Other Income and Expense (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Loss related to sale of certain assets	$ 56us-gaap_GainLossOnDispositionOfAssets1	$ 28us-gaap_GainLossOnDispositionOfAssets1	$ (52)us-gaap_GainLossOnDispositionOfAssets1
Williams Partners [Member]
Segment Reporting Information [Line Items]
Contingency gain settlement	(154)	0	0
Impairment of certain assets	40	0	0
Net gain related to partial acreage dedication release	(12)	0	0
Amortization of regulatory assets associated with asset retirement obligations	33	30	7
Project feasibility costs	2	4	21
Capitalization of project feasibility costs previously expensed	(5)	(1)	(19)
Williams Partners [Member] \| Producer Claim [Member]
Segment Reporting Information [Line Items]
Loss associated with a producer claim	0	25	0
Williams Partners [Member] \| Asset Impairment for Regulatory Action [Member]
Segment Reporting Information [Line Items]
Impairment of certain assets	(3)	12	0
Insurance recoveries associated with the Eminence abandonment	0	(16)	0
Access Midstream [Member]
Segment Reporting Information [Line Items]
Loss related to sale of certain assets	10	0	0
Impairment of certain pipe and equipment held for sale	12	0	0
Williams NGL & Petchem Services [Member]
Segment Reporting Information [Line Items]
Impairment of certain assets	$ 0	$ 20	$ 0

The expense charged against earnings during the period to allocate the capitalized costs of regulatory assets over the periods expected to benefit from such costs.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-Section 45

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Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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Development costs incurred, including capitalized costs and costs charged to expense, in oil and gas activities.

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Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee.

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The aggregate amount of write-downs for impairments recognized during the period for long-lived assets held for abandonment, exchange or sale.

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-Publisher FASB

-Name Accounting Standards Codification

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The amount recovered from insurance. These recoveries reduce costs and losses that are reported as a separate line item under operating expenses.

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The amount of loss pertaining to the specified contingency that was charged against earnings in the period, including the effects of revisions in previously reported estimates.

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-Publisher FASB

-Name Accounting Standards Codification

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Capitalization Of Project Feasibility Costs Previously Expensed

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Income from release of a customer's acreage dedication.

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Gain related to claims from purchase of business in a prior period

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