Segment Disclosures (Tables)

9 Months Ended

Sep. 30, 2017

Segment Reporting [Abstract]

Reconciliation of Revenue from Segments to Consolidated [Table Text Block]

The following table reflects the reconciliation of Segment revenues to Total revenues as reported in the Consolidated Statement of Operations and Total assets by reportable segment.

	Williams Partners		Other		Eliminations			Total
	(Millions)
Three Months Ended September 30, 2017
Segment revenues:
Service revenues
External	$	1,304	$	6	$	—		$	1,310
Internal	—		2		(2		)	—
Total service revenues	1,304		8		(2		)	1,310
Product sales
External	581		—		—			581
Internal	—		—		—			—
Total product sales	581		—		—			581
Total revenues	$	1,885	$	8	$	(2	)	$	1,891
Three Months Ended September 30, 2016
Segment revenues:
Service revenues
External	$	1,241	$	6	$	—		$	1,247
Internal	11		3		(14		)	—
Total service revenues	1,252		9		(14		)	1,247
Product sales
External	655		3		—			658
Internal	—		6		(6		)	—
Total product sales	655		9		(6		)	658
Total revenues	$	1,907	$	18	$	(20	)	$	1,905
Nine Months Ended September 30, 2017
Segment revenues:
Service revenues
External	$	3,836	$	17	$	—		$	3,853
Internal	1		8		(9		)	—
Total service revenues	3,837		25		(9		)	3,853
Product sales
External	1,950		—		—			1,950
Internal	—		—		—			—
Total product sales	1,950		—		—			1,950
Total revenues	$	5,787	$	25	$	(9	)	$	5,803
Nine Months Ended September 30, 2016
Segment revenues:
Service revenues
External	$	3,656	$	22	$	—		$	3,678
Internal	32		17		(49		)	—
Total service revenues	3,688		39		(49		)	3,678
Product sales
External	1,613		10		—			1,623
Internal	—		16		(16		)	—
Total product sales	1,613		26		(16		)	1,623
Total revenues	$	5,301	$	65	$	(65	)	$	5,301
September 30, 2017
Total assets	$	45,635	$	570	$	(85	)	$	46,120
December 31, 2016
Total assets	$	46,265	$	685	$	(115	)	$	46,835

Reconciliation of Modified EBITDA to Net Income (Loss) [Table Text Block]

The following table reflects the reconciliation of Modified EBITDA to Net income (loss) as reported in the Consolidated Statement of Operations.

	Three Months Ended   September 30,						Nine Months Ended   September 30,
	2017			2016			2017			2016
	(Millions)
Modified EBITDA by segment:
Williams Partners	$	1,000		$	1,070		$	3,208		$	2,629
Other	(61		)	(67		)	(60		)	(534		)
	939			1,003			3,148			2,095
Accretion expense associated with asset retirement obligations for nonregulated operations	(7		)	(9		)	(23		)	(24		)
Depreciation and amortization expenses	(433		)	(435		)	(1,308		)	(1,326		)
Equity earnings (losses)	115			104			347			302
Impairment of equity-method investments	—			—			—			(112		)
Other investing income (loss) – net	4			28			278			64
Proportional Modified EBITDA of equity-method investments	(202		)	(194		)	(611		)	(574		)
Interest expense	(267		)	(297		)	(818		)	(886		)
(Provision) benefit for income taxes	(24		)	(69		)	(126		)	74
Net income (loss)	$	125		$	131		$	887		$	(387	)