The Williams Companies, Inc. (WMB) 10-Q 3 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 30, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	Williams Companies Inc
Entity Central Index Key	107,263
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Amendment Flag	false
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		827,610,837

Consolidated Statement of Incom

Consolidated Statement of Income (Unaudited) - USD ($) shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues:
Service revenues	$ 1,351	$ 1,261
Service revenues – commodity consideration (Note 2)	101	0
Product sales	636	727
Total revenues	2,088	1,988
Costs and expenses:
Product costs	613	579
Processing commodity expenses (Note 2)	35	0
Operating and maintenance expenses	357	371
Depreciation and amortization expenses	431	442
Selling, general, and administrative expenses	132	161
Other (income) expense – net	29	5
Total costs and expenses	1,597	1,558
Operating income (loss)	491	430
Equity earnings (losses)	82	107
Other investing income (loss) – net (Note 4)	4	272
Interest incurred	(282)	(287)
Interest capitalized	9	7
Other income (expense) – net	21	77
Income (loss) before income taxes	325	606
Provision (benefit) for income taxes	55	37
Net income (loss)	270	569
Less: Net income (loss) attributable to noncontrolling interests	118	196
Net income (loss) attributable to The Williams Companies, Inc.	$ 152	$ 373
Basic earnings (loss) per common share:
Net income (loss)	$ 0.18	$ 0.45
Weighted-average shares (thousands)	827,509	824,548
Diluted earnings (loss) per common share:
Net income (loss)	$ 0.18	$ 0.45
Weighted-average shares (thousands)	830,197	826,476
Cash dividends declared per common share	$ 0.34	$ 0.30

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Comprehensive income (loss):
Net income (loss)	$ 270	$ 569
Cash flow hedging activities:
Net unrealized gain (loss) from derivative instruments, net of taxes of $0 in 2018 and ($1) in 2017	1	3
Pension and other postretirement benefits:
Amortization of prior service cost (credit) included in net periodic benefit cost (credit)	0	(1)
Amortization of actuarial (gain) loss included in net periodic benefit cost (credit), net of taxes of ($1) in 2018 and ($3) in 2017	5	4
Other comprehensive income (loss)	6	6
Comprehensive income (loss)	276	575
Less: Comprehensive income (loss) attributable to noncontrolling interests	119	197
Comprehensive income (loss) attributable to The Williams Companies, Inc.	$ 157	$ 378

Consolidated Statement of Comp4

Consolidated Statement of Comprehensive Income (Loss) (Parenthetical) (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax Effect [Abstract]
Other Comprehensive Income, Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	$ 0	$ (1)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax [Abstract]
Amortization of actuarial (gain) loss included in net periodic benefit cost, taxes	$ (1)	$ (3)

Consolidated Balance Sheet (Una

Consolidated Balance Sheet (Unaudited) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 1,292	$ 899
Trade accounts and other receivables (net of allowance of $10 at March 31, 2018 and $9 at December 31, 2017)	743	976
Inventories	160	113
Other current assets and deferred charges	204	191
Total current assets	2,399	2,179
Investments	6,513	6,552
Property, plant, and equipment	40,467	39,513
Accumulated depreciation and amortization	(11,620)	(11,302)
Property, plant, and equipment – net	28,847	28,211
Intangible assets – net of accumulated amortization	8,644	8,791
Regulatory assets, deferred charges, and other	649	619
Total assets	47,052	46,352
Current liabilities:
Accounts payable	776	978
Accrued liabilities	887	1,167
Long-term debt due within one year	501	501
Total current liabilities	2,164	2,646
Long-term debt	21,379	20,434
Deferred income tax liabilities	3,196	3,147
Regulatory liabilities, deferred income, and other	4,410	3,950
Contingent liabilities (Note 12)
Stockholders’ equity:
Common stock (960 million shares authorized at $1 par value; 862 million shares issued at March 31, 2018 and 861 million shares issued at December 31, 2017)	862	861
Capital in excess of par value	18,533	18,508
Retained deficit	(8,587)	(8,434)
Accumulated other comprehensive income (loss)	(294)	(238)
Treasury stock, at cost (35 million shares of common stock)	(1,041)	(1,041)
Total stockholders’ equity	9,473	9,656
Noncontrolling interests in consolidated subsidiaries	6,430	6,519
Total equity	15,903	16,175
Total liabilities and equity	$ 47,052	$ 46,352

Consolidated Balance Sheet (Par

Consolidated Balance Sheet (Parenthetical) (Unaudited) - USD ($) shares in Millions, $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Allowance for trade accounts and other receivables	$ 10	$ 9
Stockholders’ equity:
Common stock, shares authorized	960	960
Common stock, par value of shares authorized	$ 1	$ 1
Common stock, shares issued	862	861
Treasury stock, shares of common shares	35	35

Consolidated Statement of Chang

Consolidated Statement of Changes in Equity (Unaudited) - 3 months ended Mar. 31, 2018 - USD ($) $ in Millions	Total	Total Stockholders’ Equity	Common Stock	Capital in Excess of Par Value	Retained Deficit	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Noncontrolling Interests
December 31, 2017 at Dec. 31, 2017	$ 16,175	$ 9,656	$ 861	$ 18,508	$ (8,434)	$ (238)	$ (1,041)	$ 6,519
Adoption of ASC 606 (Note 1)	(121)	(84)	0	0	(84)	0	0	(37)
Adoption of ASU 2018-02 (Note 1)	0	0	0	0	61	(61)	0	0
Net income (loss)	270	152	0	0	152	0	0	118
Other comprehensive income (loss)	6	5	0	0	0	5	0	1
Cash dividends – common stock	(281)	(281)	0	0	(281)	0	0	0
Dividends and distributions to noncontrolling interests	(187)	0	0	0	0	0	0	(187)
Stock-based compensation and related common stock issuances, net of tax	19	19	1	18	0	0	0	0
Sales of limited partner units of Williams Partners L.P.	22	0	0	0	0	0	0	22
Changes in ownership of consolidated subsidiaries, net	(2)	7	0	7	0	0	0	(9)
Contributions from noncontrolling interests	3	0	0	0	0	0	0	3
Other	(1)	(1)	0	0	(1)	0	0	0
Net increase (decrease) in equity	(272)	(183)	1	25	(153)	(56)	0	(89)
March 31, 2018 at Mar. 31, 2018	$ 15,903	$ 9,473	$ 862	$ 18,533	$ (8,587)	$ (294)	$ (1,041)	$ 6,430

Consolidated Statement of Cash

Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
OPERATING ACTIVITIES:
Net income (loss)	$ 270	$ 569
Adjustments to reconcile to net cash provided (used) by operating activities:
Depreciation and amortization	431	442
Provision (benefit) for deferred income taxes	73	28
Equity (earnings) losses	(82)	(107)
Distributions from unconsolidated affiliates	140	190
Net (gain) loss on disposition of equity-method investments	0	(269)
Amortization of stock-based awards	14	21
Cash provided (used) by changes in current assets and liabilities:
Accounts and notes receivable	238	29
Inventories	(40)	(30)
Other current assets and deferred charges	(4)	18
Accounts payable	(197)	32
Accrued liabilities	(166)	(133)
Other, including changes in noncurrent assets and liabilities	17	(63)
Net cash provided (used) by operating activities	694	727
FINANCING ACTIVITIES:
Proceeds from (payments of) commercial paper – net	0	(93)
Proceeds from long-term debt	2,048	470
Payments of long-term debt	(1,060)	(2,000)
Proceeds from issuance of common stock	10	2,122
Dividends paid	(281)	(248)
Dividends and distributions paid to noncontrolling interests	(165)	(242)
Contributions from noncontrolling interests	3	4
Payments for debt issuance costs	(18)	0
Other – net	(40)	(28)
Net cash provided (used) by financing activities	497	(15)
INVESTING ACTIVITIES:
Capital expenditures (1)	(957)	(511)
Dispositions – net	(1)	(2)
Contributions in aid of construction	190	131
Proceeds from dispositions of equity-method investments	0	200
Purchases of and contributions to equity-method investments	(21)	(52)
Other – net	(9)	(9)
Net cash provided (used) by investing activities	(798)	(243)
Increase (decrease) in cash and cash equivalents	393	469
Cash and cash equivalents at beginning of year	899	170
Cash and cash equivalents at end of period	1,292	639
(1) Increases to property, plant, and equipment	(934)	(569)
Changes in related accounts payable and accrued liabilities	(23)	58
Capital expenditures (1)	$ (957)	$ (511)

General, Description of Busines

General, Description of Business, and Basis of Presentation	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General, Description of Business, and Basis of Presentation [Text Block]	Note 1 – General, Description of Business, and Basis of Presentation General Our accompanying interim consolidated financial statements do not include all the notes in our annual financial statements and, therefore, should be read in conjunction with the consolidated financial statements and notes thereto for the year ended December 31, 2017, in our Annual Report on Form 10-K. The accompanying unaudited financial statements include all normal recurring adjustments and others that, in the opinion of management, are necessary to present fairly our interim financial statements. The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates. Unless the context clearly indicates otherwise, references in this report to “Williams,” “we,” “our,” “us,” or like terms refer to The Williams Companies, Inc. and its subsidiaries. Unless the context clearly indicates otherwise, references to “Williams,” “we,” “our,” and “us” include the operations in which we own interests accounted for as equity-method investments that are not consolidated in our financial statements. When we refer to our equity investees by name, we are referring exclusively to their businesses and operations. Financial Repositioning In January 2017, we entered into agreements with Williams Partners L.P. (WPZ), wherein we permanently waived the general partner’s incentive distribution rights and converted our 2 percent general partner interest in WPZ to a noneconomic interest in exchange for 289 million newly issued WPZ common units. Pursuant to this agreement, we also purchased approximately 277 thousand WPZ common units for $10 million . Additionally, we purchased approximately 59 million common units of WPZ at a price of $36.08586 per unit in a private placement transaction, funded with proceeds from our equity offering. According to the terms of this agreement, concurrent with WPZ’s quarterly distributions in February 2017 and May 2017, we paid additional consideration totaling $56 million to WPZ for these units. Description of Business We are a Delaware corporation whose common stock is listed and traded on the New York Stock Exchange. Our operations are located principally in the United States. We have one reportable segment, Williams Partners. All remaining business activities as well as corporate activities are included in Other. Williams Partners Williams Partners consists of our consolidated master limited partnership, WPZ, and primarily includes gas pipeline and midstream businesses. WPZ’s gas pipeline businesses primarily consist of two interstate natural gas pipelines, which are Transcontinental Gas Pipe Line Company, LLC (Transco) and Northwest Pipeline LLC (Northwest Pipeline), and several joint venture investments in interstate and intrastate natural gas pipeline systems, including a 50 percent equity-method investment in Gulfstream Natural Gas System, L.L.C., and a 41 percent interest in Constitution Pipeline Company, LLC (Constitution) (a consolidated entity), which is developing a pipeline project (see Note 3 – Variable Interest Entities ). WPZ’s midstream businesses primarily consist of (1) natural gas gathering, treating, compression, and processing; (2) natural gas liquid (NGL) fractionation, storage, and transportation; (3) crude oil production handling and transportation; and (4) olefins production. WPZ sold its olefins operations in July 2017. The primary service areas are concentrated in major producing basins in Colorado, Texas, Oklahoma, Kansas, New Mexico, Wyoming, the Gulf of Mexico, Louisiana, Pennsylvania, West Virginia, New York, and Ohio, which include the Barnett, Eagle Ford, Haynesville, Marcellus, Niobrara, and Utica shale plays as well as the Mid-Continent region. The midstream businesses include equity-method investments in natural gas gathering and processing assets and NGL fractionation and transportation assets, including a 62 percent equity-method investment in Utica East Ohio Midstream, LLC, a 69 percent equity-method investment in Laurel Mountain Midstream, LLC, a 58 percent equity-method investment in Caiman Energy II, LLC, a 60 percent equity-method investment in Discovery Producer Services, LLC, a 50 percent equity-method investment in Overland Pass Pipeline, LLC, and Appalachia Midstream Services, LLC, which owns equity-method investments with an approximate average 66 percent interest in multiple gathering systems in the Marcellus Shale (Appalachia Midstream Investments), as well as our previously owned 50 percent equity-method investment in the Delaware basin gas gathering system (DBJV) in the Mid-Continent region (see Note 4 – Investing Activities ). Basis of Presentation Consolidated master limited partnership As of March 31, 2018 , we own 74 percent of the interests in WPZ, a variable interest entity (VIE) (see Note 3 – Variable Interest Entities ). Pursuant to WPZ’s distribution reinvestment program, 576,923 common units were issued to the public in February 2018 associated with reinvested distributions of $22 million . This common unit issuance and WPZ’s quarterly distribution of additional paid-in-kind Class B units to us had the combined net impact of decreasing Noncontrolling interests in consolidated subsidiaries by $9 million , and increasing Capital in excess of par value by $7 million and Deferred income tax liabilities by $2 million in the Consolidated Balance Sheet . WPZ is self-funding and maintains separate lines of bank credit and cash management accounts and also has a commercial paper program. (See Note 9 – Debt and Banking Arrangements .) Cash distributions from WPZ to limited partners, including us, are governed by WPZ’s partnership agreement. Significant risks and uncertainties We may monetize assets that are not core to our strategy which could result in impairments of certain equity-method investments, property, plant, and equipment, and intangible assets. Such impairments could potentially be caused by indications of fair value implied through the monetization process or, in the case of asset dispositions that are part of a broader asset group, the impact of the loss of future estimated cash flows. On March 15, 2018, the Federal Energy Regulatory Commission (FERC) issued a policy statement regarding the recovery of income tax costs in rates of natural gas pipelines. The FERC found that an impermissible double recovery results from granting a Master Limited Partnership (MLP) pipeline both an income tax allowance and a return on equity pursuant to the discounted cash flow methodology. The FERC will no longer permit an MLP pipeline to recover an income tax allowance in its cost of service. The FERC further stated it will address the application of this policy to non-MLP partnership forms as those issues arise in subsequent proceedings. The FERC also issued a Notice of Proposed Rulemaking proposing a process that will allow it to determine which natural gas pipelines may be collecting unjust and unreasonable rates in light of the recent reduction in the corporate income tax rate in the Tax Cuts and Jobs Act (Tax Reform) and this policy statement. Furthermore, the FERC issued a Notice of Inquiry seeking comments on the additional impacts of Tax Reform on jurisdictional rates, particularly whether, and if so how, the FERC should address changes relating to accumulated deferred income tax amounts after the corporate income tax rate reduction and bonus depreciation rules, as well as whether other features of Tax Reform require FERC action. We are evaluating the impact of these developments on our interstate natural gas pipelines and currently expect any associated impacts would be prospective and determined through subsequent rate proceedings. We also continue to monitor developments that may impact our regulatory liabilities resulting from Tax Reform. It is reasonably possible that future tariff-based rates collected by our interstate natural gas pipelines may be adversely impacted. Accounting standards issued and adopted During the first quarter of 2018, we early adopted Accounting Standards Update (ASU) 2018-02 “Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income” (ASU 2018-02). As a result of Tax Reform lowering the federal income tax rate, the tax effects of items within accumulated other comprehensive income may not reflect the appropriate tax rate. ASU 2018-02 allows for the reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from Tax Reform. The adoption of ASU 2018-02 resulted in the reclassification of $61 million from Accumulated other comprehensive income (loss) to Retained deficit on our Consolidated Balance Sheet . Effective January 1, 2018, we adopted ASU 2017-12 “Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities” (ASU 2017-12). ASU 2017-12 applies to entities that elect hedge accounting in accordance with Accounting Standards Codification (ASC) 815. The ASU affects both the designation and measurement guidance for hedging relationships and the presentation of hedging results. ASU 2017-12 was applied using a modified retrospective approach for cash flow and net investment hedges existing at the date of adoption and prospectively for the presentation and disclosure guidance. The adoption of ASU 2017-12 did not have a significant impact on our consolidated financial statements. Effective January 1, 2018, we adopted ASU 2017-07 “Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost” (ASU 2017-07). ASU 2017-07 requires employers to report the service cost component of net benefit cost in the same line item or items as other compensation costs arising from employee services. The other components of net benefit cost must be presented in the income statement separately from the service cost component and outside Operating income (loss) . Only the service cost component is now eligible for capitalization when applicable. The presentation aspect of ASU 2017-07 must be applied retrospectively and the capitalization requirement prospectively. In accordance with this adoption, we have conformed the prior year presentation, which resulted in an increase of $3 million to Operating and maintenance expenses with a corresponding decrease to Operating income (loss) and an increase of $3 million to Other income (expense) – net below Operating income (loss) in the Consolidated Statement of Income for the period ended March 31, 2017. Effective January 1, 2018, we adopted ASU 2016-15 “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments” (ASU 2016-15). Among other things, ASU 2016-15 permits an accounting policy election to classify distributions received from equity-method investees using either the cumulative earnings approach or the nature of distribution approach. We have elected to apply the nature of distribution approach and have retrospectively conformed the prior year presentation within the Consolidated Statement of Cash Flows in accordance with ASU 2016-15. For the period ended March 31, 2017, amounts previously presented as Distributions from unconsolidated affiliates in excess of cumulative earnings within Investing Activities are now presented as part of Distributions from unconsolidated affiliates within Operating Activities , resulting in an increase to Net cash provided (used) by operating activities of $121 million with a corresponding reduction in Net cash provided (used) by investing activities . In May 2014, the Financial Accounting Standards Board (FASB) issued ASU 2014-09 establishing ASC Topic 606, “Revenue from Contracts with Customers” (ASC 606). ASC 606 establishes a comprehensive new revenue recognition model designed to depict the transfer of goods or services to a customer in an amount that reflects the consideration the entity expects to be entitled to receive in exchange for those goods or services and requires significantly enhanced revenue disclosures. In August 2015, the FASB issued ASU 2015-14 “Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date” (ASU 2015-14). Per ASU 2015-14, the standard became effective for interim and annual reporting periods beginning after December 15, 2017. We adopted the provisions of ASC 606 effective January 1, 2018, utilizing the modified retrospective transition method for all contracts with customers, which included applying the provisions of ASC 606 beginning January 1, 2018, to all contracts not completed as of that date with the cumulative effect of applying the standard for periods prior to January 1, 2018, as an adjustment to Total equity , net of tax, upon adoption. As a result of our adoption, the cumulative impact to our Total equity , net of tax, at January 1, 2018, was a decrease of $121 million in the Consolidated Balance Sheet . For each revenue contract type, we conducted a formal contract review process to evaluate the impact of ASC 606. The adjustment to Total equity upon adoption of ASC 606 is primarily comprised of the impact to the timing of recognition of deferred revenue (contract liabilities) associated with certain contracts which underwent modifications in periods prior to January 1, 2018. Under the provisions of ASC 606, when a contract modification does not increase both the scope and price of the contract, and the remaining goods and services are distinct from the goods and services transferred prior to the modification, the modification is treated as a termination of the existing contract and the creation of a new contract. ASC 606 requires that the transaction price, including any remaining contract liabilities from the old contract, be allocated to the performance obligations over the term of the new contract. The contract modification adjustments are partially offset by the impact of changes to the timing of recognizing revenue which is subject to the constraint on estimates of variable consideration of certain contracts. The constraint of variable consideration will result in the acceleration of revenue recognition and corresponding de-recognition of contract liabilities for certain contracts (as compared to the previous revenue recognition model) as a result of our assessment that it is probable such recognition would not result in a significant revenue reversal in the future. Additionally, under ASC 606, our revenues will increase in situations where we receive noncash consideration, which exists primarily in certain of our gas processing contracts where we receive commodities as full or partial consideration for services provided. This increase in revenues will be offset by a similar increase in costs and expenses when the commodities received are subsequently sold. Financial systems and internal controls necessary for adoption were implemented effective January 1, 2018. (See Note 2 – Revenue Recognition .) Accounting standards issued but not yet adopted In June 2016, the FASB issued ASU 2016-13 “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” (ASU 2016-13). ASU 2016-13 changes the impairment model for most financial assets and certain other instruments. For trade and other receivables, held-to-maturity debt securities, loans, and other instruments, entities will be required to use a new forward-looking “expected loss” model that generally will result in the earlier recognition of allowances for losses. The guidance also requires increased disclosures. ASU 2016-13 is effective for interim and annual periods beginning after December 15, 2019. Early adoption is permitted. The standard requires varying transition methods for the different categories of amendments. Although we do not expect ASU 2016-13 to have a significant impact, it will impact our trade receivables as the related allowance for credit losses will be recognized earlier under the expected loss model. In February 2016, the FASB issued ASU 2016-02 “Leases (Topic 842)” (ASU 2016-02). ASU 2016-02 establishes a comprehensive new lease accounting model. ASU 2016-02 modifies the definition of a lease, requires a dual approach to lease classification similar to current lease accounting, and causes lessees to recognize operating leases on the balance sheet as a lease liability measured as the present value of the future lease payments with a corresponding right-of-use asset, with an exception for leases with a term of one year or less. Additional disclosures will also be required regarding the amount, timing, and uncertainty of cash flows arising from leases. In January 2018, the FASB issued ASU 2018-01 “Leases (Topic 842): Land Easement Practical Expedient for Transition to Topic 842” (ASU 2018-01). Per ASU 2018-01, land easements and rights-of-way are required to be assessed under ASU 2016-02 to determine whether the arrangements are or contain a lease. ASU 2018-01 permits an entity to elect a transition practical expedient to not apply ASU 2016-02 to land easements that exist or expired before the effective date of ASU 2016-02 and that were not previously assessed under the previous lease guidance in ASC Topic 840 “Leases.” ASU 2016-02 is effective for interim and annual periods beginning after December 15, 2018. Early adoption is permitted. We expect to adopt ASU 2016-02 effective January 1, 2019. ASU 2016-02 currently requires a modified retrospective transition for financing or operating leases existing at or entered into after the beginning of the earliest comparative period presented in the financial statements. In January 2018, the FASB proposed an ASU titled “Leases (Topic 842): Targeted Improvements,” which is an update to ASU 2016-02 allowing entities an additional transition method to the existing requirements whereby an entity could adopt the provisions of ASU 2016-02 by recognizing a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption without adjustment to the financial statements for periods prior to adoption. We are in the process of reviewing contracts to identify leases based on the modified definition of a lease, implementing a financial lease accounting system, and evaluating internal control changes to support management in the accounting for and disclosure of leasing activities. While we are still in the process of completing our implementation evaluation of ASU 2016-02, we currently believe the most significant changes to our financial statements relate to the recognition of a lease liability and offsetting right-of-use asset in our consolidated balance sheet for operating leases. We are also evaluating ASU 2016-02’s currently available and proposed practical expedients on adoption.

Revenue Recognition

Revenue Recognition	3 Months Ended
	Mar. 31, 2018
Revenue Recognition [Abstract]
Revenue Recognition [Text Block]	Note 2 – Revenue Recognition Customers in our gas pipeline businesses are comprised of public utilities, municipalities, gas marketers and producers, intrastate pipelines, direct industrial users, and electrical generators. Customers in our midstream businesses are comprised of oil and natural gas producer counterparties. Customers for our product sales are comprised of public utilities, gas marketers, and direct industrial users. A performance obligation is a promise in a contract to transfer a distinct good or service (or integrated package of goods or services) to the customer. A contract’s transaction price is allocated to each distinct performance obligation and recognized as revenue, when, or as, the performance obligation is satisfied. A performance obligation is distinct if the service is separately identifiable from other items in the integrated package of services and if a customer can benefit from it on its own or with other resources that are readily available to the customer. An integrated package of services typically represents a single performance obligation if the services are contained within the same contract or within multiple contracts entered into in contemplation with one another that are highly interdependent or highly interrelated, meaning each of the services is significantly affected by one or more of the other services in the contract. Service revenue contracts from our gas pipeline and midstream businesses contain a series of distinct services, with the majority of our contracts having a single performance obligation that is satisfied over time as the customer simultaneously receives and consumes the benefits provided by our performance. Most of our product sales contracts have a single performance obligation with revenue recognized at a point in time when the products have been sold and delivered to the customer. Certain customers reimburse us for costs we incur associated with construction of property, plant, and equipment utilized in our operations. For our rate-regulated gas pipeline businesses that apply ASC 980. "Regulated Operations" (Topic 980), we follow FERC guidelines with respect to reimbursement of construction costs. FERC tariffs only allow for cost reimbursement and are non-negotiable in nature; thus, the construction activities do not represent an ongoing major and central operation of our gas pipelines business and are not within the scope of ASC 606. Accordingly, cost reimbursements are treated as a reduction to the cost of the constructed asset. For our midstream businesses, reimbursement and service contracts with customers are viewed together as providing the same commercial objective, as we have the ability to negotiate the mix of consideration between reimbursements and amounts billed over time. Accordingly, we generally recognize reimbursements of construction costs from customers on a gross basis as a contract liability separate from the associated costs included within property, plant, and equipment. The contract liability is recognized into service revenues as the underlying performance obligations are satisfied. Service Revenues Gas pipeline businesses Revenues from our interstate natural gas pipeline businesses, which are included within the caption “Regulated interstate natural gas transportation and storage” in the revenue by category table below and are subject to regulation by certain state and federal authorities, including the FERC, include both firm and interruptible transportation and storage contracts. Firm transportation and storage agreements provide for a reservation charge based on the pipeline or storage capacity reserved, and a commodity charge based on the volume of natural gas delivered/stored, each at rates specified in our FERC tariffs or based on negotiated contractual rates, with contract terms that are generally long-term in nature. Most of our long-term contracts contain an evergreen provision, which allows the contracts to be extended for periods primarily up to one year in length an indefinite number of times following the specified contract term and until terminated generally by either us or the customer. Interruptible transportation and storage agreements provide for a volumetric charge based on actual commodity transportation or storage utilized in the period in which those services are provided, and the contracts are generally limited to one month periods or less. Our performance obligations related to our interstate natural gas pipeline businesses include the following: • Guaranteed transportation or storage under firm transportation and storage contracts—an integrated package of services typically constituting a single performance obligation, which includes standing ready to provide such services and receiving, transporting or storing (as applicable), and redelivering commodities; • Interruptible transportation and storage under interruptible transportation and storage contracts—an integrated package of services typically constituting a single performance obligation, which includes receiving, transporting or storing (as applicable), and redelivering commodities upon nomination by the customer. In situations where we consider the integrated package of services a single performance obligation, which represents a majority of our interstate natural gas pipeline contracts with customers, we do not consider there to be multiple performance obligations because the nature of the overall promise in the contract is to stand ready (with regard to firm transportation and storage contracts), receive, transport or store, and redeliver natural gas to the customer; therefore, revenue is recognized at the completion of the integrated package of services which represents a single performance obligation. We recognize revenues for reservation charges over the performance obligation period, which is the contract term, regardless of the volume of natural gas that is transported or stored. Revenues for commodity charges from both firm and interruptible transportation services and storage services are recognized when natural gas is delivered at the agreed upon delivery point or when natural gas is injected or withdrawn from the storage facility because they specifically relate to our efforts to transfer these distinct services. Generally, reservation charges and commodity charges in our interstate natural gas pipeline businesses are recognized as revenue in the same period they are invoiced to our customers. As a result of the ratemaking process, certain amounts collected by us may be subject to refunds upon the issuance of final orders by the FERC in pending rate proceedings. We record estimates of rate refund liabilities considering our and other third-party regulatory proceedings, advice of counsel, and other risks. Midstream businesses Revenues from our midstream businesses, which are included in the caption titled “Non-regulated gathering, processing, transportation, and storage” in the revenue by category table below, include contracts for natural gas gathering, processing, treating, compression, transportation, and other related services with contract terms that are generally long-term in nature and may extend up to the production life of the associated reservoir. Additionally, our midstream businesses generate revenues from fees charged for storing customers’ natural gas and NGLs, generally under prepaid contracted storage capacity contracts. In situations where we provide an integrated package of services combined into a single performance obligation, which represents a majority of this class of contracts with customers, we do not consider there to be multiple performance obligations because the nature of the overall promise in the contract is to provide gathering, processing, transportation, storage, and related services resulting in the delivery, or redelivery in the context of storage services, of pipeline-quality natural gas and NGLs to the customer. As such, revenue is recognized at the daily completion of the integrated package of services as the integrated package represents a single performance obligation. Additionally, certain contracts in our midstream businesses contain fixed or upfront payment terms that result in the deferral of revenues until such services have been performed or such capacity has been made available. We also earn revenues from offshore crude oil and natural gas gathering and transportation and offshore production handling. These services represent an integrated package of services and are considered a single distinct performance obligation for which we recognize revenues as the services are provided to the customer. We generally earn a contractually-stated fee per unit for the volume of product transported, gathered, processed, or stored. The rate is generally fixed; however, certain contracts contain variable rates that are subject to change based on commodity prices, levels of throughput, or an annual adjustment based on a formulaic cost of service calculation. In addition, we have contracts with contractually-stated fees that decline over the contract term, such as declines based on the passage of time periods or achievement of cumulative throughput amounts. For all of our contracts, we allocate the transaction price to each performance obligation based on the relative standalone selling price. The excess of consideration received over revenue recognized results in the deferral of those amounts until future periods based on a units of production or straight-line methodology. Certain of our gas gathering and processing agreements have minimum volume commitments (MVC). If a customer under such an agreement fails to meet its MVC for a specified period (thus not exercising all the contractual rights to gathering and processing services within the specified period, herein referred to as “breakage”), it is obligated to pay a contractually determined fee based upon the shortfall between the actual gathered or processed volumes and the MVC for the period contained in the contract. When we conclude it is probable that the customer will not exercise all or a portion of its remaining rights, we recognize revenue associated with such breakage amount in proportion to the pattern of exercised rights within the respective MVC period. Under keep-whole and percent-of-liquids processing contracts, we receive commodity consideration in the form of NGLs and take title to the NGLs at the tailgate of the plant. We recognize such commodity consideration as service revenue based on the market value of the NGLs retained at the time the processing is provided. The current market value, as opposed to the market value at the contract inception date, is used due to a combination of factors, including the fact that the volume, mix, and market price of NGL consideration to be received is unknown at the time of contract execution and is not specified in our contracts with customers. Additionally, product sales revenue (discussed below) is recognized upon the sale of the NGLs to a third party based on the sales price at the time of sale. As a result, revenue is recognized both at the time the processing service is provided in Service revenues – commodity consideration and at the time the NGLs retained as part of the processing service are sold in Product sales . The recognition of revenue related to commodity consideration has the impact of increasing the book value of NGL inventory, resulting in higher cost of goods sold at the time of sale. Given that most inventory is sold in the same period that it is generated, the impact of these transactions is expected to have little impact to operating income. Product Sales In the course of providing transportation services to customers of our gas pipeline businesses and gathering and processing services to customers of our midstream businesses, we may receive different quantities of natural gas from customers than the quantities delivered on behalf of those customers. The resulting imbalances are primarily settled through the purchase or sale of natural gas with each customer under terms provided for in our FERC tariffs or gathering and processing agreements, respectively. Revenue is recognized from the sale of natural gas upon settlement of imbalances. In certain instances, we purchase NGLs, crude oil, and natural gas from our oil and natural gas producer customers. In addition, we retain NGLs as consideration in certain processing arrangements, as discussed above in the Service Revenues - Midstream businesses section. We recognize revenue from the sale of these commodities when the products have been sold and delivered. Our product sales contracts are primarily short-term contracts based on prevailing market rates at the time of the transaction. Revenue by Category The following table presents our revenue disaggregated by major service line: Northeast Midstream Atlantic- Gulf Midstream West Midstream Transco Northwest Pipeline Other Intercompany Eliminations Total (Millions) Three Months Ended March 31, 2018 Revenues from contracts with customers: Service revenues: Non-regulated gathering, processing, transportation, and storage: Monetary consideration $ 202 $ 137 $ 408 $ — $ — $ — $ (18 ) $ 729 Commodity consideration 4 15 82 — — — — 101 Regulated interstate natural gas transportation and storage — — — 461 112 — (1 ) 572 Other 21 6 11 — — 8 (6 ) 40 Total service revenues 227 158 501 461 112 8 (25 ) 1,442 Product Sales: NGL and natural gas 98 68 521 25 — — (85 ) 627 Other — — 4 — — — — 4 Total product sales 98 68 525 25 — — (85 ) 631 Total revenues from contracts with customers 325 226 1,026 486 112 8 (110 ) 2,073 Other revenues (1) 5 2 5 3 — — — 15 Total revenues $ 330 $ 228 $ 1,031 $ 489 $ 112 $ 8 $ (110 ) $ 2,088 (1) We provide management services to operated joint ventures and other investments for which we receive a management fee that is categorized as Service revenues in our Consolidated Statement of Income. These management fees do not constitute revenue from contracts with customers. Product sales in our Consolidated Statement of Income include amounts associated with our derivative contracts that are not within the scope of ASC 606. Contract Assets Our contract assets primarily consist of revenue recognized under contracts containing MVC features whereby management has concluded it is probable there will be a short-fall payment at the end of the current MVC period, which typically follows the calendar year, and that a significant reversal of revenue recognized currently for the future MVC payment will not occur. As a result, our contract assets related to our future MVC payments are generally expected to be collected within the next 12 months and are included within Other current assets and deferred charges in our Consolidated Balance Sheet until such time as the MVC short-fall payments are invoiced to the customer. The following table presents a reconciliation of the beginning and ending balances of our contract assets for the period ended March 31, 2018: 2018 (Millions) Balance at January 1 $ 4 Revenue recognized in excess of cash received 20 Minimum volume commitments invoiced — Balance at March 31 $ 24 Contract Liabilities Our contract liabilities consist of advance payments primarily from midstream business customers which include construction reimbursements, prepayments, and other billings for which future services are to be provided under the contract. These amounts are deferred until recognized in revenue when the associated performance obligation has been satisfied, which is primarily based on a units of production methodology over the remaining contractual service periods, and are classified as current or noncurrent according to when such amounts are expected to be recognized. Current and noncurrent contract liabilities are included within Accrued liabilities and Regulatory liabilities, deferred income, and other , respectively, in our Consolidated Balance Sheet. Contracts requiring advance payments and the recognition of contract liabilities are evaluated to determine whether the advance payments provide us with a significant financing benefit. This determination is based on the combined effect of the expected length of time between when we transfer the promised good or service to the customer, when the customer pays for those goods or services, and the prevailing interest rates. We have assessed our contracts for significant financing components and determined that one group of contracts entered into in contemplation of one another for certain capital reimbursements contains a significant financing component. As a result, we recognize noncash interest expense based on the effective interest method and revenue (noncash) is recognized when the underlying asset is placed into service utilizing a units of production or straight-line methodology over the life of the corresponding customer contract. The following table presents a reconciliation of the beginning and ending balances of our contract liabilities for the period ended March 31, 2018: 2018 (Millions) Balance at January 1 $ 1,596 Payments received and deferred 92 Recognized in revenue (114 ) Balance at March 31 $ 1,574 The following table presents the amount of the contract liabilities balance as of March 31, 2018, expected to be recognized as revenue in each of the next five years as performance obligations are expected to be satisfied: (Millions) 2018 (remainder) $ 251 2019 252 2020 120 2021 100 2022 94 2023 88 Thereafter 669 Remaining Performance Obligations The following table presents the transaction price allocated to the remaining performance obligations under certain contracts as of March 31, 2018. These primarily include long-term contracts containing MVCs associated with our midstream businesses, fixed payments associated with offshore production handling, and reservation charges on contracted capacity on our gas pipeline firm transportation contracts with customers, as well as storage capacity contracts. Amounts included in the table below for our interstate natural gas pipeline businesses reflect the rates for such services in our current FERC tariffs for the life of the related contracts; however, these rates may change based on future tariffs approved by the FERC and the amount and timing of these changes is not currently known. As a practical expedient permitted by ASC 606, this table excludes variable consideration as well as consideration in contracts that is recognized in revenue as billed. It also excludes consideration received prior to March 31, 2018, that will be recognized in future periods (see above for Contract Liabilities and the expected recognition of those amounts within revenue). As noted above, certain of our contracts contain evergreen and other renewal provisions for periods beyond the initial term of the contract. The remaining performance obligation as of March 31, 2018, does not consider potential future performance obligations for which the renewal has not been exercised. The table below also does not include contracts with customers for which the underlying facilities have not received FERC authorization to be placed into service. (Millions) 2018 (remainder) $ 1,927 2019 2,410 2020 2,210 2021 1,891 2022 1,758 2023 1,566 Thereafter 11,679 Total $ 23,441 Accounts Receivable We do not offer extended payment terms and typically receive payment within one month. We consider receivables past due if full payment is not received by the contractual due date. Interest income related to past due accounts receivable is generally recognized at the time full payment is received or collectability is assured. The following is a summary of our Trade accounts and other receivables as it relates to contracts with customers: March 31, 2018 (Millions) Accounts receivable related to revenues from contracts with customers $ 704 Other accounts receivable 39 Total reflected in Trade accounts and other receivables $ 743 Impact of Adoption of ASC 606 The following table depicts the impact of the adoption of ASC 606 on our 2018 financial statements. The adjustment to Intangible assets – net of accumulated amortization in the table below relates to the recognition under ASC 606 of contract assets for MVC-related contracts associated with a 2014 acquisition. The recognition of these contract assets resulted in a lower purchase price allocation to intangible assets. The adoption of ASC 606 did not result in adjustments to total operating, investing, or financing cash flows. As Reported Adjustments resulting from adoption of ASC 606 Balance without adoption of ASC 606 (Millions) Consolidated Statement of Income Three Months Ended March 31, 2018 Service revenues $ 1,351 $ 5 $ 1,356 Service revenues – commodity consideration 101 (101 ) — Product sales 636 10 646 Total revenues 2,088 (86 ) 2,002 Product costs 613 (55 ) 558 Processing commodity expenses 35 (35 ) — Operating and maintenance expenses 357 (1 ) 356 Depreciation and amortization expenses 431 1 432 Total costs and expenses 1,597 (90 ) 1,507 Operating income (loss) 491 4 495 Interest incurred (282 ) 3 (279 ) Interest capitalized 9 (2 ) 7 Income (loss) before income taxes 325 5 330 Net income (loss) 270 5 275 Less: Net income (loss) attributable to noncontrolling interests 118 2 120 Net income (loss) attributable to The Williams Companies, Inc. 152 3 155 Consolidated Statement of Comprehensive income Three Months Ended March 31, 2018 Net income (loss) $ 270 $ 5 $ 275 Comprehensive income (loss) 276 5 281 Less: Comprehensive income (loss) attributable to noncontrolling interests 119 2 121 Comprehensive income (loss) attributable to The Williams Companies, Inc. 157 3 160 Consolidated Balance Sheet March 31, 2018 Inventories $ 160 $ (8 ) $ 152 Other current assets and deferred charges 204 (20 ) 184 Total current assets 2,399 (28 ) 2,371 Investments 6,513 (1 ) 6,512 Property, plant, and equipment 40,467 (2 ) 40,465 Property, plant, and equipment – net 28,847 (2 ) 28,845 Intangible assets – net of accumulated amortization 8,644 63 8,707 Regulatory assets, deferred charges, and other 649 (4 ) 645 Total assets 47,052 28 47,080 Deferred income tax liabilities 3,196 27 3,223 Regulatory liabilities, deferred income, and other 4,410 (125 ) 4,285 Retained deficit (8,587 ) 87 (8,500 ) Total stockholders’ equity 9,473 87 9,560 Noncontrolling interests in consolidated subsidiaries 6,430 39 6,469 Total equity 15,903 126 16,029 Total liabilities and equity 47,052 28 47,080 Consolidated Statement of Changes in Equity March 31, 2018 Adoption of ASC 606 $ (121 ) $ 121 $ — Net income (loss) 270 5 275 Net increase (decrease) in equity (272 ) 126 (146 ) Balance - March 31, 2018 15,903 126 16,029

Variable Interest Entities

Variable Interest Entities	3 Months Ended
	Mar. 31, 2018
Variable Interest Entity Disclosures [Abstract]
Variable Interest Entities [Text Block]	Note 3 – Variable Interest Entities WPZ We own a 74 percent interest in WPZ, a master limited partnership that is a VIE due to the limited partners’ lack of substantive voting rights, such as either participating rights or kick-out rights that can be exercised with a simple majority of the vote of the limited partners. We are the primary beneficiary of WPZ because we have the power, through our general partner interest, to direct the activities that most significantly impact WPZ’s economic performance. The following table presents amounts included in our Consolidated Balance Sheet that are for the use or obligation of WPZ and/or its subsidiaries, and which comprise a significant portion of our consolidated assets and liabilities. March 31, December 31, Classification (Millions) Assets (liabilities): Cash and cash equivalents $ 1,268 $ 881 Cash and cash equivalents Trade accounts and other receivables – net 718 972 Trade accounts and other receivables Inventories 160 113 Inventories Other current assets 198 176 Other current assets and deferred charges Investments 6,513 6,552 Investments Property, plant, and equipment – net 28,547 27,912 Property, plant, and equipment – net Intangible assets – net 8,643 8,790 Intangible assets – net of accumulated amortization Regulatory assets, deferred charges, and other noncurrent assets 528 507 Regulatory assets, deferred charges, and other Accounts payable (755 ) (957 ) Accounts payable Accrued liabilities including current asset retirement obligations (682 ) (857 ) Accrued liabilities Long-term debt due within one year (501 ) (501 ) Long-term debt due within one year Long-term debt (17,011 ) (15,996 ) Long-term debt Deferred income tax liabilities (15 ) (16 ) Deferred income tax liabilities Noncurrent asset retirement obligations (987 ) (944 ) Regulatory liabilities, deferred income, and other Regulatory liabilities, deferred income, and other noncurrent liabilities (3,221 ) (2,809 ) Regulatory liabilities, deferred income, and other The assets and liabilities presented in the table above also include the consolidated interests of the following individual VIEs within WPZ: Gulfstar One WPZ owns a 51 percent interest in Gulfstar One LLC (Gulfstar One), a subsidiary that, due to certain risk-sharing provisions in its customer contracts, is a VIE. Gulfstar One includes a proprietary floating-production system, Gulfstar FPS, and associated pipelines which provide production handling and gathering services in the eastern deepwater Gulf of Mexico. WPZ is the primary beneficiary because it has the power to direct the activities that most significantly impact Gulfstar One’s economic performance. Constitution WPZ owns a 41 percent interest in Constitution, a subsidiary that, due to shipper fixed-payment commitments under its long-term firm transportation contracts, is a VIE. WPZ is the primary beneficiary because it has the power to direct the activities that most significantly impact Constitution’s economic performance. WPZ, as operator of Constitution, is responsible for constructing the proposed pipeline connecting its gathering system in Susquehanna County, Pennsylvania, to the Iroquois Gas Transmission and the Tennessee Gas Pipeline systems. The total remaining cost of the project is estimated to be approximately $740 million , which would be funded with capital contributions from WPZ and the other equity partners on a proportional basis. In December 2014, Constitution received approval from the FERC to construct and operate its proposed pipeline. However, in April 2016, the New York State Department of Environmental Conservation (NYSDEC) denied the necessary water quality certification under Section 401 of the Clean Water Act for the New York portion of the pipeline. In May 2016, Constitution appealed the NYSDEC’s denial of the Section 401 certification to the United States Court of Appeals for the Second Circuit, and in August 2017 the court issued a decision denying in part and dismissing in part Constitution’s appeal. The court expressly declined to rule on Constitution’s argument that the delay in the NYSDEC’s decision on Constitution’s Section 401 application constitutes a waiver of the certification requirement. The court determined that it lacked jurisdiction to address that contention, and found that jurisdiction over the waiver issue lies exclusively with the United States Court of Appeals for the District of Columbia Circuit. As to the denial itself, the court determined that NYSDEC’s action was not arbitrary or capricious. Constitution filed a petition for rehearing with the Second Circuit Court of Appeals, but in October the court denied our petition. In October 2017, WPZ filed a petition for declaratory order requesting the FERC to find that, by operation of law, the Section 401 certification requirement for the New York State portion of Constitution’s pipeline project was waived due to the failure by the NYSDEC to act on Constitution’s Section 401 application within a reasonable period of time as required by the express terms of such statute. In January 2018, the FERC denied WPZ’s petition, finding that Section 401 provides that a state waives certification only when it does not act on an application within one year from the date of the application. The project’s sponsors remain committed to the project. In February 2018, we filed a request with the FERC for rehearing of its finding that the NYSDEC did not waive the Section 401 certification requirement. If the FERC denies such request, we will file a petition for review with the D.C. Circuit Court of Appeals. In January 2018, we filed a petition with the United States Supreme Court to review the decision of the Second Circuit Court of Appeals that upheld the merits of the NYSDEC’s denial of the Section 401 certification. However, on April 30, 2018, the Court denied our petition. This decision is separate and independent from (and thus has no impact on) our request for rehearing (or appeal) of the FERC’s decision that the NYSDEC did not waive the Section 401 certification requirement. Should any court or FERC decision determine that the NYSDEC waived the Section 401 certification requirement, we estimate that the target in-service date for the project would be approximately 10 to 12 months following any such determination. An unfavorable resolution could result in the impairment of a significant portion of the capitalized project costs, which total $379 million on a consolidated basis at March 31, 2018 , and are included within Property, plant, and equipment in the Consolidated Balance Sheet . Beginning in April 2016, we discontinued capitalization of development costs related to this project. It is also possible that we could incur certain supplier-related costs in the event of a prolonged delay or termination of the project. Cardinal WPZ owns a 66 percent interest in Cardinal Gas Services, L.L.C. (Cardinal), a subsidiary that provides gathering services for the Utica Shale region and is a VIE due to certain risks shared with customers. WPZ is the primary beneficiary because it has the power to direct the activities that most significantly impact Cardinal’s economic performance. Future expansion activity is expected to be funded with capital contributions from WPZ and the other equity partner on a proportional basis. Jackalope WPZ owns a 50 percent interest in Jackalope Gas Gathering Services, L.L.C. (Jackalope), a subsidiary that provides gathering and processing services for the Powder River basin and is a VIE due to certain risks shared with customers. WPZ is the primary beneficiary because it has the power to direct the activities that most significantly impact Jackalope’s economic performance. Future expansion activity is expected to be funded with capital contributions from WPZ and the other equity partner on a proportional basis.

Investing Activities

Investing Activities	3 Months Ended
	Mar. 31, 2018
Equity Method Investments and Joint Ventures [Abstract]
Investing Activities [Text Block]	Note 4 – Investing Activities Acquisition of Additional Interests in Appalachia Midstream Investments During the first quarter of 2017, WPZ exchanged all of its 50 percent interest in DBJV for an increased interest in two natural gas gathering systems that are part of the Appalachia Midstream Investments and $155 million in cash. This transaction was recorded based on our estimate of the fair value of the interests received as we have more insight to this value as we operate the underlying assets. Following this exchange, WPZ has an approximate average 66 percent interest in the Appalachia Midstream Investments. We continue to account for this investment under the equity-method due to the significant participatory rights of our partners such that we do not exercise control. WPZ also sold all of its interest in Ranch Westex JV LLC for $45 million . These transactions resulted in a total gain of $269 million reflected in Other investing income (loss) – net in the Consolidated Statement of Income . The fair value of the increased interests in the Appalachia Midstream Investments received as consideration was estimated to be $1.1 billion using an income approach based on expected cash flows and an appropriate discount rate (a Level 3 measurement within the fair value hierarchy). The determination of estimated future cash flows involved significant assumptions regarding gathering volumes, rates, and related capital spending. A 9.5 percent discount rate was utilized and reflected our estimate of the cost of capital as impacted by market conditions and risks associated with the underlying business.

Other Income and Expenses

Other Income and Expenses	3 Months Ended
	Mar. 31, 2018
Other Income and Expenses [Abstract]
Other Income and Expenses [Text Block]	Note 5 – Other Income and Expenses The following table presents certain gains or losses reflected in Other (income) expense – net within Costs and expenses in our Consolidated Statement of Income : Three Months Ended 2018 2017 (Millions) Williams Partners Gains on contract settlements and terminations $ — $ (13 ) Additional Items Certain additional items included in the Consolidated Statement of Income are as follows: • Other income (expense) – net below Operating income (loss) includes income of $20 million and $18 million for the three months ended March 31, 2018 and 2017, respectively, for allowance for equity funds used during construction primarily within the Williams Partners segment. Other income (expense) – net below Operating income (loss) also includes income of $5 million and $28 million for the three months ended March 31, 2018 and 2017, respectively of income associated with a regulatory asset related to deferred taxes on equity funds used during construction. • Other income (expense) – net below Operating income (loss) for the three months ended March 31, 2018, includes a $7 million net loss associated with the March 28, 2018, early retirement of $750 million of 4.875 percent senior unsecured notes that were due in 2024. The net loss within the Williams Partners segment reflects $34 million in premiums paid, partially offset by $27 million of unamortized premium. For the three months ended March 31, 2017, Other income (expense) – net below Operating income (loss) includes a net gain of $30 million associated with the February 23, 2017, early retirement of $750 million of 6.125 percent senior unsecured notes that were due in 2022. The net gain within Williams Partners reflects $53 million of unamortized premium, partially offset by $23 million in premiums paid. (See Note 9 – Debt and Banking Arrangements .)

Provision (Benefit) for Income

Provision (Benefit) for Income Taxes	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Provision (Benefit) for Income Taxes [Text Block]	Note 6 – Provision (Benefit) for Income Taxes The Provision (benefit) for income taxes includes: Three Months Ended 2018 2017 (Millions) Current: Federal $ (19 ) $ 3 State 1 6 (18 ) 9 Deferred: Federal 64 15 State 9 13 73 28 Provision (benefit) for income taxes $ 55 $ 37 The effective income tax rate for the total provision for the three months ended March 31, 2018 , is less than the federal statutory rate. This is primarily due to the impact of the allocation of income to nontaxable noncontrolling interests, partially offset by the effect of state income taxes. The effective income tax rate for the total provision for the three months ended March 31, 2017 , is less than the federal statutory rate primarily due to releasing a $127 million valuation allowance on a capital loss carryover and the impact of nontaxable noncontrolling interests, partially offset by the effect of state income taxes. The sale of the Geismar olefins facility in 2017 generated capital gains sufficient to offset the capital loss carryover, thereby allowing us to reverse the valuation allowance in full. On December 22, 2017, Tax Reform was enacted. Under the guidance provided by Securities and Exchange Commission Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act, we recorded provisional adjustments related to the impact of Tax Reform in the fourth quarter of 2017. We consider all amounts recorded related to Tax Reform to be reasonable estimates. The amounts recorded continue to be provisional for the reasons disclosed in our Annual Report on Form 10-K filed February 22, 2018, as our interpretation, assessment, and presentation of the impact of the tax law change may be further clarified with additional guidance from regulatory, tax, and accounting authorities. We are continuing to gather additional information to determine the final impact and should additional guidance be provided by these authorities or other sources, we will review the provisional amounts and adjust as appropriate. During the next 12 months, we do not expect ultimate resolution of any unrecognized tax benefit associated with domestic or international matters to have a material impact on our unrecognized tax benefit position.

Earnings Per Common Share

Earnings Per Common Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Earnings Per Common Share [Text Block]	Note 7 – Earnings Per Common Share Three Months Ended 2018 2017 (Dollars in millions, except per-share amounts; shares in thousands) Net income attributable to The Williams Companies, Inc. available to common stockholders for basic and diluted earnings per common share $ 152 $ 373 Basic weighted-average shares 827,509 824,548 Effect of dilutive securities: Nonvested restricted stock units 2,095 1,305 Stock options 593 623 Diluted weighted-average shares 830,197 826,476 Earnings per common share: Basic $ .18 $ .45 Diluted $ .18 $ .45

Employee Benefit Plans

Employee Benefit Plans	3 Months Ended
	Mar. 31, 2018
Retirement Benefits [Abstract]
Employee Benefit Plans [Text Block]	Note 8 – Employee Benefit Plans Net periodic benefit cost (credit) is as follows: Pension Benefits Three Months Ended 2018 2017 (Millions) Components of net periodic benefit cost (credit): Service cost $ 14 $ 13 Interest cost 11 15 Expected return on plan assets (16 ) (20 ) Amortization of net actuarial loss 6 7 Net periodic benefit cost (credit) $ 15 $ 15 Other Postretirement Benefits Three Months Ended 2018 2017 (Millions) Components of net periodic benefit cost (credit): Interest cost $ 2 $ 2 Expected return on plan assets (3 ) (3 ) Amortization of prior service credit (1 ) (3 ) Reclassification to regulatory liability 1 1 Net periodic benefit cost (credit) $ (1 ) $ (3 ) The components of Net periodic benefit cost (credit) other than the Service cost component are included in Other income (expense) – net below Operating income (loss) in the Consolidated Statement of Income . Amortization of prior service credit included in Net periodic benefit cost (credit) for our other postretirement benefit plans associated with Transco and Northwest Pipeline is recorded to regulatory assets/liabilities instead of O ther comprehensive income (loss). The amounts of Amortization of prior service credit recognized in regulatory liabilities were $1 million and $2 million for the three months ended March 31, 2018 and 2017 respectively. During the three months ended March 31, 2018 , we contributed $2 million to our pension plans and $1 million to our other postretirement benefit plans. We presently anticipate making additional contributions of approximately $84 million to our pension plans and approximately $5 million to our other postretirement benefit plans in the remainder of 2018.

Debt and Banking Arrangements

Debt and Banking Arrangements	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Debt and Banking Arrangements [Text Block]	Note 9 – Debt and Banking Arrangements Long-Term Debt Issuances and retirements On March 5, 2018, WPZ completed a public offering of $800 million of 4.85 percent senior unsecured notes due 2048. WPZ used the net proceeds for general partnership purposes, primarily the March 28, 2018 repayment of $750 million of 4.875 percent senior unsecured notes that were due in 2024. On March 15, 2018, Transco issued $400 million of 4 percent senior unsecured notes due 2028 and $600 million of 4.6 percent senior unsecured notes due 2048 to investors in a private debt placement. Transco intends to use the net proceeds to retire $250 million of 6.05 percent senior unsecured notes due June 2018, and for general corporate purposes, including the funding of capital expenditures. As part of the issuance, Transco entered into a registration rights agreement with the initial purchasers of the unsecured notes. Transco is obligated to file and consummate a registration statement for an offer to exchange the notes for a new issue of substantially identical notes registered under the Securities Act of 1933, as amended, within 365 days from closing and to use commercially reasonable efforts to complete the exchange offer. Transco is required to provide a shelf registration statement to cover resales of the notes under certain circumstances. If Transco fails to fulfill these obligations, additional interest will accrue on the affected securities. The rate of additional interest will be 0.25 percent per annum on the principal amount of the affected securities for the first 90-day period immediately following the occurrence of a registration default, increasing by an additional 0.25 percent per annum with respect to each subsequent 90-day period thereafter, up to a maximum amount for all such registration defaults of 0.5 percent annually. Following the cure of any registration defaults, the accrual of additional interest will cease. Other financing obligation During the first quarter of 2018, Transco received an additional $19 million of funding from a co-owner related to the construction of the Dalton expansion project. This additional funding is reflected as Long-term debt in the Consolidated Balance Sheet . Commercial Paper Program As of March 31, 2018, no commercial paper was outstanding under WPZ’s $3 billion commercial paper program. Credit Facilities March 31, 2018 Stated Capacity Outstanding (Millions) WMB Long-term credit facility $ 1,500 $ 200 Letters of credit under certain bilateral bank agreements 13 WPZ Long-term credit facility (1) 3,500 — Letters of credit under certain bilateral bank agreements 1 (1) In managing our available liquidity, we do not expect a maximum outstanding amount in excess of the capacity of WPZ’s credit facility inclusive of any outstanding amounts under its commercial paper program.

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2018
Stockholders' Equity Note [Abstract]
Stockholders' Equity [Text Block]	Note 10 – Stockholders’ Equity AOCI The following table presents the changes in Accumulated other comprehensive income (loss) (AOCI) by component, net of income taxes: Cash Flow Hedges Foreign Currency Translation Pension and Other Postretirement Benefits Total (Millions) Balance at December 31, 2017 $ (2 ) $ (1 ) $ (235 ) $ (238 ) Adoption of ASU 2018-02 (Note 1) — — (61 ) (61 ) Amounts reclassified from accumulated other comprehensive income (loss) — — 5 5 Balance at March 31, 2018 $ (2 ) $ (1 ) $ (291 ) $ (294 ) Reclassifications out of AOCI are presented in the following table by component for the three months ended March 31, 2018 : Component Reclassifications Classification (Millions) Pension and other postretirement benefits: Amortization of actuarial (gain) loss included in net periodic benefit cost (credit) $ 6 Note 8 – Employee Benefit Plans Income tax benefit (1 ) Provision (benefit) for income taxes Reclassifications during the period $ 5

Fair Value Measurements and Gua

Fair Value Measurements and Guarantees	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements and Guarantees [Text Block]	Note 11 – Fair Value Measurements and Guarantees The following table presents, by level within the fair value hierarchy, certain of our financial assets and liabilities. The carrying values of cash and cash equivalents, accounts receivable, and accounts payable approximate fair value because of the short-term nature of these instruments. Therefore, these assets and liabilities are not presented in the following table. Fair Value Measurements Using Carrying Amount Fair Value Quoted Prices In Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (Millions) Assets (liabilities) at March 31, 2018: Measured on a recurring basis: ARO Trust investments $ 145 $ 145 $ 145 $ — $ — Energy derivatives assets designated as hedging instruments 2 2 2 — — Energy derivatives assets not designated as hedging instruments 4 4 4 — — Energy derivatives liabilities designated as hedging instruments (3 ) (3 ) (3 ) — — Energy derivatives liabilities not designated as hedging instruments (4 ) (4 ) (1 ) — (3 ) Additional disclosures: Other receivables 7 7 7 — — Long-term debt, including current portion (21,880 ) (23,061 ) — (23,061 ) — Guarantees (43 ) (30 ) — (14 ) (16 ) Assets (liabilities) at December 31, 2017: Measured on a recurring basis: ARO Trust investments $ 135 $ 135 $ 135 $ — $ — Energy derivatives liabilities designated as hedging instruments (3 ) (3 ) (2 ) (1 ) — Energy derivatives liabilities not designated as hedging instruments (3 ) (3 ) — — (3 ) Additional disclosures: Other receivables 7 7 7 — — Long-term debt, including current portion (20,935 ) (23,005 ) — (23,005 ) — Guarantees (43 ) (30 ) — (14 ) (16 ) Fair Value Methods We use the following methods and assumptions in estimating the fair value of our financial instruments: Assets and liabilities measured at fair value on a recurring basis ARO Trust investments : Transco deposits a portion of its collected rates, pursuant to its rate case settlement, into an external trust (ARO Trust) that is specifically designated to fund future asset retirement obligations (ARO). The ARO Trust invests in a portfolio of actively traded mutual funds that are measured at fair value on a recurring basis based on quoted prices in an active market and is reported in Regulatory assets, deferred charges, and other in the Consolidated Balance Sheet. Both realized and unrealized gains and losses are ultimately recorded as regulatory assets or liabilities. Energy derivatives : Energy derivatives include commodity-based exchange-traded contracts and over-the-counter contracts, which consist of physical forwards, futures, and swaps that are measured at fair value on a recurring basis. The fair value amounts are presented on a gross basis and do not reflect the netting of asset and liability positions permitted under the terms of our master netting arrangements. Further, the amounts do not include cash held on deposit in margin accounts that we have received or remitted to collateralize certain derivative positions. Energy derivatives assets are reported in Other current assets and deferred charges and Regulatory assets, deferred charges, and other in the Consolidated Balance Sheet. Energy derivatives liabilities are reported in Accrued liabilities and Regulatory liabilities, deferred income, and other in the Consolidated Balance Sheet. Reclassifications of fair value between Level 1, Level 2, and Level 3 of the fair value hierarchy, if applicable, are made at the end of each quarter. No transfers between Level 1 and Level 2 occurred during the three months ended March 31, 2018 or 2017 . Additional fair value disclosures Other receivables: Other receivables consist of margin deposits, which are reported in Other current assets and deferred charges in the Consolidated Balance Sheet. The disclosed fair value of our margin deposits is considered to approximate the carrying value generally due to the short-term nature of these items. Long-term debt, including current portion : The disclosed fair value of our long-term debt is determined primarily by a market approach using broker quoted indicative period-end bond prices. The quoted prices are based on observable transactions in less active markets for our debt or similar instruments. Guarantees : Guarantees primarily consist of a guarantee we have provided in the event of nonpayment by our previously owned communications subsidiary, Williams Communications Group (WilTel), on a lease performance obligation that extends through 2042. Guarantees also include an indemnification related to a disposed operation. To estimate the fair value of the WilTel guarantee, an estimated default rate is applied to the sum of the future contractual lease payments using an income approach. The estimated default rate is determined by obtaining the average cumulative issuer-weighted corporate default rate based on the credit rating of WilTel’s current owner and the term of the underlying obligation. The default rate is published by Moody’s Investors Service. The carrying value of the WilTel guarantee is reported in Accrued liabilities in the Consolidated Balance Sheet. The maximum potential undiscounted exposure is approximately $30 million at March 31, 2018 . Our exposure declines systematically through the remaining term of WilTel’s obligation. The fair value of the guarantee associated with the indemnification related to a disposed operation was estimated using an income approach that considered probability-weighted scenarios of potential levels of future performance. The terms of the indemnification do not limit the maximum potential future payments associated with the guarantee. The carrying value of this guarantee is reported in Regulatory liabilities, deferred income, and other in the Consolidated Balance Sheet. We are required by our revolving credit agreements to indemnify lenders for certain taxes required to be withheld from payments due to the lenders and for certain tax payments made by the lenders. The maximum potential amount of future payments under these indemnifications is based on the related borrowings and such future payments cannot currently be determined. These indemnifications generally continue indefinitely unless limited by the underlying tax regulations and have no carrying value. We have never been called upon to perform under these indemnifications and have no current expectation of a future claim.

Contingent Liabilities

Contingent Liabilities	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Contingent Liabilities [Text Block]	Note 12 – Contingent Liabilities Reporting of Natural Gas-Related Information to Trade Publications Direct and indirect purchasers of natural gas in various states filed individual and class actions against us, our former affiliate WPX Energy, Inc. (WPX) and its subsidiaries, and others alleging the manipulation of published gas price indices and seeking unspecified amounts of damages. Such actions were transferred to the Nevada federal district court for consolidation of discovery and pre-trial issues. We have agreed to indemnify WPX and its subsidiaries related to this matter. In the individual action, filed by Farmland Industries Inc. (Farmland), the court issued an order on May 24, 2016, granting one of our co-defendant’s motion for summary judgment as to Farmland’s claims. On January 5, 2017, the court extended such ruling to us, entering final judgment in our favor. Farmland appealed. On March 27, 2018, the appellate court reversed the district court’s grant of summary judgment, and on April 10, 2018, the defendants filed a petition for rehearing with the appellate court. In the putative class actions, on March 30, 2017, the court issued an order denying the plaintiffs’ motions for class certification. On June 13, 2017, the United States Court of Appeals for the Ninth Circuit granted the plaintiffs’ petition for permission to appeal the order, and the appeal is now pending. Because of the uncertainty around the remaining pending unresolved issues, we cannot reasonably estimate a range of potential exposure at this time. However, it is reasonably possible that the ultimate resolution of these actions and our related indemnification obligation could result in a potential loss that may be material to our results of operations. In connection with this indemnification, we have an accrued liability balance associated with this matter, and as a result, have exposure to future developments. Alaska Refinery Contamination Litigation We are involved in litigation arising from our ownership and operation of the North Pole Refinery in North Pole, Alaska, from 1980 until 2004, through our wholly-owned subsidiaries, Williams Alaska Petroleum Inc. (WAPI) and MAPCO Inc. We sold the refinery to Flint Hills Resources Alaska, LLC (FHRA), a subsidiary of Koch Industries, Inc., in 2004. The litigation involves three cases, with filing dates ranging from 2010 to 2014. The actions arise from sulfolane contamination allegedly emanating from the refinery. A putative class action lawsuit was filed by James West in 2010 naming us, WAPI, and FHRA as defendants. We and FHRA filed claims against each other seeking, among other things, contractual indemnification alleging that the other party caused the sulfolane contamination. In 2011, we and FHRA settled the claim with James West. Certain claims by FHRA against us were resolved by the Alaska Supreme Court in our favor. FHRA’s claims against us for contractual indemnification and statutory claims for damages related to off-site sulfolane remain pending. The State of Alaska filed its action in March 2014, seeking damages. The City of North Pole (North Pole) filed its lawsuit in November 2014, seeking past and future damages, as well as punitive damages. Both we and WAPI asserted counterclaims against the State of Alaska and North Pole, and cross-claims against FHRA. FHRA has also filed cross-claims against us. The underlying factual basis and claims in the cases are similar and may duplicate exposure. As such, in February 2017, the three cases were consolidated into one action in state court containing the remaining claims from the James West case and those of the State of Alaska and North Pole. A trial encompassing all three cases was originally scheduled to commence in May 2017 but has been continued. A new trial date has not been scheduled. Due to the ongoing assessment of the level and extent of sulfolane contamination, the lack of an articulated cleanup level for sulfolane, and the lack of a concrete remedial proposal and cost estimate, we are unable to estimate a range of exposure to the State of Alaska or North Pole at this time. We currently estimate that our reasonably possible loss exposure to FHRA could range from an insignificant amount up to $32 million , although uncertainties inherent in the litigation process, expert evaluations, and jury dynamics might cause our exposure to exceed that amount. Independent of the litigation matter described in the preceding paragraphs, in 2013, the Alaska Department of Environmental Conservation indicated that it views FHRA and us as responsible parties, and that it intended to enter a compliance order to address the environmental remediation of sulfolane and other possible contaminants including cleanup work outside the refinery’s boundaries. To date, no compliance order has been issued. Due to the ongoing assessment of the level and extent of sulfolane contamination, the ultimate cost of remediation and division of costs among the potentially responsible parties, and the previously described separate litigation, we are unable to estimate a range of exposure at this time. Royalty Matters Certain of our customers, including one major customer, have been named in various lawsuits alleging underpayment of royalties and claiming, among other things, violations of anti-trust laws and the Racketeer Influenced and Corrupt Organizations Act. We have also been named as a defendant in certain of these cases filed in Pennsylvania based on allegations that we improperly participated with that major customer in causing the alleged royalty underpayments. We believe that the claims asserted are subject to indemnity obligations owed to us by that major customer. Due to the preliminary status of the cases, we are unable to estimate a range of potential loss at this time. Shareholder Litigation On March 7, 2016, a purported unitholder of WPZ filed a putative class action on behalf of certain purchasers of WPZ units in U.S. District Court in Oklahoma. The action names as defendants us, WPZ, Williams Partners GP LLC, Alan S. Armstrong, and former Chief Financial Officer Donald R. Chappel and alleges violations of certain federal securities laws for failure to disclose Energy Transfer Equity, L.P.’s (Energy Transfer) intention to pursue a purchase of us conditioned on us not closing the May 2015 agreement for a unit-for-stock transaction whereby we would have acquired all of the publicly held outstanding common units of WPZ in exchange for shares of our common stock (WPZ Merger Agreement) when announcing the WPZ Merger Agreement. The complaint seeks, among other things, damages and an award of costs and attorneys’ fees. The plaintiff filed an amended complaint on August 31, 2016. On October 17, 2016, we requested the court dismiss the action, and on March 8, 2017, the court dismissed the complaint with prejudice. On April 7, 2017, the plaintiff filed a notice of appeal. We cannot reasonably estimate a range of potential loss at this time. Litigation Against Energy Transfer and Related Parties On April 6, 2016, we filed suit in Delaware Chancery Court against Energy Transfer and LE GP, LLC (the general partner for Energy Transfer) alleging willful and material breaches of the Agreement and Plan of Merger (Merger Agreement) with Energy Transfer resulting from the private offering by Energy Transfer on March 8, 2016, of Series A Convertible Preferred Units (Special Offering) to certain Energy Transfer insiders and other accredited investors. The suit seeks, among other things, an injunction ordering the defendants to unwind the Special Offering and to specifically perform their obligations under the Merger Agreement. On April 19, 2016, we filed an amended complaint seeking the same relief. On May 3, 2016, Energy Transfer and LE GP, LLC filed an answer and counterclaims. On May 13, 2016, we filed a separate complaint in Delaware Chancery Court against Energy Transfer, LE GP, LLC, and the other Energy Transfer affiliates that are parties to the Merger Agreement, alleging material breaches of the Merger Agreement for failing to cooperate and use necessary efforts to obtain a tax opinion required under the Merger Agreement (Tax Opinion) and for otherwise failing to use necessary efforts to consummate the merger under the Merger Agreement wherein we would be merged with and into the newly formed Energy Transfer Corp LP (ETC) (ETC Merger). The suit sought, among other things, a declaratory judgment and injunction preventing Energy Transfer from terminating or otherwise avoiding its obligations under the Merger Agreement due to any failure to obtain the Tax Opinion. The Court of Chancery coordinated the Special Offering and Tax Opinion suits. On May 20, 2016, the Energy Transfer defendants filed amended affirmative defenses and verified counterclaims in the Special Offering and Tax Opinion suits, alleging certain breaches of the Merger Agreement by us and seeking, among other things, a declaration that we were not entitled to specific performance, that Energy Transfer could terminate the ETC Merger, and that Energy Transfer is entitled to a $1.48 billion termination fee. On June 24, 2016, following a two-day trial, the court issued a Memorandum Opinion and Order denying our requested relief in the Tax Opinion suit. The court did not rule on the substance of our claims related to the Special Offering or on the substance of Energy Transfer’s counterclaims. On June 27, 2016, we filed an appeal of the court’s decision with the Supreme Court of Delaware, seeking reversal and remand to pursue damages. On March 23, 2017, the Supreme Court of Delaware affirmed the Court of Chancery’s ruling. On March 30, 2017, we filed a motion for reargument with the Supreme Court of Delaware, which was denied on April 5, 2017. On September 16, 2016, we filed an amended complaint with the Court of Chancery seeking damages for breaches of the Merger Agreement by defendants. On September 23, 2016, Energy Transfer filed a second amended and supplemental affirmative defenses and verified counterclaim with the Court of Chancery seeking, among other things, payment of the $1.48 billion termination fee due to our alleged breaches of the Merger Agreement. On December 1, 2017, the court granted our motion to dismiss certain of Energy Transfer’s counterclaims, including its claim seeking payment of the $1.48 billion termination fee. On December 8, 2017, Energy Transfer filed a motion for reargument, which the Court of Chancery denied on April 16, 2018. The Court of Chancery scheduled trial for May 20 through May 24, 2019. Environmental Matters We are a participant in certain environmental activities in various stages including assessment studies, cleanup operations, and/or remedial processes at certain sites, some of which we currently do not own. We are monitoring these sites in a coordinated effort with other potentially responsible parties, the U.S. Environmental Protection Agency (EPA), or other governmental authorities. We are jointly and severally liable along with unrelated third parties in some of these activities and solely responsible in others. Certain of our subsidiaries have been identified as potentially responsible parties at various Superfund and state waste disposal sites. In addition, these subsidiaries have incurred, or are alleged to have incurred, various other hazardous materials removal or remediation obligations under environmental laws. As of March 31, 2018 , we have accrued liabilities totaling $39 million for these matters, as discussed below. Estimates of the most likely costs of cleanup are generally based on completed assessment studies, preliminary results of studies, or our experience with other similar cleanup operations. At March 31, 2018 , certain assessment studies were still in process for which the ultimate outcome may yield different estimates of most likely costs. Therefore, the actual costs incurred will depend on the final amount, type, and extent of contamination discovered at these sites, the final cleanup standards mandated by the EPA or other governmental authorities, and other factors. The EPA and various state regulatory agencies routinely promulgate and propose new rules, and issue updated guidance to existing rules. More recent rules and rulemakings include, but are not limited to, rules for reciprocating internal combustion engine maximum achievable control technology, air quality standards for one hour nitrogen dioxide emissions, and volatile organic compound and methane new source performance standards impacting design and operation of storage vessels, pressure valves, and compressors. On October 1, 2015, the EPA issued its rule regarding National Ambient Air Quality Standards for ground-level ozone, setting a stricter standard of 70 parts per billion . We are monitoring the rule’s implementation as the reduction will trigger additional federal and state regulatory actions that may impact our operations. Implementation of the regulations is expected to result in impacts to our operations and increase the cost of additions to Property, plant, and equipment – net in the Consolidated Balance Sheet for both new and existing facilities in affected areas. We are unable to reasonably estimate the cost of additions that may be required to meet the regulations at this time due to uncertainty created by various legal challenges to these regulations and the need for further specific regulatory guidance. Continuing operations Our interstate gas pipelines are involved in remediation activities related to certain facilities and locations for polychlorinated biphenyls, mercury, and other hazardous substances. These activities have involved the EPA and various state environmental authorities, resulting in our identification as a potentially responsible party at various Superfund waste sites. At March 31, 2018 , we have accrued liabilities of $7 million for these costs. We expect that these costs will be recoverable through rates. We also accrue environmental remediation costs for natural gas underground storage facilities, primarily related to soil and groundwater contamination. At March 31, 2018 , we have accrued liabilities totaling $10 million for these costs. Former operations, including operations classified as discontinued We have potential obligations in connection with assets and businesses we no longer operate. These potential obligations include remediation activities at the direction of federal and state environmental authorities and the indemnification of the purchasers of certain of these assets and businesses for environmental and other liabilities existing at the time the sale was consummated. Our responsibilities relate to the operations of the assets and businesses described below. • Former agricultural fertilizer and chemical operations and former retail petroleum and refining operations; • Former petroleum products and natural gas pipelines; • Former petroleum refining facilities; • Former exploration and production and mining operations; • Former electricity and natural gas marketing and trading operations. At March 31, 2018 , we have accrued environmental liabilities of $22 million related to these matters. Other Divestiture Indemnifications Pursuant to various purchase and sale agreements relating to divested businesses and assets, we have indemnified certain purchasers against liabilities that they may incur with respect to the businesses and assets acquired from us. The indemnities provided to the purchasers are customary in sale transactions and are contingent upon the purchasers incurring liabilities that are not otherwise recoverable from third parties. The indemnities generally relate to breach of warranties, tax, historic litigation, personal injury, property damage, environmental matters, right of way, and other representations that we have provided. At March 31, 2018 , other than as previously disclosed, we are not aware of any material claims against us involving the indemnities; thus, we do not expect any of the indemnities provided pursuant to the sales agreements to have a material impact on our future financial position. Any claim for indemnity brought against us in the future may have a material adverse effect on our results of operations in the period in which the claim is made. In addition to the foregoing, various other proceedings are pending against us which are incidental to our operations, none of which are expected to be material to our expected future annual results of operations, liquidity, and financial position. Summary We have disclosed our estimated range of reasonably possible losses for certain matters above, as well as all significant matters for which we are unable to reasonably estimate a range of possible loss. We estimate that for all other matters for which we are able to reasonably estimate a range of loss, our aggregate reasonably possible losses beyond amounts accrued are immaterial to our expected future annual results of operations, liquidity, and financial position. These calculations have been made without consideration of any potential recovery from third parties.

Segment Disclosures

Segment Disclosures	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Segment Disclosures [Text Block]	Note 13 – Segment Disclosures We have one reportable segment, Williams Partners. All remaining business activities are included in Other. (See Note 1 – General, Description of Business, and Basis of Presentation .) Our segment presentation of Williams Partners, which includes our consolidated master limited partnership, is reflective of the parent-level focus by our chief operating decision-maker, considering the resource allocation and governance provisions associated with the master limited partnership structure. This partnership maintains capital and cash management structures that are separate from ours. It is self-funding and maintains its own lines of bank credit and cash management accounts. These factors serve to differentiate the management of this entity as a whole. Performance Measurement We evaluate segment operating performance based upon Modified EBITDA (earnings before interest, taxes, depreciation, and amortization). This measure represents the basis of our internal financial reporting and is the primary performance measure used by our chief operating decision maker in measuring performance and allocating resources among our reportable segments. We define Modified EBITDA as follows: • Net income (loss) before: ◦ Income (loss) from discontinued operations; ◦ Provision (benefit) for income taxes; ◦ Interest incurred, net of interest capitalized; ◦ Equity earnings (losses); ◦ Gain on remeasurement of equity-method investment; ◦ Impairment of equity-method investments; ◦ Other investing income (loss) – net; ◦ Impairment of goodwill; ◦ Depreciation and amortization expenses; ◦ Accretion expense associated with asset retirement obligations for nonregulated operations. • This measure is further adjusted to include our proportionate share (based on ownership interest) of Modified EBITDA from our equity-method investments calculated consistently with the definition described above. The following table reflects the reconciliation of Segment revenues to Total revenues as reported in the Consolidated Statement of Income and Total assets by reportable segment. Williams Partners Other Eliminations Total (Millions) Three Months Ended March 31, 2018 Segment revenues: Service revenues External $ 1,346 $ 5 $ — $ 1,351 Internal — 3 (3 ) — Total service revenues 1,346 8 (3 ) 1,351 Total service revenues – commodity consideration (external only) 101 — — 101 Product sales External 636 — — 636 Internal — — — — Total product sales 636 — — 636 Total revenues $ 2,083 $ 8 $ (3 ) $ 2,088 Three Months Ended March 31, 2017 Segment revenues: Service revenues External $ 1,256 $ 5 $ — $ 1,261 Internal — 3 (3 ) — Total service revenues 1,256 8 (3 ) 1,261 Product sales External 727 — — 727 Internal — — — — Total product sales 727 — — 727 Total revenues $ 1,983 $ 8 $ (3 ) $ 1,988 March 31, 2018 Total assets $ 46,575 $ 541 $ (64 ) $ 47,052 December 31, 2017 Total assets $ 45,903 $ 589 $ (140 ) $ 46,352 The following table reflects the reconciliation of Modified EBITDA to Net income (loss) as reported in the Consolidated Statement of Income . Three Months Ended 2018 2017 (Millions) Modified EBITDA by segment: Williams Partners $ 1,107 $ 1,132 Other 13 18 1,120 1,150 Accretion expense associated with asset retirement obligations for nonregulated operations (8 ) (7 ) Depreciation and amortization expenses (431 ) (442 ) Equity earnings (losses) 82 107 Other investing income (loss) – net 4 272 Proportional Modified EBITDA of equity-method investments (169 ) (194 ) Interest expense (273 ) (280 ) (Provision) benefit for income taxes (55 ) (37 ) Net income (loss) $ 270 $ 569

Revenue Recognition Revenue Rec

Revenue Recognition Revenue Recognition (Tables)	3 Months Ended
	Mar. 31, 2018
Revenue Recognition [Abstract]
Disaggregation of Revenue [Table Text Block]	The following table presents our revenue disaggregated by major service line: Northeast Midstream Atlantic- Gulf Midstream West Midstream Transco Northwest Pipeline Other Intercompany Eliminations Total (Millions) Three Months Ended March 31, 2018 Revenues from contracts with customers: Service revenues: Non-regulated gathering, processing, transportation, and storage: Monetary consideration $ 202 $ 137 $ 408 $ — $ — $ — $ (18 ) $ 729 Commodity consideration 4 15 82 — — — — 101 Regulated interstate natural gas transportation and storage — — — 461 112 — (1 ) 572 Other 21 6 11 — — 8 (6 ) 40 Total service revenues 227 158 501 461 112 8 (25 ) 1,442 Product Sales: NGL and natural gas 98 68 521 25 — — (85 ) 627 Other — — 4 — — — — 4 Total product sales 98 68 525 25 — — (85 ) 631 Total revenues from contracts with customers 325 226 1,026 486 112 8 (110 ) 2,073 Other revenues (1) 5 2 5 3 — — — 15 Total revenues $ 330 $ 228 $ 1,031 $ 489 $ 112 $ 8 $ (110 ) $ 2,088 (1) We provide management services to operated joint ventures and other investments for which we receive a management fee that is categorized as Service revenues in our Consolidated Statement of Income. These management fees do not constitute revenue from contracts with customers. Product sales in our Consolidated Statement of Income include amounts associated with our derivative contracts that are not within the scope of ASC 606.
Contract with Customer, Asset and Liability [Table Text Block]	The following table presents a reconciliation of the beginning and ending balances of our contract assets for the period ended March 31, 2018: 2018 (Millions) Balance at January 1 $ 4 Revenue recognized in excess of cash received 20 Minimum volume commitments invoiced — Balance at March 31 $ 24
Contract with Customer, Liability [Table Text Block]	The following table presents a reconciliation of the beginning and ending balances of our contract liabilities for the period ended March 31, 2018: 2018 (Millions) Balance at January 1 $ 1,596 Payments received and deferred 92 Recognized in revenue (114 ) Balance at March 31 $ 1,574
Contract with Customer, Liablity Expected Timing of Revenue Recognition [Table Text Block]	The following table presents the amount of the contract liabilities balance as of March 31, 2018, expected to be recognized as revenue in each of the next five years as performance obligations are expected to be satisfied: (Millions) 2018 (remainder) $ 251 2019 252 2020 120 2021 100 2022 94 2023 88 Thereafter 669
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block]	The following table presents the transaction price allocated to the remaining performance obligations under certain contracts as of March 31, 2018. These primarily include long-term contracts containing MVCs associated with our midstream businesses, fixed payments associated with offshore production handling, and reservation charges on contracted capacity on our gas pipeline firm transportation contracts with customers, as well as storage capacity contracts. Amounts included in the table below for our interstate natural gas pipeline businesses reflect the rates for such services in our current FERC tariffs for the life of the related contracts; however, these rates may change based on future tariffs approved by the FERC and the amount and timing of these changes is not currently known. As a practical expedient permitted by ASC 606, this table excludes variable consideration as well as consideration in contracts that is recognized in revenue as billed. It also excludes consideration received prior to March 31, 2018, that will be recognized in future periods (see above for Contract Liabilities and the expected recognition of those amounts within revenue). As noted above, certain of our contracts contain evergreen and other renewal provisions for periods beyond the initial term of the contract. The remaining performance obligation as of March 31, 2018, does not consider potential future performance obligations for which the renewal has not been exercised. The table below also does not include contracts with customers for which the underlying facilities have not received FERC authorization to be placed into service. (Millions) 2018 (remainder) $ 1,927 2019 2,410 2020 2,210 2021 1,891 2022 1,758 2023 1,566 Thereafter 11,679 Total $ 23,441
Contract With Customer Accounts Receivable [Table Text Block]	The following is a summary of our Trade accounts and other receivables as it relates to contracts with customers: March 31, 2018 (Millions) Accounts receivable related to revenues from contracts with customers $ 704 Other accounts receivable 39 Total reflected in Trade accounts and other receivables $ 743
Revenue Recognition Modified Retrospective Adoption Impact [Table Text Block]	The following table depicts the impact of the adoption of ASC 606 on our 2018 financial statements. The adjustment to Intangible assets – net of accumulated amortization in the table below relates to the recognition under ASC 606 of contract assets for MVC-related contracts associated with a 2014 acquisition. The recognition of these contract assets resulted in a lower purchase price allocation to intangible assets. The adoption of ASC 606 did not result in adjustments to total operating, investing, or financing cash flows. As Reported Adjustments resulting from adoption of ASC 606 Balance without adoption of ASC 606 (Millions) Consolidated Statement of Income Three Months Ended March 31, 2018 Service revenues $ 1,351 $ 5 $ 1,356 Service revenues – commodity consideration 101 (101 ) — Product sales 636 10 646 Total revenues 2,088 (86 ) 2,002 Product costs 613 (55 ) 558 Processing commodity expenses 35 (35 ) — Operating and maintenance expenses 357 (1 ) 356 Depreciation and amortization expenses 431 1 432 Total costs and expenses 1,597 (90 ) 1,507 Operating income (loss) 491 4 495 Interest incurred (282 ) 3 (279 ) Interest capitalized 9 (2 ) 7 Income (loss) before income taxes 325 5 330 Net income (loss) 270 5 275 Less: Net income (loss) attributable to noncontrolling interests 118 2 120 Net income (loss) attributable to The Williams Companies, Inc. 152 3 155 Consolidated Statement of Comprehensive income Three Months Ended March 31, 2018 Net income (loss) $ 270 $ 5 $ 275 Comprehensive income (loss) 276 5 281 Less: Comprehensive income (loss) attributable to noncontrolling interests 119 2 121 Comprehensive income (loss) attributable to The Williams Companies, Inc. 157 3 160 Consolidated Balance Sheet March 31, 2018 Inventories $ 160 $ (8 ) $ 152 Other current assets and deferred charges 204 (20 ) 184 Total current assets 2,399 (28 ) 2,371 Investments 6,513 (1 ) 6,512 Property, plant, and equipment 40,467 (2 ) 40,465 Property, plant, and equipment – net 28,847 (2 ) 28,845 Intangible assets – net of accumulated amortization 8,644 63 8,707 Regulatory assets, deferred charges, and other 649 (4 ) 645 Total assets 47,052 28 47,080 Deferred income tax liabilities 3,196 27 3,223 Regulatory liabilities, deferred income, and other 4,410 (125 ) 4,285 Retained deficit (8,587 ) 87 (8,500 ) Total stockholders’ equity 9,473 87 9,560 Noncontrolling interests in consolidated subsidiaries 6,430 39 6,469 Total equity 15,903 126 16,029 Total liabilities and equity 47,052 28 47,080 Consolidated Statement of Changes in Equity March 31, 2018 Adoption of ASC 606 $ (121 ) $ 121 $ — Net income (loss) 270 5 275 Net increase (decrease) in equity (272 ) 126 (146 ) Balance - March 31, 2018 15,903 126 16,029

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	3 Months Ended
	Mar. 31, 2018
Variable Interest Entity Disclosures [Abstract]
Schedule of Variable Interest Entities [Table Text Block]	The following table presents amounts included in our Consolidated Balance Sheet that are for the use or obligation of WPZ and/or its subsidiaries, and which comprise a significant portion of our consolidated assets and liabilities. March 31, December 31, Classification (Millions) Assets (liabilities): Cash and cash equivalents $ 1,268 $ 881 Cash and cash equivalents Trade accounts and other receivables – net 718 972 Trade accounts and other receivables Inventories 160 113 Inventories Other current assets 198 176 Other current assets and deferred charges Investments 6,513 6,552 Investments Property, plant, and equipment – net 28,547 27,912 Property, plant, and equipment – net Intangible assets – net 8,643 8,790 Intangible assets – net of accumulated amortization Regulatory assets, deferred charges, and other noncurrent assets 528 507 Regulatory assets, deferred charges, and other Accounts payable (755 ) (957 ) Accounts payable Accrued liabilities including current asset retirement obligations (682 ) (857 ) Accrued liabilities Long-term debt due within one year (501 ) (501 ) Long-term debt due within one year Long-term debt (17,011 ) (15,996 ) Long-term debt Deferred income tax liabilities (15 ) (16 ) Deferred income tax liabilities Noncurrent asset retirement obligations (987 ) (944 ) Regulatory liabilities, deferred income, and other Regulatory liabilities, deferred income, and other noncurrent liabilities (3,221 ) (2,809 ) Regulatory liabilities, deferred income, and other

Other Income and Expenses (Tabl

Other Income and Expenses (Tables)	3 Months Ended
	Mar. 31, 2018
Other Income and Expenses [Abstract]
Other Income and Expenses [Table Text Block]	The following table presents certain gains or losses reflected in Other (income) expense – net within Costs and expenses in our Consolidated Statement of Income : Three Months Ended 2018 2017 (Millions) Williams Partners Gains on contract settlements and terminations $ — $ (13 )

Provision (Benefit) for Incom25

Provision (Benefit) for Income Taxes (Tables)	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]	The Provision (benefit) for income taxes includes: Three Months Ended 2018 2017 (Millions) Current: Federal $ (19 ) $ 3 State 1 6 (18 ) 9 Deferred: Federal 64 15 State 9 13 73 28 Provision (benefit) for income taxes $ 55 $ 37

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Earnings per common share [Table Text Block]	Three Months Ended 2018 2017 (Dollars in millions, except per-share amounts; shares in thousands) Net income attributable to The Williams Companies, Inc. available to common stockholders for basic and diluted earnings per common share $ 152 $ 373 Basic weighted-average shares 827,509 824,548 Effect of dilutive securities: Nonvested restricted stock units 2,095 1,305 Stock options 593 623 Diluted weighted-average shares 830,197 826,476 Earnings per common share: Basic $ .18 $ .45 Diluted $ .18 $ .45

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2018
Retirement Benefits [Abstract]
Schedule of Net Benefit Costs [Table Text Block]	Net periodic benefit cost (credit) is as follows: Pension Benefits Three Months Ended 2018 2017 (Millions) Components of net periodic benefit cost (credit): Service cost $ 14 $ 13 Interest cost 11 15 Expected return on plan assets (16 ) (20 ) Amortization of net actuarial loss 6 7 Net periodic benefit cost (credit) $ 15 $ 15 Other Postretirement Benefits Three Months Ended 2018 2017 (Millions) Components of net periodic benefit cost (credit): Interest cost $ 2 $ 2 Expected return on plan assets (3 ) (3 ) Amortization of prior service credit (1 ) (3 ) Reclassification to regulatory liability 1 1 Net periodic benefit cost (credit) $ (1 ) $ (3 )

Debt and Banking Arrangements (

Debt and Banking Arrangements (Tables)	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Schedule of Line of Credit Facilities [Table Text Block]	Credit Facilities March 31, 2018 Stated Capacity Outstanding (Millions) WMB Long-term credit facility $ 1,500 $ 200 Letters of credit under certain bilateral bank agreements 13 WPZ Long-term credit facility (1) 3,500 — Letters of credit under certain bilateral bank agreements 1 (1) In managing our available liquidity, we do not expect a maximum outstanding amount in excess of the capacity of WPZ’s credit facility inclusive of any outstanding amounts under its commercial paper program.

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2018
Stockholders' Equity Note [Abstract]
Accumulated Other Comprehensive Income (Loss) [Table Text Block]	AOCI The following table presents the changes in Accumulated other comprehensive income (loss) (AOCI) by component, net of income taxes: Cash Flow Hedges Foreign Currency Translation Pension and Other Postretirement Benefits Total (Millions) Balance at December 31, 2017 $ (2 ) $ (1 ) $ (235 ) $ (238 ) Adoption of ASU 2018-02 (Note 1) — — (61 ) (61 ) Amounts reclassified from accumulated other comprehensive income (loss) — — 5 5 Balance at March 31, 2018 $ (2 ) $ (1 ) $ (291 ) $ (294 )
Reclassifications Out Of Accumulated Other Comprehensive Income [Table Text Block]	Reclassifications out of AOCI are presented in the following table by component for the three months ended March 31, 2018 : Component Reclassifications Classification (Millions) Pension and other postretirement benefits: Amortization of actuarial (gain) loss included in net periodic benefit cost (credit) $ 6 Note 8 – Employee Benefit Plans Income tax benefit (1 ) Provision (benefit) for income taxes Reclassifications during the period $ 5

Fair Value Measurements and G30

Fair Value Measurements and Guarantees (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Assets and Liabilities Measured On Recurring Basis [Table Text Block]	The following table presents, by level within the fair value hierarchy, certain of our financial assets and liabilities. The carrying values of cash and cash equivalents, accounts receivable, and accounts payable approximate fair value because of the short-term nature of these instruments. Therefore, these assets and liabilities are not presented in the following table. Fair Value Measurements Using Carrying Amount Fair Value Quoted Prices In Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (Millions) Assets (liabilities) at March 31, 2018: Measured on a recurring basis: ARO Trust investments $ 145 $ 145 $ 145 $ — $ — Energy derivatives assets designated as hedging instruments 2 2 2 — — Energy derivatives assets not designated as hedging instruments 4 4 4 — — Energy derivatives liabilities designated as hedging instruments (3 ) (3 ) (3 ) — — Energy derivatives liabilities not designated as hedging instruments (4 ) (4 ) (1 ) — (3 ) Additional disclosures: Other receivables 7 7 7 — — Long-term debt, including current portion (21,880 ) (23,061 ) — (23,061 ) — Guarantees (43 ) (30 ) — (14 ) (16 ) Assets (liabilities) at December 31, 2017: Measured on a recurring basis: ARO Trust investments $ 135 $ 135 $ 135 $ — $ — Energy derivatives liabilities designated as hedging instruments (3 ) (3 ) (2 ) (1 ) — Energy derivatives liabilities not designated as hedging instruments (3 ) (3 ) — — (3 ) Additional disclosures: Other receivables 7 7 7 — — Long-term debt, including current portion (20,935 ) (23,005 ) — (23,005 ) — Guarantees (43 ) (30 ) — (14 ) (16 )

Segment Disclosures (Tables)

Segment Disclosures (Tables)	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Reconciliation of Revenue from Segments to Consolidated [Table Text Block]	The following table reflects the reconciliation of Segment revenues to Total revenues as reported in the Consolidated Statement of Income and Total assets by reportable segment. Williams Partners Other Eliminations Total (Millions) Three Months Ended March 31, 2018 Segment revenues: Service revenues External $ 1,346 $ 5 $ — $ 1,351 Internal — 3 (3 ) — Total service revenues 1,346 8 (3 ) 1,351 Total service revenues – commodity consideration (external only) 101 — — 101 Product sales External 636 — — 636 Internal — — — — Total product sales 636 — — 636 Total revenues $ 2,083 $ 8 $ (3 ) $ 2,088 Three Months Ended March 31, 2017 Segment revenues: Service revenues External $ 1,256 $ 5 $ — $ 1,261 Internal — 3 (3 ) — Total service revenues 1,256 8 (3 ) 1,261 Product sales External 727 — — 727 Internal — — — — Total product sales 727 — — 727 Total revenues $ 1,983 $ 8 $ (3 ) $ 1,988 March 31, 2018 Total assets $ 46,575 $ 541 $ (64 ) $ 47,052 December 31, 2017 Total assets $ 45,903 $ 589 $ (140 ) $ 46,352
Reconciliation of Modified EBITDA to Net Income (Loss) [Table Text Block]	The following table reflects the reconciliation of Modified EBITDA to Net income (loss) as reported in the Consolidated Statement of Income . Three Months Ended 2018 2017 (Millions) Modified EBITDA by segment: Williams Partners $ 1,107 $ 1,132 Other 13 18 1,120 1,150 Accretion expense associated with asset retirement obligations for nonregulated operations (8 ) (7 ) Depreciation and amortization expenses (431 ) (442 ) Equity earnings (losses) 82 107 Other investing income (loss) – net 4 272 Proportional Modified EBITDA of equity-method investments (169 ) (194 ) Interest expense (273 ) (280 ) (Provision) benefit for income taxes (55 ) (37 ) Net income (loss) $ 270 $ 569

General, Description of Busin32

General, Description of Business, and Basis of Presentation (Details) - USD ($) $ / shares in Units, $ in Millions	Jan. 09, 2017	Feb. 03, 2017	Jan. 31, 2017	Mar. 31, 2018	Mar. 31, 2017	Jun. 30, 2017	Jan. 01, 2018
Schedule of Equity Method Investments [Line Items]
Number Of Interstate Natural Gas Pipelines				2
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Operating Costs and Expenses				$ 357	$ 371
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Net				(2)
Other Nonoperating Income (Expense)				21	77
Operating Income (Loss)				(491)	(430)
Net Cash Provided by (Used in) Operating Activities				694	727
Net Cash Provided by (Used in) Investing Activities				$ 798	243
Constitution Pipeline Company LLC [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Variable Interest Entity Ownership Percentage				41.00%
Appalachia Midstream Services, LLC [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest				66.00%
Noncontrolling Interest [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Net				$ (9)
Capital in excess of par value [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Net				$ 7
Limited Partner [Member] | Williams Partners L.P. [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Variable Interest Entity Ownership Percentage				74.00%
Financial Repositioning [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Sale of Stock, Number of Shares Issued in Transaction	277,000	59,000,000	289,000,000
Payments to Acquire Limited Partnership Interests	$ 10					$ 56
Sale of Stock, Price Per Share		$ 36.08586
Financial Repositioning [Member] | Williams Partners L.P. [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest			2.00%
Williams Partners [Member] | Dividend Reinvestment Program [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Sale of Stock, Number of Shares Issued in Transaction				576,923
Sale of Stock, Consideration Received on Transaction				$ 22
Accounting Standards Update 201707 [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Operating Costs and Expenses					3
Other Nonoperating Income (Expense)					3
Operating Income (Loss)					3
Accounting Standards Update 2016-15 [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Net Cash Provided by (Used in) Operating Activities					121
Net Cash Provided by (Used in) Investing Activities					$ 121
Accounting Standards Update 2014-09 [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets							$ 121
Gulfstream Natural Gas System, L.L.C.[Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage				50.00%
Utica East Ohio Midstream, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage				62.00%
Delaware Basin Gas Gathering System [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage					50.00%
Delaware Basin Gas Gathering System [Member] | Williams Partners [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage					50.00%
Laurel Mountain Midstream, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage				69.00%
Caiman Energy II [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage				58.00%
Discovery Producer Services LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage				60.00%
Overland Pass Pipeline Company LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage				50.00%
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accounting Standards Update 2018-02 [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets							61
Retained Deficit | Accounting Standards Update 2018-02 [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets							$ (61)

Revenue Recognition Revenue by

Revenue Recognition Revenue by Category (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		$ 2,073
Other Revenue, Net	[1]	15
Total revenues		2,088	$ 1,988
Northeast Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		325
Other Revenue, Net	[1]	5
Total revenues		330
Atlantic Gulf Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		226
Other Revenue, Net	[1]	2
Total revenues		228
West Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		1,026
Other Revenue, Net	[1]	5
Total revenues		1,031
Transco [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		486
Other Revenue, Net	[1]	3
Total revenues		489
Northwest Pipeline [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		112
Other Revenue, Net	[1]	0
Total revenues		112
Other Geographical [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		8
Other Revenue, Net	[1]	0
Total revenues		8
Intercompany Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		(110)
Other Revenue, Net	[1]	0
Total revenues		(110)
NonRegulated Service Monetary Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		729
NonRegulated Service Monetary Consideration [Member] | Northeast Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		202
NonRegulated Service Monetary Consideration [Member] | Atlantic Gulf Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		137
NonRegulated Service Monetary Consideration [Member] | West Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		408
NonRegulated Service Monetary Consideration [Member] | Transco [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
NonRegulated Service Monetary Consideration [Member] | Northwest Pipeline [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
NonRegulated Service Monetary Consideration [Member] | Other Geographical [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
NonRegulated Service Monetary Consideration [Member] | Intercompany Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		(18)
NonRegulated Service Commodity Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		101
NonRegulated Service Commodity Consideration [Member] | Northeast Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		4
NonRegulated Service Commodity Consideration [Member] | Atlantic Gulf Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		15
NonRegulated Service Commodity Consideration [Member] | West Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		82
NonRegulated Service Commodity Consideration [Member] | Transco [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
NonRegulated Service Commodity Consideration [Member] | Northwest Pipeline [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
NonRegulated Service Commodity Consideration [Member] | Other Geographical [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
NonRegulated Service Commodity Consideration [Member] | Intercompany Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
Regulated Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		572
Regulated Service [Member] | Northeast Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
Regulated Service [Member] | Atlantic Gulf Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
Regulated Service [Member] | West Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
Regulated Service [Member] | Transco [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		461
Regulated Service [Member] | Northwest Pipeline [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		112
Regulated Service [Member] | Other Geographical [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
Regulated Service [Member] | Intercompany Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		(1)
Other Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		40
Other Service [Member] | Northeast Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		21
Other Service [Member] | Atlantic Gulf Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		6
Other Service [Member] | West Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		11
Other Service [Member] | Transco [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
Other Service [Member] | Northwest Pipeline [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
Other Service [Member] | Other Geographical [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		8
Other Service [Member] | Intercompany Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		(6)
Total Service Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		1,442
Total Service Revenues [Member] | Northeast Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		227
Total Service Revenues [Member] | Atlantic Gulf Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		158
Total Service Revenues [Member] | West Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		501
Total Service Revenues [Member] | Transco [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		461
Total Service Revenues [Member] | Northwest Pipeline [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		112
Total Service Revenues [Member] | Other Geographical [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		8
Total Service Revenues [Member] | Intercompany Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		(25)
NGL And Natural Gas Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		627
NGL And Natural Gas Product Sales [Member] | Northeast Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		98
NGL And Natural Gas Product Sales [Member] | Atlantic Gulf Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		68
NGL And Natural Gas Product Sales [Member] | West Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		521
NGL And Natural Gas Product Sales [Member] | Transco [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		25
NGL And Natural Gas Product Sales [Member] | Northwest Pipeline [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
NGL And Natural Gas Product Sales [Member] | Other Geographical [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
NGL And Natural Gas Product Sales [Member] | Intercompany Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		(85)
Other Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		4
Other Product Sales [Member] | Northeast Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
Other Product Sales [Member] | Atlantic Gulf Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
Other Product Sales [Member] | West Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		4
Other Product Sales [Member] | Transco [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
Other Product Sales [Member] | Northwest Pipeline [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
Other Product Sales [Member] | Other Geographical [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
Other Product Sales [Member] | Intercompany Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
Total Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		631
Total Product Sales [Member] | Northeast Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		98
Total Product Sales [Member] | Atlantic Gulf Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		68
Total Product Sales [Member] | West Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		525
Total Product Sales [Member] | Transco [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		25
Total Product Sales [Member] | Northwest Pipeline [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
Total Product Sales [Member] | Other Geographical [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0
Total Product Sales [Member] | Intercompany Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		$ (85)
[1]	We provide management services to operated joint ventures and other investments for which we receive a management fee that is categorized as Service revenues in our Consolidated Statement of Income. These management fees do not constitute revenue from contracts with customers. Product sales in our Consolidated Statement of Income include amounts associated with our derivative contracts that are not within the scope of ASC 606.

Revenue Recognition Contract As

Revenue Recognition Contract Assets (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Revenue Recognition [Abstract]
Contract with Customer, Asset, Net	$ 24	$ 4
Contract with Customer Asset Amounts Recognized In Excess Of Cash Received	20
Contract With Customer Asset Minimum Volume Commitments Invoiced	$ 0

Revenue Recognition Contract Li

Revenue Recognition Contract Liabilities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Revenue Recognition [Abstract]
Contract with Customer, Liability	$ 1,574	$ 1,596
Contract with Customer, Liability, Cumulative Catch-up Adjustment to Revenue, Change in Estimate of Transaction Price	92
Contract with Customer, Liability, Revenue Recognized	(114)
Performance Obligations Related To Contract Liabilities [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 251
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	9 months
Performance Obligations Related To Contract Liabilities [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 252
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Performance Obligations Related To Contract Liabilities [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 120
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Performance Obligations Related To Contract Liabilities [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 100
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Performance Obligations Related To Contract Liabilities [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 94
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Performance Obligations Related To Contract Liabilities [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 88
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Performance Obligations Related To Contract Liabilities [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 669

Revenue Recognition Remaining P

Revenue Recognition Remaining Performance Obligations (Details) - Remaining Performance Obligations [Member] $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 1,927
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 2,410
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 2,210
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 1,891
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 1,758
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 1,566
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 23,441

Revenue Recognition Accounts Re

Revenue Recognition Accounts Receivable (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables, Net, Current	$ 743	$ 976
Accounts Receivable Related To Contracts With Customers [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables, Net, Current	704
Other Accounts Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables, Net, Current	$ 39

Revenue Recognition Impact of A

Revenue Recognition Impact of Adoption of ASC 606 (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Sales Revenue, Services, Net	$ 1,351	$ 1,261
Sales revenue services commodity consideration	101	0
Sales Revenue, Goods, Net	636	727
Total revenues	2,088	1,988
Cost of Purchased Oil and Gas	613	579
Processing commodity expenses	35	0
Operating Costs and Expenses	357	371
Depreciation and amortization expenses	431	442
Costs and Expenses	1,597	1,558
Operating Income (Loss)	491	430
Interest Costs Incurred	(282)	(287)
Interest Costs Capitalized Adjustment	9	7
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	325	606
Provision (benefit) for income taxes	55	37
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	270	569
Net Income (Loss) Attributable to Noncontrolling Interest	118	196
Net income (loss) attributable to The Williams Companies Inc	152	373
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	276	575
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	119	197
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	157	$ 378
Inventory, Net	160		$ 113
Other Assets, Current	204		191
Assets, Current	2,399		2,179
Property, plant, and equipment	40,467		39,513
Property, Plant and Equipment, Net	28,847		28,211
Equity Method Investments	6,513		6,552
Intangible assets - net of accumulated amortization	8,644		8,791
Other Assets, Noncurrent	649		619
Total assets	47,052		46,352
Deferred Tax Liabilities, Net, Noncurrent	3,196		3,147
Other Liabilities and Deferred Revenue, Noncurrent	4,410		3,950
Retained deficit	(8,587)		(8,434)
Stockholders' Equity Attributable to Parent	9,473		9,656
Stockholders' Equity Attributable to Noncontrolling Interest	6,430		6,519
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	15,903		16,175
Liabilities and Equity	47,052		$ 46,352
Adoption of ASC 606	(121)
Stockholders' Equity, Period Increase (Decrease)	(272)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Sales Revenue, Services, Net	5
Sales revenue services commodity consideration	(101)
Sales Revenue, Goods, Net	10
Total revenues	(86)
Cost of Purchased Oil and Gas	(55)
Processing commodity expenses	(35)
Operating Costs and Expenses	(1)
Depreciation and amortization expenses	1
Costs and Expenses	(90)
Operating Income (Loss)	4
Interest Costs Incurred	3
Interest Costs Capitalized Adjustment	(2)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	5
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	5
Net Income (Loss) Attributable to Noncontrolling Interest	2
Net income (loss) attributable to The Williams Companies Inc	3
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	5
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	2
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	3
Inventory, Net	(8)
Other Assets, Current	(20)
Assets, Current	(28)
Property, plant, and equipment	(2)
Property, Plant and Equipment, Net	(2)
Equity Method Investments	(1)
Intangible assets - net of accumulated amortization	63
Other Assets, Noncurrent	(4)
Total assets	28
Deferred Tax Liabilities, Net, Noncurrent	27
Other Liabilities and Deferred Revenue, Noncurrent	(125)
Retained deficit	87
Stockholders' Equity Attributable to Parent	87
Stockholders' Equity Attributable to Noncontrolling Interest	39
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	126
Liabilities and Equity	28
Adoption of ASC 606	121
Stockholders' Equity, Period Increase (Decrease)	126
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Sales Revenue, Services, Net	1,356
Sales revenue services commodity consideration	0
Sales Revenue, Goods, Net	646
Total revenues	2,002
Cost of Purchased Oil and Gas	558
Processing commodity expenses	0
Operating Costs and Expenses	356
Depreciation and amortization expenses	432
Costs and Expenses	1,507
Operating Income (Loss)	495
Interest Costs Incurred	(279)
Interest Costs Capitalized Adjustment	7
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	330
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	275
Net Income (Loss) Attributable to Noncontrolling Interest	120
Net income (loss) attributable to The Williams Companies Inc	155
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	281
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	121
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	160
Inventory, Net	152
Other Assets, Current	184
Assets, Current	2,371
Property, plant, and equipment	40,465
Property, Plant and Equipment, Net	28,845
Equity Method Investments	6,512
Intangible assets - net of accumulated amortization	8,707
Other Assets, Noncurrent	645
Total assets	47,080
Deferred Tax Liabilities, Net, Noncurrent	3,223
Other Liabilities and Deferred Revenue, Noncurrent	4,285
Retained deficit	(8,500)
Stockholders' Equity Attributable to Parent	9,560
Stockholders' Equity Attributable to Noncontrolling Interest	6,469
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	16,029
Liabilities and Equity	47,080
Adoption of ASC 606	0
Stockholders' Equity, Period Increase (Decrease)	$ (146)

Variable Interest Entities (Det

Variable Interest Entities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Constitution Pipeline Company LLC [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	41.00%
Variable Interest Entity, Primary Beneficiary [Member] | Cash and Cash Equivalents [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	$ 1,268	$ 881
Variable Interest Entity, Primary Beneficiary [Member] | Trade accounts and other receivables - net [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	718	972
Variable Interest Entity, Primary Beneficiary [Member] | Inventories [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	160	113
Variable Interest Entity, Primary Beneficiary [Member] | Other Current Assets [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	198	176
Variable Interest Entity, Primary Beneficiary [Member] | Investments [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	6,513	6,552
Variable Interest Entity, Primary Beneficiary [Member] | Property Plant And Equipment, net [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	28,547	27,912
Variable Interest Entity, Primary Beneficiary [Member] | Intangible Assets, net [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	8,643	8,790
Variable Interest Entity, Primary Beneficiary [Member] | Regulatory assets, Deferred Charges, and Other Noncurrent Assets [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	528	507
Variable Interest Entity, Primary Beneficiary [Member] | Accounts Payable [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	(755)	(957)
Variable Interest Entity, Primary Beneficiary [Member] | Accrued Liabilities including current asset retirement obligations [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	(682)	(857)
Variable Interest Entity, Primary Beneficiary [Member] | Long-term debt due within one year [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	(501)	(501)
Variable Interest Entity, Primary Beneficiary [Member] | Long-term Debt [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	(17,011)	(15,996)
Variable Interest Entity, Primary Beneficiary [Member] | Deferred Income Tax Liabilities [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	(15)	(16)
Variable Interest Entity, Primary Beneficiary [Member] | Noncurrent Asset Retirement Obligation [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	(987)	(944)
Variable Interest Entity, Primary Beneficiary [Member] | Other Noncurrent Liabilities [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	$ (3,221)	$ (2,809)
Variable Interest Entity, Primary Beneficiary [Member] | Gulfstar One [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	51.00%
Variable Interest Entity, Primary Beneficiary [Member] | Constitution Pipeline Company LLC [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	41.00%
Variable Interest Entity, Primary Beneficiary [Member] | Constitution Pipeline Company LLC [Member] | Estimated Remaining Construction Costs For Variable Interest Entity [Member]
Variable Interest Entity [Line Items]
Other commitment	$ 740
Variable Interest Entity, Primary Beneficiary [Member] | Constitution Pipeline Company LLC [Member] | Property Plant And Equipment, net [Member]
Variable Interest Entity [Line Items]
Capitalized Project Development Costs	$ 379
Variable Interest Entity, Primary Beneficiary [Member] | Cardinal Gas Services LLC [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	66.00%
Variable Interest Entity, Primary Beneficiary [Member] | Jackalope Gas Gathering Services LLC [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	50.00%
Limited Partner [Member] | Williams Partners L.P. [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	74.00%

Investing Activities (Details)

Investing Activities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Schedule of Equity Method Investments [Line Items]
Proceeds from Sale of Equity Method Investments	$ 0	$ 200
Gain from sale of an equity-method investment interest	0	269
Investing income, nonoperating	$ 4	$ 272
Delaware Basin Gas Gathering System [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage		50.00%
Laurel Mountain Midstream, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	69.00%
Williams Partners [Member] | Delaware Basin Gas Gathering System [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage		50.00%
Proceeds from Sale of Equity Method Investments		$ 155
Gain from sale of an equity-method investment interest		269
Williams Partners [Member] | Appalachia Midstream Services, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	66.00%
Williams Partners [Member] | Ranch Westex JV LLC [Member]
Schedule of Equity Method Investments [Line Items]
Proceeds from Sale of Equity Method Investments		45
Appalachia Midstream Services, LLC [Member] | Williams Partners [Member]
Schedule of Equity Method Investments [Line Items]
Investments, Fair Value Disclosure		$ 1,100
Equity Method Investment, Summarized Financial Information [Abstract]
Fair Value Inputs, Discount Rate		9.50%

Other Income and Expenses (Deta

Other Income and Expenses (Details) - USD ($) $ in Millions	Mar. 28, 2018	Feb. 23, 2017	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Debt Instrument, Unamortized Discount (Premium), Net	$ 7	$ 30
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums	27	53
Debt Instrument, Unamortized Premium	34	23
Other income (expense) - net [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Gain (Loss) on Contract Termination			$ 0	$ (13)
Other Nonoperating Income (Expense) [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Allowance for funds used during construction, capitalized cost of equity			20	18
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			$ 5	$ 28
4.875% Senior Unsecured Notes due 2024 [Member] | Williams Partners L.P. [Member]
Segment Reporting Information [Line Items]
Long-term debt retired	$ 750
Long-term debt interest rate	4.875%
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%

Provision (Benefit) for Incom42

Provision (Benefit) for Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Current:
Federal	$ (19)	$ 3
State	1	6
Total	(18)	9
Deferred:
Federal	64	15
State	9	13
Total	73	28
Provision (benefit) for income taxes	$ 55	37
Valuation Allowance, Deferred Tax Asset, Decrease Amount		$ 127

Earnings Per Common Share (Deta

Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share Table [Line Items]
Net income attributable to The Williams Companies, Inc. available to common stockholders for basic and diluted earnings per common share	$ 152	$ 373
Basic weighted-average shares	827,509	824,548
Effect of dilutive securities:
Diluted weighted-average shares	830,197	826,476
Earnings per common share:
Basic	$ 0.18	$ 0.45
Diluted	$ 0.18	$ 0.45
Nonvested restricted stock units [Member]
Effect of dilutive securities:
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	2,095	1,305
Stock Options [Member]
Effect of dilutive securities:
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	593	623

Employee Benefit Plans (Quarter

Employee Benefit Plans (Quarterly Info) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Pension Benefits [Member]
Components of net periodic benefit cost (credit):
Service cost	$ 14	$ 13
Interest cost	11	15
Expected return on plan assets	(16)	(20)
Amortization of net actuarial loss	6	7
Net periodic benefit cost (credit)	15	15
Employer contributions	2
Estimated future employer contributions in current fiscal year	84
Other Postretirement Benefits [Member]
Components of net periodic benefit cost (credit):
Interest cost	2	2
Expected return on plan assets	(3)	(3)
Amortization of prior service cost (credit)	(1)	(3)
Reclassification to regulatory liability	1	1
Net periodic benefit cost (credit)	(1)	(3)
Amortization of prior service cost (credit) from regulatory assets (liabilities)	(1)	$ (2)
Employer contributions	1
Estimated future employer contributions in current fiscal year	$ 5

Debt and Banking Arrangements L

Debt and Banking Arrangements Long-Term Debt Issuances and Retirements (Details 1) - USD ($) $ in Millions	Jun. 15, 2018	Mar. 28, 2018	Mar. 31, 2018	Mar. 15, 2018	Mar. 05, 2018
Transcontinental Gas Pipe Line Company, LLC [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Other Long-term Debt			$ 19
4.875% Senior Unsecured Notes due 2024 [Member] | Williams Partners L.P. [Member]
Debt Instrument [Line Items]
Long-term debt interest rate		4.875%
Long-term debt retired		$ 750
4.85%SeniorUnsecuredNotesDue2048 [Member] | Williams Partners L.P. [Member]
Debt Instrument [Line Items]
Long-term debt face amount					$ 800
Long-term debt interest rate					4.85%
4%SeniorUnsecuredNotesDue2028 [Member] | Transcontinental Gas Pipe Line Company, LLC [Member]
Debt Instrument [Line Items]
Long-term debt face amount				$ 400
Long-term debt interest rate				4.00%
Additional interest rate accrued for default of registration rights agreements first period				0.25%
Additional interest rate accrued for default of registration rights agreements each subsequent period				0.25%
Maximum additional interest rate accrued for default of registration rights agreements all periods				0.50%
4.6%SeniorUnsecuredNotesDue2048 [Member] | Transcontinental Gas Pipe Line Company, LLC [Member]
Debt Instrument [Line Items]
Long-term debt face amount				$ 600
Long-term debt interest rate				4.60%
Additional interest rate accrued for default of registration rights agreements first period				0.25%
Additional interest rate accrued for default of registration rights agreements each subsequent period				0.25%
Maximum additional interest rate accrued for default of registration rights agreements all periods				0.50%
6.05% Senior Unsecured Notes due 2018 [Member] | Transcontinental Gas Pipe Line Company, LLC [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Long-term debt interest rate	6.05%
Long-term debt retired	$ 250

Debt and Banking Arrangements C

Debt and Banking Arrangements Credit Facilities and Commercial Paper (Details 2) $ in Millions	Mar. 31, 2018USD ($)
Williams Companies Inc [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity	$ 1,500
Credit facility, loans outstanding	200
Williams Partners L.P. [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity	3,500	[1]
Credit facility, loans outstanding	0	[1]
Commercial Paper [Member] | Williams Partners L.P. [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity	3,000
Commercial paper, outstanding	0
Letters Of Credit Under Certain Bilateral Bank Agreements [Member] | Williams Companies Inc [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, letters of credit outstanding	13
Letters Of Credit Under Certain Bilateral Bank Agreements [Member] | Williams Partners L.P. [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, letters of credit outstanding	$ 1
[1]	In managing our available liquidity, we do not expect a maximum outstanding amount in excess of the capacity of WPZ’s credit facility inclusive of any outstanding amounts under its commercial paper program.

Stockholders' Equity Stockholde

Stockholders' Equity Stockholders' Equity (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Stockholders' Equity Note [Abstract]
Proceeds from Issuance of Common Stock	$ 10	$ 2,122

Stockholders' Equity Table Of C

Stockholders' Equity Table Of Changes In AOCI (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 01, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance	$ (238)
Other comprehensive income (loss)	6	$ 6
Total, Ending Balance	(294)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance	(238)
Adoption of ASU 2018-02 (Note 1)			$ (61)
Amounts reclassified from accumulated other comprehensive income (loss)	5
Other comprehensive income (loss)	5
Total, Ending Balance	(294)
Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance	(2)
Adoption of ASU 2018-02 (Note 1)			0
Amounts reclassified from accumulated other comprehensive income (loss)	0
Total, Ending Balance	(2)
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance	(1)
Adoption of ASU 2018-02 (Note 1)			0
Amounts reclassified from accumulated other comprehensive income (loss)	0
Total, Ending Balance	(1)
Pension and Other Postretirement Benefits
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance	(235)
Adoption of ASU 2018-02 (Note 1)			$ (61)
Amounts reclassified from accumulated other comprehensive income (loss)	5
Total, Ending Balance	(291)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss)	$ 5

Stockholders' Equity Table Of R

Stockholders' Equity Table Of Reclassifications from AOCI (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax benefit	$ 55	$ 37
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss)	0
Pension and Other Postretirement Benefits
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss)	5
Foreign Currency Translation
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss)	0
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax benefit	(1)
Amounts reclassified from accumulated other comprehensive income (loss)	5
Reclassification out of Accumulated Other Comprehensive Income [Member] | Pension and Other Postretirement Benefits
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of actuarial (gain) loss included in net periodic benefit cost (credit)	$ 6

Fair Value Measurements Recurri

Fair Value Measurements Recurring Measurements and Additional (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Additional disclosures:
Fair Value, Level 1 to level 2 Transfers, Amount	$ 0		$ 0
Fair Value, Level 2 to level 1 Transfers, Amount	0		$ 0
Carrying Amount [Member]
Additional disclosures:
Other receivables	7	$ 7
Long-term debt, including current portion	(21,880)	(20,935)
Guarantees	(43)	(43)
Fair Value [Member]
Additional disclosures:
Other receivables	7	7
Long-term debt, including current portion	(23,061)	(23,005)
Guarantees	(30)	(30)
Level 1 [Member]
Additional disclosures:
Other receivables	7	7
Long-term debt, including current portion	0	0
Guarantees	0	0
Level 2 [Member]
Additional disclosures:
Other receivables	0	0
Long-term debt, including current portion	(23,061)	(23,005)
Guarantees	(14)	(14)
Level 3 [Member]
Additional disclosures:
Other receivables	0	0
Long-term debt, including current portion	0	0
Guarantees	(16)	(16)
Fair Value, Measurements, Recurring [Member] | Carrying Amount [Member]
Measured on a recurring basis:
ARO Trust investments	145	135
Fair Value, Measurements, Recurring [Member] | Carrying Amount [Member] | Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	2
Energy derivatives liabilities	(3)	(3)
Fair Value, Measurements, Recurring [Member] | Carrying Amount [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	4
Energy derivatives liabilities	(4)	(3)
Fair Value, Measurements, Recurring [Member] | Fair Value [Member]
Measured on a recurring basis:
ARO Trust investments	145	135
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	2
Energy derivatives liabilities	(3)	(3)
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	4
Energy derivatives liabilities	(4)	(3)
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Measured on a recurring basis:
ARO Trust investments	145	135
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	2
Energy derivatives liabilities	(3)	(2)
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	4
Energy derivatives liabilities	(1)	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Measured on a recurring basis:
ARO Trust investments	0	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	0
Energy derivatives liabilities	0	(1)
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	0
Energy derivatives liabilities	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Measured on a recurring basis:
ARO Trust investments	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	0
Energy derivatives liabilities	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	0
Energy derivatives liabilities	(3)	$ (3)
WilTel Guarantee [Member]
Additional disclosures:
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 30

Contingent Liabilities (Details

Contingent Liabilities (Details) - USD ($) $ in Millions	May 20, 2016	Mar. 31, 2018
Loss Contingencies [Line Items]
Accrued environmental loss liabilities		$ 39
Energy Transfer Merger [Member]
Loss Contingencies [Line Items]
Loss contingency, damages sought, value	$ 1,480
Gas Pipeline [Member]
Loss Contingencies [Line Items]
Accrued environmental loss liabilities		7
Natural Gas Underground Storage Facilities [Member]
Loss Contingencies [Line Items]
Accrued environmental loss liabilities		10
Former Operations [Member]
Loss Contingencies [Line Items]
Accrued environmental loss liabilities		22
Maximum [Member] | Former Alaska Refinery [Member]
Loss Contingencies [Line Items]
Loss contingency, range of possible loss		$ 32

Segment Disclosures Reconciliat

Segment Disclosures Reconciliation of Segment Revenues to Consolidated (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment revenues
Service revenues	$ 1,351	$ 1,261
Sales revenue services commodity consideration	101	0
Product sales	636	727
Total revenues	2,088	1,988
Williams Partners [Member]
Segment revenues
Service revenues	1,346	1,256
Product sales	636	727
Other [Member]
Segment revenues
Service revenues	5	5
Product sales	0	0
Intersegment Elimination [Member]
Segment revenues
Service revenues	(3)	(3)
Sales revenue services commodity consideration	0
Product sales	0	0
Total revenues	(3)	(3)
Intersegment Elimination [Member] | Williams Partners [Member]
Segment revenues
Service revenues	0	0
Product sales	0	0
Intersegment Elimination [Member] | Other [Member]
Segment revenues
Service revenues	(3)	(3)
Product sales	0	0
Operating Segments [Member] | Williams Partners [Member]
Segment revenues
Service revenues	1,346	1,256
Sales revenue services commodity consideration	101
Product sales	636	727
Total revenues	2,083	1,983
Operating Segments [Member] | Other [Member]
Segment revenues
Service revenues	8	8
Sales revenue services commodity consideration	0
Product sales	0	0
Total revenues	$ 8	$ 8

Segment Disclosures Reconcili53

Segment Disclosures Reconciliation of Segment Assets to Consolidated (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Segment assets:
Total assets	$ 47,052	$ 46,352
Williams Partners [Member]
Segment assets:
Total assets	46,575	45,903
Other [Member]
Segment assets:
Total assets	541	589
Intersegment Elimination [Member]
Segment assets:
Total assets	$ (64)	$ (140)

Segment Disclosures Reconcili54

Segment Disclosures Reconciliation of Segment Modified EBITDA to Consolidated Net Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Reconciliation of Modified EBITDA to Net Income (Loss):
Modified EBITDA Earnings (Loss)	$ 1,120	$ 1,150
Accretion expense associated with asset retirement obligations for nonregulated operations	(8)	(7)
Depreciation and amortization expenses	(431)	(442)
Equity earnings (losses)	82	107
Other investing income (loss) – net	(4)	(272)
Proportional Modified EBITDA of equity-method investments	(169)	(194)
Interest expense	(273)	(280)
(Provision) benefit for income taxes	(55)	(37)
Net income (loss)	270	569
Operating Segments [Member] | Williams Partners [Member]
Reconciliation of Modified EBITDA to Net Income (Loss):
Modified EBITDA Earnings (Loss)	1,107	1,132
Operating Segments [Member] | Other [Member]
Reconciliation of Modified EBITDA to Net Income (Loss):
Modified EBITDA Earnings (Loss)	$ 13	$ 18