INCOME TAXES - Reconciliation of Tax Expense to Statutory Federal Income Tax Rate (Details) - USD ($) $ in Millions	1 Months Ended		3 Months Ended	12 Months Ended
	Dec. 31, 2017	Jan. 31, 2017	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Computed income tax expense				$ (57.2)	$ 3.0	$ 38.8
State and local taxes, net of U.S. federal income tax benefit				6.1	1.8	11.1
Foreign and U.S. tax effects attributable to operations outside the U.S.				(6.5)	3.1	13.6
Net establishment (release) of valuation allowance				(1.2)	2.0	(15.5)
Foreign dividends and earnings taxable in the U.S.				1.8	1.7	3.2
Impairment for which there is no tax benefit				0.4	8.9	0.0
Tax effect of basis reclassification				23.7	0.0	0.0
Impact of Tax Cuts and Jobs Act	$ 17.6	$ 30.3		47.9	0.0	0.0
Other				6.8	5.0	0.2
Provision for income taxes			$ 59.6	$ 21.8	$ 25.5	$ 51.4