CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
NET LOSS	$ (76.7)	$ (28.7)	$ (189.0)	$ (18.4)
OTHER COMPREHENSIVE INCOME:
Net changes in pension and other postretirement plan assets and benefit obligations recognized in other comprehensive income, net of income tax expense of $4.2 and $0 for the three months ended June 30, 2018, and 2017, respectively and $4.2 and $0 for the six months ended June 30, 2018, and 2017, respectively (see Note 5).	15.9	0.0	15.9	0.0
Net reclassification adjustment for amounts recognized in net loss as a component of net periodic benefit cost, net of income tax expense of $0.5 and $0.5 for the three months ended June 30, 2018, and 2017, respectively, and $1.2 and $1.0 for the six months ended June 30, 2018, and 2017, respectively (see Note 5 and 9).	1.9	0.8	4.7	1.7
Total Other Comprehensive Income	17.8	0.8	20.6	1.7
COMPREHENSIVE LOSS	$ (58.9)	$ (27.9)	$ (168.4)	$ (16.7)