Segment Disclosures (Tables)

3 Months Ended

Mar. 31, 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 March 31, 2017
Segment revenues:
Service revenues
External	$	1,256	$	5	$	—		$	1,261
Internal	—		3		(3		)	—
Total service revenues	1,256		8		(3		)	1,261
Product sales
External	727		—		—			727
Internal	—		—		—			—
Total product sales	727		—		—			727
Total revenues	$	1,983	$	8	$	(3	)	$	1,988
Three Months Ended March 31, 2016
Segment revenues:
Service revenues
External	$	1,222	$	7	$	—		$	1,229
Internal	4		11		(15		)	—
Total service revenues	1,226		18		(15		)	1,229
Product sales
External	428		3		—			431
Internal	—		—		—			—
Total product sales	428		3		—			431
Total revenues	$	1,654	$	21	$	(15	)	$	1,660
March 31, 2017
Total assets	$	46,938	$	656	$	(82	)	$	47,512
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   March 31,
	2017			2016
	(Millions)
Modified EBITDA by segment:
Williams Partners	$	1,132		$	955
Other	18			(37		)
	1,150			918
Accretion expense associated with asset retirement obligations for nonregulated operations	(7		)	(7		)
Depreciation and amortization expenses	(442		)	(445		)
Equity earnings (losses)	107			97
Impairment of equity-method investments	—			(112		)
Other investing income (loss) – net	272			18
Proportional Modified EBITDA of equity-method investments	(194		)	(189		)
Interest expense	(280		)	(291		)
(Provision) benefit for income taxes	(37		)	(2		)
Net income (loss)	$	569		$	(13	)