Other Income and Expenses (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other income (expense) - net [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Impairment of certain assets		$ 145	$ 52	$ 0
Amortization of regulatory assets associated with asset retirement obligations		33	33	30
Contingency gain settlement	[1]	0	(154)	0
Net gain related to partial acreage dedication release		0	(12)	0
Loss related to sale of certain assets		0	10	0
Other income (expense) - net [Member] | Williams Partners [Member] | Asset Impairment for Regulatory Action [Member]
Segment Reporting Information [Line Items]
Impairment of certain assets		0	(3)	12
Insurance recoveries		0	0	(16)
Other income (expense) - net [Member] | Williams Partners [Member] | Producer Claim [Member]
Segment Reporting Information [Line Items]
Loss associated with a producer claim		0	0	25
Other income (expense) - net [Member] | Williams NGL & Petchem Services [Member]
Segment Reporting Information [Line Items]
Impairment of certain assets		64	0	20
Net insurance recoveries - Geismar incident [Member] | Williams Partners [Member] | Geismar Incident [Member]
Segment Reporting Information [Line Items]
Insurance recoveries		(126)	(246)	(50)
Insurable expenses in excess of our deductibles			14	10
Selling, general and administrative expenses [Member] | Williams Partners [Member] | Acquisition and Merger [Member]
Segment Reporting Information [Line Items]
Business combination, acquisition related costs		26	27
Selling, general and administrative expenses [Member] | Williams Partners [Member] | Acquisition [Member]
Segment Reporting Information [Line Items]
Business combination, acquisition related costs			16
Selling, general and administrative expenses [Member] | Williams Partners [Member] | Transition [Member]
Segment Reporting Information [Line Items]
Business combination, integration related costs		9	15
Selling, general and administrative expenses [Member] | Other Segment [Member] | Other Restructuring [Member]
Segment Reporting Information [Line Items]
Business combination, integration related costs		32	10
Strategic alternative costs		30
Selling, general and administrative expenses [Member] | Williams NGL & Petchem Services [Member] | Bluegrass Pipeline Company Llc [Member]
Segment Reporting Information [Line Items]
Project development costs			18
Operation and maintenance [Member] | Williams Partners [Member] | Geismar Incident [Member]
Segment Reporting Information [Line Items]
Insurance deductible expense				13
Operation and maintenance [Member] | Williams Partners [Member] | Transition [Member]
Segment Reporting Information [Line Items]
Business combination, integration related costs		12	15
Interest expense [Member] | Acquisition [Member]
Segment Reporting Information [Line Items]
Business combination, acquisition related costs			9
Interest expense [Member] | Merger [Member]
Segment Reporting Information [Line Items]
Business combination, acquisition related costs		2
Service revenues [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Minimum volume commitment fees		239	167
Product costs [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Inventory Write-down		6	27
Other income (expense) - net [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Allowance for funds used during construction, capitalized cost of equity		95	$ 44	$ 22
Gain on extinguishment of debt		$ 14

[1] In November 2014, we settled a claim arising from the resolution of a contingent gain related to claims associated with the purchase of a business in a prior period. Pursuant to the settlement, we received $154 million in cash, all of which was recognized as a gain in the fourth quarter of 2014.