Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- 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.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Gross amount of debt extinguished.

+ References

No definition available.

+ Details

Name:	us-gaap_ExtinguishmentOfDebtAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	dei_LegalEntityAxis=wmb_WilliamsCompaniesIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=wmb_A8.75PercentSeniorUnsecuredNotesDue2020Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=wmb_A7.625SeniorUnsecuredNotesDue2019Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=wmb_A4.85PercentSeniorUnsecuredNotesDue2048Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=wmb_WilliamsPartnersLPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=wmb_A4.875PercentSeniorUnsecuredNotesDue2024Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=wmb_NorthwestPipelineLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=wmb_A4PercentSeniorUnsecuredNotesDue2027Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=wmb_A6.05PercentSeniorUnsecuredNotesDue2018Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=wmb_TranscontinentalGasPipeLineCompanyLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=wmb_A4PercentSeniorUnsecuredNotesDue2028Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=wmb_A4.6PercentSeniorUnsecuredNotesDue2048Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Long-Term Debt Issuances and Retirements (Details) - USD ($) $ in Millions	Jan. 15, 2020	Jul. 15, 2019	Jun. 15, 2018	Mar. 28, 2018	Dec. 31, 2019	Dec. 31, 2018	Aug. 24, 2018	Mar. 15, 2018	Mar. 05, 2018
The Williams Companies, Inc. [Member] \| 8.75 Percent Senior Unsecured Notes Due 2020 [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Extinguishment of Debt, Amount	$ 14
Long-term debt interest rate	8.75%
The Williams Companies, Inc. [Member] \| 7.625% Senior Unsecured Notes Due 2019 [Member]
Debt Instrument [Line Items]
Extinguishment of Debt, Amount		$ 32
Long-term debt interest rate		7.625%
The Williams Companies, Inc. [Member] \| 4.85 Percent Senior Unsecured Notes Due 2048 [Member]
Debt Instrument [Line Items]
Long-term debt interest rate					4.85%
Long-term debt					$ 800	$ 800
Williams Partners L.P. [Member] \| 4.85 Percent Senior Unsecured Notes Due 2048 [Member]
Debt Instrument [Line Items]
Long-term debt face amount									$ 800
Long-term debt interest rate									4.85%
Williams Partners L.P. [Member] \| 4.875% Senior Unsecured Notes Due 2024 [Member]
Debt Instrument [Line Items]
Extinguishment of Debt, Amount				$ 750
Long-term debt interest rate				4.875%
Northwest Pipeline LLC [Member] \| 4% Senior Unsecured Notes Due 2027 [Member]
Debt Instrument [Line Items]
Long-term debt face amount							$ 250
Long-term debt interest rate					4.00%		4.00%
Long-term debt					$ 500	500
Northwest Pipeline LLC [Member] \| 6.05% Senior Unsecured Notes Due 2018 [Member]
Debt Instrument [Line Items]
Extinguishment of Debt, Amount			$ 250
Long-term debt interest rate			6.05%
Transcontinental Gas Pipe Line Company, LLC [Member] \| 6.05% Senior Unsecured Notes Due 2018 [Member]
Debt Instrument [Line Items]
Extinguishment of Debt, Amount			$ 250
Long-term debt interest rate			6.05%
Transcontinental Gas Pipe Line Company, LLC [Member] \| 4% Senior Unsecured Notes Due 2028 [Member]
Debt Instrument [Line Items]
Long-term debt face amount								$ 400
Long-term debt interest rate					4.00%			4.00%
Long-term debt					$ 400	400
Transcontinental Gas Pipe Line Company, LLC [Member] \| 4.6% Senior Unsecured Notes Due 2048 [Member]
Debt Instrument [Line Items]
Long-term debt face amount								$ 600
Long-term debt interest rate					4.60%			4.60%
Long-term debt					$ 600	$ 600