Asset Sales, Impairments and Other Accruals (Details) (USD $) In Millions	12 Months Ended
Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Unusual or Infrequent Item [Line Items]
Impairment of goodwill	$ 1,000
Williams Partners [Member]
Unusual or Infrequent Item [Line Items]
Involuntary conversion gains	(18)	(4)	(17)
Gains on sales of certain assets	(12)	(40)	(10)
Accrual of regulatory liability related to overcollection of certain employee expenses	10
Impairments of certain gathering and transportation assets	9		6
Exploration and Production [Member]
Unusual or Infrequent Item [Line Items]
Gain on sale of contractual right to an international production payment			(148)
Impairment of goodwill	1,003
Impairments of producing properties and acquired unproved reserves	678	15
Penalties from early release of drilling rigs		32
Midstream Canada & Olefins [Member]
Unusual or Infrequent Item [Line Items]
Gulf Liquids litigation contingency accrual reversal			$ (32)

This element represents the income received from or payment made to a third party in connection with the termination of a contract between the parties. The termination may be due to many causes including early termination of a lease by a lessee, a breach of contract by one or the other party, a failure to perform.

Name:	us-gaap_GainLossOnContractTermination
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The excess or deficiency of net proceeds from sale in the period compared to carrying value of intangible assets as of consummation date of the sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Concepts (CON)
-Number 6
-Paragraph 82, 83, 87

+ Details

Name:	us-gaap_GainLossOnDispositionOfIntangibleAssets
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The gains and losses included in results of operations resulting from the sale or disposal of other assets not otherwise defined.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 144
-Paragraph 47

+ Details

Name:	us-gaap_GainLossOnDispositionOfOtherAssets
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The net proceeds or assets obtained in excess of (less than) the net carrying amount of assets recorded, or assets distributed and liabilities assumed less than (in excess of) litigation reserves extinguished, in settlement of a litigation matter. Represents (for other than an insurance entity in its normal claims settlement process), the amount of income (expense) recognized in the period to settle pending or threatened litigation and insurance claims.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 5
-Paragraph 9, 10, 11, 12

+ Details

Name:	us-gaap_GainLossRelatedToLitigationSettlement
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Loss recognized during the period that results from the write-down of goodwill after comparing the implied fair value of reporting unit goodwill with the carrying amount of that goodwill. Goodwill is assessed at least annually for impairment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 142
-Paragraph 45
-Subparagraph e(2)

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 142
-Paragraph 43

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 142
-Paragraph 47
-Subparagraph b

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 142
-Paragraph 20

+ Details

Name:	us-gaap_GoodwillImpairmentLoss
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The expense recorded to reduce the value of oil and gas assets consisting of proved properties and unproved properties as the estimate of future successful production from these properties is reduced.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 19
-Paragraph 27, 28, 29

+ Details

Name:	us-gaap_ImpairmentOfOilAndGasProperties
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The excess or deficiency of insurance recoveries compared to the recorded loss incurred from an insured event (including a conversion of nonmonetary assets to monetary assets). An excess would occur from recovery of lost profits, and recoveries at current replacement cost less carrying amounts of assets that were damaged or destroyed. This element should be used whenever a relevant insurance event concept is needed, and should be moved to the portion of the income statement to correspond to the entity's classification as a component of operating results, nonoperating item, discontinued operations, or extraordinary item.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Interpretation (FIN)
-Number 30
-Paragraph 2

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 5
-Paragraph 9, 17

+ Details

Name:	us-gaap_InsuredEventGainLoss
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ Details

Name:	us-gaap_UnusualOrInfrequentItemLineItems
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Accrual of regulatory liability related to overcollection of certain employee expenses.

+ Details

Name:	wmb_AccrualOfRegulatoryLiabilityRelatedToOvercollectionOfCertainEmployeeExpenses
Namespace Prefix:	wmb
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Impairments of certain gathering and transportation assets.

+ Details

Name:	wmb_ImpairmentsOfCertainGatheringAndTransportationAssets
Namespace Prefix:	wmb
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration