Equity Activity (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at the beginning of year	$ (20.8)	$ 0.8	$ 1.5
Change during the period	(1.5)	(21.6)	(0.7)
Balance at the end of year	(22.3)	(20.8)	0.8
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at the beginning of year	0.7	2.3	0.7
Change during the period	1.4	(1.6)	1.6
Balance at the end of year	2.1	0.7	2.3
Post-Retirement Liability Adjustment, net [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at the beginning of year	(21.5)	(1.5)	0.8
Change during the period	(2.9)	(20.0)	(2.3)
Balance at the end of year	$ (24.4)	$ (21.5)	$ (1.5)