Asset Sales And Discontinued Operations (Discontinued Operations) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012		Dec. 31, 2011
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pretax income from discontinued operations			$ 11		$ 2
Income tax expense			4
Income from discontinued operations, net of tax expense	7		7	[1]	2	[2]
Panhandle [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Operating gain, before tax			11
Operating gain			7
CMS Viron [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Operating gain			$ 3

[1] Includes an $11 million ($7 million net of tax) reversal of a loss on disposal due to the elimination of a liability associated with the 2003 sale of Panhandle.

[2] Includes an operating gain of $3 million related to a litigation settlement at CMS Viron.