Taxes (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Taxes [Abstract]
Stock options and other equity based compensation, tax expense (benefit)	$ (0.4)	$ (0.8)	$ 0.2
Operating loss carryforwards	779.1			145.1
Operating loss carryforwards, expiration dates		expire between 2012 and 2031
Tax credit carryforward	151.4
Future cash tax benefits accrue	0.8	1.3	4.8
Increases (decreases) in valuation allowance	2.1	(0.4)	0.7
Interest and penalties accrued related to unrecognized tax benefits	0.8	0.6
Interest and penalties recognized	$ 0.2	$ 0.1