FAIR VALUE MEASUREMENTS (Fair Value of Assets and Liabilities Measured on Recurring Basis) (Details) - USD ($) $ in Millions	Feb. 28, 2016	May. 31, 2015
Assets:
Derivative assets	$ 27.6	$ 32.2
Available-for-sale securities	2.8	2.8
Deferred compensation assets	0.9	0.9
Total assets	31.3	35.9
Liabilities:
Derivative liabilities	8.1	14.2
Deferred compensation liabilities	45.9	43.7
Total liabilities	54.0	57.9
Level 1
Assets:
Derivative assets	3.2	13.6
Available-for-sale securities	2.8	2.8
Deferred compensation assets	0.9	0.9
Total assets	6.9	17.3
Liabilities:
Derivative liabilities	0.0	0.0
Deferred compensation liabilities	45.9	43.7
Total liabilities	45.9	43.7
Level 2
Assets:
Derivative assets	24.4	18.6
Available-for-sale securities	0.0	0.0
Deferred compensation assets	0.0	0.0
Total assets	24.4	18.6
Liabilities:
Derivative liabilities	8.1	14.2
Deferred compensation liabilities	0.0	0.0
Total liabilities	8.1	14.2
Level 3
Assets:
Derivative assets	0.0	0.0
Available-for-sale securities	0.0	0.0
Deferred compensation assets	0.0	0.0
Total assets	0.0	0.0
Liabilities:
Derivative liabilities	0.0	0.0
Deferred compensation liabilities	0.0	0.0
Total liabilities	$ 0.0	$ 0.0