The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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)(1)

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Business And Significant Accounting Policies (Details)	9 Months Ended
Business And Significant Accounting Policies (Details)	Sep. 30, 2014	Sep. 30, 2014 Oncor [Member]	Nov. 30, 2008 Oncor [Member]
Variable Interest Entity [Line Items]
Equity Method Investment, Maximum Ownership Percentage For Accounting Treatment	50.00%
Business and Significant Accounting Policies
Equity method investment, ownership (as a percent)		80.00%
Sale of equity ownership interest (as a percent)			19.75%