Condensed Consolidated Statements of Comprehensive Income (Loss) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 17.1	$ 117.5	$ 24.5	$ 116.9	[1]
Other comprehensive income:
Change in foreign currency translation adjustment	0.4	1.2	0.4	(4.5)
Change in unrecognized gains related to pension benefit plans, net of income tax expense of $0.4, $0.0, $0.8, and $0.5, respectively	0.6	2.1	1.4	5.4
Unrealized net gain (loss) on derivatives, net of income tax expense (benefit) of $(0.1), $0.2, $(0.1), and $0.0, respectively	(0.2)	1.1	(0.2)	0.5
Total other comprehensive income	0.8	4.4	1.6	1.4
Comprehensive income (loss)	$ 17.9	$ 121.9	$ 26.1	$ 118.3

[1] The change in actuarial losses in the three and six months ended June 30, 2014 includes $1.4 million and $2.7 million of actuarial losses that have been included in the computation of net postretirement pension expense for the period.