Reportable Business Segments (Tables)

6 Months Ended

Jun. 30, 2016

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment [Table Text Block]

Financial data for business segments is as follows:

	For the Three Months Ended June 30, 2016
	Revenues from External Customers		Inter-segment Revenues			Operating Income
	(in millions)
Natural Gas Distribution	$	414	$	7		$	20
Energy Services	393		4			—
Midstream Investments (1)	—		—			—
Other Operations	—		—			(2		)
Reconciling Eliminations	—		(11		)	—
Consolidated	$	807	$	—		$	18

	For the Three Months Ended June 30, 2015
	Revenues from External Customers		Inter-segment Revenues			Operating Income (Loss)
	(in millions)
Natural Gas Distribution	$	420	$	7		$	19
Energy Services	404		4			9
Midstream Investments (1)	—		—			—
Other Operations	—		—			(1		)
Reconciling Eliminations	—		(11		)	—
Consolidated	$	824	$	—		$	27

	For the Six Months Ended June 30, 2016
	Revenues from External Customers		Inter-segment Revenues			Operating Income			Total Assets as of June 30, 2016
	(in millions)
Natural Gas Distribution	$	1,302	$	14		$	180		$	5,585
Energy Services	825		11			6			973
Midstream Investments (1)	—		—			—			2,536
Other Operations	—		—			(2		)	362
Reconciling Eliminations	—		(25		)	—			(828		)
Consolidated	$	2,127	$	—		$	184		$	8,628

	For the Six Months Ended June 30, 2015
	Revenues from External Customers		Inter-segment Revenues			Operating Income		Total Assets as of December 31, 2015
	(in millions)
Natural Gas Distribution	$	1,605	$	15		$	165	$	5,657
Energy Services	1,036		22			22		857
Midstream Investments (1)	—		—			—		2,594
Other Operations	—		—			—		777
Reconciling Eliminations	—		(37		)	—		(744		)
Consolidated	$	2,641	$	—		$	187	$	9,141

(1) Midstream Investments’ equity earnings are as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2016		2015		2016		2015
	(in millions)
Enable	$	31	$	43	$	91	$	95

Midstream Investments’ total assets are as follows:

	June 30, 2016		December 31, 2015
	(in millions)
Enable	$	2,536	$	2,594

Midstream Investments [Table Text Block]

Midstream Investments’ equity earnings are as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2016		2015		2016		2015
	(in millions)
Enable	$	31	$	43	$	91	$	95

Midstream Investments’ total assets are as follows:

	June 30, 2016		December 31, 2015
	(in millions)
Enable	$	2,536	$	2,594