SUPPLEMENTARY FINANCIAL STATEMENT INFORMATION SUPPLEMENTARY FINANCIAL STATEMENT INFORMATION (Cash Flow Information) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure Text Block [Abstract]
Capital additions		$ 689.8	$ 394.8	$ 156.0
Non-cash accruals		15.3	93.6	(2.2)
Right-of-use asset - finance leases		29.3	7.6	6.5
Grants		(10.8)	(2.5)	0.0
Payments To Acquire Property Plant And Equipment Net		656.0	296.1	151.7
Capital expenditure related to discontinued operations		0.0	0.1	2.8
Taxes paid on income		0.2	2.9	1.7
Income tax refunds		(117.9)	(11.3)	(7.8)
Interest paid on debt obligations net of capitalized interest		97.6	105.7	139.0
Capitalized interest		$ 24.8	$ 6.5	$ 0.0
Common Stock, Dividends, Per Share, Declared	$ 0.06	$ 0.27	$ 0.05	$ 0
Dividends Payable	$ 16.2	$ 16.2