PENSION AND POSTRETIREMENT BENEFITS - Schedule of Funded Status and Amounts Recognized (Details) - USD ($) $ in Millions	May 31, 2020	Feb. 23, 2020	Jan. 31, 2020	Dec. 31, 2019	Nov. 24, 2019	May 26, 2019
Pension Benefits
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded Status	$ (52.1)					$ (131.7)
Amounts Recognized in Consolidated Balance Sheets
Other assets	202.4					61.2
Other accrued liabilities	(8.9)					(10.2)
Other noncurrent liabilities	(245.6)					(182.7)
Net Amount Recognized	(52.1)					(131.7)
Amounts Recognized in Accumulated Other Comprehensive (Income) Loss (Pre-tax)
Actuarial net loss (gain)	51.2					115.8
Net prior service cost (benefit)	8.6					12.1
Total	$ 59.8					$ 127.9
Weighted-Average Actuarial Assumptions Used to Determine Benefit Obligations at May 31, 2020 and May 26, 2019
Discount rate	2.98%	2.96%	3.86%	3.37%	3.89%	3.88%
Other Benefits
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded Status	$ (86.4)					$ (87.8)
Amounts Recognized in Consolidated Balance Sheets
Other assets	2.9					2.8
Other accrued liabilities	(10.0)					(10.8)
Other noncurrent liabilities	(79.3)					(79.8)
Net Amount Recognized	(86.4)					(87.8)
Amounts Recognized in Accumulated Other Comprehensive (Income) Loss (Pre-tax)
Actuarial net loss (gain)	(15.0)					(47.8)
Net prior service cost (benefit)	(40.1)					(17.1)
Total	$ (55.1)					$ (64.9)
Weighted-Average Actuarial Assumptions Used to Determine Benefit Obligations at May 31, 2020 and May 26, 2019
Discount rate	2.39%					3.48%