Financial Instruments, Risk Management Activities, and Fair Values (Schedule of offsetting assets and liabilities) (Details) - USD ($) $ in Millions	May 31, 2020	May 26, 2019
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets	$ 59.4	$ 22.6
Gross Liabilities Offset in the Balance Sheet	0.0	0.0
Net Amounts of Assets	59.4	22.6
Financial Instruments, Gross Amounts Not Offset in the Balance Sheet	(8.7)	(10.7)
Cash Collateral Received, Gross Amounts Not Offset in the Balance Sheet	0.0	0.0
Net Amount	50.7	11.9
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	(42.1)	(21.1)
Gross Assets Offset in the Balance Sheet	0.0	0.0
Net Amounts of Liabilities	(42.1)	(21.1)
Financial Instruments, Gross Amounts Not Offset in the Balance Sheet	8.7	10.7
Cash Collateral Pledged, Gross Amounts Not Offset in the Balance Sheet	15.9	0.0
Net Amount	(17.5)	(10.4)
Commodity Contracts [Member]
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets	6.2	6.6
Gross Liabilities Offset in the Balance Sheet	0.0	0.0
Net Amounts of Assets	6.2	6.6
Financial Instruments, Gross Amounts Not Offset in the Balance Sheet	(4.2)	(4.9)
Cash Collateral Received, Gross Amounts Not Offset in the Balance Sheet	0.0	0.0
Net Amount	2.0	1.7
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	(30.1)	(7.9)
Gross Assets Offset in the Balance Sheet	0.0	0.0
Net Amounts of Liabilities	(30.1)	(7.9)
Financial Instruments, Gross Amounts Not Offset in the Balance Sheet	4.2	4.9
Cash Collateral Pledged, Gross Amounts Not Offset in the Balance Sheet	15.9	0.0
Net Amount	(10.0)	(3.0)
Interest Rate Contracts [Member]
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets	6.0	0.0
Gross Liabilities Offset in the Balance Sheet	0.0	0.0
Net Amounts of Assets	6.0	0.0
Financial Instruments, Gross Amounts Not Offset in the Balance Sheet	(0.8)	0.0
Cash Collateral Received, Gross Amounts Not Offset in the Balance Sheet	0.0	0.0
Net Amount	5.2	0.0
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	(8.0)	(2.2)
Gross Assets Offset in the Balance Sheet	0.0	0.0
Net Amounts of Liabilities	(8.0)	(2.2)
Financial Instruments, Gross Amounts Not Offset in the Balance Sheet	0.8	0.0
Cash Collateral Pledged, Gross Amounts Not Offset in the Balance Sheet	0.0	0.0
Net Amount	(7.2)	(2.2)
Foreign Exchange Contracts [Member]
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets	38.6	15.3
Gross Liabilities Offset in the Balance Sheet	0.0	0.0
Net Amounts of Assets	38.6	15.3
Financial Instruments, Gross Amounts Not Offset in the Balance Sheet	(3.7)	(5.1)
Cash Collateral Received, Gross Amounts Not Offset in the Balance Sheet	0.0	0.0
Net Amount	34.9	10.2
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	(4.0)	(5.2)
Gross Assets Offset in the Balance Sheet	0.0	0.0
Net Amounts of Liabilities	(4.0)	(5.2)
Financial Instruments, Gross Amounts Not Offset in the Balance Sheet	3.7	5.1
Cash Collateral Pledged, Gross Amounts Not Offset in the Balance Sheet	0.0	0.0
Net Amount	(0.3)	(0.1)
Equity Contracts [Member]
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets	8.6	0.7
Gross Liabilities Offset in the Balance Sheet	0.0	0.0
Net Amounts of Assets	8.6	0.7
Financial Instruments, Gross Amounts Not Offset in the Balance Sheet	0.0	(0.7)
Cash Collateral Received, Gross Amounts Not Offset in the Balance Sheet	0.0	0.0
Net Amount	8.6	0.0
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	0.0	(5.8)
Gross Assets Offset in the Balance Sheet	0.0	0.0
Net Amounts of Liabilities	0.0	(5.8)
Financial Instruments, Gross Amounts Not Offset in the Balance Sheet	0.0	0.7
Cash Collateral Pledged, Gross Amounts Not Offset in the Balance Sheet	0.0	0.0
Net Amount	$ 0.0	$ (5.1)