Reportable Business Segments (Tables)

6 Months Ended

Jun. 30, 2017

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, 2017
	Revenues from External Customers			Inter-segment Revenues			Operating Income
	(in millions)
Natural Gas Distribution	$	470		$	7		$	37
Energy Services	918			13			16
Midstream Investments (1)	—			—			—
Other Operations	(1		)	—			—
Reconciling Eliminations	—			(20		)	—
Consolidated	$	1,387		$	—		$	53

	For the Three Months Ended June 30, 2016
	Revenues from External Customers		Inter-segment Revenues			Operating Income (Loss)
	(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 Six Months Ended June 30, 2017
	Revenues from External Customers		Inter-segment Revenues			Operating Income (Loss)			Total Assets as of June 30, 2017
	(in millions)
Natural Gas Distribution	$	1,377	$	16		$	201		$	6,022
Energy Services	2,103		24			51			1,388
Midstream Investments (1)	—		—			—			2,487
Other Operations	—		—			(5		)	82
Reconciling Eliminations	—		(40		)	—			(644		)
Consolidated	$	3,480	$	—		$	247		$	9,335

	For the Six Months Ended June 30, 2016
	Revenues from External Customers		Inter-segment Revenues			Operating Income (Loss)			Total Assets as of December 31, 2016
	(in millions)
Natural Gas Distribution	$	1,302	$	14		$	180		$	6,099
Energy Services	825		11			6			1,102
Midstream Investments (1)	—		—			—			2,505
Other Operations	—		—			(2		)	75
Reconciling Eliminations	—		(25		)	—			(563		)
Consolidated	$	2,127	$	—		$	184		$	9,218

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

	Three Months Ended June 30,				Six Months Ended June 30,
	2017		2016		2017		2016
	(in millions)
Enable	$	59	$	31	$	131	$	91

Midstream Investments [Table Text Block]

Midstream Investments’ equity earnings are as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2017		2016		2017		2016
	(in millions)
Enable	$	59	$	31	$	131	$	91