PENSION AND POSTRETIREMENT BENEFITS (Fair Value Hierarchy) (Details) - USD ($) $ in Millions	May. 31, 2015	May. 25, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	$ 3,539.0	$ 3,546.0
Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	82.7	152.6
U.S. equity securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	633.1	628.6
International equity securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	811.7	822.0
Government bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	334.4	380.3
Corporate bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	444.5	408.4
Mortgage-backed bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	73.5	127.9
Real estate funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	351.5	197.4
Multi-strategy hedge funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	484.5	462.3
Private equity funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	93.0	81.3
Master limited partnerships
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	191.4	263.3
Private natural resources funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	31.8	16.6
Net receivables for unsettled transactions
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	6.9	5.3
Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	1,248.8	1,626.9
Level 1 | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	2.4	2.4
Level 1 | U.S. equity securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	542.2	535.4
Level 1 | International equity securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	362.9	589.7
Level 1 | Government bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	43.9	114.0
Level 1 | Corporate bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	49.6	63.8
Level 1 | Mortgage-backed bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	49.5	50.2
Level 1 | Real estate funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	0.0	2.8
Level 1 | Multi-strategy hedge funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	0.0	0.0
Level 1 | Private equity funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	0.0	0.0
Level 1 | Master limited partnerships
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	191.4	263.3
Level 1 | Private natural resources funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total 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 assets	6.9	5.3
Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	1,347.9	1,188.3
Level 2 | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	80.3	150.2
Level 2 | U.S. equity securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	90.9	93.2
Level 2 | International equity securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	448.8	232.3
Level 2 | Government bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	290.5	266.3
Level 2 | Corporate bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	394.9	344.6
Level 2 | Mortgage-backed bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	24.0	77.7
Level 2 | Real estate funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	6.6	24.0
Level 2 | Multi-strategy hedge funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	0.0	0.0
Level 2 | Private equity funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	0.0	0.0
Level 2 | Master limited partnerships
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total 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 assets	11.9	0.0
Level 2 | Net receivables for unsettled transactions
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	0.0	0.0
Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	942.3	730.8
Level 3 | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total 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 assets	0.0	0.0
Level 3 | International equity securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	0.0	0.0
Level 3 | Government bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	0.0	0.0
Level 3 | Corporate bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	0.0	0.0
Level 3 | Mortgage-backed bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	0.0	0.0
Level 3 | Real estate funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	344.9	170.6
Level 3 | Multi-strategy hedge funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	484.5	462.3
Level 3 | Private equity funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	93.0	81.3
Level 3 | Master limited partnerships
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total 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 assets	19.9	16.6
Level 3 | Net receivables for unsettled transactions
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total assets	$ 0.0	$ 0.0