PENSION AND POSTRETIREMENT BENEFITS - Schedule of Changes in Benefit Obligations and Plan Assets (Details) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
	Jan. 31, 2020	Feb. 23, 2020	May 31, 2020	May 26, 2019	May 27, 2018
Change in Plan Assets
Fair value of plan assets at beginning of year			$ 3,601.5
Fair value of plan assets at end of year			3,820.4	$ 3,601.5
Pension Benefits
Change in Benefit Obligation
Benefit obligation at beginning of year			3,733.2	3,423.6
Service cost			11.5	10.9	$ 42.8
Interest cost			118.4	132.6	111.1
Amendments				1.4
Actuarial loss (gain)			411.6	150.1
Plan settlements			(201.7)
Curtailments	$ 4.3		(0.8)
Benefits paid			(199.3)	(191.2)
Currency			(0.4)	(0.6)
Business acquisitions and divestitures				206.4
Benefit obligation at end of year			3,872.5	3,733.2	3,423.6
Change in Plan Assets
Fair value of plan assets at beginning of year			3,601.5	3,355.1
Actual return on plan assets			557.5	252.2
Employer contributions			17.5	14.7
Plan settlements		$ (154.6)	(156.3)
Benefits paid			(199.3)	(191.2)
Currency			(0.5)	(0.6)
Business acquisitions and divestitures				171.3
Fair value of plan assets at end of year			3,820.4	3,601.5	3,355.1
Other Benefits
Change in Benefit Obligation
Benefit obligation at beginning of year			91.2	119.3
Service cost			0.1	0.1	0.2
Interest cost			2.6	3.8	3.9
Plan participants' contributions				2.5
Amendments				(0.8)
Actuarial loss (gain)			3.0	(24.3)
Plan settlements			(0.1)	(0.5)
Curtailments				(0.6)
Benefits paid			(6.9)	(9.8)
Currency			(0.1)	(0.2)
Business acquisitions and divestitures				1.7
Benefit obligation at end of year			89.8	91.2	119.3
Change in Plan Assets
Fair value of plan assets at beginning of year			3.4	3.7
Actual return on plan assets			0.1	0.2
Employer contributions			6.9	7.3
Plan participants' contributions				2.5
Plan settlements			(0.1)	(0.5)
Benefits paid			(6.9)	(9.8)
Fair value of plan assets at end of year			$ 3.4	$ 3.4	$ 3.7