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		6 Months Ended		1 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Mar. 31, 2011 IEA [Member]	Jun. 30, 2011 RMT [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net proceeds					$ 5	$ 12
Operating revenues	93.9	107.0	148.5	175.9
Operating expenses	93.0	105.6	154.9	171.0
Interest expense and other	0.2	0	0.2	0.1
Income (loss) before income taxes	0.7	1.4	(6.6)	4.8
Income tax expense (benefit)	0.3	0.6	(2.6)	2.5
Income (loss) from discontinued operations, net of tax	$ 0.4	$ 0.8	$ (4.0)	$ 2.3