BUSINESS SEGMENTS AND RELATED INFORMATION - Schedule of Net Derivative Gains (Losses) from Economic Hedges of Forecasted Commodity Consumption and Foreign Currency Risk (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2020	May 26, 2019	May 27, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Net derivative losses incurred	$ (4.5)
Commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Net derivative losses incurred	(12.9)	$ (3.6)	$ (0.9)
Commodity contracts | Reporting segments
Derivative Instruments, Gain (Loss) [Line Items]
Net derivative losses incurred	(7.4)	(1.8)	(7.1)
Commodity contracts | Reporting segments | Grocery & Snacks
Derivative Instruments, Gain (Loss) [Line Items]
Net derivative losses incurred	(4.7)	(2.5)	0.2
Commodity contracts | Reporting segments | Refrigerated & Frozen
Derivative Instruments, Gain (Loss) [Line Items]
Net derivative losses incurred	(2.5)	(1.5)	(0.3)
Commodity contracts | Reporting segments | International
Derivative Instruments, Gain (Loss) [Line Items]
Net derivative losses incurred	0.1	2.8	(6.9)
Commodity contracts | Reporting segments | Foodservice
Derivative Instruments, Gain (Loss) [Line Items]
Net derivative losses incurred	(0.3)	(0.6)	(0.1)
Commodity contracts | Corporate
Derivative Instruments, Gain (Loss) [Line Items]
Net derivative losses incurred	$ (5.5)	$ (1.8)	$ 6.2