corporate Items [Member]
Segment Reporting Information [Line Items]
Operating profit	106.3	53.6
Significant Reconciling Items [Member]
Segment Reporting Information [Line Items]
Restructuring, impairment, and other exit costs (recoveries)	(1.4)	5.2
North America Retail [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	2,387.8	2,438.2
Operating profit	548.1	533.2
U.S. Meals & Baking [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	837.5	856.0
U.S. Cereal [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	584.4	578.6
U.S. Snacks [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	533.5	558.6
U.S. Yogurt & Other [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	219.1	223.4
Canada [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	213.3	221.6
Europe & Australia [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	500.7	491.9
Operating profit	34.5	30.6
Convenience Stores & Foodservice [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	463.2	447.1
Operating profit	97.1	84.8
Asia & Latin America [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	399.0	392.0
Operating profit	12.2	15.5
Pet [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	343.3	0.0
Operating profit	$ 14.5	$ 0.0

The net result for the period of deducting operating expenses from operating revenues.

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- Definition

Amount of restructuring charges, remediation cost, and asset impairment loss.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.3)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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Aggregate revenue during the period from the sale of goods in the normal course of business, after deducting returns, allowances and discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1(a))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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+ References

No definition available.

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