Discontinued Operations And Assets And Liabilities Held For Sale (Assets And Liabilities Of Discontinued Operations And Held For Sale) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Property, Plant, and Equipment, Net	$ 21.5
Disposal Group Including Discontinued Operation, Price Risk Management Assets	107.0
Disposal Group, Including Discontinued Operation, Other Assets	5.4
Assets of Disposal Group, Including Discontinued Operation	133.9
Disposal Group Including Discontinued Operation, Price Risk Management Liabilities	104.7
Disposal Group, Including Discontinued Operation, Other Liabilities	3.9
Liabilities of Disposal Group, Including Discontinued Operation	108.6
Gas Distribution Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Property, Plant, and Equipment, Net	21.5
Disposal Group Including Discontinued Operation, Price Risk Management Assets	0
Disposal Group, Including Discontinued Operation, Other Assets	4.5
Assets of Disposal Group, Including Discontinued Operation	26.0
Disposal Group Including Discontinued Operation, Price Risk Management Liabilities	0
Disposal Group, Including Discontinued Operation, Other Liabilities	3.3
Liabilities of Disposal Group, Including Discontinued Operation	3.3
Electric Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Property, Plant, and Equipment, Net	0
Disposal Group Including Discontinued Operation, Price Risk Management Assets	0
Disposal Group, Including Discontinued Operation, Other Assets	0.7
Assets of Disposal Group, Including Discontinued Operation	0.7
Disposal Group Including Discontinued Operation, Price Risk Management Liabilities	0
Disposal Group, Including Discontinued Operation, Other Liabilities	0.6
Liabilities of Disposal Group, Including Discontinued Operation	0.6
Corporate and Other [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Property, Plant, and Equipment, Net	0
Disposal Group Including Discontinued Operation, Price Risk Management Assets	107.0
Disposal Group, Including Discontinued Operation, Other Assets	0.2
Assets of Disposal Group, Including Discontinued Operation	107.2
Disposal Group Including Discontinued Operation, Price Risk Management Liabilities	104.7
Disposal Group, Including Discontinued Operation, Other Liabilities	$ 0