EMPLOYEE BENEFITS (Amounts in AOCI not Recognized as Components of Net Periodic Benefit Cost) (Details) $ in Millions	12 Months Ended
	Jun. 30, 2018 USD ($)
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax [Abstract]
Total plans, at the beginning of period	$ (0.8)
Total - Recognition of net periodic benefit expense	0.3
Total plans - Deferrals	(13.8)
Total plans - Net Change in AOCL	(13.5)
Total plans, at the end of period	(14.3)
Pension Plans
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax [Abstract]
Prior service benefit/(cost) - Recognition of net periodic benefit expense	0.4
Deferred income tax benefit/(expense) - Recognition of net periodic benefit expense	(0.1)
Total - Recognition of net periodic benefit expense	0.3
Net actuarial/(loss) gain - Deferrals	(11.2)
Prior service benefit/(cost) - Deferrals	(7.8)
Deferred income tax benefit/(expense) - Deferrals	5.6
Total plans - Deferrals	(13.4)
Net actuarial/(loss) gain - Net Change in AOCL	(11.2)
Prior service benefit/(cost) - Net Change in AOCL	(7.4)
Deferred income tax benefit/(expense) - Net Change in AOCL	5.5
Total plans - Net Change in AOCL	(13.1)
Net actuarial/(loss) gain, at the end of period	(11.2)
Prior service benefit/(cost), at the end of period	(7.4)
Deferred income tax benefit/(expense), at the end of period	5.5
Total plans, at the end of period	(13.1)
OPEB Plans
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax [Abstract]
Net actuarial (loss)/gain, at the beginning of period	(1.2)
Deferred income tax benefit/(expense), at the beginning of period	0.4
Total plans, at the beginning of period	(0.8)
Net actuarial/(loss) gain - Deferrals	(0.4)
Total plans - Deferrals	(0.4)
Net actuarial/(loss) gain - Net Change in AOCL	(0.4)
Total plans - Net Change in AOCL	(0.4)
Net actuarial/(loss) gain, at the end of period	(1.6)
Deferred income tax benefit/(expense), at the end of period	0.4
Total plans, at the end of period	$ (1.2)