Segment Disclosures (Tables)

12 Months Ended

Dec. 31, 2015

Segment Reporting [Abstract]

Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block]

The following geographic area data includes Revenues from external customers based on product shipment origin and Long-lived assets based upon physical location.

		United States		Canada		Total
		(Millions)
Revenues from external customers:
	2015	$	7,247	$	113	$	7,360
	2014	7,229		408		7,637
	2013	6,703		157		6,860
Long-lived assets:
	2015	$	38,016	$	1,580	$	39,596
	2014	38,290		1,364		39,654
	2013	19,260		1,240		20,500

Reconciliation of segment revenues [Table Text Block]

The following table reflects the reconciliation of Segment revenues to Total revenues as reported in the Consolidated Statement of Operations and Other financial information.

	Williams Partners		Williams NGL & Petchem Services (1)			Other		Eliminations			Total
	(Millions)
2015
Segment revenues:
Service revenues
External	$	5,134	$	2		$	28	$	—		$	5,164
Internal	1		—			158		(159		)	—
Total service revenues	5,135		2			186		(159		)	5,164
Product sales
External	2,196		—			—		—			2,196
Internal	—		—			—		—			—
Total product sales	2,196		—			—		—			2,196
Total revenues	$	7,331	$	2		$	186	$	(159	)	$	7,360
Other financial information:
Additions to long-lived assets	$	2,960	$	360		$	28	$	(12	)	$	3,336
Proportional Modified EBITDA of equity-method investments	699		—			—					699
2014
Segment revenues:
Service revenues
External	$	3,887	$	—		$	229	$	—		$	4,116
Internal	1		—			30		(31		)	—
Total service revenues	3,888		—			259		(31		)	4,116
Product sales
External	3,521		—			—		—			3,521
Internal	—		—			—		—			—
Total product sales	3,521		—			—		—			3,521
Total revenues	$	7,409	$	—		$	259	$	(31	)	$	7,637
Other financial information:
Additions to long-lived assets (2)	$	20,413	$	291		$	54	$	(2	)	$	20,756
Proportional Modified EBITDA of equity-method investments	431		(78		)	85					438
2013
Segment revenues:
Service revenues
External	$	2,914	$	—		$	25	$	—		$	2,939
Internal	—		—			11		(11		)	—
Total service revenues	2,914		—			36		(11		)	2,939
Product sales
External	3,921		—			—		—			3,921
Internal	—		—			—		—			—
Total product sales	3,921		—			—		—			3,921
Total revenues	$	6,835	$	—		$	36	$	(11	)	$	6,860
Other financial information:
Additions to long-lived assets	$	3,409	$	295		$	27	$	—		$	3,731
Proportional Modified EBITDA of equity-method investments	209		—			197					406

__________

(1) Includes certain projects under development and thus nominal reported revenues to date.

(2) 2014 Additions to long-lived assets within our Williams Partners segment primarily includes the acquisition-date fair value of long-lived assets from the ACMP Acquisition. (See Note 2 - Acquisitions.)

Reconciliation of Modified EBITDA from Segments to Consolidated [Table Text Block]

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

	Years Ended December 31,
	2015			2014			2013
	(Millions)
Modified EBITDA by segment:
Williams Partners	$	4,003		$	3,244		$	2,447
Williams NGL & Petchem Services	(83		)	(115		)	(33		)
Other	(29		)	103			197
	3,891			3,232			2,611
Accretion expense associated with asset retirement obligations for nonregulated operations	(28		)	(18		)	(15		)
Depreciation and amortization expenses	(1,738		)	(1,176		)	(815		)
Impairment of goodwill	(1,098		)	—			—
Equity earnings (losses)	335			144			134
Gain on remeasurement of equity-method investment	—			2,544			—
Impairment of equity-method investments	(1,359		)	—			—
Other investing income (loss) – net	27			43			81
Proportional Modified EBITDA of equity-method investments	(699		)	(438		)	(406		)
Interest expense	(1,044		)	(747		)	(510		)
(Provision) benefit for income taxes	399			(1,249		)	(401		)
Income (loss) from discontinued operations, net of tax	—			4			(11		)
Net income (loss)	$	(1,314	)	$	2,339		$	668

Total assets and equity method investments by reporting segment [Table Text Block]

The following table reflects Total assets and Equity-method investments by reportable segments:

	Total Assets						Equity-Method Investments
	December 31, 2015			December 31, 2014			December 31, 2015		December 31, 2014
	(Millions)
Williams Partners	$	47,870		$	49,248		$	7,336	$	8,399
Williams NGL & Petchem Services	835			612			—		—
Other	850			1,186			—		1
Eliminations	(535		)	(591		)	—		—
Total	$	49,020		$	50,455		$	7,336	$	8,400