Financial Instruments, Risk Management Activities, and Fair Values (Schedule of Marketable Debt and Equity Securities) (Details) - USD ($) $ in Millions	12 Months Ended
	May 26, 2024	May 28, 2023
Financial Instruments, Risk Management Activities, and Fair Values [Abstract]
Available for sale debt securities, Cost	$ 2.3	$ 2.3
Equity securities, Cost	0.3	117.5
Total, Cost	2.6	119.8
Available for sale debt securities, Fair Value	2.3	2.3
Equity securities, Fair Value	4.6	122.7
Total, Fair Value	6.9	125.0
Available for sale debt securities, Gross Unrealized Gains	0.0	0.0
Equity securities, Gross Unrealized Gains	4.3	5.2
Total, Gross Unrealized Gains	4.3	5.2
Available for sale debt securities, Gross Unrealized Losses	0.0	0.0
Equity securities, Gross Unrealized Losses	0.0	10.0
Total, Gross Unrealized Losses	$ 0.0	$ 10.0