Discontinued Operations And Assets And Liabilities Held For Sale (Components Of Discontinued Operations In Condensed Consolidated Statements Of Income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Operating revenues	$ 0.9	$ 54.6
Operating expenses	5.6	61.9
Income (loss) before income taxes	(4.7)	(7.3)
Income tax expense (benefit)	(1.7)	(2.9)
Income (loss) from discontinued operations, net of tax	$ (3.0)	$ (4.4)