Business Segment and Geographic Information (Schedule of operating segment results) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Feb. 27, 2022	Feb. 28, 2021	Feb. 27, 2022	Feb. 28, 2021
Segment Reporting Information [Line Items]
Net sales	$ 4,537.7	$ 4,520.0	$ 14,101.6	$ 13,603.4
Operating profit	815.3	826.6	2,459.7	2,596.9
Divestitures gain	(170.1)	0.0	(170.1)	0.0
Restructuring, impairment, and other exit costs	7.1	11.0	5.1	11.9
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	4,537.7	4,520.0	14,101.6	13,603.4
Operating profit	793.2	813.1	2,623.6	2,707.1
Unallocated Corporate Items [Member]
Segment Reporting Information [Line Items]
Operating profit	140.9	(24.5)	328.9	98.3
North America Retail [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	2,811.9	2,786.0	8,567.1	8,539.3
Operating profit	611.5	628.8	1,935.5	2,076.8
U.S. Meals & Baking [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	968.0	990.7	3,032.6	3,169.0
U.S. Morning Foods [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	858.0	823.2	2,514.4	2,495.8
U.S. Snacks [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	745.0	726.8	2,282.3	2,172.0
Canada [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	240.9	245.3	737.8	702.5
International [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	721.0	939.8	2,566.0	2,710.9
Operating profit	35.9	41.4	155.9	180.8
Pet [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	567.7	436.3	1,649.1	1,288.0
Operating profit	110.6	102.3	357.3	311.9
North America Foodservice [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	437.1	357.9	1,319.4	1,065.2
Operating profit	$ 35.2	$ 40.6	$ 174.9	$ 137.6

Amount of gain (loss) from sale and disposal of integrated set of activities and assets capable of being conducted and managed for purpose of providing return in form of dividend, lower cost, or other economic benefit to investor, owner, member and participant.

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