PENSION AND POSTRETIREMENT BENEFITS - Schedule of Fair Value of Plan Assets, Summarized by Level (Details) - USD ($) $ in Millions	May 28, 2017	May 29, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	$ 2,983.6	$ 2,959.4
Fair value measurement of pension plan assets in the fair value hierarchy	1,678.3	1,616.3
Investments measured at net asset value	1,305.3	1,343.1
Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	95.0	74.3
U.S. equity securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	507.7	466.7
International equity securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	263.1	280.0
Government bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	275.4	271.7
Corporate bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	283.9	250.2
Mortgage-backed bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	69.5	114.4
Real estate funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	9.5	0.0
Multi-strategy hedge funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Private equity funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Master limited partnerships
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	173.5	155.8
Private natural resources funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Net receivables for unsettled transactions
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.7	3.2
Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	1,047.4	1,005.9
Level 1 | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	1.0	0.9
Level 1 | U.S. equity securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	494.0	453.5
Level 1 | International equity securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	249.9	267.5
Level 1 | Government bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	51.1	43.3
Level 1 | Corporate bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	4.4	23.6
Level 1 | Mortgage-backed bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	63.3	58.1
Level 1 | Real estate funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	9.5	0.0
Level 1 | Multi-strategy hedge funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Level 1 | Private equity funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Level 1 | Master limited partnerships
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	173.5	155.8
Level 1 | Private natural resources funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Level 1 | Net receivables for unsettled transactions
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.7	3.2
Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	630.9	610.4
Level 2 | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	94.0	73.4
Level 2 | U.S. equity securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	13.7	13.2
Level 2 | International equity securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	13.2	12.5
Level 2 | Government bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	224.3	228.4
Level 2 | Corporate bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	279.5	226.6
Level 2 | Mortgage-backed bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	6.2	56.3
Level 2 | Real estate funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Level 2 | Multi-strategy hedge funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Level 2 | Private equity funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Level 2 | Master limited partnerships
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Level 2 | Private natural resources funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Level 2 | Net receivables for unsettled transactions
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Level 3 | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Level 3 | U.S. equity securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Level 3 | International equity securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Level 3 | Government bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Level 3 | Corporate bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Level 3 | Mortgage-backed bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Level 3 | Real estate funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Level 3 | Multi-strategy hedge funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Level 3 | Private equity funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Level 3 | Master limited partnerships
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Level 3 | Private natural resources funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	0.0	0.0
Level 3 | Net receivables for unsettled transactions
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan assets	$ 0.0	$ 0.0