REVENUE Contract Assets and Liabilities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Contract with Customer, Asset and Liability [Abstract]
Short-term contract asset (see Note 2)	$ 25.8	$ 43.2	$ 0.0
Current Contract Assets, Percentage Change from Prior Period	(40.30%)
Contract with Customer, Asset, Net, Noncurrent	$ 0.7	0.0
Noncurrent Contract Assets, Percentage Change from Prior Period	100.00%
Contract with Customer, Liability	$ (57.5)	(61.7)
Current Contract Liabilities, Percentage Change from Prior Period	(6.80%)
Net Contract Liabilities	$ (31.0)	$ (18.5)
Net Contract Liability, Change from Prior Year	$ (12.5)
Net Contract Liability, Percentage Change from Prior Period	67.60%