Organization and Basis of Presentation (Details Textuals) customer in Millions, $ in Millions	Dec. 31, 2015 USD ($) customer	Dec. 31, 2014 USD ($)
Entity Information [Line Items]
Number of electric utility customers	2.2
Number of gas utility customers	1.2
Amount in excess of carrying amount \| $	$ 81	$ 81

Difference between amount at which an investment accounted for under the equity method of accounting is carried (reported) on the balance sheet and amount of underlying equity in net assets the reporting Entity has in the investee.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

Name:	us-gaap_EquityMethodInvestmentDifferenceBetweenCarryingAmountAndUnderlyingEquity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant