CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
NET INCOME (LOSS)	$ 5.5	$ (239.4)	$ 345.0	$ (31.0)
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 $10.3 for the three and nine months ended September 2016 (See Note 3)	19.2	0.0	19.2	0.0
Net reclassification adjustment for amounts recognized in net income (loss) as a component of net periodic benefit cost, net of income tax expense of $0.5 and $1.9 for the three months ended September 30, 2016 and 2015, and $3.2 and $5.5 for the nine months ended September 30, 2016 and 2015, respectively (See Notes 3 and 8)	1.0	3.4	6.0	10.2
OTHER COMPREHENSIVE INCOME	20.2	3.4	25.2	10.2
COMPREHENSIVE INCOME (LOSS)	$ 25.7	$ (236.0)	$ 370.2	$ (20.8)