Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net income (loss)	$ 788.7	$ 358.8	$ (621.4)
Other comprehensive (loss) income, net of tax:
Less: reclassification adjustment for loss realized in net other assets, net of tax effect	0.7	0.0	0.0
Pension, SERP and Retiree medical adjustments, net of tax	12.5	(78.0)	84.8
Unrealized foreign exchange gain (loss) on intercompany loan, net of effect	(3.5)	(3.5)	1.2
Foreign currency translation adjustments	(16.4)	(16.6)	4.6
Total other comprehensive (loss) income	(6.7)	(99.2)	90.6
Total comprehensive income (loss)	782.0	259.6	(530.8)
Interest rate swaps [Member]
Other comprehensive (loss) income, net of tax:
Unrealized gain (loss) on derivatives arising during period, net of tax effect	$ 0.0	$ (1.1)	$ 0.0