Other Income and Expenses (Details) - USD ($) $ in Millions			3 Months Ended		6 Months Ended
		Feb. 23, 2017	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting Information [Line Items]
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums		$ 53
Debt Instrument, Unamortized Premium		23
Debt Instrument, Unamortized Discount (Premium), Net		30
Williams Partners [Member]
Segment Reporting Information [Line Items]
Revenue adjustment associated with litigation						$ (15)
Other income (expense) - net [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Amortization of regulatory assets associated with asset retirement obligations			$ 9	$ 9	$ 17	17
Net foreign currency exchange (gains) losses (1)	[1]		0	0	0	11
Gain (Loss) on Disposition of Assets			(12)	0	(12)	0
Gain (Loss) on Contract Termination			(2)	0	(15)	0
Other income (expense) - net [Member] | Other [Member]
Segment Reporting Information [Line Items]
Gain on sale of unused pipe			0	0	0	(10)
Selling, general, and administrative expenses [Member] | Other [Member]
Segment Reporting Information [Line Items]
Project development costs				11		45
Selling, general, and administrative expenses and Operating and maintenance expenses [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Severance and other related costs			4		13	$ 26
Approximate percentage of workforce reductions						10.00%
Other Nonoperating Income (Expense) [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Allowance for funds used during construction, capitalized cost of equity			19	13	37	$ 30
Deferred taxes on equity funds used during construction [Member] | Other [Member]
Segment Reporting Information [Line Items]
Allowance for funds used during construction, capitalized cost of equity			9	5	37	9
6.125% Senior Unsecured Notes due 2022 [Member] | Williams Partners L.P. [Member]
Segment Reporting Information [Line Items]
Long-term debt retired		$ 750
Long-term debt interest rate		6.125%
Acquisition and Merger [Member] | Selling, general, and administrative expenses [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Business combination, merger related costs			$ 3	$ 13	$ 4	$ 19

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