Other Income and Expenses (Details) - USD ($)			3 Months Ended			6 Months Ended
		Jun. 16, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Revenue adjustment associated with litigation		$ 170,000
Other income (expense) - net [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Amortization of regulatory assets associated with asset retirement obligations			$ 9,000,000		$ 9,000,000	$ 17,000,000	$ 17,000,000
Net foreign currency exchange (gains) losses (1)	[1]		0		1,000,000	11,000,000	(4,000,000)
Other income (expense) - net [Member] | Williams NGL & Petchem Services [Member]
Segment Reporting Information [Line Items]
Gain on sale of unused pipe			0		0	(10,000,000)	0
Selling, general, and administrative expenses [Member]
Segment Reporting Information [Line Items]
Business combination, integration related costs					7,000,000		13,000,000
Selling, general, and administrative expenses [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Business combination, merger related costs					5,000,000	5,000,000	34,000,000
Selling, general, and administrative expenses [Member] | Williams NGL & Petchem Services [Member]
Segment Reporting Information [Line Items]
Project development costs			11,000,000			45,000,000
Selling, general, and administrative expenses [Member] | Other [Member]
Segment Reporting Information [Line Items]
Strategic alternative costs			13,000,000			19,000,000
Operating and maintenance expenses [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Business combination, integration related costs					8,000,000		12,000,000
Selling, general, and administrative expenses and Operating and maintenance expenses [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Severance and other related costs						26,000,000
Approximate percentage of workforce reductions				10.00%
Interest incurred [Member]
Segment Reporting Information [Line Items]
Business combination, merger related costs							2,000,000
Net insurance recoveries - Geismar incident [Member] | Williams Partners [Member] | Geismar Incident [Member]
Segment Reporting Information [Line Items]
Insurance recoveries					126,000,000		126,000,000
Service revenues [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Revenue adjustment associated with litigation						15,000,000
Other income (expense) - net [Member]
Segment Reporting Information [Line Items]
Gain on extinguishment of debt					14,000,000		14,000,000
Other income (expense) - net [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Allowance for funds used during construction, capitalized cost of equity			$ 18,000,000		$ 25,000,000	$ 39,000,000	$ 44,000,000

[1] Primarily relates to losses incurred on foreign currency transactions and the remeasurement of U.S. dollar denominated current assets and liabilities within our Canadian operations.