Reportable Business Segments (Tables)

9 Months Ended

Sep. 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 September 30, 2017
	Revenues from External Customers		Inter-segment Revenues			Operating Income
	(in millions)
Natural Gas Distribution	$	390	$	8		$	19
Energy Services	861		10			7
Midstream Investments (1)	—		—			—
Other Operations	—		—			—
Reconciling Eliminations	—		(18		)	—
Consolidated	$	1,251	$	—		$	26

	For the Three Months Ended September 30, 2016
	Revenues from External Customers		Inter-segment Revenues			Operating Income (Loss)
	(in millions)
Natural Gas Distribution	$	370	$	7		$	22
Energy Services	608		6			5
Midstream Investments (1)	—		—			—
Other Operations	—		—			(1		)
Reconciling Eliminations	—		(13		)	—
Consolidated	$	978	$	—		$	26

	For the Nine Months Ended September 30, 2017
	Revenues from External Customers		Inter-segment Revenues			Operating Income (Loss)			Total Assets as of September 30, 2017
	(in millions)
Natural Gas Distribution	$	1,767	$	24		$	220		$	6,067
Energy Services	2,964		34			58			1,337
Midstream Investments (1)	—		—			—			2,481
Other Operations	—		—			(5		)	73
Reconciling Eliminations	—		(58		)	—			(582		)
Consolidated	$	4,731	$	—		$	273		$	9,376

	For the Nine Months Ended September 30, 2016
	Revenues from External Customers		Inter-segment Revenues			Operating Income (Loss)			Total Assets as of December 31, 2016
	(in millions)
Natural Gas Distribution	$	1,672	$	21		$	202		$	6,099
Energy Services	1,433		17			11			1,102
Midstream Investments (1)	—		—			—			2,505
Other Operations	—		—			(3		)	75
Reconciling Eliminations	—		(38		)	—			(563		)
Consolidated	$	3,105	$	—		$	210		$	9,218

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

	Three Months Ended September 30,				Nine Months Ended September 30,
	2017		2016		2017		2016
	(in millions)
Enable	$	68	$	73	$	199	$	164

Midstream Investments [Table Text Block]

Midstream Investments’ equity earnings are as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2017		2016		2017		2016
	(in millions)
Enable	$	68	$	73	$	199	$	164