The Williams Companies, Inc. (WMB) 10-Q 2 Nov 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Oct. 30, 2017
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	Sep. 30, 2017
Amendment Flag	false
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		826,746,549

Consolidated Statement of Opera

Consolidated Statement of Operations (Unaudited) - USD ($) shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues:
Service revenues	$ 1,310	$ 1,247	$ 3,853	$ 3,678
Product sales	581	658	1,950	1,623
Total revenues	1,891	1,905	5,803	5,301
Costs and expenses:
Product costs	504	461	1,620	1,180
Operating and maintenance expenses	400	394	1,157	1,179
Depreciation and amortization expenses	433	435	1,308	1,326
Selling, general, and administrative expenses	138	177	452	556
Gain on sale of Geismar Interest (Note 3)	(1,095)	0	(1,095)	0
Impairment of certain assets (Note 11)	1,210	1	1,236	811
Other (income) expense – net	24	92	34	130
Total costs and expenses	1,614	1,560	4,712	5,182
Operating income (loss)	277	345	1,091	119
Equity earnings (losses)	115	104	347	302
Impairment of equity-method investments (Note 11)	0	0	0	(112)
Other investing income (loss) – net (Note 4)	4	28	278	64
Interest incurred	(275)	(304)	(842)	(916)
Interest capitalized	8	7	24	30
Other income (expense) – net	20	20	115	52
Income (loss) before income taxes	149	200	1,013	(461)
Provision (benefit) for income taxes	24	69	126	(74)
Net income (loss)	125	131	887	(387)
Less: Net income (loss) attributable to noncontrolling interests	92	70	400	22
Net income (loss) attributable to The Williams Companies, Inc.	$ 33	$ 61	$ 487	$ (409)
Basic earnings (loss) per common share:
Net income (loss)	$ 0.04	$ 0.08	$ 0.59	$ (0.55)
Weighted-average shares (thousands)	826,779	750,754	825,925	750,579
Diluted earnings (loss) per common share:
Net income (loss)	$ 0.04	$ 0.08	$ 0.59	$ (0.55)
Weighted-average shares (thousands)	829,368	751,858	828,150	750,579
Cash dividends declared per common share	$ 0.30	$ 0.20	$ 0.90	$ 1.48

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Comprehensive income (loss):
Net income (loss)	$ 125	$ 131	$ 887	$ (387)
Cash flow hedging activities:
Net unrealized gain (loss) from derivative instruments, net of taxes of $2 and $1 in 2017	(9)	2	(5)	2
Reclassifications into earnings of net derivative instruments (gain) loss, net of taxes of $1 and $1 in 2017	2	0	0	0
Foreign currency translation activities:
Foreign currency translation adjustments, net of taxes of ($25) and ($37) in 2016	0	(49)	0	50
Reclassification into earnings upon sale of foreign entity, net of taxes of ($36) in 2016	0	119	0	119
Pension and other postretirement benefits:
Amortization of prior service cost (credit) included in net periodic benefit cost, net of taxes of $1 and $2 in 2017 and $0 and $1 in 2016	0	(1)	(2)	(3)
Net actuarial gain (loss) arising during the year, net of taxes of $2 in 2016	0	0	0	(3)
Amortization of actuarial (gain) loss included in net periodic benefit cost, net of taxes of ($2) and ($7) in 2017 and ($3) and ($9) in 2016	4	5	13	15
Other comprehensive income (loss)	(3)	76	6	180
Comprehensive income (loss)	122	207	893	(207)
Less: Comprehensive income (loss) attributable to noncontrolling interests	89	108	398	91
Comprehensive income (loss) attributable to The Williams Companies, Inc.	$ 33	$ 99	$ 495	$ (298)

Consolidated Statement of Comp4

Consolidated Statement of Comprehensive Income (Loss) (Parenthetical) (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax Effect [Abstract]
Other Comprehensive Income, Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	$ 2	$ 0	$ 1	$ 0
Other Comprehensive Income Loss Reclassification Adjustment On Derivatives Included In Net Income Tax	1	0	1	0
Other Comprehensive Income (Loss), Tax [Abstract]
Foreign currency translation adjustments, taxes	0	(25)	0	(37)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation,Tax	0	(36)	0	(36)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax [Abstract]
Amortization of prior service cost (credit) included in net periodic benefit cost, taxes	1	0	2	1
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax	0	0	0	2
Amortization of actuarial (gain) loss included in net periodic benefit cost, taxes	$ (2)	$ (3)	$ (7)	$ (9)

Consolidated Balance Sheet (Una

Consolidated Balance Sheet (Unaudited) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 1,172	$ 170
Trade accounts and other receivables (net of allowance of $6 at September 30, 2017 and $6 at December 31, 2016)	783	938
Inventories	144	138
Other current assets and deferred charges	194	216
Total current assets	2,293	1,462
Investments	6,615	6,701
Property, plant, and equipment	38,712	38,912
Accumulated depreciation and amortization	(11,003)	(10,484)
Property, plant, and equipment – net	27,709	28,428
Intangible assets – net of accumulated amortization	8,873	9,663
Regulatory assets, deferred charges, and other	630	581
Total assets	46,120	46,835
Current liabilities:
Accounts payable	773	623
Accrued liabilities	1,079	1,448
Commercial paper	0	93
Long-term debt due within one year	502	785
Total current liabilities	2,354	2,949
Long-term debt	20,567	22,624
Deferred income tax liabilities	5,211	4,238
Regulatory liabilities, deferred income, and other	3,106	2,978
Contingent liabilities (Note 12)
Stockholders’ equity:
Common stock (960 million shares authorized at $1 par value; 861 million shares issued at September 30, 2017 and 785 million shares issued at December 31, 2016)	861	785
Capital in excess of par value	18,492	14,887
Retained deficit	(9,872)	(9,649)
Accumulated other comprehensive income (loss)	(331)	(339)
Treasury stock, at cost (35 million shares of common stock)	(1,041)	(1,041)
Total stockholders’ equity	8,109	4,643
Noncontrolling interests in consolidated subsidiaries	6,773	9,403
Total equity	14,882	14,046
Total liabilities and equity	$ 46,120	$ 46,835

Consolidated Balance Sheet (Par

Consolidated Balance Sheet (Parenthetical) (Unaudited) - USD ($) shares in Millions, $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Allowance for trade accounts and other receivables	$ 6	$ 6
Stockholders’ equity:
Common stock, shares authorized	960	960
Common stock, par value of shares authorized	$ 1	$ 1
Common stock, shares issued	861	785
Treasury stock, shares of common shares	35	35

Consolidated Statement of Chang

Consolidated Statement of Changes in Equity (Unaudited) - 9 months ended Sep. 30, 2017 - 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, 2016 at Dec. 31, 2016	$ 14,046	$ 4,643	$ 785	$ 14,887	$ (9,649)	$ (339)	$ (1,041)	$ 9,403
Net income (loss)	887	487	0	0	487	0	0	400
Other comprehensive income (loss)	6	8	0	0	0	8	0	(2)
Issuance of common stock (Note 10)	2,118	2,118	75	2,043	0	0	0	0
Cash dividends – common stock	(744)	(744)	0	0	(744)	0	0	0
Dividends and distributions to noncontrolling interests	(679)	0	0	0	0	0	0	(679)
Stock-based compensation and related common stock issuances, net of tax	60	60	1	59	0	0	0	0
Adoption of ASU 2016-09 (Note 1)	37	37	0	1	36	0	0	0
Sales of limited partner units of Williams Partners L.P.	43	0	0	0	0	0	0	43
Changes in ownership of consolidated subsidiaries, net	(907)	1,497	0	1,497	0	0	0	(2,404)
Contributions from noncontrolling interests	15	0	0	0	0	0	0	15
Other	0	3	0	5	(2)	0	0	(3)
Net increase (decrease) in equity	836	3,466	76	3,605	(223)	8	0	(2,630)
September 30, 2017 at Sep. 30, 2017	$ 14,882	$ 8,109	$ 861	$ 18,492	$ (9,872)	$ (331)	$ (1,041)	$ 6,773

Consolidated Statement of Cash

Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
OPERATING ACTIVITIES:
Net income (loss)	$ 887	$ (387)
Adjustments to reconcile to net cash provided (used) by operating activities:
Depreciation and amortization	1,308	1,326
Provision (benefit) for deferred income taxes	99	(74)
Net (gain) loss on disposition of equity-method investments	(269)	0
Impairment of equity-method investments	0	112
Gain on sale of Geismar Interest (Note 3)	(1,095)	0
Impairment of and net (gain) loss on sale of assets and businesses	1,225	867
Amortization of stock-based awards	61	55
Cash provided (used) by changes in current assets and liabilities:
Accounts and notes receivable	118	172
Inventories	(23)	(7)
Other current assets and deferred charges	(11)	(11)
Accounts payable	47	(6)
Accrued liabilities	(161)	129
Other, including changes in noncurrent assets and liabilities	(349)	(79)
Net cash provided (used) by operating activities	1,837	2,097
FINANCING ACTIVITIES:
Proceeds from (payments of) commercial paper – net	(93)	(499)
Proceeds from long-term debt	3,013	5,708
Payments of long-term debt	(5,475)	(4,966)
Proceeds from issuance of common stock	2,130	8
Dividends paid	(744)	(1,111)
Dividends and distributions paid to noncontrolling interests	(636)	(715)
Contributions from noncontrolling interests	15	27
Payments for debt issuance costs	(14)	(8)
Contribution to Gulfstream for repayment of debt	0	(148)
Other – net	(87)	(16)
Net cash provided (used) by financing activities	(1,891)	(1,720)
INVESTING ACTIVITIES:
Capital expenditures (1)	(1,700)	(1,577)
Dispositions – net	(27)	29
Proceeds from sale of businesses, net of cash divested	2,056	712
Proceeds from dispositions of equity-method investments	200	0
Purchases of and contributions to equity-method investments	(103)	(132)
Distributions from unconsolidated affiliates in excess of cumulative earnings	394	341
Other – net	236	227
Net cash provided (used) by investing activities	1,056	(400)
Increase (decrease) in cash and cash equivalents	1,002	(23)
Cash and cash equivalents at beginning of year	170	100
Cash and cash equivalents at end of period	1,172	77
(1) Increases to property, plant, and equipment	(1,826)	(1,468)
Changes in related accounts payable and accrued liabilities	126	(109)
Capital expenditures (1)	$ (1,700)	$ (1,577)

General, Description of Busines

General, Description of Business, and Basis of Presentation	9 Months Ended
	Sep. 30, 2017
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, 2016, in Exhibit 99.1 of our Form 8-K dated May 25, 2017. 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 announced agreements with Williams Partners L.P. (WPZ), wherein we permanently waived the general partner’s incentive distribution rights (IDRs) 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 (see Note 10 – Stockholders’ Equity ). 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. Subsequent to these transactions and as of September 30, 2017 , we own a 74 percent limited partner interest in WPZ. 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 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. (Gulfstream), and a 41 percent interest in Constitution Pipeline Company, LLC (Constitution) (a consolidated entity), which is under development. 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 (see Note 3 – Divestitures ). 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 (UEOM), a 69 percent equity-method investment in Laurel Mountain Midstream, LLC (Laurel Mountain), a 58 percent equity-method investment in Caiman Energy II, LLC (Caiman II), a 60 percent equity-method investment in Discovery Producer Services LLC (Discovery), a 50 percent equity-method investment in Overland Pass Pipeline, LLC (OPPL), 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 ). The midstream businesses also included our Canadian midstream operations, which were comprised of an oil sands offgas processing plant near Fort McMurray, Alberta, and an NGL/olefin fractionation facility at Redwater, Alberta. In September 2016, we completed the sale of our Canadian operations. Other Our former Williams NGL & Petchem Services segment included certain domestic olefins pipeline assets as well as certain Canadian assets, which included a liquids extraction plant located near Fort McMurray, Alberta, that began operations in March 2016, and a propane dehydrogenation facility which was under development. In September 2016, the Canadian assets were sold. Considering this, the remaining assets are now reported within Other, effective January 1, 2017. Other also includes business activities that are not operating segments, as well as corporate operations. Prior period segment disclosures have been recast for this segment change. Basis of Presentation Consolidated master limited partnership As of September 30, 2017 , we own 74 percent of the interests in WPZ, a variable interest entity (VIE) (see Note 2 – Variable Interest Entities ). WPZ units issued to us in connection with the Financial Repositioning, WPZ’s quarterly distribution of additional paid-in-kind Class B units to us, and other equity issuances by WPZ had the combined net impact of decreasing Noncontrolling interests in consolidated subsidiaries by $2.404 billion , and increasing Capital in excess of par value by $1.497 billion and Deferred income tax liabilities by $907 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 us, including any associated with our previous IDRs, occur through the normal partnership distributions from WPZ to all partners. 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. Accounting standards issued and adopted Effective January 1, 2017, we adopted Accounting Standards Update (ASU) 2016-09, “Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting” (ASU 2016-09). ASU 2016-09 changed the accounting for income taxes such that all excess tax benefits and all tax deficiencies are now recognized as a discrete item in the provision for income taxes in the financial reporting period they occur and the recognition of tax benefits is no longer delayed until the tax benefit is realized through a reduction in income taxes payable. These changes are applied prospectively beginning in 2017. We recorded a cumulative-effect adjustment as of January 1, 2017, decreasing Retained deficit by $37 million in the Consolidated Balance Sheet to recognize tax benefits that were not previously recognized. ASU 2016-09 requires entities to classify excess tax benefits as an operating activity on the statement of cash flows. We are applying this part of the guidance prospectively beginning in 2017; therefore, the cash flows for prior periods were not adjusted. In recognizing compensation cost from share-based payments, ASU 2016-09 allows entities to make an accounting policy election to either recognize forfeitures when they occur or estimate the number of forfeitures expected to occur. We are recognizing forfeitures when they occur and as a result of the change in our accounting policy, we increased our Retained deficit for an insignificant cumulative-effect adjustment as of January 1, 2017. ASU 2016-09 requires entities to classify as a financing activity, on the statement of cash flows, cash paid by an employer to a taxing authority when directly withholding shares from an employee’s award to satisfy the employer’s statutory tax withholding obligation. This guidance must be applied retrospectively and we have adjusted operating and financing activities on the Consolidated Statement of Cash Flows for prior periods. Accounting standards issued but not yet adopted In August 2017, the Financial Accounting Standards Board (FASB) issued 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 is effective for interim and annual periods beginning after December 15, 2018. Early adoption is permitted. ASU 2017-12 will be 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. We do not expect ASU 2017-12 to have a material impact on our consolidated financial statements. In March 2017, the FASB issued 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 a subtotal of income from operations, if one is presented. Only the service cost component is now eligible for capitalization when applicable. ASU 2017-07 is effective beginning January 1, 2018. The presentation aspect of ASU 2017-07 must be applied retrospectively and the capitalization requirement prospectively. In light of the settlement charge we expect to recognize in the fourth quarter of 2017 related to a program to payout certain deferred vested pension benefits (see Note 8 – Employee Benefit Plans ), we continue to evaluate the impact of ASU 2017-07 on our consolidated financial statements. In January 2017, the FASB issued ASU 2017-04 “Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment” (ASU 2017-04). ASU 2017-04 modifies the concept of goodwill impairment to represent the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. Under ASU 2017-04, entities will no longer be required to determine the implied fair value of goodwill by assigning the fair value of a reporting unit to its individual assets and liabilities as if that reporting unit had been acquired in a business combination. ASU 2017-04 is effective for goodwill impairment testing for interim and annual periods beginning after December 15, 2019, and requires a prospective transition. Early adoption is permitted for interim and annual goodwill impairment tests performed after January 1, 2017, and we plan to adopt ASU 2017-04 in the fourth quarter of 2017. Our Williams Partners reportable segment has $47 million of goodwill included in Intangible assets - net of accumulated amortization in the Consolidated Balance Sheet . In August 2016, the FASB issued ASU 2016-15 “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments” (ASU 2016-15). ASU 2016-15 provides specific guidance on eight cash flow classification issues, including debt prepayment or debt extinguishment costs and distributions received from equity method investees, to reduce diversity in practice. ASU 2016-15 is effective for interim and annual periods beginning after December 15, 2017. Early adoption is permitted. ASU 2016-15 requires a retrospective transition. We do not expect ASU 2016-15 to have a material impact on our consolidated financial statements. 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. ASU 2016-13 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 clarifies the definition of a lease, requires a dual approach to lease classification similar to current lease classifications, and causes lessees to recognize leases on the balance sheet as a lease liability with a corresponding right-of-use asset. ASU 2016-02 is effective for interim and annual periods beginning after December 15, 2018. Early adoption is permitted. ASU 2016-02 requires a modified retrospective transition for capital or operating leases existing at or entered into after the beginning of the earliest comparative period presented in the financial statements. We are in the process of reviewing contracts to identify leases, as well as evaluating the applicability of ASU 2016-02 to contracts involving easements/rights-of-way. In May 2014, the 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 is effective for interim and annual reporting periods beginning after December 15, 2017. ASC 606 allows either full retrospective or modified retrospective transition and early adoption is permitted for annual periods beginning after December 15, 2016. We continue to evaluate the impact ASC 606 may have on our financial statements. For each revenue contract type, we conducted a formal contract review process to evaluate the impact, if any, that ASC 606 may have. As a result of that process, we expect our revenues will increase associated with accounting for noncash consideration, which exists primarily in certain of our gas processing contracts where we receive commodities as full or partial consideration for services provided. We also expect the increase in revenues will be offset by a similar increase in costs when the commodities received are subsequently monetized. We continue to evaluate contracts with a significant financing component, which may exist in situations where the timing of the consideration we receive varies significantly from the timing of when we provide the service, as well as certain contracts with tiered pricing structures, minimum volume commitments, and prepayments for services. As such, we are unable to determine the potential impact upon the amount and timing of revenue recognition. We continue to develop and evaluate disclosures required under ASC 606, with a particular focus on the scope of contracts subject to disclosure of remaining performance obligations. Additionally, we have identified possible financial system and internal control changes necessary for adoption. We currently anticipate utilizing a modified retrospective transition upon the adoption of ASC 606 as of January 1, 2018. Termination of WPZ Merger Agreement On May 12, 2015, we entered into an 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). On September 28, 2015, we entered into a Termination Agreement and Release (Termination Agreement), terminating the WPZ Merger Agreement. Under the terms of the Termination Agreement, we were required to pay a $428 million termination fee to WPZ, at which time we owned approximately 60 percent , including the interests of the general partner and incentive distribution rights (IDRs). Such termination fee settled through a reduction of quarterly incentive distributions we were entitled to receive from WPZ (such reduction not to exceed $209 million per quarter). The distributions from WPZ in November 2015, February 2016, and May 2016 were reduced by $209 million , $209 million , and $10 million , respectively, related to this termination fee.

Variable Interest Entities

Variable Interest Entities	9 Months Ended
	Sep. 30, 2017
Variable Interest Entity Disclosures [Abstract]
Variable Interest Entities [Text Block]	Note 2 – 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. September 30, December 31, Classification (Millions) Assets (liabilities): Cash and cash equivalents $ 1,165 $ 145 Cash and cash equivalents Trade accounts and other receivables – net 778 925 Trade accounts and other receivables Inventories 144 138 Inventories Other current assets 183 205 Other current assets and deferred charges Investments 6,615 6,701 Investments Property, plant, and equipment – net 27,411 28,021 Property, plant, and equipment – net Intangible assets – net 8,872 9,662 Intangible assets – net of accumulated amortization Regulatory assets, deferred charges, and other noncurrent assets 467 467 Regulatory assets, deferred charges, and other Accounts payable (751 ) (589 ) Accounts payable Accrued liabilities including current asset retirement obligations (818 ) (1,122 ) Accrued liabilities Commercial paper — (93 ) Commercial paper Long-term debt due within one year (502 ) (785 ) Long-term debt due within one year Long-term debt (16,000 ) (17,685 ) Long-term debt Deferred income tax liabilities (14 ) (20 ) Deferred income tax liabilities Noncurrent asset retirement obligations (876 ) (798 ) Regulatory liabilities, deferred income, and other Regulatory liabilities, deferred income, and other noncurrent liabilities (1,986 ) (1,860 ) 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 construction manager for 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 $691 million , which is expected to be funded with capital contributions from WPZ and the other equity partners on a proportional basis. In December 2014, Constitution received approval from the Federal Energy Regulatory Commission (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 of the Second Circuit Court’s decision, but in October the court denied our petition. We remain steadfastly committed to the project, and in October 2017 we 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 light of the NYSDEC’s denial of the water quality certification and the actions taken to challenge the decision, the anticipated target in-service date is as early as the first half of 2019, which assumes the timely receipt of a Notice to Proceed from the FERC. An unfavorable resolution could result in the impairment of a significant portion of the capitalized project costs, which total $381 million on a consolidated basis at September 30, 2017 , 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.

Divestitures

Divestitures	9 Months Ended
	Sep. 30, 2017
Discontinued Operations and Disposal Groups [Abstract]
Divestitures [Text Block]	Note 3 – Divestitures On July 6, 2017, WPZ completed the sale of Williams Olefins, L.L.C., a wholly owned subsidiary which owned our 88.5 percent undivided interest in the Geismar, Louisiana, olefins plant (Geismar Interest) for total consideration of $2.084 billion in cash. We received a final working capital adjustment of $12 million in October 2017. Upon closing of the sale, WPZ entered into a long-term supply and transportation agreement with the purchaser to provide feedstock to the plant via its Bayou Ethane pipeline system. The assets and liabilities of the Geismar olefins plant were designated as held for sale within the Williams Partners segment during the first quarter of 2017. As a result of this sale, we recorded a gain of $1.095 billion in the third quarter of 2017. Following this sale, the cash proceeds were used to repay WPZ’s $850 million term loan. WPZ also plans to use these proceeds to fund a portion of the capital and investment expenditures that are a part of its growth portfolio. The following table presents the results of operations for the Geismar Interest, excluding the gain noted above. Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 (Millions) Income (loss) before income taxes of the Geismar Interest $ 1 $ 61 $ 26 $ 109 Income (loss) before income taxes of the Geismar Interest attributable to The Williams Companies, Inc. 1 36 19 65 In September 2016, we completed the sale of subsidiaries conducting Canadian operations, including subsidiaries of WPZ, (such subsidiaries, the Canada disposal group). Consideration received totaled $1.020 billion , net of $31 million of cash divested and subject to customary working capital adjustments. In connection with the sale, we waived $150 million of incentive distributions otherwise payable by WPZ to us in the fourth quarter of 2016 in recognition of certain affiliate contracts wherein WPZ’s Canadian operations provided services to certain of our other businesses. The proceeds were primarily used to reduce borrowings on credit facilities. During the second quarter of 2016, we designated these operations as held for sale. As a result, we measured the fair value of the disposal group as of June 30, 2016, resulting in an impairment charge of $747 million , reflected in Impairment of certain assets in the Consolidated Statement of Operations . (See Note 11 - Fair Value Measurements.) Upon completion of the sale, we recorded an additional loss of $65 million for the three and nine months ended September 30, 2016, primarily reflecting revisions to the sales price and estimated contingent consideration and including a $15 million benefit related to transactions to hedge our foreign currency exchange risk on the Canadian proceeds, reflected in Other (income) expense – net within Costs and expenses in the Consolidated Statement of Operations . The total loss consists of a loss of $32 million and $33 million at Williams Partners and Williams Other segments, respectively. The following table presents the results of operations for the Canada disposal group, excluding the impairment and loss noted above. Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 (Millions) Income (loss) before income taxes of the Canadian disposal group $ — $ (9 ) $ — $ (98 ) Income (loss) before income taxes of the Canadian disposal group attributable to The Williams Companies, Inc. — (16 ) — (95 )

Investing Activities

Investing Activities	9 Months Ended
	Sep. 30, 2017
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, we have 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 Operations. 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. Impairments The nine months ended September 30, 2016 , includes $59 million and $50 million of other-than-temporary impairment charges related to WPZ’s equity-method investments in DBJV and Laurel Mountain, respectively (see Note 11 – Fair Value Measurements and Guarantees ). Investing Income The three and nine months ended September 30, 2016 , includes a $27 million gain from the sale of an equity-method investment interest in a gathering system that was part of WPZ’s Appalachia Midstream Investments. Interest Income and Other The nine months ended September 30, 2016 , includes $36 million of income associated with payments received on a receivable related to the sale of certain former Venezuela assets reflected in Other investing income (loss) – net in the Consolidated Statement of Operations .

Other Income and Expenses

Other Income and Expenses	9 Months Ended
	Sep. 30, 2017
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 Operations : Three Months Ended Nine Months Ended 2017 2016 2017 2016 (Millions) Williams Partners Amortization of regulatory assets associated with asset retirement obligations $ 8 $ 8 $ 25 $ 25 Accrual of regulatory liability related to overcollection of certain employee expenses 5 6 16 19 Project development costs related to Constitution (see Note 2) 4 11 12 19 Gains on contract settlements and terminations — — (15 ) — Gain on sale of Refinery Grade Propylene Splitter — — (12 ) — Net foreign currency exchange (gains) losses (1) — — — 11 Loss on sale of Canadian operations (see Note 3) 4 32 — 32 Other Gain on sale of unused pipe — — — (10 ) Loss on sale of Canadian operations (see Note 3) — 33 1 33 (1) Primarily relates to gains and losses incurred on foreign currency transactions and the remeasurement of U.S. dollar denominated current assets and liabilities within our former Canadian operations. Additional Items Certain additional items included in the Consolidated Statement of Operations are as follows: • Service revenues were reduced by $15 million for the nine months ended September 30, 2016 , related to potential refunds associated with a ruling received in certain rate case litigation within the Williams Partners segment. • Selling, general, and administrative expenses includes $5 million and $9 million for the three and nine months ended September 30, 2017, respectively, and $21 million and $40 million for the three and nine months ended September 30, 2016, respectively, of costs associated with our evaluation of strategic alternatives within the Other segment. Selling, general, and administrative expenses also includes $16 million and $61 million for the three and nine months ended September 30, 2016, respectively, of project development costs related to a proposed propane dehydrogenation facility in Alberta, Canada within the Other segment. Beginning in the first quarter of 2016, these costs did not qualify for capitalization. • Selling, general, and administrative expenses and Operating and maintenance expenses include $5 million and $18 million in severance and other related costs for the three and nine months ended September 30, 2017 for the Williams Partners segment. The nine months ended September 30, 2016 included $26 million in severance and other related costs associated with an approximate 10 percent reduction in workforce in the first quarter of 2016, primarily within the Williams Partners segment. • Other income (expense) – net below Operating income (loss) includes $17 million and $55 million for the three and nine months ended September 30, 2017 , respectively, and $17 million and $46 million for the three and nine months ended September 30, 2016 , 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 $8 million and $44 million , for the three and nine months ended September 30, 2017 , respectively, and $6 million and $16 million for the three and nine months ended September 30, 2016 , 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 September 30, 2017 includes a net loss of $3 million associated with the July 3, 2017 early retirement of $1.4 billion of 4.875 percent senior unsecured notes that were due in 2023. The net loss for the July 3, 2017 early retirement within the Williams Partners segment reflects $51 million of unamortized premium, offset by $54 million in premiums paid. (See Note 9 – Debt and Banking Arrangements .) • Other income (expense) – net below Operating income (loss) for the nine months ended September 30, 2017 , includes a net gain of $27 million associated with the early retirement of debt. The gain is comprised of a $30 million net gain associated with the February 23, 2017 early retirement of $750 million of 6.125 percent senior unsecured notes that were due in 2022, partially offset by a $3 million net loss associated with the July 3, 2017 early retirement discussed above. The net gain for the February 23, 2017 early retirement 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	9 Months Ended
	Sep. 30, 2017
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 Nine Months Ended 2017 2016 2017 2016 (Millions) Current: Federal $ 7 $ — $ 10 $ — State 9 1 17 1 Foreign — — — (1 ) 16 1 27 — Deferred: Federal (11 ) 8 63 (49 ) State 19 71 36 60 Foreign — (11 ) — (85 ) 8 68 99 (74 ) Provision (benefit) for income taxes $ 24 $ 69 $ 126 $ (74 ) The effective income tax rate for the three months ended September 30, 2017 , 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, including an $18 million provision related to an increase in the deferred state income tax rate (net of federal benefit). The effective income tax rate for the nine months ended September 30, 2017 , is less than the federal statutory rate. This is primarily due to the impact of the allocation of income to nontaxable noncontrolling interests and releasing a $127 million valuation allowance on a deferred tax asset associated with a capital loss carryover, partially offset by the effect of state income taxes, including an $18 million provision related to an increase in the deferred state income tax rate (net of federal benefit). In 2016, we recorded a valuation allowance on a deferred tax asset associated with a capital loss that was incurred with the sale of our Canadian operations. The sale of the Geismar olefins facility in July 2017 (see Note 3 – Divestitures ) generated capital gains sufficient to offset the capital loss carryover, thereby allowing us to reverse the valuation allowance in full. The effective income tax rate for the three months ended September 30, 2016 , is less than the federal statutory rate primarily due to the impact of the allocation of income to nontaxable noncontrolling interests and the effects of taxes on foreign operations, partially offset by the effect of state income taxes, including a $43 million provision related to an increase in the deferred state income tax rate (net of federal benefit). The effective income tax rate for the nine months ended September 30, 2016 , is less than the federal statutory rate primarily due to the effects of taxes on foreign operations, which includes the reversal of anticipatory foreign tax credits and a valuation allowance associated with impairments and losses on the sale of our Canadian operations (see Note 3 – Divestitures ), and the effect of state income taxes, including a $43 million provision related to an increase in the deferred state income tax rate (net of federal benefit). These decreases are partially offset by the impact of the allocation of income to nontaxable noncontrolling interests. The foreign income tax provision includes the tax effect of the impairments associated with our Canadian disposition. (See Note 11 – Fair Value Measurements and Guarantees .) 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 (Loss) Per Common Shar

Earnings (Loss) Per Common Share	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Earnings (Loss) Per Common Share [Text Block]	Note 7 – Earnings (Loss) Per Common Share Three Months Ended Nine Months Ended 2017 2016 2017 2016 (Dollars in millions, except per-share amounts; shares in thousands) Net income (loss) attributable to The Williams Companies, Inc. available to common stockholders for basic and diluted earnings (loss) per common share $ 33 $ 61 $ 487 $ (409 ) Basic weighted-average shares 826,779 750,754 825,925 750,579 Effect of dilutive securities: Nonvested restricted stock units 1,889 568 1,567 — Stock options 700 536 658 — Diluted weighted-average shares 829,368 751,858 828,150 750,579 Earnings (loss) per common share: Basic $ .04 $ .08 $ .59 $ (.55 ) Diluted $ .04 $ .08 $ .59 $ (.55 )

Employee Benefit Plans

Employee Benefit Plans	9 Months Ended
	Sep. 30, 2017
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 Nine Months Ended 2017 2016 2017 2016 (Millions) Components of net periodic benefit cost (credit): Service cost $ 13 $ 13 $ 38 $ 40 Interest cost 15 16 44 47 Expected return on plan assets (21 ) (22 ) (62 ) (64 ) Amortization of net actuarial loss 6 8 20 23 Net actuarial loss from settlements — — — 1 Net periodic benefit cost (credit) $ 13 $ 15 $ 40 $ 47 Other Postretirement Benefits Three Months Ended Nine Months Ended 2017 2016 2017 2016 (Millions) Components of net periodic benefit cost (credit): Service cost $ — $ — $ 1 $ 1 Interest cost 2 2 6 6 Expected return on plan assets (3 ) (3 ) (9 ) (9 ) Amortization of prior service credit (3 ) (3 ) (10 ) (11 ) Reclassification to regulatory liability 1 1 3 3 Net periodic benefit cost (credit) $ (3 ) $ (3 ) $ (9 ) $ (10 ) Amortization of prior service credit and net actuarial loss included in net periodic benefit cost (credit) for our other postretirement benefit plans associated with Transco and Northwest Pipeline are recorded to regulatory assets/liabilities instead of other comprehensive income (loss). The amounts of amortization of prior service credit recognized in regulatory liabilities were $2 million for the three months ended September 30, 2017 and 2016 , and $6 million and $7 million for the nine months ended September 30, 2017 and 2016, respectively. During the nine months ended September 30, 2017 , we contributed $83 million to our pension plans and $4 million to our other postretirement benefit plans. We presently anticipate making additional contributions of approximately $1 million to our pension plans and approximately $1 million to our other postretirement benefit plans in the remainder of 2017. In September 2017, we initiated a program to pay out certain deferred vested pension benefits to reduce investment risk, cash funding volatility, and administrative costs. Eligible participants had until October 31, 2017, to make elections. We expect to make the lump-sum payments and commence the annuity payments in December 2017, and intend to fund the payments from existing assets in our pension plans. As a result of these payouts and based on current assumptions, we expect to record a pre-tax, non-cash settlement charge in the fourth quarter of 2017 that we estimate will be between $70 million and $100 million . The ultimate amount of the charge will largely depend upon the actual level of participation as well as the actuarial assumptions used to measure the pension plans’ assets and obligations, including the discount rates.

Debt and Banking Arrangements

Debt and Banking Arrangements	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Debt and Banking Arrangements [Text Block]	Note 9 – Debt and Banking Arrangements Long-Term Debt Issuances and retirements On July 6, 2017, WPZ repaid its $850 million variable interest rate term loan that was due December 2018 using proceeds from the sale of its Geismar Interest. On June 5, 2017, WPZ issued $1.45 billion of 3.75 percent senior unsecured notes due 2027. WPZ used the proceeds for general partnership purposes, primarily the July 3, 2017 repayment of $1.4 billion of 4.875 percent senior unsecured notes that were due in 2023. On April 3, 2017, Northwest Pipeline issued $250 million of 4.0 percent senior unsecured notes due 2027 to investors in a private debt placement. Northwest Pipeline used the net proceeds to retire $185 million of 5.95 percent senior unsecured notes that matured on April 15, 2017, and for general corporate purposes. As part of the issuance, Northwest Pipeline entered into a registration rights agreement with the initial purchasers of the unsecured notes. Northwest Pipeline 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. Northwest Pipeline is required to provide a shelf registration statement to cover resales of the notes under certain circumstances. If Northwest Pipeline 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. On February 23, 2017, using proceeds received from the Financial Repositioning (see Note 1 – General, Description of Business, and Basis of Presentation ) , WPZ early retired $750 million of 6.125 percent senior unsecured notes that were due in 2022. WPZ retired $600 million of 7.25 percent senior unsecured notes that matured on February 1, 2017. Other financing obligation During the construction of Transco’s Dalton expansion project, WPZ received funding from a partner for its proportionate share of construction costs related to its undivided ownership interest in the project. Amounts received were recorded within noncurrent liabilities. Upon placing the project in service during the third quarter of 2017, WPZ began leasing this partner’s undivided interest in the lateral, including the associated pipeline capacity, and reclassified approximately $237 million of funding previously received from its partner from noncurrent liabilities to debt to reflect the financing obligation payable to its partner over an expected term of 35 years . Commercial Paper Program As of September 30, 2017, no Commercial paper was outstanding under WPZ’s $3 billion commercial paper program. Credit Facilities September 30, 2017 Stated Capacity Outstanding (Millions) WMB Long-term credit facility $ 1,500 $ 400 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	9 Months Ended
	Sep. 30, 2017
Stockholders' Equity Note [Abstract]
Stockholders' Equity [Text Block]	Note 10 – Stockholders’ Equity In January 2017, we issued 65 million shares of common stock in a public offering at a price of $29.00 per share. In February 2017, we issued 9.75 million shares of common stock pursuant to the full exercise of the underwriter’s option to purchase additional shares. The net proceeds of approximately $2.1 billion were used to purchase newly issued common units in WPZ as part of our Financial Repositioning. (See Note 1 – General, Description of Business, and Basis of Presentation .) 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 Post Retirement Benefits Total (Millions) Balance at December 31, 2016 $ — $ (2 ) $ (337 ) $ (339 ) Other comprehensive income (loss) before reclassifications (3 ) — — (3 ) Amounts reclassified from accumulated other comprehensive income (loss) — — 11 11 Other comprehensive income (loss) (3 ) — 11 8 Balance at September 30, 2017 $ (3 ) $ (2 ) $ (326 ) $ (331 ) Reclassifications out of AOCI are presented in the following table by component for the nine months ended September 30, 2017 : Component Reclassifications Classification (Millions) Cash flow hedges: Energy commodity contracts $ (1 ) Product sales Pension and other postretirement benefits: Amortization of prior service cost (credit) included in net periodic benefit cost (4 ) Note 8 – Employee Benefit Plans Amortization of actuarial (gain) loss included in net periodic benefit cost 20 Note 8 – Employee Benefit Plans Total before tax 15 Income tax benefit (4 ) Provision (benefit) for income taxes Reclassifications during the period $ 11

Fair Value Measurements and Gua

Fair Value Measurements and Guarantees	9 Months Ended
	Sep. 30, 2017
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, commercial paper, 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 September 30, 2017: Measured on a recurring basis: ARO Trust investments $ 127 $ 127 $ 127 $ — $ — Energy derivatives assets not designated as hedging instruments 2 2 1 — 1 Energy derivatives liabilities designated as hedging instruments (6 ) (6 ) (5 ) (1 ) — Energy derivatives liabilities not designated as hedging instruments (5 ) (5 ) (2 ) — (3 ) Additional disclosures: Other receivables 12 12 12 — — Long-term debt, including current portion (21,069 ) (22,979 ) — (22,979 ) — Guarantees (44 ) (30 ) — (14 ) (16 ) Assets (liabilities) at December 31, 2016: Measured on a recurring basis: ARO Trust investments $ 96 $ 96 $ 96 $ — $ — Energy derivatives assets designated as hedging instruments 2 2 — 2 — Energy derivatives assets not designated as hedging instruments 1 1 — — 1 Energy derivatives liabilities not designated as hedging instruments (6 ) (6 ) — — (6 ) Additional disclosures: Other receivables 15 15 15 — — Long-term debt, including current portion (23,409 ) (24,090 ) — (24,090 ) — Guarantees (44 ) (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, is classified as available-for-sale, 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 nine months ended September 30, 2017 or 2016 . 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. The fair value of the financing obligation associated with our Dalton lateral, which is included within long-term debt, was determined using an income approach (see Note 9 - Debt and Banking Arrangements). 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 disclosed 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 $31 million at September 30, 2017 . 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. Nonrecurring fair value measurements The following table presents impairments of assets and investments associated with certain nonrecurring fair value measurements within Level 3 of the fair value hierarchy. Impairments Nine Months Ended September 30, Classification Segment Date of Measurement Fair Value 2017 2016 (Millions) Certain gathering operations (1) Property, plant, and equipment - net and Intangible assets - net of accumulated amortization Williams Partners September 30, 2017 $ 439 $ 1,019 Certain gathering operations (2) Property, plant, and equipment - net and Intangible assets - net of accumulated amortization Williams Partners September 30, 2017 21 115 Certain NGL pipeline (3) Property, plant, and equipment – net Other September 30, 2017 32 68 Certain olefins pipeline project (4) Property, plant, and equipment – net Other June 30, 2017 18 23 Canadian operations (5) Assets held for sale Williams Partners June 30, 2016 924 $ 341 Canadian operations (5) Assets held for sale Other June 30, 2016 206 406 Certain gathering operations (6) Property, plant, and equipment – net Williams Partners June 30, 2016 18 48 Level 3 fair value measurements of certain assets 1,225 795 Other impairments and write-downs (7) 11 16 Impairment of certain assets $ 1,236 $ 811 Equity-method investments (8) Investments Williams Partners March 31, 2016 $ 1,294 $ 109 Other equity-method investment Investments Williams Partners March 31, 2016 — 3 Impairment of equity-method investments $ 112 _______________ (1) Relates to certain gathering operations in the Mid-Continent region. During the third quarter of 2017, we received solicitations and engaged in negotiations for the sale of certain of these assets which led to our impairment evaluation. The estimated fair value was determined using an income approach and incorporated market inputs based on ongoing negotiations for a potential sale of a portion of the underlying assets. For the income approach, we utilized a discount rate of 10.2 percent , reflecting an estimate of our cost of capital and risks associated with the underlying assets. (2) Relates to certain gathering operations in the Marcellus South region resulting from an anticipated decline in future volumes following a third-quarter 2017 shut-in by the primary producer. The estimated fair value was determined by the income approach utilizing a discount rate of 11.1 percent , reflecting an estimate of our cost of capital and risks associated with the underlying assets. (3) Relates to an NGL pipeline near the Houston Ship Channel region which we anticipate will be underutilized for the foreseeable future. The estimated fair value was primarily determined by using a market approach based on our analysis of observable inputs in the principal market. (4) Relates primarily to project development costs associated with an olefins pipeline project in the Gulf Coast region, the likelihood of completion of which is now considered remote. The estimated fair value of the remaining pipe and equipment considered a market approach based on our analysis of observable inputs in the principal market, as well as an estimate of replacement cost. (5) Relates to our Canadian operations. We designated these operations as held for sale as of June 30, 2016. As a result, we measured the fair value of the disposal group, resulting in an impairment charge. The estimated fair value was determined by a market approach based primarily on inputs received in the marketing process and reflected our estimate of the potential assumed proceeds. We disposed of our Canadian operations through a sale during the third quarter of 2016. (6) Relates to certain gathering assets within the Mid-Continent region. The estimated fair value was determined by a market approach based on our analysis of observable inputs in the principal market. (7) Reflects multiple individually insignificant impairments and write-downs of other certain assets that may no longer be in use or are surplus in nature for which the fair value was determined to be lower than the carrying value. (8) Relates to Williams Partners’ previously owned interest in DBJV and current equity-method investment in Laurel Mountain. Our carrying values in these equity-method investments had been written down to fair value at December 31, 2015. Our first-quarter 2016 analysis reflected higher discount rates for both of these equity-method investments, along with lower natural gas prices for Laurel Mountain. We estimated the fair value of these equity-method investments using an income approach based on expected future cash flows and appropriate discount rates. The determination of estimated future cash flows involved significant assumptions regarding gathering volumes and related capital spending. Discount rates utilized ranged from 13.0 percent to 13.3 percent and reflected increases in our estimated cost of capital, revised estimates of expected future cash flows, and risks associated with the underlying businesses.

Contingent Liabilities

Contingent Liabilities	9 Months Ended
	Sep. 30, 2017
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 an 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 has appealed. 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 in this matter. Geismar Incident On June 13, 2013, an explosion and fire occurred at our formerly owned Geismar olefins plant and rendered the facility temporarily inoperable (Geismar Incident). As a result, there were two fatalities and numerous individuals (including employees and contractors) reported injuries. We are addressing the following contingent liabilities in connection with the Geismar Incident. On October 21, 2013, the U.S. Environmental Protection Agency (EPA) issued an Inspection Report pursuant to the Clean Air Act’s Risk Management Program following its inspection of the facility on June 24 through June 28, 2013. The report notes the EPA’s preliminary determinations about the facility’s documentation regarding process safety, process hazard analysis, as well as operating procedures, employee training, and other matters. On June 16, 2014, we received a request for information related to the Geismar Incident from the EPA under Section 114 of the Clean Air Act to which we responded on August 13, 2014. The EPA could issue penalties pertaining to final determinations. Multiple lawsuits, including class actions for alleged offsite impacts, property damage, customer claims, and personal injury, have been filed against us. The first two trials, for nine plaintiffs claiming personal injury, were held in Louisiana state court in Iberville Parish, Louisiana in September and November 2016. The juries returned adverse verdicts against us, our subsidiary Williams Olefins, LLC, and other defendants. To date, we have settled those cases as well as settled or agreed in principle to settle numerous other personal injury claims, and such aggregate amount greater than our $2 million retention (deductible) value has been or will be recovered from our insurers. We believe these settlements to date substantially resolve any material exposure to such claims arising from the Geismar Incident. We believe that any additional losses arising from our alleged liability will be immaterial to our expected future annual results of operations, liquidity, and financial position and will be substantially covered by our general liability insurance policy, which has an aggregate limit of $610 million applicable to this event. Alaska Refinery Contamination Litigation In 2010, James West filed a class action lawsuit in state court in Fairbanks, Alaska on behalf of individual property owners whose water contained sulfolane contamination allegedly emanating from the Flint Hills Oil Refinery in North Pole, Alaska. The suit named our subsidiary, Williams Alaska Petroleum Inc. (WAPI), and Flint Hills Resources Alaska, LLC (FHRA), a subsidiary of Koch Industries, Inc., as defendants. We owned and operated the refinery until 2004 when we sold it to FHRA. We and FHRA made claims under the pollution liability insurance policy issued in connection with the sale of the North Pole refinery to FHRA. We and FHRA also 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 James West claim. 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. On March 6, 2014, the State of Alaska filed suit against FHRA, WAPI, and us in state court in Fairbanks seeking injunctive relief and damages in connection with sulfolane contamination of the water supply near the Flint Hills Oil Refinery in North Pole, Alaska. On May 5, 2014, FHRA filed cross-claims against us in the State of Alaska suit for contractual indemnification and statutory claims for damages related to off-site sulfolane. On November 26, 2014, the City of North Pole (North Pole) filed suit in Alaska state court in Fairbanks against FHRA, WAPI, and us alleging nuisance and violations of municipal ordinances and state statutes based upon the same alleged sulfolane contamination of the water supply. North Pole claims an unspecified amount of past and future damages as well as punitive damages against WAPI. FHRA filed cross-claims against us. In October of 2015, the court consolidated the State of Alaska and North Pole cases. Both we and WAPI asserted counterclaims against both the State of Alaska and North Pole, and cross-claims against FHRA. The underlying factual basis and claims in the consolidated State of Alaska and North Pole action are similar to and may duplicate exposure in the James West case. As such, on February 9, 2017, the remaining claims in the James West case were consolidated into the State of Alaska and North Pole action. A trial encompassing all three consolidated 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. Due to the ongoing assessment of the level and extent of sulfolane contamination and the ultimate cost of remediation and division of costs among the potentially responsible parties, 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 and Oklahoma based on allegations that we improperly participated with that major customer in causing the alleged royalty underpayments. The Oklahoma case was transferred to Texas and, on October 2, 2017, voluntarily dismissed by the plaintiff. 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 Between October 2015 and December 2015, purported shareholders of us filed six putative class action lawsuits in the Delaware Court of Chancery that were consolidated into a single suit on January 13, 2016. This consolidated putative class action lawsuit relates to our terminated merger with Energy Transfer Equity, L.P. (Energy Transfer). The complaint asserts various claims against the individual members of our Board of Directors, including that they breached their fiduciary duties by agreeing to sell us through an allegedly unfair process and for an allegedly unfair price and by allegedly failing to disclose allegedly material information about the merger. The complaint seeks, among other things, an injunction against the merger and an award of costs and attorneys’ fees. On March 22, 2016, the court granted the parties’ proposed order in the consolidated action to stay the proceedings pending the close of the transaction with Energy Transfer. The plaintiffs have not filed an amended complaint. On July 19, 2017, the court dismissed the action with prejudice as to plaintiffs and without prejudice as to all other shareholders of us. A purported shareholder filed a separate class action lawsuit in the Delaware Court of Chancery on January 15, 2016. The putative class action complaint alleged that the individual members of our Board of Directors breached their fiduciary duties by, among other things, agreeing to the WPZ Merger Agreement, which purportedly reduced the merger consideration to have been received in the subsequently proposed but now terminated merger with Energy Transfer. The plaintiff filed a motion to voluntarily dismiss, which the court granted on January 13, 2017. On September 2, 2016, the same purported shareholder filed a derivative action claiming that the members of our Board of Directors breached their fiduciary duties by executing the WPZ Merger Agreement as a defensive measure against Energy Transfer. On September 28, 2016, we requested the court dismiss this action, and on May 15, 2017, the court dismissed the action. On June 6, 2017, the plaintiff filed a notice of appeal. 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’s intention to pursue a purchase of us conditioned on us not closing the 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 related to these matters 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. We filed a motion to dismiss Energy Transfer’s counterclaims, which was fully briefed on November 14, 2016, and oral argument occurred on November 30, 2016. Environmental Matters We are a participant in certain environmental activities in various stages including assessment studies, cleanup operations, and 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 EPA, and 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 September 30, 2017 , we have accrued liabilities totaling $40 million for these matters, as discussed below. Our accrual reflects the most likely costs of cleanup, which are generally based on completed assessment studies, preliminary results of studies, or our experience with other similar cleanup operations. Certain assessment studies are still in process for which the ultimate outcome may yield significantly different estimates of most likely costs. Any incremental amount in excess of amounts currently accrued cannot be reasonably estimated at this time due to uncertainty about the actual number of contaminated sites ultimately identified, the actual amount and extent of contamination discovered, and the final cleanup standards mandated by the EPA and other governmental authorities. 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 standard of 70 parts per billion . We are monitoring the rule’s implementation and evaluating potential impacts to our operations. For these and other new regulations, we are unable to estimate the costs of asset additions or modifications necessary to comply due to uncertainty created by the 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 September 30, 2017 , we have accrued liabilities of $8 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 September 30, 2017 , we have accrued liabilities totaling $8 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 September 30, 2017 , we have accrued environmental liabilities of $24 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 September 30, 2017 , 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	9 Months Ended
	Sep. 30, 2017
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 Operations and Total assets by reportable segment. Williams Partners Other Eliminations Total (Millions) Three Months Ended September 30, 2017 Segment revenues: Service revenues External $ 1,304 $ 6 $ — $ 1,310 Internal — 2 (2 ) — Total service revenues 1,304 8 (2 ) 1,310 Product sales External 581 — — 581 Internal — — — — Total product sales 581 — — 581 Total revenues $ 1,885 $ 8 $ (2 ) $ 1,891 Three Months Ended September 30, 2016 Segment revenues: Service revenues External $ 1,241 $ 6 $ — $ 1,247 Internal 11 3 (14 ) — Total service revenues 1,252 9 (14 ) 1,247 Product sales External 655 3 — 658 Internal — 6 (6 ) — Total product sales 655 9 (6 ) 658 Total revenues $ 1,907 $ 18 $ (20 ) $ 1,905 Nine Months Ended September 30, 2017 Segment revenues: Service revenues External $ 3,836 $ 17 $ — $ 3,853 Internal 1 8 (9 ) — Total service revenues 3,837 25 (9 ) 3,853 Product sales External 1,950 — — 1,950 Internal — — — — Total product sales 1,950 — — 1,950 Total revenues $ 5,787 $ 25 $ (9 ) $ 5,803 Nine Months Ended September 30, 2016 Segment revenues: Service revenues External $ 3,656 $ 22 $ — $ 3,678 Internal 32 17 (49 ) — Total service revenues 3,688 39 (49 ) 3,678 Product sales External 1,613 10 — 1,623 Internal — 16 (16 ) — Total product sales 1,613 26 (16 ) 1,623 Total revenues $ 5,301 $ 65 $ (65 ) $ 5,301 September 30, 2017 Total assets $ 45,635 $ 570 $ (85 ) $ 46,120 December 31, 2016 Total assets $ 46,265 $ 685 $ (115 ) $ 46,835 The following table reflects the reconciliation of Modified EBITDA to Net income (loss) as reported in the Consolidated Statement of Operations . Three Months Ended Nine Months Ended 2017 2016 2017 2016 (Millions) Modified EBITDA by segment: Williams Partners $ 1,000 $ 1,070 $ 3,208 $ 2,629 Other (61 ) (67 ) (60 ) (534 ) 939 1,003 3,148 2,095 Accretion expense associated with asset retirement obligations for nonregulated operations (7 ) (9 ) (23 ) (24 ) Depreciation and amortization expenses (433 ) (435 ) (1,308 ) (1,326 ) Equity earnings (losses) 115 104 347 302 Impairment of equity-method investments — — — (112 ) Other investing income (loss) – net 4 28 278 64 Proportional Modified EBITDA of equity-method investments (202 ) (194 ) (611 ) (574 ) Interest expense (267 ) (297 ) (818 ) (886 ) (Provision) benefit for income taxes (24 ) (69 ) (126 ) 74 Net income (loss) $ 125 $ 131 $ 887 $ (387 )

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	9 Months Ended
	Sep. 30, 2017
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. September 30, December 31, Classification (Millions) Assets (liabilities): Cash and cash equivalents $ 1,165 $ 145 Cash and cash equivalents Trade accounts and other receivables – net 778 925 Trade accounts and other receivables Inventories 144 138 Inventories Other current assets 183 205 Other current assets and deferred charges Investments 6,615 6,701 Investments Property, plant, and equipment – net 27,411 28,021 Property, plant, and equipment – net Intangible assets – net 8,872 9,662 Intangible assets – net of accumulated amortization Regulatory assets, deferred charges, and other noncurrent assets 467 467 Regulatory assets, deferred charges, and other Accounts payable (751 ) (589 ) Accounts payable Accrued liabilities including current asset retirement obligations (818 ) (1,122 ) Accrued liabilities Commercial paper — (93 ) Commercial paper Long-term debt due within one year (502 ) (785 ) Long-term debt due within one year Long-term debt (16,000 ) (17,685 ) Long-term debt Deferred income tax liabilities (14 ) (20 ) Deferred income tax liabilities Noncurrent asset retirement obligations (876 ) (798 ) Regulatory liabilities, deferred income, and other Regulatory liabilities, deferred income, and other noncurrent liabilities (1,986 ) (1,860 ) Regulatory liabilities, deferred income, and other

Divestitures (Tables)

Divestitures (Tables)	9 Months Ended
	Sep. 30, 2017
Williams Olefins, L.L.C. [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Results of Operations of Disposal Group [Table Text Block]	The following table presents the results of operations for the Geismar Interest, excluding the gain noted above. Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 (Millions) Income (loss) before income taxes of the Geismar Interest $ 1 $ 61 $ 26 $ 109 Income (loss) before income taxes of the Geismar Interest attributable to The Williams Companies, Inc. 1 36 19 65
Canadian Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Results of Operations of Disposal Group [Table Text Block]	The following table presents the results of operations for the Canada disposal group, excluding the impairment and loss noted above. Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 (Millions) Income (loss) before income taxes of the Canadian disposal group $ — $ (9 ) $ — $ (98 ) Income (loss) before income taxes of the Canadian disposal group attributable to The Williams Companies, Inc. — (16 ) — (95 )

Other Income and Expenses (Tabl

Other Income and Expenses (Tables)	9 Months Ended
	Sep. 30, 2017
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 Operations : Three Months Ended Nine Months Ended 2017 2016 2017 2016 (Millions) Williams Partners Amortization of regulatory assets associated with asset retirement obligations $ 8 $ 8 $ 25 $ 25 Accrual of regulatory liability related to overcollection of certain employee expenses 5 6 16 19 Project development costs related to Constitution (see Note 2) 4 11 12 19 Gains on contract settlements and terminations — — (15 ) — Gain on sale of Refinery Grade Propylene Splitter — — (12 ) — Net foreign currency exchange (gains) losses (1) — — — 11 Loss on sale of Canadian operations (see Note 3) 4 32 — 32 Other Gain on sale of unused pipe — — — (10 ) Loss on sale of Canadian operations (see Note 3) — 33 1 33 (1) Primarily relates to gains and losses incurred on foreign currency transactions and the remeasurement of U.S. dollar denominated current assets and liabilities within our former Canadian operations.

Provision (Benefit) for Incom25

Provision (Benefit) for Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2017
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 Nine Months Ended 2017 2016 2017 2016 (Millions) Current: Federal $ 7 $ — $ 10 $ — State 9 1 17 1 Foreign — — — (1 ) 16 1 27 — Deferred: Federal (11 ) 8 63 (49 ) State 19 71 36 60 Foreign — (11 ) — (85 ) 8 68 99 (74 ) Provision (benefit) for income taxes $ 24 $ 69 $ 126 $ (74 )

Earnings (Loss) Per Common Sh26

Earnings (Loss) Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Earnings (loss) per common share [Table Text Block]	Three Months Ended Nine Months Ended 2017 2016 2017 2016 (Dollars in millions, except per-share amounts; shares in thousands) Net income (loss) attributable to The Williams Companies, Inc. available to common stockholders for basic and diluted earnings (loss) per common share $ 33 $ 61 $ 487 $ (409 ) Basic weighted-average shares 826,779 750,754 825,925 750,579 Effect of dilutive securities: Nonvested restricted stock units 1,889 568 1,567 — Stock options 700 536 658 — Diluted weighted-average shares 829,368 751,858 828,150 750,579 Earnings (loss) per common share: Basic $ .04 $ .08 $ .59 $ (.55 ) Diluted $ .04 $ .08 $ .59 $ (.55 )

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2017
Retirement Benefits [Abstract]
Schedule of Net Benefit Costs [Table Text Block]	Net periodic benefit cost (credit) is as follows: Pension Benefits Three Months Ended Nine Months Ended 2017 2016 2017 2016 (Millions) Components of net periodic benefit cost (credit): Service cost $ 13 $ 13 $ 38 $ 40 Interest cost 15 16 44 47 Expected return on plan assets (21 ) (22 ) (62 ) (64 ) Amortization of net actuarial loss 6 8 20 23 Net actuarial loss from settlements — — — 1 Net periodic benefit cost (credit) $ 13 $ 15 $ 40 $ 47 Other Postretirement Benefits Three Months Ended Nine Months Ended 2017 2016 2017 2016 (Millions) Components of net periodic benefit cost (credit): Service cost $ — $ — $ 1 $ 1 Interest cost 2 2 6 6 Expected return on plan assets (3 ) (3 ) (9 ) (9 ) Amortization of prior service credit (3 ) (3 ) (10 ) (11 ) Reclassification to regulatory liability 1 1 3 3 Net periodic benefit cost (credit) $ (3 ) $ (3 ) $ (9 ) $ (10 )

Debt and Banking Arrangements (

Debt and Banking Arrangements (Tables)	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Schedule of Line of Credit Facilities [Table Text Block]	Credit Facilities September 30, 2017 Stated Capacity Outstanding (Millions) WMB Long-term credit facility $ 1,500 $ 400 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)	9 Months Ended
	Sep. 30, 2017
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 Post Retirement Benefits Total (Millions) Balance at December 31, 2016 $ — $ (2 ) $ (337 ) $ (339 ) Other comprehensive income (loss) before reclassifications (3 ) — — (3 ) Amounts reclassified from accumulated other comprehensive income (loss) — — 11 11 Other comprehensive income (loss) (3 ) — 11 8 Balance at September 30, 2017 $ (3 ) $ (2 ) $ (326 ) $ (331 )
Reclassifications Out Of Accumulated Other Comprehensive Income [Table Text Block]	Reclassifications out of AOCI are presented in the following table by component for the nine months ended September 30, 2017 : Component Reclassifications Classification (Millions) Cash flow hedges: Energy commodity contracts $ (1 ) Product sales Pension and other postretirement benefits: Amortization of prior service cost (credit) included in net periodic benefit cost (4 ) Note 8 – Employee Benefit Plans Amortization of actuarial (gain) loss included in net periodic benefit cost 20 Note 8 – Employee Benefit Plans Total before tax 15 Income tax benefit (4 ) Provision (benefit) for income taxes Reclassifications during the period $ 11

Fair Value Measurements and G30

Fair Value Measurements and Guarantees (Tables)	9 Months Ended
	Sep. 30, 2017
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, commercial paper, 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 September 30, 2017: Measured on a recurring basis: ARO Trust investments $ 127 $ 127 $ 127 $ — $ — Energy derivatives assets not designated as hedging instruments 2 2 1 — 1 Energy derivatives liabilities designated as hedging instruments (6 ) (6 ) (5 ) (1 ) — Energy derivatives liabilities not designated as hedging instruments (5 ) (5 ) (2 ) — (3 ) Additional disclosures: Other receivables 12 12 12 — — Long-term debt, including current portion (21,069 ) (22,979 ) — (22,979 ) — Guarantees (44 ) (30 ) — (14 ) (16 ) Assets (liabilities) at December 31, 2016: Measured on a recurring basis: ARO Trust investments $ 96 $ 96 $ 96 $ — $ — Energy derivatives assets designated as hedging instruments 2 2 — 2 — Energy derivatives assets not designated as hedging instruments 1 1 — — 1 Energy derivatives liabilities not designated as hedging instruments (6 ) (6 ) — — (6 ) Additional disclosures: Other receivables 15 15 15 — — Long-term debt, including current portion (23,409 ) (24,090 ) — (24,090 ) — Guarantees (44 ) (30 ) — (14 ) (16 )
Fair Value Measurements, Nonrecurring [Table Text Block]	Nonrecurring fair value measurements The following table presents impairments of assets and investments associated with certain nonrecurring fair value measurements within Level 3 of the fair value hierarchy. Impairments Nine Months Ended September 30, Classification Segment Date of Measurement Fair Value 2017 2016 (Millions) Certain gathering operations (1) Property, plant, and equipment - net and Intangible assets - net of accumulated amortization Williams Partners September 30, 2017 $ 439 $ 1,019 Certain gathering operations (2) Property, plant, and equipment - net and Intangible assets - net of accumulated amortization Williams Partners September 30, 2017 21 115 Certain NGL pipeline (3) Property, plant, and equipment – net Other September 30, 2017 32 68 Certain olefins pipeline project (4) Property, plant, and equipment – net Other June 30, 2017 18 23 Canadian operations (5) Assets held for sale Williams Partners June 30, 2016 924 $ 341 Canadian operations (5) Assets held for sale Other June 30, 2016 206 406 Certain gathering operations (6) Property, plant, and equipment – net Williams Partners June 30, 2016 18 48 Level 3 fair value measurements of certain assets 1,225 795 Other impairments and write-downs (7) 11 16 Impairment of certain assets $ 1,236 $ 811 Equity-method investments (8) Investments Williams Partners March 31, 2016 $ 1,294 $ 109 Other equity-method investment Investments Williams Partners March 31, 2016 — 3 Impairment of equity-method investments $ 112 _______________ (1) Relates to certain gathering operations in the Mid-Continent region. During the third quarter of 2017, we received solicitations and engaged in negotiations for the sale of certain of these assets which led to our impairment evaluation. The estimated fair value was determined using an income approach and incorporated market inputs based on ongoing negotiations for a potential sale of a portion of the underlying assets. For the income approach, we utilized a discount rate of 10.2 percent , reflecting an estimate of our cost of capital and risks associated with the underlying assets. (2) Relates to certain gathering operations in the Marcellus South region resulting from an anticipated decline in future volumes following a third-quarter 2017 shut-in by the primary producer. The estimated fair value was determined by the income approach utilizing a discount rate of 11.1 percent , reflecting an estimate of our cost of capital and risks associated with the underlying assets. (3) Relates to an NGL pipeline near the Houston Ship Channel region which we anticipate will be underutilized for the foreseeable future. The estimated fair value was primarily determined by using a market approach based on our analysis of observable inputs in the principal market. (4) Relates primarily to project development costs associated with an olefins pipeline project in the Gulf Coast region, the likelihood of completion of which is now considered remote. The estimated fair value of the remaining pipe and equipment considered a market approach based on our analysis of observable inputs in the principal market, as well as an estimate of replacement cost. (5) Relates to our Canadian operations. We designated these operations as held for sale as of June 30, 2016. As a result, we measured the fair value of the disposal group, resulting in an impairment charge. The estimated fair value was determined by a market approach based primarily on inputs received in the marketing process and reflected our estimate of the potential assumed proceeds. We disposed of our Canadian operations through a sale during the third quarter of 2016. (6) Relates to certain gathering assets within the Mid-Continent region. The estimated fair value was determined by a market approach based on our analysis of observable inputs in the principal market. (7) Reflects multiple individually insignificant impairments and write-downs of other certain assets that may no longer be in use or are surplus in nature for which the fair value was determined to be lower than the carrying value. (8) Relates to Williams Partners’ previously owned interest in DBJV and current equity-method investment in Laurel Mountain. Our carrying values in these equity-method investments had been written down to fair value at December 31, 2015. Our first-quarter 2016 analysis reflected higher discount rates for both of these equity-method investments, along with lower natural gas prices for Laurel Mountain. We estimated the fair value of these equity-method investments using an income approach based on expected future cash flows and appropriate discount rates. The determination of estimated future cash flows involved significant assumptions regarding gathering volumes and related capital spending. Discount rates utilized ranged from 13.0 percent to 13.3 percent and reflected increases in our estimated cost of capital, revised estimates of expected future cash flows, and risks associated with the underlying businesses.

Segment Disclosures (Tables)

Segment Disclosures (Tables)	9 Months Ended
	Sep. 30, 2017
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 Operations and Total assets by reportable segment. Williams Partners Other Eliminations Total (Millions) Three Months Ended September 30, 2017 Segment revenues: Service revenues External $ 1,304 $ 6 $ — $ 1,310 Internal — 2 (2 ) — Total service revenues 1,304 8 (2 ) 1,310 Product sales External 581 — — 581 Internal — — — — Total product sales 581 — — 581 Total revenues $ 1,885 $ 8 $ (2 ) $ 1,891 Three Months Ended September 30, 2016 Segment revenues: Service revenues External $ 1,241 $ 6 $ — $ 1,247 Internal 11 3 (14 ) — Total service revenues 1,252 9 (14 ) 1,247 Product sales External 655 3 — 658 Internal — 6 (6 ) — Total product sales 655 9 (6 ) 658 Total revenues $ 1,907 $ 18 $ (20 ) $ 1,905 Nine Months Ended September 30, 2017 Segment revenues: Service revenues External $ 3,836 $ 17 $ — $ 3,853 Internal 1 8 (9 ) — Total service revenues 3,837 25 (9 ) 3,853 Product sales External 1,950 — — 1,950 Internal — — — — Total product sales 1,950 — — 1,950 Total revenues $ 5,787 $ 25 $ (9 ) $ 5,803 Nine Months Ended September 30, 2016 Segment revenues: Service revenues External $ 3,656 $ 22 $ — $ 3,678 Internal 32 17 (49 ) — Total service revenues 3,688 39 (49 ) 3,678 Product sales External 1,613 10 — 1,623 Internal — 16 (16 ) — Total product sales 1,613 26 (16 ) 1,623 Total revenues $ 5,301 $ 65 $ (65 ) $ 5,301 September 30, 2017 Total assets $ 45,635 $ 570 $ (85 ) $ 46,120 December 31, 2016 Total assets $ 46,265 $ 685 $ (115 ) $ 46,835
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 Operations . Three Months Ended Nine Months Ended 2017 2016 2017 2016 (Millions) Modified EBITDA by segment: Williams Partners $ 1,000 $ 1,070 $ 3,208 $ 2,629 Other (61 ) (67 ) (60 ) (534 ) 939 1,003 3,148 2,095 Accretion expense associated with asset retirement obligations for nonregulated operations (7 ) (9 ) (23 ) (24 ) Depreciation and amortization expenses (433 ) (435 ) (1,308 ) (1,326 ) Equity earnings (losses) 115 104 347 302 Impairment of equity-method investments — — — (112 ) Other investing income (loss) – net 4 28 278 64 Proportional Modified EBITDA of equity-method investments (202 ) (194 ) (611 ) (574 ) Interest expense (267 ) (297 ) (818 ) (886 ) (Provision) benefit for income taxes (24 ) (69 ) (126 ) 74 Net income (loss) $ 125 $ 131 $ 887 $ (387 )

General, Description of Busin32

General, Description of Business, and Basis of Presentation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	Jan. 09, 2017	Sep. 28, 2015	Feb. 03, 2017	Jan. 31, 2017	May 31, 2016	Feb. 29, 2016	Nov. 30, 2015	Sep. 30, 2017	Jan. 01, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Number Of Interstate Natural Gas Pipelines								2
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Net								$ (907)
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets									$ 37
WPZ Merger Agreement [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Termination Fee		$ 428
Maximum Reduction Of Quarterly Incentive Distributions		$ 209
Reduction in incentive distribution rights payment					$ 10	$ 209	$ 209
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								$ (2,404)
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								$ 1,497
General and Limited Partner [Member] | Williams Partners L.P. [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Variable Interest Entity Ownership Percentage		60.00%
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		59,000	289,000
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%
Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest								74.00%
Williams Partners [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Goodwill								$ 47
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%

Variable Interest Entities (Det

Variable Interest Entities (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
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	$ 1,165	$ 145
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	778	925
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	144	138
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	183	205
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	6,615	6,701
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	27,411	28,021
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	8,872	9,662
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	467	467
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	(751)	(589)
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	(818)	(1,122)
Variable Interest Entity, Primary Beneficiary [Member] | Commercial Paper [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	0	(93)
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	(502)	(785)
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	(16,000)	(17,685)
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	(14)	(20)
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	(876)	(798)
Variable Interest Entity, Primary Beneficiary [Member] | Regulatory liabilities, deferred income, and other noncurrent liabilities [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	$ (1,986)	$ (1,860)
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	$ 691
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	$ 381
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%

Divestitures (Details)

Divestitures (Details) - USD ($) $ in Millions	Jul. 06, 2017	Sep. 30, 2017	Sep. 30, 2016	Jun. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Oct. 26, 2017	Dec. 31, 2016
Williams Olefins, L.L.C. [Member]
Income Statement and Additional Disclosures by Disposal Groups [Line Items]
Disposal Group, Consideration	$ 2,084
Gain (Loss) on Disposition of Business		$ 1,095
Income (Loss) from Individually Significant Component Disposed of Attributable to Parent, before Income Tax [Abstract]
Income (loss) before income taxes of disposal group		1	$ 61		$ 26	$ 109
Income (loss) before income taxes of disposal group attributable to the Williams Companies, Inc.		1	36		19	65
Williams Olefins, L.L.C. [Member] | Subsequent Event [Member]
Income Statement and Additional Disclosures by Disposal Groups [Line Items]
Disposal Group, Consideration							$ 12
Canadian Operations [Member]
Income Statement and Additional Disclosures by Disposal Groups [Line Items]
Disposal Group, Consideration								$ 1,020
Cash								31
Income (Loss) from Individually Significant Component Disposed of Attributable to Parent, before Income Tax [Abstract]
Income (loss) before income taxes of disposal group		0	(9)		0	(98)
Income (loss) before income taxes of disposal group attributable to the Williams Companies, Inc.		$ 0	(16)		$ 0	(95)
Disposal Group, Not Discontinued Operation, Loss (Gain) on Write-down				$ 747
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal			65			65
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments			15			15
Reduction In Incentive Distribution Rights Payment [Member]
Income Statement and Additional Disclosures by Disposal Groups [Line Items]
Disposal Group, Consideration								$ 150
Williams Partners L.P. [Member]
Income (Loss) from Individually Significant Component Disposed of Attributable to Parent, before Income Tax [Abstract]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal			32			32
Williams Partners L.P. [Member] | Variable Interest Term Loan due 2018 [Member]
Income (Loss) from Individually Significant Component Disposed of Attributable to Parent, before Income Tax [Abstract]
Extinguishment of Debt, Amount	$ 850
Other [Member]
Income (Loss) from Individually Significant Component Disposed of Attributable to Parent, before Income Tax [Abstract]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal			$ 33			$ 33
Geismar [Member] | NGL And Petchem Services [Member]
Income Statement and Additional Disclosures by Disposal Groups [Line Items]
Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest					88.50%

Investing Activities (Details)

Investing Activities (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Proceeds from Sale of Equity Method Investments			$ 200	$ 0
Gain from sale of an equity-method investment interest			269	0
Impairment of equity-method investments	$ 0	$ 0	0	112
Investing income, nonoperating	$ 4	28	$ 278	64
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%		69.00%
Gulfstream Natural Gas System, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	50.00%		50.00%
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
Impairment of equity-method investments				59
Williams Partners [Member] | Appalachia Midstream Services, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	66.00%		66.00%
Williams Partners [Member] | Appalachia Midstream Services, LLC [Member] | Other investing income (loss) - net [Member]
Schedule of Equity Method Investments [Line Items]
Gain from sale of an equity-method investment interest		$ 27		27
Williams Partners [Member] | Ranch Westex JV LLC [Member]
Schedule of Equity Method Investments [Line Items]
Proceeds from Sale of Equity Method Investments			$ 45
Williams Partners [Member] | Laurel Mountain Midstream, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Impairment of equity-method investments				50
Former Venezuela Operations [Member]
Schedule of Equity Method Investments [Line Items]
Investing income, nonoperating				$ 36
Appalachia Midstream Services, LLC [Member] | Williams Partners [Member]
Schedule of Equity Method Investments [Line Items]
Investments, Fair Value Disclosure	$ 1,100		$ 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		Jul. 03, 2017	Feb. 23, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Gain (Loss) on Disposition of Assets				$ 1,095	$ 0	$ 1,095	$ 0
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums		$ 51	$ 53
Debt Instrument, Unamortized Premium		54	23
Debt Instrument, Unamortized Discount (Premium), Net		3	30	27		27
Williams Partners [Member]
Segment Reporting Information [Line Items]
Revenue adjustment associated with litigation							(15)
Other income (expense) - net [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Amortization of regulatory assets associated with asset retirement obligations				8	8	25	25
Accrual of regulatory liability related to overcollection of certain employee expenses				5	6	16	19
Net foreign currency exchange (gains) losses (1)	[1]			0	0	0	11
Gain (Loss) on Disposition of Assets				0	0	(12)	0
Gain (Loss) on Contract Termination				0	0	(15)	0
Project development costs				4	11	12	19
Other income (expense) - net [Member] | Other [Member]
Segment Reporting Information [Line Items]
Gain on sale of unused pipe				0	0	0	(10)
Selling, general, and administrative expenses [Member] | Other [Member]
Segment Reporting Information [Line Items]
Project development costs					16		61
Selling, general, and administrative expenses and Operating and maintenance expenses [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Severance and other related costs				5		18	$ 26
Approximate percentage of workforce reductions							10.00%
Other Nonoperating Income (Expense) [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Allowance for funds used during construction, capitalized cost of equity				17	17	55	$ 46
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				8	6	44	16
Canadian Operations [Member]
Segment Reporting Information [Line Items]
Loss on sale of Canadian operations (see Note 2)					(65)		(65)
Disposal Group, Not Discontinued Operations [Member] | Canadian Operations [Member] | Other income (expense) - net [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Loss on sale of Canadian operations (see Note 2)				4	32	0	32
Disposal Group, Not Discontinued Operations [Member] | Canadian Operations [Member] | Other income (expense) - net [Member] | Williams Ngl And Petchem Services [Member]
Segment Reporting Information [Line Items]
Loss on sale of Canadian operations (see Note 2)				0	33	1	33
Williams Partners L.P. [Member]
Segment Reporting Information [Line Items]
Loss on sale of Canadian operations (see Note 2)					(32)		(32)
4.875% Senior Unsecured Notes due 2023 [Member] | Williams Partners L.P. [Member]
Segment Reporting Information [Line Items]
Long-term debt retired		$ 1,400
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%
Acquisition and Merger [Member] | Selling, general, and administrative expenses [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Business combination, merger related costs				$ 5	$ 21	$ 9	$ 40
[1]	Primarily relates to gains and losses incurred on foreign currency transactions and the remeasurement of U.S. dollar denominated current assets and liabilities within our former Canadian operations.

Provision (Benefit) for Incom37

Provision (Benefit) for Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Current:
Federal	$ 7	$ 0	$ 10	$ 0
State	9	1	17	1
Foreign	0	0	0	(1)
Total	16	1	27	0
Deferred:
Federal	(11)	8	63	(49)
State	19	71	36	60
Foreign	0	(11)	0	(85)
Total	8	68	99	(74)
Provision (benefit) for income taxes	24	69	126	(74)
Provision Related To Increase In Deferred State Income Tax Rate	$ 18	$ 43	18	$ 43
Valuation Allowance, Deferred Tax Asset, Decrease Amount			$ 127

Earnings (Loss) Per Common Sh38

Earnings (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share Table [Line Items]
Net income (loss) attributable to The Williams Companies, Inc. available to common stockholders for basic and diluted earnings (loss) per common share	$ 33	$ 61	$ 487	$ (409)
Basic weighted-average shares	826,779	750,754	825,925	750,579
Effect of dilutive securities:
Diluted weighted-average shares	829,368	751,858	828,150	750,579
Earnings (loss) per common share:
Basic	$ 0.04	$ 0.08	$ 0.59	$ (0.55)
Diluted	$ 0.04	$ 0.08	$ 0.59	$ (0.55)
Nonvested restricted stock units [Member]
Effect of dilutive securities:
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	1,889	568	1,567	0
Stock Options [Member]
Effect of dilutive securities:
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	700	536	658	0

Employee Benefit Plans (Quarter

Employee Benefit Plans (Quarterly Info) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Pension Benefits [Member]
Components of net periodic benefit cost (credit):
Service cost		$ 13	$ 13	$ 38	$ 40
Interest cost		15	16	44	47
Expected return on plan assets		(21)	(22)	(62)	(64)
Amortization of net actuarial loss		6	8	20	23
Net actuarial loss from settlements		0	0	0	1
Net periodic benefit cost (credit)		13	15	40	47
Employer contributions				83
Estimated future employer contributions in current fiscal year		1		1
Pension Benefits [Member] | Subsequent Event [Member] | Minimum [Member]
Components of net periodic benefit cost (credit):
Net actuarial loss from settlements	$ 70
Pension Benefits [Member] | Subsequent Event [Member] | Maximum [Member]
Components of net periodic benefit cost (credit):
Net actuarial loss from settlements	$ 100
Other Postretirement Benefits [Member]
Components of net periodic benefit cost (credit):
Service cost		0	0	1	1
Interest cost		2	2	6	6
Expected return on plan assets		(3)	(3)	(9)	(9)
Amortization of prior service cost (credit)		(3)	(3)	(10)	(11)
Reclassification to regulatory liability		1	1	3	3
Net periodic benefit cost (credit)		(3)	(3)	(9)	(10)
Amortization of prior service cost (credit) from regulatory assets (liabilities)		(2)	$ (2)	(6)	$ (7)
Employer contributions				4
Estimated future employer contributions in current fiscal year		$ 1		$ 1

Debt and Banking Arrangements L

Debt and Banking Arrangements Long-Term Debt Issuances and Retirements (Details 1) - USD ($) $ in Millions	Jul. 06, 2017	Jul. 03, 2017	Apr. 15, 2017	Feb. 23, 2017	Feb. 01, 2017	Sep. 30, 2017	Jun. 05, 2017	Apr. 03, 2017
Transcontinental Gas Pipe Line Company, LLC [Member]
Debt Instrument [Line Items]
Other Long-term Debt, Noncurrent						$ 237
Debt Instrument, Term						35 years
Variable Interest Term Loan due 2018 [Member] | Williams Partners L.P. [Member]
Debt Instrument [Line Items]
Long-term debt retired	$ 850
3.75% Senior Notes Due 2027 [Member] | Williams Partners L.P. [Member]
Debt Instrument [Line Items]
Long-term debt face amount							$ 1,450
Long-term debt interest rate							3.75%
4.875% Senior Unsecured Notes due 2023 [Member] | Williams Partners L.P. [Member]
Debt Instrument [Line Items]
Long-term debt interest rate		4.875%
Long-term debt retired		$ 1,400
6.125% Senior Unsecured Notes due 2022 [Member] | Williams Partners L.P. [Member]
Debt Instrument [Line Items]
Long-term debt interest rate				6.125%
Long-term debt retired				$ 750
4% Senior Unsecured Notes Due 2027 [Member] | Northwest Pipeline LLC [Member]
Debt Instrument [Line Items]
Long-term debt face amount								$ 250
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%
5.95% Senior Unsecured Notes due 2017 [Member] | Northwest Pipeline LLC [Member]
Debt Instrument [Line Items]
Long-term debt interest rate			5.95%
Long-term debt retired			$ 185
7.25% Senior Unsecured Notes due 2017 [Member] | Williams Partners L.P. [Member]
Debt Instrument [Line Items]
Long-term debt interest rate					7.25%
Long-term debt retired					$ 600

Debt and Banking Arrangements C

Debt and Banking Arrangements Credit Facilities and Commercial Paper (Details 2) - USD ($) $ in Millions		Sep. 30, 2017	Dec. 31, 2016
Credit Facility and Commercial Paper [Line Items]
Commercial paper, outstanding		$ 0	$ 93
Williams Companies Inc [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity		1,500
Credit facility, loans outstanding		400
Williams Partners L.P. [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity	[1]	3,500
Credit facility, loans outstanding	[1]	0
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 ($) $ / shares in Units, shares in Thousands, $ in Millions	1 Months Ended		3 Months Ended	9 Months Ended
	Feb. 28, 2017	Jan. 31, 2017	Mar. 31, 2017	Sep. 30, 2017	Sep. 30, 2016	Jan. 13, 2017
Stockholders' Equity Note [Abstract]
Stock Issued During Period, Shares, New Issues	9,750	65,000
Equity Issuance, Price Per Share						$ 29
Proceeds from Issuance of Common Stock			$ 2,100	$ 2,130	$ 8

Stockholders' Equity Table Of C

Stockholders' Equity Table Of Changes In AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			$ (339)
Other comprehensive income (loss)	$ (3)	$ 76	6	$ 180
Total, Ending Balance	(331)		(331)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			(339)
Other comprehensive income (loss) before reclassifications			(3)
Amounts reclassified from accumulated other comprehensive income (loss)			11
Other comprehensive income (loss)			8
Total, Ending Balance	(331)		(331)
Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			0
Other comprehensive income (loss) before reclassifications			(3)
Amounts reclassified from accumulated other comprehensive income (loss)			0
Other comprehensive income (loss)			(3)
Total, Ending Balance	(3)		(3)
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			(2)
Other comprehensive income (loss) before reclassifications			0
Amounts reclassified from accumulated other comprehensive income (loss)			0
Other comprehensive income (loss)			0
Total, Ending Balance	(2)		(2)
Pension and Other Post Retirement Benefits
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			(337)
Other comprehensive income (loss) before reclassifications			0
Amounts reclassified from accumulated other comprehensive income (loss)			11
Other comprehensive income (loss)			11
Total, Ending Balance	$ (326)		(326)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss)			$ 11

Stockholders' Equity Table Of R

Stockholders' Equity Table Of Reclassifications from AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax benefit	$ 24	$ 69	$ 126	$ (74)
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 Post Retirement Benefits
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss)			11
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			(4)
Amounts reclassified from accumulated other comprehensive income (loss)			11
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Energy Commodity Contracts [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax			(1)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Pension and Other Post Retirement Benefits
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service cost (credit) included in net periodic benefit cost			(4)
Amortization of actuarial (gain) loss included in net periodic benefit cost			20
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, before Tax			$ 15

Fair Value Measurements Recurri

Fair Value Measurements Recurring Measurements and Additional (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
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	12	$ 15
Long-term debt, including current portion	(21,069)	(23,409)
Guarantees	(44)	(44)
Fair Value [Member]
Additional disclosures:
Other receivables	12	15
Long-term debt, including current portion	(22,979)	(24,090)
Guarantees	(30)	(30)
Level 1 [Member]
Additional disclosures:
Other receivables	12	15
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	(22,979)	(24,090)
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	127	96
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	(6)
Fair Value, Measurements, Recurring [Member] | Carrying Amount [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	2	1
Energy derivatives liabilities	(5)	(6)
Fair Value, Measurements, Recurring [Member] | Fair Value [Member]
Measured on a recurring basis:
ARO Trust investments	127	96
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	(6)
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	2	1
Energy derivatives liabilities	(5)	(6)
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Measured on a recurring basis:
ARO Trust investments	127	96
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets		0
Energy derivatives liabilities	(5)
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	1	0
Energy derivatives liabilities	(2)	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		2
Energy derivatives liabilities	(1)
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	0	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
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	1	1
Energy derivatives liabilities	(3)	$ (6)
WilTel Guarantee [Member]
Additional disclosures:
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 31

Fair Value Measurements Nonrecu

Fair Value Measurements Nonrecurring Measurements (Details) - USD ($) $ in Millions		3 Months Ended							9 Months Ended
		Sep. 30, 2017		Jun. 30, 2017	[4]	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2017		Sep. 30, 2016
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Asset Impairment Charges		$ 1,210				$ 1			$ 1,236		$ 811
Impairment of equity-method investments		0				$ 0			0		112
Canadian Operations [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Disposal Group, Not Discontinued Operation, Loss (Gain) on writedown							$ 747
Williams Partners [Member] | Delaware Basin Gas Gathering System [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Impairment of equity-method investments											59
Impairment Of Certain Assets [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Impairment of certain assets									1,236		811
Fair Value, Measurements, Nonrecurring [Member] | Impairment Of Certain Assets [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Impairment of certain assets	[1]								11		16
Fair Value, Measurements, Nonrecurring [Member] | Impairment Of Equity-Method Investments [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Impairment of equity-method investments											112
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Property Plant And Equipment, net [Member] | Williams Partners [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Fair Value of Property, Plant, and Equipment	[2]						18
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Property Plant And Equipment, net [Member] | Other [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Fair Value of Property, Plant, and Equipment		32	[3]	$ 18					32	[3]
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Assets Held For Sale [Member] | Williams Partners [Member] | Canadian Operations [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Assets Held-for-sale, Long-Lived, Fair Value Disclosure	[5]						924
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Assets Held For Sale [Member] | Other [Member] | Canadian Operations [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Assets Held-for-sale, Long-Lived, Fair Value Disclosure	[5]						206
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Investments [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Fair value of investment								$ 0
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Investments [Member] | Williams Partners [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Fair value of investment	[6]							$ 1,294
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Investments [Member] | Williams Partners [Member] | Minimum [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Discount rate								13.00%
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Investments [Member] | Williams Partners [Member] | Maximum [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Discount rate								13.30%
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Impairment Of Certain Assets [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Impairment of certain assets									1,225		$ 795
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Impairment Of Certain Assets [Member] | Williams Partners [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Impairment of certain assets	[2]						48
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Impairment Of Certain Assets [Member] | Williams Partners [Member] | Canadian Operations [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Disposal Group, Not Discontinued Operation, Loss (Gain) on writedown	[5]						341
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Impairment Of Certain Assets [Member] | Other [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Impairment of certain assets		68	[3]	$ 23
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Impairment Of Certain Assets [Member] | Other [Member] | Canadian Operations [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Disposal Group, Not Discontinued Operation, Loss (Gain) on writedown	[5]						$ 406
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Impairment Of Equity-Method Investments [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Impairment of equity-method investments								$ 3
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Impairment Of Equity-Method Investments [Member] | Williams Partners [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Impairment of equity-method investments	[6]							$ 109
Mid Continent [Member] | Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Property Plant And Equipment, Net And Intangible Assets, Net Of Accumulated Amortization [Member] | Williams Partners [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Property Plant And Equipment And Intangibles, Fair Value Disclosure	[7]	$ 439							439
Discount rate		10.20%
Mid Continent [Member] | Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Impairment Of Certain Assets [Member] | Williams Partners [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Asset Impairment Charges	[7]	$ 1,019
Marcellus South [Member] | Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Property Plant And Equipment, Net And Intangible Assets, Net Of Accumulated Amortization [Member] | Williams Partners [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Property Plant And Equipment And Intangibles, Fair Value Disclosure	[8]	$ 21							$ 21
Discount rate		11.10%
Marcellus South [Member] | Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Impairment Of Certain Assets [Member] | Williams Partners [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Asset Impairment Charges	[8]	$ 115
[1]	Reflects multiple individually insignificant impairments and write-downs of other certain assets that may no longer be in use or are surplus in nature for which the fair value was determined to be lower than the carrying value.
[2]	Relates to certain gathering assets within the Mid-Continent region. The estimated fair value was determined by a market approach based on our analysis of observable inputs in the principal market.
[3]	Relates to an NGL pipeline near the Houston Ship Channel region which we anticipate will be underutilized for the foreseeable future. The estimated fair value was primarily determined by using a market approach based on our analysis of observable inputs in the principal market.
[4]	Relates primarily to project development costs associated with an olefins pipeline project in the Gulf Coast region, the likelihood of completion of which is now considered remote. The estimated fair value of the remaining pipe and equipment considered a market approach based on our analysis of observable inputs in the principal market, as well as an estimate of replacement cost.
[5]	Relates to our Canadian operations. We designated these operations as held for sale as of June 30, 2016. As a result, we measured the fair value of the disposal group, resulting in an impairment charge. The estimated fair value was determined by a market approach based primarily on inputs received in the marketing process and reflected our estimate of the potential assumed proceeds. We disposed of our Canadian operations through a sale during the third quarter of 2016.
[6]	Relates to Williams Partners’ previously owned interest in DBJV and current equity-method investment in Laurel Mountain. Our carrying values in these equity-method investments had been written down to fair value at December 31, 2015. Our first-quarter 2016 analysis reflected higher discount rates for both of these equity-method investments, along with lower natural gas prices for Laurel Mountain. We estimated the fair value of these equity-method investments using an income approach based on expected future cash flows and appropriate discount rates. The determination of estimated future cash flows involved significant assumptions regarding gathering volumes and related capital spending. Discount rates utilized ranged from 13.0 percent to 13.3 percent and reflected increases in our estimated cost of capital, revised estimates of expected future cash flows, and risks associated with the underlying businesses.
[7]	Relates to certain gathering operations in the Mid-Continent region. During the third quarter of 2017, we received solicitations and engaged in negotiations for the sale of certain of these assets which led to our impairment evaluation. The estimated fair value was determined using an income approach and incorporated market inputs based on ongoing negotiations for a potential sale of a portion of the underlying assets. For the income approach, we utilized a discount rate of 10.2 percent, reflecting an estimate of our cost of capital and risks associated with the underlying assets.
[8]	Relates to certain gathering operations in the Marcellus South region resulting from an anticipated decline in future volumes following a third-quarter 2017 shut-in by the primary producer. The estimated fair value was determined by the income approach utilizing a discount rate of 11.1 percent, reflecting an estimate of our cost of capital and risks associated with the underlying assets.

Contingent Liabilities (Details

Contingent Liabilities (Details) - USD ($) $ in Millions	May 20, 2016	Sep. 30, 2017
Loss Contingencies [Line Items]
Accrued environmental loss liabilities		$ 40
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		8
Natural Gas Underground Storage Facilities [Member]
Loss Contingencies [Line Items]
Accrued environmental loss liabilities		8
Former Operations [Member]
Loss Contingencies [Line Items]
Accrued environmental loss liabilities		24
Williams Partners [Member] | General Liability [Member] | Geismar Incident [Member]
Loss Contingencies [Line Items]
Insurance deductibles		2
Aggregate limit of insurance		610
Maximum [Member] | Former Alaska Refinery [Member]
Loss Contingencies [Line Items]
Loss contingency, range of possible loss, maximum		$ 32

Segment Disclosures Reconciliat

Segment Disclosures Reconciliation of Segment Revenues to Consolidated (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment revenues
Service revenues	$ 1,310	$ 1,247	$ 3,853	$ 3,678
Product sales	581	658	1,950	1,623
Total revenues	1,891	1,905	5,803	5,301
Williams Partners [Member]
Segment revenues
Service revenues	1,304	1,241	3,836	3,656
Product sales	581	655	1,950	1,613
Other [Member]
Segment revenues
Service revenues	6	6	17	22
Product sales	0	3	0	10
Intersegment Elimination [Member]
Segment revenues
Service revenues	(2)	(14)	(9)	(49)
Product sales	0	(6)	0	(16)
Total revenues	(2)	(20)	(9)	(65)
Intersegment Elimination [Member] | Williams Partners [Member]
Segment revenues
Service revenues	0	(11)	(1)	(32)
Product sales	0	0	0	0
Intersegment Elimination [Member] | Other [Member]
Segment revenues
Service revenues	(2)	(3)	(8)	(17)
Product sales	0	(6)	0	(16)
Operating Segments [Member] | Williams Partners [Member]
Segment revenues
Service revenues	1,304	1,252	3,837	3,688
Product sales	581	655	1,950	1,613
Total revenues	1,885	1,907	5,787	5,301
Operating Segments [Member] | Other [Member]
Segment revenues
Service revenues	8	9	25	39
Product sales	0	9	0	26
Total revenues	$ 8	$ 18	$ 25	$ 65

Segment Disclosures Reconcili49

Segment Disclosures Reconciliation of Segment Assets to Consolidated (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Segment assets:
Total assets	$ 46,120	$ 46,835
Williams Partners [Member]
Segment assets:
Total assets	45,635	46,265
Other [Member]
Segment assets:
Total assets	570	685
Intersegment Elimination [Member]
Segment assets:
Total assets	$ (85)	$ (115)

Segment Disclosures Reconcili50

Segment Disclosures Reconciliation of Segment Modified EBITDA to Consolidated Net Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Reconciliation of Modified EBITDA to Net Income (Loss):
Modified EBITDA Earnings (Loss)	$ 939	$ 1,003	$ 3,148	$ 2,095
Accretion expense associated with asset retirement obligations for nonregulated operations	(7)	(9)	(23)	(24)
Depreciation and amortization expenses	(433)	(435)	(1,308)	(1,326)
Equity earnings (losses)	115	104	347	302
Impairment of equity-method investments	0	0	0	112
Other investing income (loss) – net	(4)	(28)	(278)	(64)
Proportional Modified EBITDA of equity-method investments	(202)	(194)	(611)	(574)
Interest expense	(267)	(297)	(818)	(886)
(Provision) benefit for income taxes	(24)	(69)	(126)	74
Net income (loss)	125	131	887	(387)
Operating Segments [Member] | Williams Partners [Member]
Reconciliation of Modified EBITDA to Net Income (Loss):
Modified EBITDA Earnings (Loss)	1,000	1,070	3,208	2,629
Operating Segments [Member] | Other [Member]
Reconciliation of Modified EBITDA to Net Income (Loss):
Modified EBITDA Earnings (Loss)	$ (61)	$ (67)	$ (60)	$ (534)