INCOME TAXES - Expirations of tax loss carry forwards (Details) $ in Millions	Jun. 30, 2018 USD ($)
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	$ 1,134.1
Tax Year 2020
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	15.2
Tax Year 2021
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	75.3
Tax Year 2022
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	13.2
Tax Year 2022
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	23.3
Tax Year 2023 and Thereafter
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	1,007.1
United States
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	1.7
United States | Tax Year 2020
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	0.0
United States | Tax Year 2021
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	0.0
United States | Tax Year 2022
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	0.0
United States | Tax Year 2022
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	0.0
United States | Tax Year 2023 and Thereafter
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	1.7
Western Europe
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	831.6
Western Europe | Tax Year 2020
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	0.0
Western Europe | Tax Year 2021
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	0.0
Western Europe | Tax Year 2022
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	0.8
Western Europe | Tax Year 2022
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	1.9
Western Europe | Tax Year 2023 and Thereafter
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	828.9
Rest of World
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	300.8
Rest of World | Tax Year 2020
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	15.2
Rest of World | Tax Year 2021
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	75.3
Rest of World | Tax Year 2022
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	12.4
Rest of World | Tax Year 2022
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	21.4
Rest of World | Tax Year 2023 and Thereafter
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	$ 176.5