Income Taxes (Income Before Income Taxes and Provision for Income Taxes) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income before income taxes
Domestic	$ 53.1	$ 107.0	$ 59.6
Foreign	4.9	5.3	3.1
Total	58.0	112.3	62.7
Income tax provision
Federal	(1.8)	28.7	3.9
State	1.5	2.5	1.4
Foreign	1.5	1.7	0.7
Total current	1.2	32.9	6.0
Deferred tax provision (benefit):
Federal	14.1	(0.2)	9.3
State	0.6	0.3	0.3
Foreign	(0.1)	(0.2)	0
Total deferred	14.6	(0.1)	9.6
Total income expense (benefit)	$ 15.8	$ 32.8	$ 15.6