Segment Information (Details) - Operating Revenues - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating revenues	$ 584	$ 589	$ 2,979	$ 3,940
Third Party Gross Costs	146	198	1,303	2,000
Operating Segments [Member] \| Wholesale Services [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating revenues	34	5	128	383
Third Party Gross Costs	1	3	10	13
Third Party Gross Revenues [Member] \| Operating Segments [Member] \| Wholesale Services [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating revenues	1,440	1,885	4,876	8,313
Intercompany Revenues [Member] \| Operating Segments [Member] \| Wholesale Services [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating revenues	90	126	329	584
Total Gross Revenues [Member] \| Operating Segments [Member] \| Wholesale Services [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating revenues	1,530	2,011	5,205	8,897
Third Party Gross Costs [Member] \| Operating Segments [Member] \| Wholesale Services [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Third Party Gross Costs	$ 1,496	$ 2,006	$ 5,077	$ 8,514

The aggregate cost of goods produced and sold and services rendered during the reporting period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.2)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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+ References

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