The Williams Companies, Inc. (WMB) 10-Q 31 Oct 19 2019 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Oct. 28, 2019
Document and Entity Information [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Document Transition Report	false
Entity File Number	1-4174
Entity Registrant Name	WILLIAMS COMPANIES, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	73-0569878
Entity Address, Address Line One	One Williams Center
Entity Address, City or Town	Tulsa
Entity Address, State or Province	OK
Entity Address, Postal Zip Code	74172-0172
City Area Code	918
Local Phone Number	573-2000
Title of 12(b) Security	Common Stock, $1.00 par value
Trading Symbol	WMB
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		1,212,048,836
Entity Central Index Key	0000107263
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31

Consolidated Statement of Incom

Consolidated Statement of Income (Unaudited) - USD ($) shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Revenues	$ 1,999	$ 2,303	$ 6,094	$ 6,482
Costs and expenses:
Operating and maintenance expenses	364	389	1,091	1,134
Depreciation and amortization expenses	435	425	1,275	1,290
Selling, general, and administrative expenses	130	174	410	436
Impairment of certain assets (Note 13)	0	0	76	66
Other (income) expense – net	(11)	(6)	30	24
Total costs and expenses	1,371	1,802	4,407	5,080
Operating income (loss)	628	501	1,687	1,402
Equity earnings (losses)	93	105	260	279
Other investing income (loss) – net (Note 5)	(107)	2	(54)	74
Interest incurred	(303)	(286)	(915)	(856)
Interest capitalized	7	16	27	38
Other income (expense) – net	1	52	19	99
Income (loss) before income taxes	319	390	1,024	1,036
Provision (benefit) for income taxes	77	190	244	297
Net income (loss)	242	200	780	739
Less: Net income (loss) attributable to noncontrolling interests	21	71	54	323
Net income (loss) attributable to The Williams Companies, Inc.	221	129	726	416
Preferred stock dividends	1	0	2	0
Net income (loss) available to common stockholders	$ 220	$ 129	$ 724	$ 416
Basic earnings (loss) per common share:
Net income (loss)	$ 0.18	$ 0.13	$ 0.60	$ 0.47
Weighted-average shares (thousands)	1,212,270	1,023,587	1,211,938	893,706
Diluted earnings (loss) per common share:
Net income (loss)	$ 0.18	$ 0.13	$ 0.60	$ 0.46
Weighted-average shares (thousands)	1,214,165	1,026,504	1,213,943	896,322
Service [Member]
Revenues:
Revenues	$ 1,495	$ 1,371	$ 4,424	$ 4,062
NonRegulated Service Commodity Consideration [Member]
Revenues:
Revenues	38	121	158	316
Product [Member]
Revenues:
Revenues	466	811	1,512	2,104
Oil and Gas, Purchased [Member]
Costs and expenses:
Cost of Goods and Service, Excluding Depreciation, Depletion, and Amortization	434	790	1,442	2,039
Natural Gas Purchased For Shrink [Member]
Costs and expenses:
Cost of Goods and Service, Excluding Depreciation, Depletion, and Amortization	$ 19	$ 30	$ 83	$ 91

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Comprehensive income (loss):
Net income (loss)	$ 242	$ 200	$ 780	$ 739
Net unrealized gain (loss) from derivative instruments, net of taxes of $3 and $6 in 2018	0	(5)	0	(19)
Reclassifications into earnings of net derivative instruments (gain) loss, net of taxes of ($2) and ($3) in 2018	0	7	0	10
Pension and other postretirement benefits:
Net actuarial gain (loss) arising during the year, net of taxes of $1 and $1 in 2019, and ($0) and ($1) in 2018	(5)	0	(5)	4
Amortization of actuarial (gain) loss and net actuarial loss from settlements included in net periodic benefit cost (credit), net of taxes of ($0) and ($3) in 2019, and ($3) and ($5) in 2018	4	4	9	14
Other comprehensive income (loss)	(1)	6	4	9
Comprehensive income (loss)	241	206	784	748
Less: Comprehensive income (loss) attributable to noncontrolling interests	21	72	54	321
Comprehensive income (loss) attributable to The Williams Companies, Inc.	$ 220	$ 134	$ 730	$ 427

Consolidated Statement of Com_2

Consolidated Statement of Comprehensive Income (Parenthetical) (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Other Comprehensive Income (Loss), Tax [Abstract]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax	$ 0	$ 3	$ 0	$ 6
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax	0	(2)	0	(3)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax [Abstract]
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax	1	0	1	(1)
Amortization of actuarial (gain) loss included in net periodic benefit cost, taxes	$ 0	$ (3)	$ (3)	$ (5)

Consolidated Balance Sheet (Una

Consolidated Balance Sheet (Unaudited) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 247	$ 168
Trade accounts and other receivables (net of allowance of $6 at September 30, 2019 and $9 at December 31, 2018)	875	992
Inventories	129	130
Other current assets and deferred charges	183	174
Total current assets	1,434	1,464
Investments	6,228	7,821
Property, plant, and equipment	41,647	38,661
Accumulated depreciation and amortization	(12,034)	(11,157)
Property, plant, and equipment – net	29,613	27,504
Intangible assets – net of accumulated amortization	8,041	7,767
Regulatory assets, deferred charges, and other	965	746
Total assets	46,281	45,302
Current liabilities:
Accounts payable	602	662
Accrued liabilities	1,184	1,102
Long-term debt due within one year	1,538	47
Total current liabilities	3,324	1,811
Long-term debt	20,719	22,367
Deferred income tax liabilities	1,651	1,524
Regulatory liabilities, deferred income, and other	3,728	3,603
Contingent liabilities (Note 14)
Stockholders’ equity:
Preferred Stock	35	35
Common stock ($1 par value; 1,470 million shares authorized at September 30, 2019 and December 31, 2018; 1,247 million shares issued at September 30, 2019 and 1,245 million shares issued at December 31, 2018)	1,247	1,245
Capital in excess of par value	24,310	24,693
Retained deficit	(10,664)	(10,002)
Accumulated other comprehensive income (loss)	(266)	(270)
Treasury stock, at cost (35 million shares of common stock)	(1,041)	(1,041)
Total stockholders’ equity	13,621	14,660
Noncontrolling interests in consolidated subsidiaries	3,238	1,337
Total equity	16,859	15,997
Total liabilities and equity	$ 46,281	$ 45,302

Consolidated Balance Sheet (Par

Consolidated Balance Sheet (Parenthetical) (Unaudited) - USD ($) shares in Millions, $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Allowance for trade accounts and other receivables	$ 6	$ 9
Stockholders’ equity:
Common stock, shares authorized	1,470	1,470
Common stock, par value of shares authorized	$ 1	$ 1
Common stock, shares issued	1,247	1,245
Treasury stock, shares of common shares	35	35

Consolidated Statement of Chang

Consolidated Statement of Changes in Equity (Unaudited) - USD ($) $ in Millions	Total	Total Stockholders’ Equity	Preferred Stock	Common Stock	Capital in Excess of Par Value	Retained Deficit	AOCI	Treasury Stock	Noncontrolling Interests
Period Start at Dec. 31, 2017	$ 16,175	$ 9,656	$ 0	$ 861	$ 18,508	$ (8,434)	$ (238)	$ (1,041)	$ 6,519
Adoption of new accounting standards	(121)	(84)	0	0	0	(23)	(61)	0	(37)
Net income (loss)	739	416	0	0	0	416	0	0	323
Other comprehensive income (loss)	9	11	0	0	0	0	11	0	(2)
WPZ Merger (Note 1)	1,862	6,491	0	382	6,112	0	(3)	0	(4,629)
Issuance of preferred stock (Note 12)	35	35	35	0	0	0	0	0	0
Cash dividends – common stock	(974)	(974)	0	0	0	(974)	0	0	0
Dividends and distributions to noncontrolling interests	(598)	0	0	0	0	0	0	0	(598)
Stock-based compensation and related common stock issuances, net of tax	49	49	0	1	48	0	0	0	0
Sales of limited partner units of Williams Partners L.P.	46	0	0	0	0	0	0	0	46
Changes in ownership of consolidated subsidiaries, net	(4)	14	0	0	14	0	0	0	(18)
Contributions from noncontrolling interests	13	0	0	0	0	0	0	0	13
Deconsolidation of subsidiary (Note 5)	267	0	0	0	0	0	0	0	267
Other	(5)	(4)	0	1	(2)	(3)	0	0	(1)
Net increase (decrease) in equity	784	5,954	35	384	6,172	(584)	(53)	0	(5,170)
Period End at Sep. 30, 2018	16,959	15,610	35	1,245	24,680	(9,018)	(291)	(1,041)	1,349
Period Start at Jun. 30, 2018	15,447	9,345	0	862	18,552	(8,735)	(293)	(1,041)	6,102
Net income (loss)	200	129	0	0	0	129	0	0	71
Other comprehensive income (loss)	6	5	0	0	0	0	5	0	1
WPZ Merger (Note 1)	1,862	6,491	0	382	6,112	0	(3)	0	(4,629)
Issuance of preferred stock (Note 12)	35	35	35	0	0	0	0	0	0
Cash dividends – common stock	(411)	(411)	0	0	0	(411)	0	0	0
Dividends and distributions to noncontrolling interests	(196)	0	0	0	0	0	0	0	(196)
Stock-based compensation and related common stock issuances, net of tax	16	16	0	0	16	0	0	0	0
Changes in ownership of consolidated subsidiaries, net	0	1	0	0	1	0	0	0	(1)
Contributions from noncontrolling interests	2	0	0	0	0	0	0	0	2
Deconsolidation of subsidiary (Note 5)			0
Other	(2)	(1)		1	(1)	(1)	0	0	(1)
Net increase (decrease) in equity	1,512	6,265	35	383	6,128	(283)	2	0	(4,753)
Period End at Sep. 30, 2018	16,959	15,610	35	1,245	24,680	(9,018)	(291)	(1,041)	1,349
Period Start at Dec. 31, 2018	15,997	14,660	35	1,245	24,693	(10,002)	(270)	(1,041)	1,337
Net income (loss)	780	726	0	0	0	726	0	0	54
Other comprehensive income (loss)	4	4	0	0	0	0	4	0	0
Cash dividends – common stock	(1,382)	(1,382)	0	0	0	(1,382)	0	0	0
Dividends and distributions to noncontrolling interests	(86)	0	0	0	0	0	0	0	(86)
Stock-based compensation and related common stock issuances, net of tax	45	45	0	2	43	0	0	0	0
Sale of partial interest in consolidated subsidiary (Note 2)	1,333	0	0	0	0	0	0	0	1,333
Changes in ownership of consolidated subsidiaries, net	142	(426)	0	0	(426)	0	0	0	568
Contributions from noncontrolling interests	32	0	0	0	0	0	0	0	32
Other	(6)	(6)	0	0	0	(6)	0	0	0
Net increase (decrease) in equity	862	(1,039)	0	2	(383)	(662)	4	0	1,901
Period End at Sep. 30, 2019	16,859	13,621	35	1,247	24,310	(10,664)	(266)	(1,041)	3,238
Period Start at Jun. 30, 2019	17,081	13,848	35	1,246	24,296	(10,423)	(265)	(1,041)	3,233
Net income (loss)	242	221	0	0	0	221	0	0	21
Other comprehensive income (loss)	(1)	(1)	0	0	0	0	(1)	0	0
Cash dividends – common stock	(461)	(461)	0	0	0	(461)	0	0	0
Dividends and distributions to noncontrolling interests	(18)	0	0	0	0	0	0	0	(18)
Stock-based compensation and related common stock issuances, net of tax	17	17	0	1	16	0	0	0	0
Changes in ownership of consolidated subsidiaries, net	1	(1)	0	0	(1)	0	0	0	2
Other	(2)	(2)	0	0	(1)	(1)	0	0	0
Net increase (decrease) in equity	(222)	(227)	0	1	14	(241)	(1)	0	5
Period End at Sep. 30, 2019	$ 16,859	$ 13,621	$ 35	$ 1,247	$ 24,310	$ (10,664)	$ (266)	$ (1,041)	$ 3,238

Consolidated Statement of Cha_2

Consolidated Statement of Changes in Equity (Parenthetical) (Unaudited) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Common Stock, Dividends, Per Share, Declared	$ 0.38	$ 0.34	$ 1.14	$ 1.02

Consolidated Statement of Cash

Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
OPERATING ACTIVITIES:
Net income (loss)	$ 780	$ 739
Adjustments to reconcile to net cash provided (used) by operating activities:
Depreciation and amortization	1,275	1,290
Provision (benefit) for deferred income taxes	268	351
Equity (earnings) losses	(260)	(279)
Distributions from unconsolidated affiliates	458	507
Net (gain) loss on disposition of equity-method investments (Note 5)	(122)	0
Impairment of equity-method investments (Note 13)	186	0
(Gain) loss on deconsolidation of businesses (Note 5)	2	(62)
Impairment of and net (gain) loss on sale of certain assets	76	64
Amortization of stock-based awards	44	43
Cash provided (used) by changes in current assets and liabilities:
Accounts and notes receivable	159	75
Inventories	7	(39)
Other current assets and deferred charges	(10)	(44)
Accounts payable	(76)	(76)
Accrued liabilities	76	(62)
Other, including changes in noncurrent assets and liabilities	(161)	(176)
Net cash provided (used) by operating activities	2,702	2,331
FINANCING ACTIVITIES:
Proceeds from (payments of) commercial paper – net	(4)	821
Proceeds from long-term debt	736	3,745
Payments of long-term debt	(904)	(3,201)
Proceeds from issuance of common stock	10	15
Proceeds from sale of partial interest in consolidated subsidiary (Note 2)	1,330	0
Common dividends paid	(1,382)	(974)
Dividends and distributions paid to noncontrolling interests	(86)	(552)
Contributions from noncontrolling interests	32	13
Payments for debt issuance costs	0	(26)
Other – net	(11)	(46)
Net cash provided (used) by financing activities	(279)	(205)
INVESTING ACTIVITIES:
Capital expenditures (1)	(1,705)	(2,659)
Dispositions – net	(32)	(2)
Contributions in aid of construction	25	395
Purchases of businesses, net of cash acquired (Note 2)	(728)	0
Proceeds from dispositions of equity-method investments (Note 5)	485	0
Purchases of and contributions to equity-method investments	(361)	(803)
Other – net	(28)	86
Net cash provided (used) by investing activities	(2,344)	(2,983)
Increase (decrease) in cash and cash equivalents	79	(857)
Cash and cash equivalents at beginning of year	168	899
Cash and cash equivalents at end of period	247	42
(1) Increases to property, plant, and equipment	(1,707)	(2,482)
Changes in related accounts payable and accrued liabilities	2	(177)
Capital expenditures (1)	$ (1,705)	$ (2,659)

General, Description of Busines

General, Description of Business, and Basis of Presentation	9 Months Ended
	Sep. 30, 2019
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, 2018, in our Annual Report on Form 10-K. The accompanying unaudited financial statements include all normal recurring adjustments and others that, in the opinion of management, are necessary to present fairly our interim financial statements. The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates. Unless the context clearly indicates otherwise, references in this report to “Williams,” “we,” “our,” “us,” or like terms refer to The Williams Companies, Inc. and its subsidiaries. Unless the context clearly indicates otherwise, references to “Williams,” “we,” “our,” and “us” include the operations in which we own interests accounted for as equity-method investments that are not consolidated in our financial statements. When we refer to our equity investees by name, we are referring exclusively to their businesses and operations. WPZ Merger On August 10, 2018, we completed our merger with Williams Partners L.P. (WPZ), our previously consolidated master limited partnership, pursuant to which we acquired all of the approximately 256 million publicly held outstanding common units of WPZ in exchange for 382 million shares of our common stock (WPZ Merger). Williams continued as the surviving entity. The WPZ Merger was accounted for as a noncash equity transaction resulting in increases to Common stock of $382 million , Capital in excess of par value of $6.112 billion , and Regulatory assets, deferred charges, and other of $33 million and decreases to Accumulated other comprehensive income (loss) (AOCI) of $3 million , Noncontrolling interests in consolidated subsidiaries of $4.629 billion , and Deferred income tax liabilities of $1.829 billion in the Consolidated Balance Sheet . Pursuant to its distribution reinvestment program, WPZ had issued 1,230,657 common units to the public in 2018 associated with reinvested distributions of $46 million . 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 in the United States and are presented within the following reportable segments: Northeast G&P, Atlantic-Gulf, and West, consistent with the manner in which our chief operating decision maker evaluates performance and allocates resources. All remaining business activities as well as corporate activities are included in Other. Northeast G&P is comprised of our midstream gathering, processing, and fractionation businesses in the Marcellus Shale region primarily in Pennsylvania, New York, and West Virginia and the Utica Shale region of eastern Ohio, including a 66 percent interest in Cardinal Gas Services, L.L.C. (Cardinal) (a consolidated entity), as well as a 69 percent equity-method investment in Laurel Mountain Midstream, LLC (Laurel Mountain), a 58 percent equity-method investment in Caiman Energy II, LLC, and Appalachia Midstream Services, LLC, which owns equity-method investments with an approximate average 66 percent interest in multiple gas gathering systems in the Marcellus Shale (Appalachia Midstream Investments). Northeast G&P includes a 65 percent interest in Ohio Valley Midstream LLC (Northeast JV) (a consolidated entity). The Northeast JV includes our Ohio Valley assets and Utica East Ohio Midstream LLC (UEOM), a former equity-method investment in which we acquired the remaining ownership interest in March 2019 (see Note 2 – Acquisitions ). Atlantic-Gulf is comprised of our interstate natural gas pipeline, Transcontinental Gas Pipe Line Company, LLC (Transco), and significant natural gas gathering and processing and crude oil production handling and transportation assets in the Gulf Coast region, including a 51 percent interest in Gulfstar One LLC (Gulfstar One) (a consolidated entity), which is a proprietary floating production system, as well as a 50 percent equity-method investment in Gulfstream Natural Gas System, L.L.C., a 60 percent equity-method investment in Discovery Producer Services LLC, and a 41 percent interest in Constitution Pipeline Company, LLC (Constitution) (a consolidated entity), which is developing a pipeline project (see Note 4 – Variable Interest Entities ). West is comprised of our interstate natural gas pipeline, Northwest Pipeline LLC (Northwest Pipeline), and our gathering, processing, and treating operations in Colorado, Wyoming, the Barnett Shale region of north-central Texas, the Eagle Ford Shale region of south Texas, the Permian Shale region of west Texas, the Haynesville Shale region of northwest Louisiana, and the Mid-Continent region which includes the Anadarko and Arkoma basins. This segment also includes our natural gas liquid (NGL) and natural gas marketing business, storage facilities, an undivided 50 percent interest in an NGL fractionator near Conway, Kansas, a 50 percent equity-method investment in Overland Pass Pipeline Company LLC, a 50 percent equity-method investment in Rocky Mountain Midstream Holdings LLC, and a 15 percent equity-method investment in Brazos Permian II, LLC (Brazos Permian II). West also included our former natural gas gathering and processing assets in the Four Corners area of New Mexico and Colorado, which were sold during the fourth quarter of 2018, and our former 50 percent interest in Jackalope Gas Gathering Services, L.L.C. (Jackalope) (an equity-method investment following deconsolidation as of June 30, 2018), which was sold in April 2019. Basis of Presentation Significant risks and uncertainties We believe that the carrying value of certain of our property, plant, and equipment and other identifiable intangible assets, notably certain acquired assets accounted for as business combinations between 2012 and 2014, may be in excess of current fair value. However, the carrying value of these assets, in our judgment, continues to be recoverable based on our evaluation of undiscounted future cash flows. It is reasonably possible that future strategic decisions, including transactions such as monetizing non-core assets or contributing assets to new ventures with third parties, as well as unfavorable changes in expected producer activities could impact our assumptions and ultimately result in impairments of these assets. Such transactions or developments may also indicate that certain of our equity-method investments have experienced other-than-temporary declines in value, which could result in impairment, or that the fair value of the reporting unit for our goodwill is less than its carrying amount, which would result in impairment. Accounting standards issued and adopted In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2016-02 “Leases (Topic 842)” (ASU 2016-02). ASU 2016-02 establishes a comprehensive new lease accounting model. ASU 2016-02 modifies the definition of a lease, requires a dual approach to lease classification similar to prior lease accounting, and causes lessees to recognize operating leases on the balance sheet as a lease liability measured as the present value of the future lease payments with a corresponding right-of-use asset, with an exception for leases with a term of one year or less. Additional disclosures are required regarding the amount, timing, and uncertainty of cash flows arising from leases. In January 2018, the FASB issued ASU 2018-01 “Leases (Topic 842): Land Easement Practical Expedient for Transition to Topic 842” (ASU 2018-01). Per ASU 2018-01, land easements and rights-of-way are required to be assessed under ASU 2016-02 to determine whether the arrangements are or contain a lease. ASU 2018-01 permits an entity to elect a transition practical expedient to not apply ASU 2016-02 to land easements that exist or expired before the effective date of ASU 2016-02 and that were not previously assessed under the previous lease guidance in Accounting Standards Codification (ASC) Topic 840 “Leases.” In July 2018, the FASB issued ASU 2018-11 “Leases (Topic 842): Targeted Improvements” (ASU 2018-11). Prior to ASU 2018-11, a modified retrospective transition was required for financing or operating leases existing at or entered into after the beginning of the earliest comparative period presented in the financial statements. ASU 2018-11 allows entities an additional transition method to the existing requirements whereby an entity could adopt the provisions of ASU 2016-02 by recognizing a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption without adjustment to the financial statements for periods prior to adoption. ASU 2018-11 also allows a practical expedient that permits lessors to not separate nonlease components from the associated lease component if certain conditions are present. ASU 2016-02 is effective for interim and annual periods beginning after December 15, 2018. We prospectively adopted ASU 2016-02 effective January 1, 2019, and did not adjust prior periods as permitted by ASU 2018-11 (see Note 10 – Leases ). We completed our review of contracts to identify leases based on the modified definition of a lease and implemented changes to our internal controls to support management in the accounting for and disclosure of leasing activities upon adoption of ASU 2016-02. We implemented a financial lease accounting system to assist management in the accounting for leases upon adoption. The most significant changes to our financial statements as a result of adopting ASU 2016-02 relate to the recognition of a $225 million lease liability and offsetting right-of-use asset in our Consolidated Balance Sheet for operating leases. We also evaluated ASU 2016-02’s available practical expedients on adoption and have generally elected to adopt the practical expedients, which includes the practical expedient to not separate lease and nonlease components by both lessees and lessors by class of underlying assets and the land easements practical expedient. Accounting standards issued but not yet adopted In June 2016, the FASB issued ASU 2016-13 “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” (ASU 2016-13). ASU 2016-13 changes the impairment model for most financial assets and certain other instruments. For trade and other receivables, held-to-maturity debt securities, loans, and other instruments, entities will be required to use a new forward-looking “expected loss” model that generally will result in the earlier recognition of allowances for losses. The guidance also requires increased disclosures. ASU 2016-13 is effective for us for interim and annual periods beginning after December 15, 2019. We plan to adopt as of January 1, 2020. We anticipate that ASU 2016-13 will primarily apply to our trade receivables. While we do not expect a significant financial impact, we have analyzed our historical credit loss experience and continue to develop and implement processes, procedures, and internal controls in order to make the necessary credit loss assessments and required disclosures upon adoption.

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
Acquisitions [Text Block]	Note 2 – Acquisitions UEOM As of December 31, 2018, we owned a 62 percent interest in UEOM which we accounted for as an equity-method investment. On March 18, 2019, we signed and closed the acquisition of the remaining 38 percent interest in UEOM. Total consideration paid, including post-closing adjustments, was $741 million in cash funded through credit facility borrowings and cash on hand. As a result of acquiring this additional interest, we obtained control of and now consolidate UEOM. UEOM is involved primarily in the processing and fractionation of natural gas and natural gas liquids in the Utica Shale play in eastern Ohio. The purpose of the acquisition is to enhance our position in the region. We expect synergies through common ownership of UEOM and our Ohio Valley midstream systems to create a more efficient platform for capital spending in the region, resulting in reduced operating and maintenance expenses and creating enhanced capabilities and benefits for producers in the area. The acquisition of UEOM was accounted for as a business combination, which requires, among other things, that identifiable assets acquired and liabilities assumed be recognized at their acquisition date fair values. In March 2019, based on the transaction price for our purchase of the remaining interest in UEOM as finalized just prior to the acquisition, we recognized a $74 million noncash impairment loss related to our existing 62 percent interest (see Note 13 – Fair Value Measurements and Guarantees ). Thus, there was no gain or loss on remeasuring our existing equity-method investment to fair value due to the impairment recognized just prior to closing the acquisition of the additional interest. The valuation techniques used to measure the acquisition date fair value of the UEOM acquisition consisted of the market approach for our previous equity-method investment in UEOM and the income approach (excess earnings method) for valuation of intangible assets and depreciated replacement costs for property, plant, and equipment. The following table presents the allocation of the acquisition date fair value of the major classes of the assets acquired, which are presented in the Northeast G&P segment, and liabilities assumed at March 18, 2019. The net assets acquired reflect the sum of the consideration transferred and the noncash elimination of the fair value of our existing equity-method investment upon our acquisition of the additional interest. The fair value of accounts receivable acquired, presented in current assets in the table, equals contractual amounts receivable. After the March 31, 2019 financial statements were issued, we received an updated valuation report from a third-party valuation firm. Significant changes from the preliminary allocation disclosed in the first quarter to the final allocation reflect an increase of $169 million in goodwill, and decreases of $106 million in property, plant, and equipment and $61 million in other intangible assets. (Millions) Current assets, including $13 million cash acquired $ 55 Property, plant, and equipment 1,387 Other intangible assets 328 Total identifiable assets acquired 1,770 Current liabilities 7 Total liabilities assumed 7 Net identifiable assets acquired 1,763 Goodwill 188 Net assets acquired $ 1,951 The goodwill recognized in the acquisition relates primarily to enhancing and diversifying our basin positions and is reported within the Northeast G&P segment. Substantially all of the goodwill is expected to be deductible for tax purposes. Goodwill is included within Intangible assets – net of accumulated amortization in the Consolidated Balance Sheet and represents the excess of the consideration, plus the fair value of any previously held equity interest, over the fair value of the net assets acquired. It is not subject to amortization but is evaluated annually as of October 1 for impairment or more frequently if impairment indicators are present that would indicate it is more likely than not that the fair value of the reporting unit is less than its carrying amount. Other intangible assets recognized in the acquisition are related to contractual customer relationships from gas gathering, processing, and fractionation agreements with our customers. The basis for determining the value of these intangible assets is estimated future net cash flows to be derived from acquired contractual customer relationships discounted using a risk-adjusted discount rate. These intangible assets are being amortized on a straight-line basis over an initial period of 20 years which represents the term over which the contractual customer relationships are expected to contribute to our cash flows. Approximately 49 percent of the expected future revenues from these contractual customer relationships are impacted by our ability and intent to renew or renegotiate existing customer contracts. We expense costs incurred to renew or extend the terms of our gas gathering, processing, and fractionation contracts with customers. Based on the estimated future revenues during the current contract periods (as estimated at the time of the acquisition), the weighted-average period prior to the next renewal or extension of the existing contractual customer relationships is approximately 10 years . The following unaudited pro forma Revenues and Net income (loss) attributable to The Williams Companies, Inc. for the three and nine months ended September 30, 2019 and 2018 , are presented as if the UEOM acquisition had been completed on January 1, 2018. These pro forma amounts are not necessarily indicative of what the actual results would have been if the acquisition had in fact occurred on the date or for the periods indicated, nor do they purport to project Revenues or Net income (loss) attributable to The Williams Companies, Inc. for any future periods or as of any date. These amounts do not give effect to any potential cost savings, operating synergies, or revenue enhancements to result from the transaction or the potential costs to achieve these cost savings, operating synergies, and revenue enhancements. Three Months Ended Nine Months Ended 2019 2018 2019 2018 (Millions) Revenues $ 1,999 $ 2,342 $ 6,126 $ 6,589 Net income (loss) attributable to The Williams Companies, Inc. $ 221 $ 138 $ 804 $ 434 Adjustments to pro forma Net income (loss) attributable to The Williams Companies, Inc. include the removal of the previously described $74 million impairment loss recognized in March 2019 just prior to the acquisition. There are no pro forma adjustments for the three months ended September 30, 2019 as UEOM was consolidated and reflected in our results during the entire quarter. During the period from the acquisition date of March 18, 2019 to September 30, 2019 , UEOM contributed Revenues of $104 million and Net income (loss) attributable to The Williams Companies, Inc. of $25 million . Costs related to this acquisition are $4 million and are reported within our Northeast G&P segment and included in Selling, general, and administrative expenses in our Consolidated Statement of Income . Northeast JV Concurrent with the UEOM acquisition, we executed an agreement whereby we contributed our consolidated interests in UEOM and our Ohio Valley midstream business to a newly formed partnership. In June 2019, our partner invested approximately $1.33 billion (subject to post-closing adjustments) for a 35 percent ownership interest, and we retained 65 percent ownership of, as well as operate and consolidate, the Northeast JV business. The change in ownership due to this transaction increased Noncontrolling interests in consolidated subsidiaries by $568 million , and decreased Capital in excess of par value by $426 million and Deferred income tax liabilities by $142 million in the Consolidated Balance Sheet . Costs related to this transaction are $6 million and are reported within our Northeast G&P segment and included in Selling, general, and administrative expenses in our Consolidated Statement of Income .

Revenue Recognition

Revenue Recognition	9 Months Ended
	Sep. 30, 2019
Revenue Recognition [Abstract]
Revenue Recognition [Text Block]	Note 3 – Revenue Recognition Revenue by Category The following table presents our revenue disaggregated by major service line: Northeast Midstream Atlantic- Gulf Midstream West Midstream Transco Northwest Pipeline Other Intercompany Eliminations Total (Millions) Three Months Ended September 30, 2019 Revenues from contracts with customers: Service revenues: Non-regulated gathering, processing, transportation, and storage: Monetary consideration $ 310 $ 117 $ 308 $ — $ — $ — $ (19 ) $ 716 Commodity consideration 1 7 30 — — — — 38 Regulated interstate natural gas transportation and storage — — — 601 111 — (2 ) 710 Other 38 8 12 — — — (5 ) 53 Total service revenues 349 132 350 601 111 — (26 ) 1,517 Product Sales: NGL and natural gas product sales 30 34 391 41 — — (28 ) 468 Total revenues from contracts with customers 379 166 741 642 111 — (54 ) 1,985 Other revenues (1) 5 2 — 3 — 7 (3 ) 14 Total revenues $ 384 $ 168 $ 741 $ 645 $ 111 $ 7 $ (57 ) $ 1,999 Three Months Ended September 30, 2018 Revenues from contracts with customers: Service revenues: Non-regulated gathering, processing, transportation, and storage: Monetary consideration $ 219 $ 139 $ 409 $ — $ — $ 1 $ (19 ) $ 749 Commodity consideration 5 19 97 — — — — 121 Regulated interstate natural gas transportation and storage — — — 457 110 — (1 ) 566 Other 23 4 11 — — — (4 ) 34 Total service revenues 247 162 517 457 110 1 (24 ) 1,470 Product Sales: NGL and natural gas 69 88 720 41 — — (117 ) 801 Other — — 12 — — — (3 ) 9 Total product sales 69 88 732 41 — — (120 ) 810 Total revenues from contracts with customers 316 250 1,249 498 110 1 (144 ) 2,280 Other revenues (1) 6 5 3 3 — 9 (3 ) 23 Total revenues $ 322 $ 255 $ 1,252 $ 501 $ 110 $ 10 $ (147 ) $ 2,303 Northeast Midstream Atlantic- Gulf Midstream West Midstream Transco Northwest Pipeline Other Intercompany Eliminations Total (Millions) Nine Months Ended September 30, 2019 Revenues from contracts with customers: Service revenues: Non-regulated gathering, processing, transportation, and storage: Monetary consideration $ 840 $ 366 $ 1,007 $ — $ — $ — $ (54 ) $ 2,159 Commodity consideration 9 33 116 — — — — 158 Regulated interstate natural gas transportation and storage — — — 1,736 335 — (4 ) 2,067 Other 104 21 32 1 — — (12 ) 146 Total service revenues 953 420 1,155 1,737 335 — (70 ) 4,530 Product Sales: NGL and natural gas product sales 114 140 1,300 88 — — (132 ) 1,510 Total revenues from contracts with customers 1,067 560 2,455 1,825 335 — (202 ) 6,040 Other revenues (1) 15 6 12 8 — 22 (9 ) 54 Total revenues $ 1,082 $ 566 $ 2,467 $ 1,833 $ 335 $ 22 $ (211 ) $ 6,094 Nine Months Ended September 30, 2018 Revenues from contracts with customers: Service revenues: Non-regulated gathering, processing, transportation, and storage: Monetary consideration $ 626 $ 404 $ 1,231 $ — $ — $ 2 $ (55 ) $ 2,208 Commodity consideration 14 45 257 — — — — 316 Regulated interstate natural gas transportation and storage — — — 1,368 330 — (2 ) 1,696 Other 65 12 35 1 — — (10 ) 103 Total service revenues 705 461 1,523 1,369 330 2 (67 ) 4,323 Product Sales: NGL and natural gas 242 232 1,799 96 — — (285 ) 2,084 Other — — 20 — — — (4 ) 16 Total product sales 242 232 1,819 96 — — (289 ) 2,100 Total revenues from contracts with customers 947 693 3,342 1,465 330 2 (356 ) 6,423 Other revenues (1) 16 14 6 8 — 24 (9 ) 59 Total revenues $ 963 $ 707 $ 3,348 $ 1,473 $ 330 $ 26 $ (365 ) $ 6,482 ______________________________ (1) Revenues not within the scope of ASC 606, “Revenue from Contracts with Customers,” consist of leasing revenues associated with our headquarters building and management fees that we receive for certain services we provide to operated equity-method investments, which are reported in Service revenues in our Consolidated Statement of Income, and amounts associated with our derivative contracts, which are reported in Product sales in our Consolidated Statement of Income. Contract Assets The following table presents a reconciliation of our contract assets: Three Months Ended Nine Months Ended 2019 2018 2019 2018 (Millions) Balance at beginning of period $ 17 $ 39 $ 4 $ 4 Revenue recognized in excess of amounts invoiced 14 17 53 53 Minimum volume commitments invoiced — — (26 ) (1 ) Balance at end of period $ 31 $ 56 $ 31 $ 56 Contract Liabilities The following table presents a reconciliation of our contract liabilities: Three Months Ended Nine Months Ended 2019 2018 2019 2018 (Millions) Balance at beginning of period $ 1,331 $ 1,535 $ 1,397 $ 1,596 Payments received and deferred 12 58 138 269 Deconsolidation of Jackalope interest (Note 5) — — — (52 ) Significant financing component 3 4 10 11 Recognized in revenue (77 ) (112 ) (276 ) (339 ) Balance at end of period $ 1,269 $ 1,485 $ 1,269 $ 1,485 Remaining Performance Obligations Remaining performance obligations primarily include reservation charges on contracted capacity for our gas pipeline firm transportation contracts with customers, storage capacity contracts, long-term contracts containing minimum volume commitments associated with our midstream businesses, and fixed payments associated with offshore production handling. For our interstate natural gas pipeline businesses, remaining performance obligations reflect the rates for such services in our current Federal Energy Regulatory Commission (FERC) tariffs for the life of the related contracts; however, these rates may change based on future tariffs approved by the FERC and the amount and timing of these changes are not currently known. Our remaining performance obligations exclude variable consideration, including contracts with variable consideration for which we have elected the practical expedient for consideration recognized in revenue as billed. Certain of our contracts contain evergreen and other renewal provisions for periods beyond the initial term of the contract. The remaining performance obligation amounts as of September 30, 2019 , do not consider potential future performance obligations for which the renewal has not been exercised and excludes contracts with customers for which the underlying facilities have not received FERC authorization to be placed into service. Consideration received prior to September 30, 2019 , that will be recognized in future periods is also excluded from our remaining performance obligations and is instead reflected in contract liabilities. The following table presents the amount of the contract liabilities balance as of September 30, 2019 , expected to be recognized as revenue as performance obligations are satisfied and the transaction price allocated to the remaining performance obligations under certain contracts as of September 30, 2019 . Contract Liabilities Remaining Performance Obligations (Millions) 2019 (remainder) $ 70 $ 762 2020 167 3,028 2021 126 2,873 2022 112 2,705 2023 103 2,244 Thereafter 691 19,840 Total $ 1,269 $ 31,452 Accounts Receivable The following is a summary of our Trade accounts and other receivables : September 30, 2019 December 31, 2018 (Millions) Accounts receivable related to revenues from contracts with customers $ 791 $ 858 Other accounts receivable 84 134 Total reflected in Trade accounts and other receivables $ 875 $ 992

Variable Interest Entities

Variable Interest Entities	9 Months Ended
	Sep. 30, 2019
Variable Interest Entity Disclosures [Abstract]
Variable Interest Entities [Text Block]	Note 4 – Variable Interest Entities Consolidated VIEs As of September 30, 2019 , we consolidate the following variable interest entities (VIEs): Gulfstar One We own a 51 percent interest in 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. We are the primary beneficiary because we have the power to direct the activities that most significantly impact Gulfstar One’s economic performance. Constitution We own 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. We are the primary beneficiary because we have the power to direct the activities that most significantly impact Constitution’s economic performance. We, as operator of Constitution, are responsible for constructing the proposed pipeline, which will extend from Susquehanna County, Pennsylvania, to the Iroquois Gas Transmission and the Tennessee Gas Pipeline systems in New York. While we previously estimated the total remaining cost of the project to be approximately $740 million , this amount is expected to increase and the revised estimate is being developed. The project costs would be funded with capital contributions from us and the other equity partners on a proportional basis. In December 2014, Constitution received approval from the FERC to construct and operate its proposed pipeline. However, in April 2016, the New York State Department of Environmental Conservation (NYSDEC) denied the necessary water quality certification under Section 401 of the Clean Water Act for the New York portion of the pipeline. In May 2016, Constitution appealed the NYSDEC’s denial of the Section 401 certification to the United States Court of Appeals for the Second Circuit, but in August 2017 the court issued a decision upholding NYSDEC’s denial. Constitution filed a petition for rehearing with the Second Circuit Court of Appeals, but in October 2017 the court denied our petition. 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. By orders issued in January 2018 and July 2018, the FERC denied our petition, finding that Section 401 provides that a state waives certification only when it does not act on an application within one year from the date of the application. Thereafter, we petitioned the D.C. Circuit for review of the FERC’s decision. In November 2018, the D.C. Circuit granted a motion filed by the FERC to hold our appeal in abeyance pending a decision by the court in the Hoopa Valley Tribe v. FERC case. In January 2019, the D.C. Circuit issued its decision in Hoopa Valley Tribe , finding that the applicant’s withdrawal and resubmission of a Clean Water Act Section 401 water quality certification request did not trigger new statutory periods of review for the state agencies, which resulted in the state agencies waiving their Section 401 authority regarding the hydropower project in question. As a result of the Hoopa Valley Tribe decision, the FERC filed a motion for voluntary remand of our appeal, and in February 2019, the D.C. Circuit granted the motion, sending our waiver case back to the FERC to determine whether or not NYSDEC waived its authority under Section 401. On August 28, 2019, the FERC issued an order finding that NYSDEC waived its water quality certification authority under Section 401 with respect to Constitution. The FERC interpreted the Hoopa Valley Tribe decision to stand for the general principle that where an applicant withdraws and resubmits an application for water quality certification for the purpose of avoiding Section 401’s one-year time limit, and the state agency does not act within one year of the receipt of the original application, the state agency has “failed or refused to act under Section 401” and, therefore, has waived its Section 401 authority. The equity partners are evaluating the next steps in connection with advancing the project. At September 30, 2019, capitalized project costs total $376 million , of which we have funded our proportionate share, 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 possible that we could incur certain supplier-related costs in the event of a continued prolonged delay or termination of the project. Cardinal We own a 66 percent interest in Cardinal, a subsidiary that provides gathering services for the Utica Shale region and is a VIE due to certain risks shared with customers. We are the primary beneficiary because we have 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 us and the other equity partner on a proportional basis. Northeast JV As a result of the June 2019 sale of a 35 percent interest in the Northeast JV (see Note 2 – Acquisitions ), we now own a 65 percent interest in the Northeast JV, a subsidiary that is a VIE due to certain of our voting rights being disproportionate to our obligation to absorb losses and substantially all of the Northeast JV’s activities being performed on our behalf. We are the primary beneficiary because we have the power to direct the activities that most significantly impact the Northeast JV’s economic performance. The Northeast JV provides midstream services for producers in the Marcellus Shale and Utica Shale regions. Future expansion activity is expected to be funded with capital contributions from us and the other equity partner on a proportional basis. The following table presents amounts included in our Consolidated Balance Sheet that are only for the use or obligation of our consolidated VIEs: September 30, December 31, (Millions) Assets (liabilities): Cash and cash equivalents $ 90 $ 33 Trade accounts and other receivables – net 152 62 Other current assets and deferred charges 5 2 Property, plant, and equipment – net 6,167 2,363 Intangible assets – net of accumulated amortization 2,697 1,177 Regulatory assets, deferred charges, and other 13 — Accounts payable (54 ) (15 ) Accrued liabilities (100 ) (115 ) Regulatory liabilities, deferred income, and other (268 ) (264 ) Nonconsolidated VIEs Jackalope At December 31, 2018, we owned a 50 percent interest in Jackalope, which provides gathering and processing services for the Powder River basin and was a VIE due to certain risks shared with customers. In April 2019, we sold our interest in Jackalope for $485 million in cash (see Note 5 – Investing Activities ). Brazos Permian II We own a 15 percent interest in Brazos Permian II, which provides gathering and processing services in the Delaware basin and is a VIE due primarily to our limited participating rights as the minority equity holder. At September 30, 2019 , the carrying value of our equity-method investment in Brazos Permian II was $197 million . Our maximum exposure to loss is limited to the carrying value of our investment.

Investing Activities

Investing Activities	9 Months Ended
	Sep. 30, 2019
Equity Method Investments and Joint Ventures [Abstract]
Investing Activities [Text Block]	Note 5 – Investing Activities The following table presents certain items reflected in Other investing income (loss) – net in the Consolidated Statement of Income : Three Months Ended Nine Months Ended 2019 2018 2019 2018 (Millions) Impairment of equity-method investments (Note 13) $ (114 ) $ — $ (186 ) $ — Gain (loss) on deconsolidation of businesses — — (2 ) 62 Gain on disposition of equity-method investments — — 122 — Other 7 2 12 12 Other investing income (loss) – net $ (107 ) $ 2 $ (54 ) $ 74 Jackalope Deconsolidation During the second quarter of 2018, we deconsolidated our 50 percent interest in Jackalope. We recorded our interest in Jackalope as an equity-method investment at its estimated fair value, resulting in a deconsolidation gain of $62 million . We estimated the fair value of our interest to be $310 million using an income approach based on expected future cash flows and an appropriate discount rate (a Level 3 measurement within the fair value hierarchy). The determination of expected future cash flows involved significant assumptions regarding gathering and processing volumes and related capital spending. A 10.9 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. The deconsolidated carrying value of the net assets of Jackalope included $47 million of goodwill. Sale of Jackalope In April 2019, we sold our 50 percent equity-method interest in Jackalope for $485 million in cash, resulting in a gain on the disposition of $122 million

Other Income and Expenses

Other Income and Expenses	9 Months Ended
	Sep. 30, 2019
Other Income and Expenses [Abstract]
Other Income and Expenses [Text Block]	Note 6 – Other Income and Expenses The following table presents, by segment, certain other items included in our Consolidated Statement of Income : Three Months Ended Nine Months Ended 2019 2018 2019 2018 (Millions) Selling, general, and administrative expenses Other Charitable contribution of preferred stock to The Williams Companies Foundation, Inc. (see Note 12) $ — $ 35 $ — $ 35 WPZ Merger costs — 15 — 19 Other (income) expense – net within Costs and expenses Atlantic-Gulf Amortization of regulatory assets associated with asset retirement obligations 1 8 17 24 Net accrual (amortization) of regulatory liability related to overcollection of certain employee expenses (9 ) 5 (11 ) 16 Adjustments to regulatory liabilities related to tax reform — — — (10 ) Amortization of regulatory liability associated with tax reform (12 ) — (19 ) — Reversal of expenditures previously capitalized — — 10 — Gain on asset retirement — (10 ) — (10 ) West Adjustments to regulatory liabilities related to tax reform — — — (7 ) Regulatory charge per approved rates related to tax reform 6 6 18 18 Charge for regulatory liability associated with the decrease in Northwest Pipeline’s estimated deferred state income tax rates following WPZ Merger — 12 — 12 Other Change to (benefit of) regulatory asset associated with Transco’s estimated deferred state income tax rate following WPZ Merger — (37 ) 12 (37 ) Other income (expense) – net below Operating income (loss) Atlantic-Gulf Allowance for equity funds used during construction 9 32 21 78 Other Income associated with a regulatory asset related to deferred taxes on equity funds used during construction 3 19 7 28 Net loss associated with early retirement of debt — — — (7 ) I n conjunction with a previously announced organizational realignment and considering asset sales in recent years, we are evaluating our cost structure and have implemented a voluntary separation program (VSP) for certain eligible employees. Operating and maintenance expenses for the three and nine months ended September 30, 2019 , reflect charges of $ 7 million and $ 30 million , respectively, and Selling, general, and administrative expenses for the three and nine months ended September 30, 2019 , reflect charges of $ 3 million and $ 23 million , respectively, for estimated severance and related costs, primarily associated with the VSP. The severance and related costs by segment are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 (Millions) Northeast G&P $ (3 ) $ 7 Atlantic-Gulf 11 30 West 2 16 Total $ 10 $ 53

Provision (Benefit) for Income

Provision (Benefit) for Income Taxes	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Provision (Benefit) for Income Taxes [Text Block]	Note 7 – Provision (Benefit) for Income Taxes The Provision (benefit) for income taxes includes: Three Months Ended Nine Months Ended 2019 2018 2019 2018 (Millions) Current: Federal $ (10 ) $ (19 ) $ (25 ) $ (55 ) State — — — 1 Foreign 1 — 1 — (9 ) (19 ) (24 ) (54 ) Deferred: Federal 73 188 225 312 State 13 21 43 39 86 209 268 351 Provision (benefit) for income taxes $ 77 $ 190 $ 244 $ 297 The effective income tax rates for the total provision for the three and nine months ended September 30, 2019 , are greater than the federal statutory rate, primarily due to the effect of state income taxes. The effective income tax rates for the total provision for the three and nine months ended September 30, 2018 , are higher than the federal statutory rate primarily due to the effect of state income taxes and a $105 million valuation allowance associated with foreign tax credits, that expire between 2024 and 2027. This is partially offset by the impact of the allocation of income to nontaxable noncontrolling interests. The state income tax provisions include a $38 million provision related to an increase in the deferred state income tax rate (net of federal benefit) partially offset by a net decrease in valuation allowances of $31 million on state net operating losses, both primarily driven by the impact that the completion of the WPZ Merger (see Note 1 – General, Description of Business, and Basis of Presentation ) had on income allocation for state tax purposes. A valuation allowance for deferred tax assets, including foreign tax credits, is recognized when it is more likely than not that some, or all, of the benefit from the deferred tax asset will not be realized. To assess that likelihood, we use estimates and judgment regarding our sources of future taxable income, including available tax planning strategies, to determine whether a valuation allowance is required. The completion of the WPZ Merger decreased our deferred income tax liability by $1.829 billion at September 30, 2018 . Increased tax depreciation from the additional tax basis will reduce taxable income in future years and may limit our ability to realize the full benefit of certain short-lived deferred tax assets. 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, 2019
Earnings Per Share [Abstract]
Earnings (Loss) Per Common Share [Text Block]	Note 8 – Earnings (Loss) Per Common Share Three Months Ended Nine Months Ended 2019 2018 2019 2018 (Dollars in millions, except per-share amounts; shares in thousands) Net income (loss) available to common stockholders $ 220 $ 129 $ 724 $ 416 Basic weighted-average shares 1,212,270 1,023,587 1,211,938 893,706 Effect of dilutive securities: Nonvested restricted stock units 1,790 2,387 1,809 2,102 Stock options 105 530 196 514 Diluted weighted-average shares 1,214,165 1,026,504 1,213,943 896,322 Earnings (loss) per common share: Basic $ .18 $ .13 $ .60 $ .47 Diluted $ .18 $ .13 $ .60 $ .46

Employee Benefit Plans

Employee Benefit Plans	9 Months Ended
	Sep. 30, 2019
Retirement Benefits [Abstract]
Employee Benefit Plans [Text Block]	Note 9 – Employee Benefit Plans Net periodic benefit cost (credit) is as follows: Pension Benefits Three Months Ended Nine Months Ended 2019 2018 2019 2018 (Millions) Components of net periodic benefit cost (credit): Service cost $ 11 $ 12 $ 33 $ 37 Interest cost 13 12 38 35 Expected return on plan assets (15 ) (16 ) (46 ) (47 ) Amortization of net actuarial loss 3 6 11 17 Net actuarial loss from settlements 1 1 1 2 Net periodic benefit cost (credit) $ 13 $ 15 $ 37 $ 44 Other Postretirement Benefits Three Months Ended Nine Months Ended 2019 2018 2019 2018 (Millions) Components of net periodic benefit cost (credit): Service cost $ 1 $ 1 $ 1 $ 1 Interest cost 2 1 6 5 Expected return on plan assets (3 ) (2 ) (8 ) (8 ) Amortization of prior service credit — — — (1 ) Reclassification to regulatory liability — — 1 1 Net periodic benefit cost (credit) $ — $ — $ — $ (2 ) The components of Net periodic benefit cost (credit) other than the Service cost component are included in Other income (expense) – net below Operating income (loss) in the Consolidated Statement of Income . Amortization of prior service credit included in Net periodic benefit cost (credit) for our other postretirement benefit plans associated with Transco and Northwest Pipeline is recorded to regulatory assets/liabilities instead of O ther comprehensive income (loss). The amount of Amortization of prior service credit recognized in regulatory liabilities was $1 million for the nine months ended September 30, 2018 . During the nine months ended September 30, 2019 , we contributed $ 63 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 2019 .

Leases

Leases	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Leases [Text Block]	Note 10 – Leases We are a lessee through noncancellable lease agreements for property and equipment consisting primarily of buildings, land, vehicles, and equipment used in both our operations and administrative functions. We recognize a lease liability with an offsetting right-of-use asset in our Consolidated Balance Sheet for operating leases based on the present value of the future lease payments. As an accounting policy, we have elected to combine lease and nonlease components for all classes of leased assets in our calculation of the lease liability and the offsetting right-of-use asset. Our lease agreements require both fixed and variable periodic payments, with initial terms typically ranging from one year to 15 years , but a certain land lease has a term of 108 years . Payment provisions in certain of our lease agreements contain escalation factors which may be based on stated rates or a change in a published index at a future time. The amount by which a lease escalates based on the change in a published index, which is not known at lease commencement, is considered a variable payment and is not included in the present value of the future lease payments, which only includes those that are stated or can be calculated based on the lease agreement at lease commencement. In addition to the noncancellable periods, many of our lease agreements provide for one or more extensions of the lease agreement for periods ranging from one year in length to an indefinite number of times following the specified contract term. Other lease agreements provide for extension terms that allow us to utilize the identified leased asset for an indefinite period of time so long as the asset continues to be utilized in our operations. In consideration of these renewal features, we assess the term of the lease agreements, which includes using judgment in the determination of which renewal periods and termination provisions, when at our sole election, will be reasonably certain of being exercised. Periods after the initial term or extension terms that allow for either party to the lease to cancel the lease are not considered in the assessment of the lease term. Additionally, we have elected to exclude leases with an original term of one year or less, including renewal periods, from the calculation of the lease liability and the offsetting right-of-use asset. We used judgment in determining the discount rate upon which the present value of the future lease payments is determined. This rate is based on a collateralized interest rate corresponding to the term of the lease agreement using company, industry, and market information available. When permitted under our lease agreements, we may sublease certain unused office space for fixed periods that could extend up to the length of the original lease agreement. Three Months Ended Nine Months Ended 2019 (Millions) Lease Cost: Operating lease cost $ 10 $ 31 Short-term lease cost — — Variable lease cost 7 21 Sublease income — (1 ) Total lease cost $ 17 $ 51 Cash paid for amounts included in the measurement of operating lease liabilities $ 10 $ 30 September 30, 2019 (Millions) Other Information: Right-of-use asset (included in Regulatory assets, deferred charges, and other in our Consolidated Balance Sheet) $ 213 Operating lease liabilities: Current (included in Accrued liabilities in our Consolidated Balance Sheet) $ 23 Noncurrent (included in Regulatory liabilities, deferred income, and other in our Consolidated Balance Sheet) $ 190 Weighted-average remaining lease term – operating leases (years) 13 Weighted-average discount rate – operating leases 4.60% As of September 30, 2019 , the following table represents our operating lease maturities, including renewal provisions that we have assessed as being reasonably certain of exercise, for each of the years ended December 31: (Millions) 2019 (remainder) $ 8 2020 32 2021 33 2022 27 2023 21 Thereafter 171 Total future lease payments 292 Less amount representing interest 79 Total obligations under operating leases $ 213 We are the lessor to certain lease agreements for office space in our headquarters building, which are insignificant to our financial statements.

Debt and Banking Arrangements

Debt and Banking Arrangements	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Debt and Banking Arrangements [Text Block]	Note 11 – Debt and Banking Arrangements Long-Term Debt Retirements We retired approximately $32 million of 7.625 percent senior unsecured notes that matured on July 15, 2019. Commercial Paper Program At September 30, 2019, no commercial paper was outstanding under our $4 billion commercial paper program. Credit Facilities September 30, 2019 Stated Capacity Outstanding (Millions) Long-term credit facility (1) $ 4,500 $ — Letters of credit under certain bilateral bank agreements 14 (1) In managing our available liquidity, we do not expect a maximum outstanding amount in excess of the capacity of our credit facility inclusive of any outstanding amounts under our commercial paper program.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2019
Stockholders' Equity Note [Abstract]
Stockholders' Equity [Text Block]	Note 12 – Stockholders’ Equity Issuance of Preferred Shares In July 2018, through a wholly owned subsidiary, we contributed 35,000 shares of newly issued Series B Non-Voting Perpetual Preferred Stock (Preferred Stock) to The Williams Companies Foundation, Inc. (a not-for-profit corporation) for use in future charitable and nonprofit causes. The charitable contribution of Preferred Stock was recorded as an expense in the third quarter of 2018. The Preferred Stock was issued for an aggregate value of $35 million and pays non-cumulative quarterly cash dividends when, as and if declared, at a rate of 7.25 percent per year. Our certificate of incorporation authorizes 30 million shares of Preferred Stock, $1 par value per shares. AOCI The following table presents the changes in AOCI by component, net of income taxes: Cash Flow Hedges Foreign Currency Translation Pension and Other Postretirement Benefits Total (Millions) Balance at December 31, 2018 $ (2 ) $ (1 ) $ (267 ) $ (270 ) Other comprehensive income (loss) before reclassifications — — (5 ) (5 ) Amounts reclassified from accumulated other comprehensive income (loss) — — 9 9 Other comprehensive income (loss) — — 4 4 Balance at September 30, 2019 $ (2 ) $ (1 ) $ (263 ) $ (266 ) Reclassifications out of AOCI are presented in the following table by component for the nine months ended September 30, 2019 : Component Reclassifications Classification (Millions) Pension and other postretirement benefits: Amortization of actuarial (gain) loss and net actuarial loss from settlements included in net periodic benefit cost (credit) $ 12 Note 9 – Employee Benefit Plans Income tax benefit (3 ) Provision (benefit) for income taxes Reclassifications during the period $ 9

Fair Value Measurements and Gua

Fair Value Measurements and Guarantees	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements and Guarantees [Text Block]	Note 13 – 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, margin deposits, 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, 2019: Measured on a recurring basis: ARO Trust investments $ 187 $ 187 $ 187 $ — $ — Energy derivatives assets not designated as hedging instruments 4 4 4 — — Energy derivatives liabilities not designated as hedging instruments (5 ) (5 ) (2 ) — (3 ) Additional disclosures: Long-term debt, including current portion (22,257 ) (25,234 ) — (25,234 ) — Guarantees (42 ) (29 ) — (13 ) (16 ) Assets (liabilities) at December 31, 2018: Measured on a recurring basis: ARO Trust investments $ 150 $ 150 $ 150 $ — $ — Energy derivatives assets not designated as hedging instruments 3 3 3 — — Energy derivatives liabilities not designated as hedging instruments (7 ) (7 ) (4 ) — (3 ) Additional disclosures: Long-term debt, including current portion (22,414 ) (23,330 ) — (23,330 ) — Guarantees (43 ) (30 ) — (14 ) (16 ) Fair Value Methods We use the following methods and assumptions in estimating the fair value of our financial instruments: Assets and liabilities measured at fair value on a recurring basis ARO Trust investments : Transco deposits a portion of its collected rates, pursuant to its rate case settlement, into an external trust (ARO Trust) that is specifically designated to fund future asset retirement obligations (ARO). The ARO Trust invests in a portfolio of actively traded mutual funds that are measured at fair value on a recurring basis based on quoted prices in an active market and is reported in Regulatory assets, deferred charges, and other in the Consolidated Balance Sheet. Both realized and unrealized gains and losses are ultimately recorded as regulatory assets or liabilities. Energy derivatives : Energy derivatives include commodity-based exchange-traded contracts and over-the-counter contracts, which consist of physical forwards, futures, and swaps that are measured at fair value on a recurring basis. The fair value amounts are presented on a gross basis and do not reflect the netting of asset and liability positions permitted under the terms of our master netting arrangements. Further, the amounts do not include cash held on deposit in margin accounts that we have received or remitted to collateralize certain derivative positions. Energy derivatives assets are reported in Other current assets and deferred charges and Regulatory assets, deferred charges, and other in the Consolidated Balance Sheet. Energy derivatives liabilities are reported in Accrued liabilities and Regulatory liabilities, deferred income, and other in the Consolidated Balance Sheet. Reclassifications of fair value between Level 1, Level 2, and Level 3 of the fair value hierarchy, if applicable, are made at the end of each quarter. No transfers between Level 1 and Level 2 occurred during the nine months ended September 30, 2019 or 2018 . Additional fair value disclosures 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 values of the financing obligations associated with our Dalton lateral and Atlantic Sunrise projects, which are included within long-term debt, were determined using an income approach. Guarantees : Guarantees primarily consist of a guarantee we have provided in the event of nonpayment by our previously owned communications subsidiary, Williams Communications Group (WilTel), on a lease performance obligation that extends through 2042. Guarantees also include an indemnification related to a disposed operation. To estimate the fair value of the WilTel guarantee, an estimated default rate is applied to the sum of the future contractual lease payments using an income approach. The estimated default rate is determined by obtaining the average cumulative issuer-weighted corporate default rate based on the credit rating of WilTel’s current owner and the term of the underlying obligation. The default rate is published by Moody’s Investors Service. The carrying value of the WilTel guarantee is reported in Accrued liabilities in the Consolidated Balance Sheet. The maximum potential undiscounted exposure is approximately $28 million at September 30, 2019 . 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 agreement 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 equity-method investments associated with certain nonrecurring fair value measurements within Level 3 of the fair value hierarchy, except as specifically noted. Impairments Nine Months Ended Segment Date of Measurement Fair Value 2019 2018 (Millions) Impairment of certain assets: Certain gathering assets (1) West June 30, 2019 $ 40 $ 59 Certain idle gathering assets (2) West March 31, 2019 — 12 Certain idle pipeline assets (3) Other June 30, 2018 25 $ 66 Other impairments and write-downs 5 — Impairment of certain assets $ 76 $ 66 Impairment of equity-method investments: Laurel Mountain (4) Northeast G&P September 30, 2019 $ 242 $ 79 Appalachia Midstream Investments (5) Northeast G&P September 30, 2019 102 17 Pennant (6) Northeast G&P August 31, 2019 11 17 UEOM (7) Northeast G&P March 17, 2019 1,210 74 Other (1 ) Impairment of equity-method investments $ 186 _______________ (1) Relates to a gas gathering system in the Eagle Ford region with expected declines in asset utilization and possible idling of the gathering system. The estimated fair value of the Property, plant, and equipment – net was determined using a market approach which incorporated indications of interest from third parties. (2) Reflects impairment of Property, plant, and equipment – net that is no longer in use for which the fair value was determined to be lower than the carrying value. (3) Relates to certain idle pipelines. The estimated fair value of the Property, plant, and equipment – net was determined by a market approach incorporating information derived from bids received for these assets, which we marketed for sale together with certain other assets. These inputs resulted in a fair value measurement within Level 2 of the fair value hierarchy. We sold these assets in the fourth quarter of 2018. (4) Relates to a gas gathering system in the Marcellus region that was adversely impacted by lower sustained forward natural gas price expectations and changes in expected producer activity. The estimated fair value was determined using an income approach. We utilized a discount rate of 10.2 percent in our analysis. This impairment is reported in Other investing income (loss) – net in the Consolidated Statement of Income . (5) Relates to a certain gathering system held in Appalachia Midstream Investments that was adversely impacted by changes in the timing of expected producer activity. The estimated fair value was determined using an income approach. We utilized a discount rate of 9.0 percent in our analysis. This impairment is reported in Other investing income (loss) – net in the Consolidated Statement of Income . (6) The estimated fair value of Pennant Midstream, LLC (“Pennant”) was determined by a market approach based on recent observable third-party transactions. These inputs resulted in a fair value measurement within Level 2 of the fair value hierarchy. This impairment is reported in Other investing income (loss) – net in the Consolidated Statement of Income . (7) The estimated fair value was determined by a market approach based on the transaction price for the purchase of the remaining interest in UEOM as finalized just prior to the signing and closing of the acquisition in March 2019 (see Note 2 – Acquisitions ). These inputs resulted in a fair value measurement within Level 2 of the fair value hierarchy. This impairment is reported in Other investing income (loss) - net in the Consolidated Statement of Income .

Contingent Liabilities

Contingent Liabilities	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Contingent Liabilities [Text Block]	Note 14 – Contingent Liabilities Reporting of Natural Gas-Related Information to Trade Publications Direct and indirect purchasers of natural gas in various states filed individual and class actions against us, our former affiliate WPX Energy, Inc. (WPX) and its subsidiaries, and others alleging the manipulation of published gas price indices and seeking unspecified amounts of damages. Such actions were transferred to the Nevada federal district court for consolidation of discovery and pre-trial issues. We have agreed to indemnify WPX and its subsidiaries related to this matter. In the individual action, filed by Farmland Industries Inc. (Farmland), the court issued an order on May 24, 2016, granting one of our co-defendant’s motion for summary judgment as to Farmland’s claims. On January 5, 2017, the court extended such ruling to us, entering final judgment in our favor. Farmland appealed. On March 27, 2018, the appellate court reversed the district court’s grant of summary judgment, and on April 10, 2018, the defendants filed a petition for rehearing with the appellate court, which was denied on May 9, 2018. The case was remanded to the Nevada federal district court and subsequently has been remanded to its originally filed court, the Kansas federal district court. In the putative class actions, on March 30, 2017, the court issued an order denying the plaintiffs’ motions for class certification. On June 13, 2017, the United States Court of Appeals for the Ninth Circuit granted the plaintiffs’ petition for permission to appeal the order. On August 6, 2018, the Ninth Circuit reversed the order denying class certification and remanded the case to the Nevada federal district court. We reached an agreement to settle two of the actions, and on April 22, 2019, the Nevada federal district court preliminarily approved the settlements, which are on behalf of Kansas and Missouri class members. The final fairness hearing on the settlement occurred August 5, 2019, and a final judgment of dismissal with prejudice was entered the same day. Two putative class actions remain unresolved, and they have been remanded to their originally filed court, the Wisconsin federal district court. Because of the uncertainty around the remaining pending unresolved issues, we cannot reasonably estimate a range of potential exposure at this time. However, it is reasonably possible that the ultimate resolution of these actions and our related indemnification obligation could result in a potential loss that may be material to our results of operations. In connection with this indemnification, we have an accrued liability balance associated with this matter, and as a result, have exposure to future developments. Alaska Refinery Contamination Litigation We are involved in litigation arising from our ownership and operation of the North Pole Refinery in North Pole, Alaska, from 1980 until 2004, through our wholly owned subsidiaries, Williams Alaska Petroleum Inc. (WAPI) and MAPCO Inc. We sold the refinery to Flint Hills Resources Alaska, LLC (FHRA), a subsidiary of Koch Industries, Inc., in 2004. The litigation involves three cases, with filing dates ranging from 2010 to 2014. The actions arise from sulfolane contamination allegedly emanating from the refinery. A putative class action lawsuit was filed by James West in 2010 naming us, WAPI, and FHRA as defendants. We and FHRA filed claims against each other seeking, among other things, contractual indemnification alleging that the other party caused the sulfolane contamination. In 2011, we and FHRA settled the claim with James West. Certain claims by FHRA against us were resolved by the Alaska Supreme Court in our favor. FHRA’s claims against us for contractual indemnification and statutory claims for damages related to off-site sulfolane remain pending. The State of Alaska filed its action in March 2014, seeking damages. The City of North Pole (North Pole) filed its lawsuit in November 2014, seeking past and future damages, as well as punitive damages. Both we and WAPI asserted counterclaims against the State of Alaska and North Pole, and cross-claims against FHRA. FHRA has also filed cross-claims against us. The underlying factual basis and claims in the cases are similar and may duplicate exposure. As such, in February 2017, the three cases were consolidated into one action in state court containing the remaining claims from the James West case and those of the State of Alaska and North Pole. Several trial dates encompassing all three cases have been scheduled and stricken. Trial commenced in October 2019. 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 intends to enter a compliance order to address the environmental remediation of sulfolane and other possible contaminants including cleanup work outside the refinery’s boundaries. To date, no compliance order has been issued. Due to the ongoing assessment of the level and extent of sulfolane contamination, the ultimate cost of remediation and division of costs among the potentially responsible parties, and the previously described separate litigation, we are unable to estimate a range of exposure at this time. Royalty Matters Certain of our customers, including one major customer, have been named in various lawsuits alleging underpayment of royalties and claiming, among other things, violations of anti-trust laws and the Racketeer Influenced and Corrupt Organizations Act. We have also been named as a defendant in certain of these cases filed in Pennsylvania based on allegations that we improperly participated with that major customer in causing the alleged royalty underpayments. We believe that the claims asserted are subject to indemnity obligations owed to us by that major customer. That customer has reached a tentative settlement to resolve substantially all Pennsylvania royalty cases pending, which settlement would apply to both the customer and us. The settlement as reported would not require any contribution from us. Litigation Against Energy Transfer and Related Parties On April 6, 2016, we filed suit in Delaware Chancery Court against Energy Transfer Equity, L.P. (Energy Transfer) and LE GP, LLC (the general partner for Energy Transfer) alleging willful and material breaches of the Agreement and Plan of Merger (ETE 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 ETE 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 ETE Merger Agreement, alleging material breaches of the ETE Merger Agreement for failing to cooperate and use necessary efforts to obtain a tax opinion required under the ETE Merger Agreement (Tax Opinion) and for otherwise failing to use necessary efforts to consummate the merger under the ETE 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 ETE 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 ETE 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 ETE 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 ETE Merger Agreement. On December 1, 2017, the court granted our motion to dismiss certain of Energy Transfer’s counterclaims, including its claim seeking payment of the $1.48 billion termination fee. On December 8, 2017, Energy Transfer filed a motion for reargument, which the Court of Chancery denied on April 16, 2018. The Court of Chancery previously scheduled trial for May 20 through May 24, 2019; the court struck the trial setting and has re-scheduled trial for June 8 through June 11 and June 15, 2020. Former Olefins Business SABIC Petrochemicals, the other interest owner in our former Geismar, Louisiana, olefins facility we sold in July 2017, is seeking recovery from us for losses it allegedly suffered, including its share of personal injury settlements in which it was a co-defendant, as well as amounts related to lost income, defense costs, and property damage associated with an explosion and fire at the plant in June 2013. Due to the complexity of the various claims and available defenses, we are unable to reliably estimate any reasonably possible losses at this time. Trial began on October 14, 2019, as scheduled, but on October 21, 2019, the Court declared a mistrial due to the conduct of an officer of SABIC Petrochemicals and SABIC Petrochemicals’ expert witness. No new trial date has been set. We believe that certain losses incurred arising directly from the explosion and fire will be covered by our general liability policy and any uninsured losses are not expected to be material. Other On August 31, 2018, Transco submitted to the FERC a general rate filing principally designed to recover increased costs and to comply with the terms of the settlement in its prior rate proceeding. The new rates became effective March 1, 2019, subject to refund and the outcome of a hearing. In October 2019, we reached an agreement on the terms of a settlement with the participants that would resolve all issues in the rate case without the need for a hearing. Final resolution of the rate case is subject to the filing of a formal stipulation and agreement with, and subsequent approval by, the FERC. As of September 30, 2019 , we have provided a $131 million reserve for rate refunds which we believe is adequate for any refunds that may be required. Environmental Matters We are a participant in certain environmental activities in various stages including assessment studies, cleanup operations, and/or remedial processes at certain sites, some of which we currently do not own. We are monitoring these sites in a coordinated effort with other potentially responsible parties, the U.S. Environmental Protection Agency (EPA), or other governmental authorities. We are jointly and severally liable along with unrelated third parties in some of these activities and solely responsible in others. Certain of our subsidiaries have been identified as potentially responsible parties at various Superfund and state waste disposal sites. In addition, these subsidiaries have incurred, or are alleged to have incurred, various other hazardous materials removal or remediation obligations under environmental laws. As of September 30, 2019 , we have accrued liabilities totaling $33 million for these matters, as discussed below. Estimates of the most likely costs of cleanup are generally based on completed assessment studies, preliminary results of studies, or our experience with other similar cleanup operations. At September 30, 2019 , certain assessment studies were still in process for which the ultimate outcome may yield different estimates of most likely costs. Therefore, the actual costs incurred will depend on the final amount, type, and extent of contamination discovered at these sites, the final cleanup standards mandated by the EPA or other governmental authorities, and other factors. The EPA and various state regulatory agencies routinely promulgate and propose new rules and issue updated guidance to existing rules. These 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. The EPA previously issued its rule regarding National Ambient Air Quality Standards for ground-level ozone. We are monitoring the rule’s implementation as it will trigger additional federal and state regulatory actions that may impact our operations. Implementation of the regulations is expected to result in impacts to our operations and increase the cost of additions to Property, plant, and equipment – net in the Consolidated Balance Sheet for both new and existing facilities in affected areas. We are unable to reasonably estimate the cost of additions that may be required to meet the regulations at this time due to uncertainty created by various legal challenges to these regulations and the need for further specific regulatory guidance. Continuing operations Our interstate gas pipelines are involved in remediation activities related to certain facilities and locations for polychlorinated biphenyls, mercury, and other hazardous substances. These activities have involved the EPA and various state environmental authorities, resulting in our identification as a potentially responsible party at various Superfund waste sites. At September 30, 2019 , we have accrued liabilities of $5 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, 2019 , we have accrued liabilities totaling $8 million for these costs. Former operations 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, 2019 , we have accrued environmental liabilities of $20 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, 2019 , 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, 2019
Segment Reporting [Abstract]
Segment Disclosures [Text Block]	Note 15 – Segment Disclosures Our reportable segments are Northeast G&P, Atlantic-Gulf, and West. All remaining business activities are included in Other. (See Note 1 – General, Description of Business, and Basis of Presentation .) 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. Intersegment revenues primarily represent the sale of NGLs from our natural gas processing plants to our marketing business. We define Modified EBITDA as follows: • Net income (loss) before: ◦ Provision (benefit) for income taxes; ◦ Interest incurred, net of interest capitalized; ◦ Equity earnings (losses); ◦ Other investing income (loss) – net; ◦ Depreciation and amortization expenses; ◦ Accretion expense associated with asset retirement obligations for nonregulated operations. • This measure is further adjusted to include our proportionate share (based on ownership interest) of Modified EBITDA from our equity-method investments calculated consistently with the definition described above. The following table reflects the reconciliation of Segment revenues to Total revenues as reported in the Consolidated Statement of Income and Total assets by reportable segment. Northeast G&P Atlantic-Gulf West Other Eliminations Total (Millions) Three Months Ended September 30, 2019 Segment revenues: Service revenues External $ 340 $ 718 $ 433 $ 4 $ — $ 1,495 Internal 13 13 — 3 (29 ) — Total service revenues 353 731 433 7 (29 ) 1,495 Total service revenues – commodity consideration 1 7 30 — — 38 Product sales External 22 66 378 — — 466 Internal 8 10 11 — (29 ) — Total product sales 30 76 389 — (29 ) 466 Total revenues $ 384 $ 814 $ 852 $ 7 $ (58 ) $ 1,999 Three Months Ended September 30, 2018 Segment revenues: Service revenues External $ 236 $ 595 $ 533 $ 7 $ — $ 1,371 Internal 11 12 — 3 (26 ) — Total service revenues 247 607 533 10 (26 ) 1,371 Total service revenues – commodity consideration 6 18 97 — — 121 Product sales External 59 46 706 — — 811 Internal 10 85 26 — (121 ) — Total product sales 69 131 732 — (121 ) 811 Total revenues $ 322 $ 756 $ 1,362 $ 10 $ (147 ) $ 2,303 Nine Months Ended September 30, 2019 Segment revenues: Service revenues External $ 925 $ 2,102 $ 1,384 $ 13 $ — $ 4,424 Internal 34 36 — 9 (79 ) — Total service revenues 959 2,138 1,384 22 (79 ) 4,424 Total service revenues – commodity consideration 9 33 116 — — 158 Product sales External 87 169 1,256 — — 1,512 Internal 27 57 46 — (130 ) — Total product sales 114 226 1,302 — (130 ) 1,512 Total revenues $ 1,082 $ 2,397 $ 2,802 $ 22 $ (209 ) $ 6,094 Northeast G&P Atlantic-Gulf West Other Eliminations Total (Millions) Nine Months Ended September 30, 2018 Segment revenues: Service revenues External $ 677 $ 1,769 $ 1,599 $ 17 $ — $ 4,062 Internal 30 37 — 9 (76 ) — Total service revenues 707 1,806 1,599 26 (76 ) 4,062 Total service revenues – commodity consideration 14 45 257 — — 316 Product sales External 214 131 1,759 — — 2,104 Internal 28 198 63 — (289 ) — Total product sales 242 329 1,822 — (289 ) 2,104 Total revenues $ 963 $ 2,180 $ 3,678 $ 26 $ (365 ) $ 6,482 September 30, 2019 Total assets $ 15,445 $ 16,888 $ 13,550 $ 928 $ (530 ) $ 46,281 December 31, 2018 Total assets $ 14,526 $ 16,346 $ 13,948 $ 849 $ (367 ) $ 45,302 The following table reflects the reconciliation of Modified EBITDA to Net income (loss) as reported in the Consolidated Statement of Income . Three Months Ended Nine Months Ended 2019 2018 2019 2018 (Millions) Modified EBITDA by segment: Northeast G&P $ 345 $ 281 $ 947 $ 786 Atlantic-Gulf 599 492 1,683 1,418 West 311 412 921 1,214 Other (2 ) 6 1 (49 ) 1,253 1,191 3,552 3,369 Accretion expense associated with asset retirement obligations for nonregulated operations (8 ) (8 ) (25 ) (26 ) Depreciation and amortization expenses (435 ) (425 ) (1,275 ) (1,290 ) Equity earnings (losses) 93 105 260 279 Other investing income (loss) – net (107 ) 2 (54 ) 74 Proportional Modified EBITDA of equity-method investments (181 ) (205 ) (546 ) (552 ) Interest expense (296 ) (270 ) (888 ) (818 ) (Provision) benefit for income taxes (77 ) (190 ) (244 ) (297 ) Net income (loss) $ 242 $ 200 $ 780 $ 739

Acquisitions (Tables)

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2019
Business Acquisition [Line Items]
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	The following table presents the allocation of the acquisition date fair value of the major classes of the assets acquired, which are presented in the Northeast G&P segment, and liabilities assumed at March 18, 2019. The net assets acquired reflect the sum of the consideration transferred and the noncash elimination of the fair value of our existing equity-method investment upon our acquisition of the additional interest. The fair value of accounts receivable acquired, presented in current assets in the table, equals contractual amounts receivable. After the March 31, 2019 financial statements were issued, we received an updated valuation report from a third-party valuation firm. Significant changes from the preliminary allocation disclosed in the first quarter to the final allocation reflect an increase of $169 million in goodwill, and decreases of $106 million in property, plant, and equipment and $61 million in other intangible assets. (Millions) Current assets, including $13 million cash acquired $ 55 Property, plant, and equipment 1,387 Other intangible assets 328 Total identifiable assets acquired 1,770 Current liabilities 7 Total liabilities assumed 7 Net identifiable assets acquired 1,763 Goodwill 188 Net assets acquired $ 1,951
Business Acquisition, Pro Forma Information [Table Text Block]	The following unaudited pro forma Revenues and Net income (loss) attributable to The Williams Companies, Inc. for the three and nine months ended September 30, 2019 and 2018 , are presented as if the UEOM acquisition had been completed on January 1, 2018. These pro forma amounts are not necessarily indicative of what the actual results would have been if the acquisition had in fact occurred on the date or for the periods indicated, nor do they purport to project Revenues or Net income (loss) attributable to The Williams Companies, Inc. for any future periods or as of any date. These amounts do not give effect to any potential cost savings, operating synergies, or revenue enhancements to result from the transaction or the potential costs to achieve these cost savings, operating synergies, and revenue enhancements. Three Months Ended Nine Months Ended 2019 2018 2019 2018 (Millions) Revenues $ 1,999 $ 2,342 $ 6,126 $ 6,589 Net income (loss) attributable to The Williams Companies, Inc. $ 221 $ 138 $ 804 $ 434

Revenue Recognition (Tables)

Revenue Recognition (Tables)	9 Months Ended
	Sep. 30, 2019
Revenue Recognition [Abstract]
Disaggregation of Revenue [Table Text Block]	The following table presents our revenue disaggregated by major service line: Northeast Midstream Atlantic- Gulf Midstream West Midstream Transco Northwest Pipeline Other Intercompany Eliminations Total (Millions) Three Months Ended September 30, 2019 Revenues from contracts with customers: Service revenues: Non-regulated gathering, processing, transportation, and storage: Monetary consideration $ 310 $ 117 $ 308 $ — $ — $ — $ (19 ) $ 716 Commodity consideration 1 7 30 — — — — 38 Regulated interstate natural gas transportation and storage — — — 601 111 — (2 ) 710 Other 38 8 12 — — — (5 ) 53 Total service revenues 349 132 350 601 111 — (26 ) 1,517 Product Sales: NGL and natural gas product sales 30 34 391 41 — — (28 ) 468 Total revenues from contracts with customers 379 166 741 642 111 — (54 ) 1,985 Other revenues (1) 5 2 — 3 — 7 (3 ) 14 Total revenues $ 384 $ 168 $ 741 $ 645 $ 111 $ 7 $ (57 ) $ 1,999 Three Months Ended September 30, 2018 Revenues from contracts with customers: Service revenues: Non-regulated gathering, processing, transportation, and storage: Monetary consideration $ 219 $ 139 $ 409 $ — $ — $ 1 $ (19 ) $ 749 Commodity consideration 5 19 97 — — — — 121 Regulated interstate natural gas transportation and storage — — — 457 110 — (1 ) 566 Other 23 4 11 — — — (4 ) 34 Total service revenues 247 162 517 457 110 1 (24 ) 1,470 Product Sales: NGL and natural gas 69 88 720 41 — — (117 ) 801 Other — — 12 — — — (3 ) 9 Total product sales 69 88 732 41 — — (120 ) 810 Total revenues from contracts with customers 316 250 1,249 498 110 1 (144 ) 2,280 Other revenues (1) 6 5 3 3 — 9 (3 ) 23 Total revenues $ 322 $ 255 $ 1,252 $ 501 $ 110 $ 10 $ (147 ) $ 2,303 Northeast Midstream Atlantic- Gulf Midstream West Midstream Transco Northwest Pipeline Other Intercompany Eliminations Total (Millions) Nine Months Ended September 30, 2019 Revenues from contracts with customers: Service revenues: Non-regulated gathering, processing, transportation, and storage: Monetary consideration $ 840 $ 366 $ 1,007 $ — $ — $ — $ (54 ) $ 2,159 Commodity consideration 9 33 116 — — — — 158 Regulated interstate natural gas transportation and storage — — — 1,736 335 — (4 ) 2,067 Other 104 21 32 1 — — (12 ) 146 Total service revenues 953 420 1,155 1,737 335 — (70 ) 4,530 Product Sales: NGL and natural gas product sales 114 140 1,300 88 — — (132 ) 1,510 Total revenues from contracts with customers 1,067 560 2,455 1,825 335 — (202 ) 6,040 Other revenues (1) 15 6 12 8 — 22 (9 ) 54 Total revenues $ 1,082 $ 566 $ 2,467 $ 1,833 $ 335 $ 22 $ (211 ) $ 6,094 Nine Months Ended September 30, 2018 Revenues from contracts with customers: Service revenues: Non-regulated gathering, processing, transportation, and storage: Monetary consideration $ 626 $ 404 $ 1,231 $ — $ — $ 2 $ (55 ) $ 2,208 Commodity consideration 14 45 257 — — — — 316 Regulated interstate natural gas transportation and storage — — — 1,368 330 — (2 ) 1,696 Other 65 12 35 1 — — (10 ) 103 Total service revenues 705 461 1,523 1,369 330 2 (67 ) 4,323 Product Sales: NGL and natural gas 242 232 1,799 96 — — (285 ) 2,084 Other — — 20 — — — (4 ) 16 Total product sales 242 232 1,819 96 — — (289 ) 2,100 Total revenues from contracts with customers 947 693 3,342 1,465 330 2 (356 ) 6,423 Other revenues (1) 16 14 6 8 — 24 (9 ) 59 Total revenues $ 963 $ 707 $ 3,348 $ 1,473 $ 330 $ 26 $ (365 ) $ 6,482 ______________________________ (1) Revenues not within the scope of ASC 606, “Revenue from Contracts with Customers,” consist of leasing revenues associated with our headquarters building and management fees that we receive for certain services we provide to operated equity-method investments, which are reported in Service revenues in our Consolidated Statement of Income, and amounts associated with our derivative contracts, which are reported in Product sales
Contract with Customer, Asset and Liability [Table Text Block]	The following table presents a reconciliation of our contract assets: Three Months Ended Nine Months Ended 2019 2018 2019 2018 (Millions) Balance at beginning of period $ 17 $ 39 $ 4 $ 4 Revenue recognized in excess of amounts invoiced 14 17 53 53 Minimum volume commitments invoiced — — (26 ) (1 ) Balance at end of period $ 31 $ 56 $ 31 $ 56 Contract Liabilities The following table presents a reconciliation of our contract liabilities: Three Months Ended Nine Months Ended 2019 2018 2019 2018 (Millions) Balance at beginning of period $ 1,331 $ 1,535 $ 1,397 $ 1,596 Payments received and deferred 12 58 138 269 Deconsolidation of Jackalope interest (Note 5) — — — (52 ) Significant financing component 3 4 10 11 Recognized in revenue (77 ) (112 ) (276 ) (339 ) Balance at end of period $ 1,269 $ 1,485 $ 1,269 $ 1,485
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block]	Remaining performance obligations primarily include reservation charges on contracted capacity for our gas pipeline firm transportation contracts with customers, storage capacity contracts, long-term contracts containing minimum volume commitments associated with our midstream businesses, and fixed payments associated with offshore production handling. For our interstate natural gas pipeline businesses, remaining performance obligations reflect the rates for such services in our current Federal Energy Regulatory Commission (FERC) tariffs for the life of the related contracts; however, these rates may change based on future tariffs approved by the FERC and the amount and timing of these changes are not currently known. Our remaining performance obligations exclude variable consideration, including contracts with variable consideration for which we have elected the practical expedient for consideration recognized in revenue as billed. Certain of our contracts contain evergreen and other renewal provisions for periods beyond the initial term of the contract. The remaining performance obligation amounts as of September 30, 2019 , do not consider potential future performance obligations for which the renewal has not been exercised and excludes contracts with customers for which the underlying facilities have not received FERC authorization to be placed into service. Consideration received prior to September 30, 2019 , that will be recognized in future periods is also excluded from our remaining performance obligations and is instead reflected in contract liabilities. The following table presents the amount of the contract liabilities balance as of September 30, 2019 , expected to be recognized as revenue as performance obligations are satisfied and the transaction price allocated to the remaining performance obligations under certain contracts as of September 30, 2019 . Contract Liabilities Remaining Performance Obligations (Millions) 2019 (remainder) $ 70 $ 762 2020 167 3,028 2021 126 2,873 2022 112 2,705 2023 103 2,244 Thereafter 691 19,840 Total $ 1,269 $ 31,452
Contract With Customer Accounts Receivable [Table Text Block]	The following is a summary of our Trade accounts and other receivables : September 30, 2019 December 31, 2018 (Millions) Accounts receivable related to revenues from contracts with customers $ 791 $ 858 Other accounts receivable 84 134 Total reflected in Trade accounts and other receivables $ 875 $ 992

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	9 Months Ended
	Sep. 30, 2019
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 only for the use or obligation of our consolidated VIEs: September 30, December 31, (Millions) Assets (liabilities): Cash and cash equivalents $ 90 $ 33 Trade accounts and other receivables – net 152 62 Other current assets and deferred charges 5 2 Property, plant, and equipment – net 6,167 2,363 Intangible assets – net of accumulated amortization 2,697 1,177 Regulatory assets, deferred charges, and other 13 — Accounts payable (54 ) (15 ) Accrued liabilities (100 ) (115 ) Regulatory liabilities, deferred income, and other (268 ) (264 )

Investing Activities (Tables)

Investing Activities (Tables)	9 Months Ended
	Sep. 30, 2019
Equity Method Investments and Joint Ventures [Abstract]
Realized Gain (Loss) on Investments [Table Text Block]	The following table presents certain items reflected in Other investing income (loss) – net in the Consolidated Statement of Income : Three Months Ended Nine Months Ended 2019 2018 2019 2018 (Millions) Impairment of equity-method investments (Note 13) $ (114 ) $ — $ (186 ) $ — Gain (loss) on deconsolidation of businesses — — (2 ) 62 Gain on disposition of equity-method investments — — 122 — Other 7 2 12 12 Other investing income (loss) – net $ (107 ) $ 2 $ (54 ) $ 74

Other Income and Expenses (Tabl

Other Income and Expenses (Tables)	9 Months Ended
	Sep. 30, 2019
Other Income and Expenses [Abstract]
Other Income and Expenses [Table Text Block]	The following table presents, by segment, certain other items included in our Consolidated Statement of Income : Three Months Ended Nine Months Ended 2019 2018 2019 2018 (Millions) Selling, general, and administrative expenses Other Charitable contribution of preferred stock to The Williams Companies Foundation, Inc. (see Note 12) $ — $ 35 $ — $ 35 WPZ Merger costs — 15 — 19 Other (income) expense – net within Costs and expenses Atlantic-Gulf Amortization of regulatory assets associated with asset retirement obligations 1 8 17 24 Net accrual (amortization) of regulatory liability related to overcollection of certain employee expenses (9 ) 5 (11 ) 16 Adjustments to regulatory liabilities related to tax reform — — — (10 ) Amortization of regulatory liability associated with tax reform (12 ) — (19 ) — Reversal of expenditures previously capitalized — — 10 — Gain on asset retirement — (10 ) — (10 ) West Adjustments to regulatory liabilities related to tax reform — — — (7 ) Regulatory charge per approved rates related to tax reform 6 6 18 18 Charge for regulatory liability associated with the decrease in Northwest Pipeline’s estimated deferred state income tax rates following WPZ Merger — 12 — 12 Other Change to (benefit of) regulatory asset associated with Transco’s estimated deferred state income tax rate following WPZ Merger — (37 ) 12 (37 ) Other income (expense) – net below Operating income (loss) Atlantic-Gulf Allowance for equity funds used during construction 9 32 21 78 Other Income associated with a regulatory asset related to deferred taxes on equity funds used during construction 3 19 7 28 Net loss associated with early retirement of debt — — — (7 )
Compensation Related Costs, General [Text Block]	I n conjunction with a previously announced organizational realignment and considering asset sales in recent years, we are evaluating our cost structure and have implemented a voluntary separation program (VSP) for certain eligible employees. Operating and maintenance expenses for the three and nine months ended September 30, 2019 , reflect charges of $ 7 million and $ 30 million , respectively, and Selling, general, and administrative expenses for the three and nine months ended September 30, 2019 , reflect charges of $ 3 million and $ 23 million , respectively, for estimated severance and related costs, primarily associated with the VSP. The severance and related costs by segment are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 (Millions) Northeast G&P $ (3 ) $ 7 Atlantic-Gulf 11 30 West 2 16 Total $ 10 $ 53

Provision (Benefit) for Incom_2

Provision (Benefit) for Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2019
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 2019 2018 2019 2018 (Millions) Current: Federal $ (10 ) $ (19 ) $ (25 ) $ (55 ) State — — — 1 Foreign 1 — 1 — (9 ) (19 ) (24 ) (54 ) Deferred: Federal 73 188 225 312 State 13 21 43 39 86 209 268 351 Provision (benefit) for income taxes $ 77 $ 190 $ 244 $ 297

Earnings (Loss) Per Common Sh_2

Earnings (Loss) Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Earnings (Loss) Per Common Share [Table Text Block]	Three Months Ended Nine Months Ended 2019 2018 2019 2018 (Dollars in millions, except per-share amounts; shares in thousands) Net income (loss) available to common stockholders $ 220 $ 129 $ 724 $ 416 Basic weighted-average shares 1,212,270 1,023,587 1,211,938 893,706 Effect of dilutive securities: Nonvested restricted stock units 1,790 2,387 1,809 2,102 Stock options 105 530 196 514 Diluted weighted-average shares 1,214,165 1,026,504 1,213,943 896,322 Earnings (loss) per common share: Basic $ .18 $ .13 $ .60 $ .47 Diluted $ .18 $ .13 $ .60 $ .46

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2019
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 2019 2018 2019 2018 (Millions) Components of net periodic benefit cost (credit): Service cost $ 11 $ 12 $ 33 $ 37 Interest cost 13 12 38 35 Expected return on plan assets (15 ) (16 ) (46 ) (47 ) Amortization of net actuarial loss 3 6 11 17 Net actuarial loss from settlements 1 1 1 2 Net periodic benefit cost (credit) $ 13 $ 15 $ 37 $ 44 Other Postretirement Benefits Three Months Ended Nine Months Ended 2019 2018 2019 2018 (Millions) Components of net periodic benefit cost (credit): Service cost $ 1 $ 1 $ 1 $ 1 Interest cost 2 1 6 5 Expected return on plan assets (3 ) (2 ) (8 ) (8 ) Amortization of prior service credit — — — (1 ) Reclassification to regulatory liability — — 1 1 Net periodic benefit cost (credit) $ — $ — $ — $ (2 )

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Lease, Cost [Table Text Block]	Three Months Ended Nine Months Ended 2019 (Millions) Lease Cost: Operating lease cost $ 10 $ 31 Short-term lease cost — — Variable lease cost 7 21 Sublease income — (1 ) Total lease cost $ 17 $ 51 Cash paid for amounts included in the measurement of operating lease liabilities $ 10 $ 30 September 30, 2019 (Millions) Other Information: Right-of-use asset (included in Regulatory assets, deferred charges, and other in our Consolidated Balance Sheet) $ 213 Operating lease liabilities: Current (included in Accrued liabilities in our Consolidated Balance Sheet) $ 23 Noncurrent (included in Regulatory liabilities, deferred income, and other in our Consolidated Balance Sheet) $ 190 Weighted-average remaining lease term – operating leases (years) 13 Weighted-average discount rate – operating leases 4.60%
Lessee, Operating Lease, Liability, Maturity [Table Text Block]	As of September 30, 2019 , the following table represents our operating lease maturities, including renewal provisions that we have assessed as being reasonably certain of exercise, for each of the years ended December 31: (Millions) 2019 (remainder) $ 8 2020 32 2021 33 2022 27 2023 21 Thereafter 171 Total future lease payments 292 Less amount representing interest 79 Total obligations under operating leases $ 213

Debt and Banking Arrangements (

Debt and Banking Arrangements (Tables)	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Schedule of Line of Credit Facilities [Table Text Block]	Credit Facilities September 30, 2019 Stated Capacity Outstanding (Millions) Long-term credit facility (1) $ 4,500 $ — Letters of credit under certain bilateral bank agreements 14 (1) In managing our available liquidity, we do not expect a maximum outstanding amount in excess of the capacity of our credit facility inclusive of any outstanding amounts under our commercial paper program.

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2019
Stockholders' Equity Note [Abstract]
Accumulated Other Comprehensive Income (Loss) [Table Text Block]	AOCI The following table presents the changes in AOCI by component, net of income taxes: Cash Flow Hedges Foreign Currency Translation Pension and Other Postretirement Benefits Total (Millions) Balance at December 31, 2018 $ (2 ) $ (1 ) $ (267 ) $ (270 ) Other comprehensive income (loss) before reclassifications — — (5 ) (5 ) Amounts reclassified from accumulated other comprehensive income (loss) — — 9 9 Other comprehensive income (loss) — — 4 4 Balance at September 30, 2019 $ (2 ) $ (1 ) $ (263 ) $ (266 )
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, 2019 : Component Reclassifications Classification (Millions) Pension and other postretirement benefits: Amortization of actuarial (gain) loss and net actuarial loss from settlements included in net periodic benefit cost (credit) $ 12 Note 9 – Employee Benefit Plans Income tax benefit (3 ) Provision (benefit) for income taxes Reclassifications during the period $ 9

Fair Value Measurements and G_2

Fair Value Measurements and Guarantees (Tables)	9 Months Ended
	Sep. 30, 2019
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, margin deposits, 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, 2019: Measured on a recurring basis: ARO Trust investments $ 187 $ 187 $ 187 $ — $ — Energy derivatives assets not designated as hedging instruments 4 4 4 — — Energy derivatives liabilities not designated as hedging instruments (5 ) (5 ) (2 ) — (3 ) Additional disclosures: Long-term debt, including current portion (22,257 ) (25,234 ) — (25,234 ) — Guarantees (42 ) (29 ) — (13 ) (16 ) Assets (liabilities) at December 31, 2018: Measured on a recurring basis: ARO Trust investments $ 150 $ 150 $ 150 $ — $ — Energy derivatives assets not designated as hedging instruments 3 3 3 — — Energy derivatives liabilities not designated as hedging instruments (7 ) (7 ) (4 ) — (3 ) Additional disclosures: Long-term debt, including current portion (22,414 ) (23,330 ) — (23,330 ) — Guarantees (43 ) (30 ) — (14 ) (16 )
Fair Value Measurements, Nonrecurring [Table Text Block]	The following table presents impairments of assets and equity-method investments associated with certain nonrecurring fair value measurements within Level 3 of the fair value hierarchy, except as specifically noted. Impairments Nine Months Ended Segment Date of Measurement Fair Value 2019 2018 (Millions) Impairment of certain assets: Certain gathering assets (1) West June 30, 2019 $ 40 $ 59 Certain idle gathering assets (2) West March 31, 2019 — 12 Certain idle pipeline assets (3) Other June 30, 2018 25 $ 66 Other impairments and write-downs 5 — Impairment of certain assets $ 76 $ 66 Impairment of equity-method investments: Laurel Mountain (4) Northeast G&P September 30, 2019 $ 242 $ 79 Appalachia Midstream Investments (5) Northeast G&P September 30, 2019 102 17 Pennant (6) Northeast G&P August 31, 2019 11 17 UEOM (7) Northeast G&P March 17, 2019 1,210 74 Other (1 ) Impairment of equity-method investments $ 186 _______________ (1) Relates to a gas gathering system in the Eagle Ford region with expected declines in asset utilization and possible idling of the gathering system. The estimated fair value of the Property, plant, and equipment – net was determined using a market approach which incorporated indications of interest from third parties. (2) Reflects impairment of Property, plant, and equipment – net that is no longer in use for which the fair value was determined to be lower than the carrying value. (3) Relates to certain idle pipelines. The estimated fair value of the Property, plant, and equipment – net was determined by a market approach incorporating information derived from bids received for these assets, which we marketed for sale together with certain other assets. These inputs resulted in a fair value measurement within Level 2 of the fair value hierarchy. We sold these assets in the fourth quarter of 2018. (4) Relates to a gas gathering system in the Marcellus region that was adversely impacted by lower sustained forward natural gas price expectations and changes in expected producer activity. The estimated fair value was determined using an income approach. We utilized a discount rate of 10.2 percent in our analysis. This impairment is reported in Other investing income (loss) – net in the Consolidated Statement of Income . (5) Relates to a certain gathering system held in Appalachia Midstream Investments that was adversely impacted by changes in the timing of expected producer activity. The estimated fair value was determined using an income approach. We utilized a discount rate of 9.0 percent in our analysis. This impairment is reported in Other investing income (loss) – net in the Consolidated Statement of Income . (6) The estimated fair value of Pennant Midstream, LLC (“Pennant”) was determined by a market approach based on recent observable third-party transactions. These inputs resulted in a fair value measurement within Level 2 of the fair value hierarchy. This impairment is reported in Other investing income (loss) – net in the Consolidated Statement of Income . (7) The estimated fair value was determined by a market approach based on the transaction price for the purchase of the remaining interest in UEOM as finalized just prior to the signing and closing of the acquisition in March 2019 (see Note 2 – Acquisitions ). These inputs resulted in a fair value measurement within Level 2 of the fair value hierarchy. This impairment is reported in Other investing income (loss) - net in the Consolidated Statement of Income .

Segment Disclosures (Tables)

Segment Disclosures (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Reconciliation of Revenue from Segments to Consolidated [Table Text Block]	The following table reflects the reconciliation of Segment revenues to Total revenues as reported in the Consolidated Statement of Income and Total assets by reportable segment. Northeast G&P Atlantic-Gulf West Other Eliminations Total (Millions) Three Months Ended September 30, 2019 Segment revenues: Service revenues External $ 340 $ 718 $ 433 $ 4 $ — $ 1,495 Internal 13 13 — 3 (29 ) — Total service revenues 353 731 433 7 (29 ) 1,495 Total service revenues – commodity consideration 1 7 30 — — 38 Product sales External 22 66 378 — — 466 Internal 8 10 11 — (29 ) — Total product sales 30 76 389 — (29 ) 466 Total revenues $ 384 $ 814 $ 852 $ 7 $ (58 ) $ 1,999 Three Months Ended September 30, 2018 Segment revenues: Service revenues External $ 236 $ 595 $ 533 $ 7 $ — $ 1,371 Internal 11 12 — 3 (26 ) — Total service revenues 247 607 533 10 (26 ) 1,371 Total service revenues – commodity consideration 6 18 97 — — 121 Product sales External 59 46 706 — — 811 Internal 10 85 26 — (121 ) — Total product sales 69 131 732 — (121 ) 811 Total revenues $ 322 $ 756 $ 1,362 $ 10 $ (147 ) $ 2,303 Nine Months Ended September 30, 2019 Segment revenues: Service revenues External $ 925 $ 2,102 $ 1,384 $ 13 $ — $ 4,424 Internal 34 36 — 9 (79 ) — Total service revenues 959 2,138 1,384 22 (79 ) 4,424 Total service revenues – commodity consideration 9 33 116 — — 158 Product sales External 87 169 1,256 — — 1,512 Internal 27 57 46 — (130 ) — Total product sales 114 226 1,302 — (130 ) 1,512 Total revenues $ 1,082 $ 2,397 $ 2,802 $ 22 $ (209 ) $ 6,094 Northeast G&P Atlantic-Gulf West Other Eliminations Total (Millions) Nine Months Ended September 30, 2018 Segment revenues: Service revenues External $ 677 $ 1,769 $ 1,599 $ 17 $ — $ 4,062 Internal 30 37 — 9 (76 ) — Total service revenues 707 1,806 1,599 26 (76 ) 4,062 Total service revenues – commodity consideration 14 45 257 — — 316 Product sales External 214 131 1,759 — — 2,104 Internal 28 198 63 — (289 ) — Total product sales 242 329 1,822 — (289 ) 2,104 Total revenues $ 963 $ 2,180 $ 3,678 $ 26 $ (365 ) $ 6,482 September 30, 2019 Total assets $ 15,445 $ 16,888 $ 13,550 $ 928 $ (530 ) $ 46,281 December 31, 2018 Total assets $ 14,526 $ 16,346 $ 13,948 $ 849 $ (367 ) $ 45,302
Reconciliation of Modified EBITDA to Net Income (Loss) [Table Text Block]	The following table reflects the reconciliation of Modified EBITDA to Net income (loss) as reported in the Consolidated Statement of Income . Three Months Ended Nine Months Ended 2019 2018 2019 2018 (Millions) Modified EBITDA by segment: Northeast G&P $ 345 $ 281 $ 947 $ 786 Atlantic-Gulf 599 492 1,683 1,418 West 311 412 921 1,214 Other (2 ) 6 1 (49 ) 1,253 1,191 3,552 3,369 Accretion expense associated with asset retirement obligations for nonregulated operations (8 ) (8 ) (25 ) (26 ) Depreciation and amortization expenses (435 ) (425 ) (1,275 ) (1,290 ) Equity earnings (losses) 93 105 260 279 Other investing income (loss) – net (107 ) 2 (54 ) 74 Proportional Modified EBITDA of equity-method investments (181 ) (205 ) (546 ) (552 ) Interest expense (296 ) (270 ) (888 ) (818 ) (Provision) benefit for income taxes (77 ) (190 ) (244 ) (297 ) Net income (loss) $ 242 $ 200 $ 780 $ 739

General, Description of Busin_2

General, Description of Business, and Basis of Presentation (Details) - USD ($) $ in Millions	Aug. 10, 2018	Jun. 30, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Apr. 30, 2019	Jan. 01, 2019
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Net			$ 1	$ 0	$ 142	$ (4)
Operating Lease, Liability			213		213
Operating Lease, Right-of-Use Asset			213		213
Accounting Standards Update 2016-02 [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Operating Lease, Liability								$ 225
Operating Lease, Right-of-Use Asset								$ 225
Northeast JV [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Increase (Decrease) in Deferred Income Taxes					$ (142)
Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest		65.00%
Dividend Reinvestment Program [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Sale of Stock, Number of Shares Issued in Transaction						1,230,657
Sale of Stock, Consideration Received on Transaction						$ 46
Northeast G And P [Member] | Cardinal Gas Services LLC [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Variable Interest Entity Ownership Percentage					66.00%
Northeast G And P [Member] | 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%
Northeast G And P [Member] | Northeast JV [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Variable Interest Entity Ownership Percentage					65.00%
Atlantic Gulf [Member] | Constitution Pipeline Company LLC [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Variable Interest Entity Ownership Percentage					41.00%
Atlantic Gulf [Member] | Gulfstar One [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Variable Interest Entity Ownership Percentage					51.00%
West [Member] | Conway Fractionator [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest					50.00%
Common Stock
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Net			0	0	$ 0	0
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)	1	(426)	14
Capital in excess of par value [Member] | Northeast JV [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Net					(426)
AOCI
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Net			0	0	0	0
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	$ (1)	568	$ (18)
Noncontrolling Interest [Member] | Northeast JV [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Net					$ 568
WPZ Merger Agreement [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Limited Partners' Capital Account, Units Outstanding	256,000,000
Stock Issued During Period, Shares, New Issues	382,000,000
Increase (Decrease) in Other Noncurrent Assets	$ 33
Increase (Decrease) in Deferred Income Taxes	(1,829)
WPZ Merger Agreement [Member] | Common Stock
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Net	382
WPZ Merger Agreement [Member] | 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	6,112
WPZ Merger Agreement [Member] | AOCI
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Net	(3)
WPZ Merger Agreement [Member] | Noncontrolling Interest [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Net	$ (4,629)
Laurel Mountain Midstream, LLC [Member] | Northeast G And P [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage			69.00%		69.00%
Caiman Energy II [Member] | Northeast G And P [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage			58.00%		58.00%
Gulfstream Natural Gas System, L.L.C.[Member] | Atlantic Gulf [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage			50.00%		50.00%
Discovery Producer Services LLC [Member] | Atlantic Gulf [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage			60.00%		60.00%
Overland Pass Pipeline Company LLC [Member] | West [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage			50.00%		50.00%
Rocky Mountain Midstream Holdings LLC [Member] | West [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage			50.00%		50.00%
Brazos Permian II LLC [Member] | West [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage			15.00%		15.00%
Jackalope Gas Gathering Services LLC [Member] | West [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage							50.00%

Acquisitions (Details)

Acquisitions (Details) - USD ($) $ in Millions	Mar. 18, 2019	Jun. 30, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2019	Sep. 30, 2018	Mar. 17, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Impairment of equity-method investments			$ 114			$ 0		$ 186	$ 0
Changes in ownership of consolidated subsidiaries, net			1			0		142	(4)
Northeast JV [Member]
Business Acquisition [Line Items]
Noncontrolling Interest in Joint Ventures		$ 1,330		$ 1,330
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners		35.00%		35.00%
Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest		65.00%
Increase (Decrease) in Deferred Income Taxes								(142)
Selling, general, and administrative expenses [Member] | Northeast JV [Member]
Business Acquisition [Line Items]
Business Combination, Acquisition Related Costs								6
Fair Value, Nonrecurring [Member] | Level 3 [Member] | Impairment Of Equity-Method Investments [Member]
Business Acquisition [Line Items]
Impairment of equity-method investments								(1)
Utica East Ohio Midstream, LLC [Member]
Business Acquisition [Line Items]
Equity Method Investment, Ownership Percentage											62.00%
Utica East Ohio Midstream, LLC [Member] | Fair Value, Nonrecurring [Member] | Level 3 [Member] | Northeast G And P [Member] | Impairment Of Equity-Method Investments [Member]
Business Acquisition [Line Items]
Impairment of equity-method investments					$ 74
Utica East Ohio Midstream, LLC Acquisition [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 741
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain (Loss), Net	0
Goodwill, Purchase Accounting Adjustments				$ 169
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Property, Plant, and Equipment				(106)
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles				$ (61)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents	13
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets	55
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	1,387
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	328
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	1,770
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities	7
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	7
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	1,763
Goodwill	188
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	1,951
Business Acquisition, Goodwill, Expected Tax Deductible Amount	$ 188
Finite-Lived Intangible Assets, Remaining Amortization Period	20 years
Percentage Of Finite Lived Intangible Assets Impacted By Our Intent Or Ability To Renew Or Extend Arrangement	49.00%
Acquired Finite-lived Intangible Asset, Weighted-Average Period before Renewal or Extension	10 years
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual							$ 104
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual							$ 25
Utica East Ohio Midstream, LLC Acquisition [Member] | Pro Forma [Member]
Business Acquisition [Line Items]
Business Acquisition, Pro Forma Revenue			1,999			2,342		6,126	6,589
Business Acquisition, Pro Forma Net Income (Loss)			221			138		804	434
Utica East Ohio Midstream, LLC Acquisition [Member] | Selling, general, and administrative expenses [Member]
Business Acquisition [Line Items]
Business Combination, Acquisition Related Costs								4
Utica East Ohio Midstream, LLC Acquisition [Member] | Utica East Ohio Midstream, LLC [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	38.00%
Business Combination, Step Acquisition, Equity Interest in Acquiree, Percentage										62.00%
Noncontrolling Interests
Business Acquisition [Line Items]
Changes in ownership of consolidated subsidiaries, net			2			(1)		568	(18)
Noncontrolling Interests | Northeast JV [Member]
Business Acquisition [Line Items]
Changes in ownership of consolidated subsidiaries, net								568
Capital in excess of par value [Member]
Business Acquisition [Line Items]
Changes in ownership of consolidated subsidiaries, net			$ (1)			$ 1		(426)	$ 14
Capital in excess of par value [Member] | Northeast JV [Member]
Business Acquisition [Line Items]
Changes in ownership of consolidated subsidiaries, net								$ (426)

Revenue Recognition Revenue by

Revenue Recognition Revenue by Category (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		$ 1,985	$ 2,280	$ 6,040	$ 6,423
Revenue Not from Contract with Customer	[1]	14	23	54	59
Total revenues		1,999	2,303	6,094	6,482
NonRegulated Service Monetary Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		716	749	2,159	2,208
NonRegulated Service Commodity Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		38	121	158	316
Total revenues		38	121	158	316
Regulated Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		710	566	2,067	1,696
Other Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		53	34	146	103
Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		1,517	1,470	4,530	4,323
Total revenues		1,495	1,371	4,424	4,062
NGL And Natural Gas Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		468	801	1,510	2,084
Other Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax			9		16
Total Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax			810		2,100
Total revenues		466	811	1,512	2,104
Northeast Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		379	316	1,067	947
Revenue Not from Contract with Customer	[1]	5	6	15	16
Total revenues		384	322	1,082	963
Northeast Midstream [Member] | NonRegulated Service Monetary Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		310	219	840	626
Northeast Midstream [Member] | NonRegulated Service Commodity Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		1	5	9	14
Northeast Midstream [Member] | Regulated Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Northeast Midstream [Member] | Other Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		38	23	104	65
Northeast Midstream [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		349	247	953	705
Northeast Midstream [Member] | NGL And Natural Gas Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		30	69	114	242
Northeast Midstream [Member] | Other Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax			0		0
Northeast Midstream [Member] | Total Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax			69		242
Atlantic Gulf Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		166	250	560	693
Revenue Not from Contract with Customer	[1]	2	5	6	14
Total revenues		168	255	566	707
Atlantic Gulf Midstream [Member] | NonRegulated Service Monetary Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		117	139	366	404
Atlantic Gulf Midstream [Member] | NonRegulated Service Commodity Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		7	19	33	45
Atlantic Gulf Midstream [Member] | Regulated Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Atlantic Gulf Midstream [Member] | Other Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		8	4	21	12
Atlantic Gulf Midstream [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		132	162	420	461
Atlantic Gulf Midstream [Member] | NGL And Natural Gas Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		34	88	140	232
Atlantic Gulf Midstream [Member] | Other Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax			0		0
Atlantic Gulf Midstream [Member] | Total Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax			88		232
West Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		741	1,249	2,455	3,342
Revenue Not from Contract with Customer	[1]	0	3	12	6
Total revenues		741	1,252	2,467	3,348
West Midstream [Member] | NonRegulated Service Monetary Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		308	409	1,007	1,231
West Midstream [Member] | NonRegulated Service Commodity Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		30	97	116	257
West Midstream [Member] | Regulated Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
West Midstream [Member] | Other Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		12	11	32	35
West Midstream [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		350	517	1,155	1,523
West Midstream [Member] | NGL And Natural Gas Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		391	720	1,300	1,799
West Midstream [Member] | Other Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax			12		20
West Midstream [Member] | Total Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax			732		1,819
Transco [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		642	498	1,825	1,465
Revenue Not from Contract with Customer	[1]	3	3	8	8
Total revenues		645	501	1,833	1,473
Transco [Member] | NonRegulated Service Monetary Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Transco [Member] | NonRegulated Service Commodity Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Transco [Member] | Regulated Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		601	457	1,736	1,368
Transco [Member] | Other Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	1	1
Transco [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		601	457	1,737	1,369
Transco [Member] | NGL And Natural Gas Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		41	41	88	96
Transco [Member] | Other Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax			0		0
Transco [Member] | Total Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax			41		96
Northwest Pipeline [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		111	110	335	330
Revenue Not from Contract with Customer	[1]	0	0	0	0
Total revenues		111	110	335	330
Northwest Pipeline [Member] | NonRegulated Service Monetary Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Northwest Pipeline [Member] | NonRegulated Service Commodity Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Northwest Pipeline [Member] | Regulated Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		111	110	335	330
Northwest Pipeline [Member] | Other Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Northwest Pipeline [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		111	110	335	330
Northwest Pipeline [Member] | NGL And Natural Gas Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Northwest Pipeline [Member] | Other Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax			0		0
Northwest Pipeline [Member] | Total Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax			0		0
Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	1	0	2
Revenue Not from Contract with Customer	[1]	7	9	22	24
Total revenues		7	10	22	26
Other [Member] | NonRegulated Service Monetary Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	1	0	2
Other [Member] | NonRegulated Service Commodity Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Other [Member] | Regulated Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Other [Member] | Other Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Other [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	1	0	2
Other [Member] | NGL And Natural Gas Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Other [Member] | Other Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax			0		0
Other [Member] | Total Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax			0		0
Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		(54)	(144)	(202)	(356)
Revenue Not from Contract with Customer	[1]	(3)	(3)	(9)	(9)
Total revenues		(57)	(147)	(211)	(365)
Intersegment Eliminations [Member] | NonRegulated Service Monetary Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		(19)	(19)	(54)	(55)
Intersegment Eliminations [Member] | NonRegulated Service Commodity Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Intersegment Eliminations [Member] | Regulated Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		(2)	(1)	(4)	(2)
Intersegment Eliminations [Member] | Other Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		(5)	(4)	(12)	(10)
Intersegment Eliminations [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		(26)	(24)	(70)	(67)
Intersegment Eliminations [Member] | NGL And Natural Gas Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		$ (28)	(117)	$ (132)	(285)
Intersegment Eliminations [Member] | Other Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax			(3)		(4)
Intersegment Eliminations [Member] | Total Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax			$ (120)		$ (289)
[1]	Revenues not within the scope of ASC 606, “Revenue from Contracts with Customers,” consist of leasing revenues associated with our headquarters building and management fees that we receive for certain services we provide to operated equity-method investments, which are reported in Service revenues in our Consolidated Statement of Income, and amounts associated with our derivative contracts, which are reported in Product sales in our Consolidated Statement of Income.

Revenue Recognition Contract As

Revenue Recognition Contract Assets (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Revenue Recognition [Abstract]
Contract with Customer, Asset, after Allowance for Credit Loss	$ 31	$ 56	$ 31	$ 56	$ 17	$ 4	$ 39	$ 4
Contract with Customer, Asset, Cumulative Catch-up Adjustment to Revenue, Change in Measure of Progress	14	17	53	53
Contract with Customer, Asset, Reclassified to Receivable	$ 0	$ 0	$ (26)	$ (1)

Revenue Recognition Contract Li

Revenue Recognition Contract Liabilities (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Contract with Customer, Asset, Allowance for Credit Loss [Roll Forward]
Contract with Customer, Liability	$ 1,331	$ 1,535	$ 1,397	$ 1,596
Contract with Customer, Liability, Cumulative Catch-up Adjustment to Revenue, Change in Measure of Progress	12	58	138	269
Contract With Customer Liability Increase Decrease For Contract Deconsolidated	0	0	0	(52)
ContractLiabilityNoncashInterestExpenseSignificantFinancingObligation	3	4	10	11
Contract with Customer, Liability, Revenue Recognized	(77)	(112)	(276)	(339)
Contract with Customer, Liability	$ 1,269	$ 1,485	$ 1,269	$ 1,485

Revenue Recognition Remaining P

Revenue Recognition Remaining Performance Obligations (Details) $ in Millions	Sep. 30, 2019USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01 | Performance Obligations Related To Contract Liabilities [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01 | Performance Obligations Excluding Contract Liabilities [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 762
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 | Performance Obligations Related To Contract Liabilities [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 | Performance Obligations Excluding Contract Liabilities [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 3,028
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | Performance Obligations Related To Contract Liabilities [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | Performance Obligations Excluding Contract Liabilities [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 2,873
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | Performance Obligations Related To Contract Liabilities [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | Performance Obligations Excluding Contract Liabilities [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 2,705
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | Performance Obligations Related To Contract Liabilities [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | Performance Obligations Excluding Contract Liabilities [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 2,244
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | Performance Obligations Related To Contract Liabilities [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | Performance Obligations Excluding Contract Liabilities [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 31,452
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period

Revenue Recognition Accounts Re

Revenue Recognition Accounts Receivable (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables, Net, Current	$ 875	$ 992
Accounts Receivable Related To Contracts With Customers [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables, Net, Current	791	858
Other Accounts Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables, Net, Current	$ 84	$ 134

Variable Interest Entities (Det

Variable Interest Entities (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	Apr. 30, 2019	Dec. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2019
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Proceeds from Sale of Equity Method Investments			$ 485	$ 0
Northeast JV [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners					35.00%
Jackalope Gas Gathering Services LLC [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Proceeds from Sale of Equity Method Investments	$ 485
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		$ 33	90
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		62	152
Variable Interest Entity, Primary Beneficiary [Member] | Other current assets and deferred charges [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets		2	5
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		2,363	6,167
Variable Interest Entity, Primary Beneficiary [Member] | Intangible assets - net of accumulated amortization [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets		1,177	2,697
Variable Interest Entity, Primary Beneficiary [Member] | Regulatory assets, deferred charges, and other [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets		0	13
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		(15)	(54)
Variable Interest Entity, Primary Beneficiary [Member] | Accrued liabilities [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities		(115)	(100)
Variable Interest Entity, Primary Beneficiary [Member] | Regulatory liabilities, deferred income, and other [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities		$ (264)	$ (268)
Variable Interest Entity, Primary Beneficiary [Member] | Gulfstar One [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage			51.00%
Variable Interest Entity, Primary Beneficiary [Member] | Constitution Pipeline Company LLC [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage			41.00%
Variable Interest Entity, Primary Beneficiary [Member] | Constitution Pipeline Company LLC [Member] | Estimated Remaining Construction Costs For Variable Interest Entity [Member]
Variable Interest Entity [Line Items]
Other commitment			$ 740
Variable Interest Entity, Primary Beneficiary [Member] | Constitution Pipeline Company LLC [Member] | Property plant and equipment, net [Member]
Variable Interest Entity [Line Items]
Capitalized Project Development Costs			$ 376
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] | Northeast JV [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage			65.00%
Variable Interest Entity, Not Primary Beneficiary [Member] | Jackalope Gas Gathering Services LLC [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage		50.00%
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Proceeds from Sale of Equity Method Investments	$ 485
Variable Interest Entity, Not Primary Beneficiary [Member] | Brazos Permian II LLC [Member] | Investments [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage			15.00%
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net			$ 197

Investing Activities (Details)

Investing Activities (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended				9 Months Ended
	Apr. 30, 2019	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Apr. 10, 2019
Schedule of Equity Method Investments [Line Items]
Impairment of equity-method investments (Note 13)		$ (114)		$ 0		$ (186)	$ 0
Gain (loss) on deconsolidation of businesses		0		0		(2)	62
Gain on disposition of equity-method investments		0		0		122	0
Other investing income (loss) - net		(107)		2		(54)	74
Proceeds from Sale of Equity Method Investments						485	0
West [Member] | Jackalope Gas Gathering Services LLC [Member]
Schedule of Equity Method Investments [Line Items]
Gain (loss) on deconsolidation of businesses					$ 62
Goodwill, Period Increase (Decrease)					$ 47
Equity Method Investment, Ownership Percentage	50.00%
Jackalope Gas Gathering Services LLC [Member]
Schedule of Equity Method Investments [Line Items]
Gain on disposition of equity-method investments			$ 122
Equity Method Investment, Ownership Percentage								50.00%
Proceeds from Sale of Equity Method Investments	$ 485
Jackalope Gas Gathering Services LLC [Member] | West [Member]
Schedule of Equity Method Investments [Line Items]
Variable Interest Entity Ownership Percentage					50.00%
Investments, Fair Value Disclosure					$ 310
Measurement Input, Discount Rate [Member] | Jackalope Gas Gathering Services LLC [Member] | West [Member]
Schedule of Equity Method Investments [Line Items]
Property Plant And Equipment And Intangibles Fair Value Inputs					10.90%
Other Income [Member]
Schedule of Equity Method Investments [Line Items]
Other investing income (loss) - net		$ 7		$ 2		$ 12	$ 12

Other Income and Expenses (Deta

Other Income and Expenses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Mar. 28, 2018
Segment Reporting Information [Line Items]
Tangible Asset Impairment Charges			$ 76	$ 64
Severance and other related costs	$ 10		53
Northeast G And P [Member]
Segment Reporting Information [Line Items]
Severance and other related costs	(3)		7
Other [Member]
Segment Reporting Information [Line Items]
Debt Instrument, Unamortized Discount (Premium), Net	0	$ 0	0	0	$ (7)
West [Member]
Segment Reporting Information [Line Items]
Severance and other related costs	2		16
Atlantic Gulf Midstream [Member]
Segment Reporting Information [Line Items]
Severance and other related costs	11		30
Operating Expense [Member]
Segment Reporting Information [Line Items]
Severance and other related costs	7		30
Other income (expense) - net [Member] | Other [Member]
Segment Reporting Information [Line Items]
Benefit of regulatory asset associated with increase in Transco's estimated deferred state income tax rate following WPZ Merger	0	(37)	12	(37)
Other income (expense) - net [Member] | Atlantic Gulf [Member]
Segment Reporting Information [Line Items]
Amortization of regulatory assets associated with asset retirement obligations	1	8	17	24
Accrual of regulatory liability related to overcollection of certain employee expenses	(9)	5	(11)	16
Adjustments to regulatory liabilities related to Tax Reform	0	0	0	(10)
Reversal of expenditures previously capitalized	0	0	10	0
Regulatory Charge Resulting From Tax Rate Change	(12)	0	(19)	0
Gain on asset retirement	0	(10)	0	(10)
Other income (expense) - net [Member] | West [Member]
Segment Reporting Information [Line Items]
Tangible Asset Impairment Charges	0	12	0	12
Adjustments to regulatory liabilities related to Tax Reform	0	0	0	(7)
Regulatory Charge Resulting From Tax Rate Change	6	6	18	18
Selling, general, and administrative expenses [Member]
Segment Reporting Information [Line Items]
Severance and other related costs	3		23
Selling, general, and administrative expenses [Member] | Other [Member]
Segment Reporting Information [Line Items]
Noncash Contribution Expense	0	35	0	35
WPZ Merger	0	15	0	19
Other Nonoperating Income (Expense) [Member] | Atlantic Gulf [Member]
Segment Reporting Information [Line Items]
Allowance for funds used during construction, capitalized cost of equity	9	32	21	78
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	$ 3	$ 19	$ 7	$ 28

Provision (Benefit) for Incom_3

Provision (Benefit) for Income Taxes (Details) - USD ($) $ in Millions	Aug. 10, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Current:
Federal		$ (10)	$ (19)	$ (25)	$ (55)
State		0	0	0	1
Foreign		1	0	1	0
Total		(9)	(19)	(24)	(54)
Deferred:
Federal		73	188	225	312
State		13	21	43	39
Total		86	209	268	351
Provision (benefit) for income taxes		$ 77	190	$ 244	297
Provision Related To Increase In Deferred State Income Tax Rate					38
Income Tax Contingency [Line Items]
Tax Credit Carryforward, Valuation Allowance			$ 105		105
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount					$ (31)
WPZ Merger Agreement [Member]
Income Tax Contingency [Line Items]
Increase (Decrease) in Deferred Income Taxes	$ (1,829)

Earnings (Loss) Per Common Sh_3

Earnings (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share Table [Line Items]
Net income (loss) available to common stockholders	$ 220	$ 129	$ 724	$ 416
Basic weighted-average shares	1,212,270	1,023,587	1,211,938	893,706
Effect of dilutive securities:
Diluted weighted-average shares	1,214,165	1,026,504	1,213,943	896,322
Earnings (loss) per common share:
Basic	$ 0.18	$ 0.13	$ 0.60	$ 0.47
Diluted	$ 0.18	$ 0.13	$ 0.60	$ 0.46
Nonvested restricted stock units [Member]
Effect of dilutive securities:
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	1,790	2,387	1,809	2,102
Stock Options [Member]
Effect of dilutive securities:
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	105	530	196	514

Employee Benefit Plans (Quarter

Employee Benefit Plans (Quarterly Info) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Pension Benefits [Member]
Components of net periodic benefit cost (credit):
Service cost	$ 11	$ 12	$ 33	$ 37
Interest cost	13	12	38	35
Expected return on plan assets	(15)	(16)	(46)	(47)
Amortization of net actuarial loss	3	6	11	17
Net actuarial loss from settlements	1	1	1	2
Net periodic benefit cost (credit)	13	15	37	44
Employer contributions			63
Estimated future employer contributions in current fiscal year	1		1
Other Postretirement Benefits [Member]
Components of net periodic benefit cost (credit):
Service cost	1	1	1	1
Interest cost	2	1	6	5
Expected return on plan assets	(3)	(2)	(8)	(8)
Amortization of prior service cost (credit)	0	0	0	(1)
Reclassification to regulatory liability	0	0	1	1
Net periodic benefit cost (credit)	0	$ 0	0	(2)
Amortization of prior service cost (credit) from regulatory assets (liabilities)				$ (1)
Employer contributions			4
Estimated future employer contributions in current fiscal year	$ 1		$ 1

Leases (Details)

Leases (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2019USD ($)
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	108 years	108 years
Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year	$ 8	$ 8
Operating Lease, Cost	10	31
Short-term Lease, Cost	0	0
Variable Lease, Cost	7	21
Sublease Income	0	(1)
Lease, Cost	17	51
Operating Lease, Payments	10	30
Operating Lease, Right-of-Use Asset	213	213
Operating Lease, Liability, Current	23	23
Operating Lease, Liability, Noncurrent	$ 190	$ 190
Operating Lease, Weighted Average Remaining Lease Term	13 years	13 years
Operating Lease, Weighted Average Discount Rate, Percent	4.60%	4.60%
Lessee, Operating Lease, Liability, Payments, Due Year Two	$ 32	$ 32
Lessee, Operating Lease, Liability, Payments, Due Year Three	33	33
Lessee, Operating Lease, Liability, Payments, Due Year Four	27	27
Lessee, Operating Lease, Liability, Payments, Due Year Five	21	21
Lessee, Operating Lease, Liability, Payments, Due after Year Five	171	171
Lessee, Operating Lease, Liability, Payments, Due	292	292
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	79	79
Operating Lease, Liability	$ 213	$ 213
Minimum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	1 year	1 year
Maximum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	15 years	15 years

Debt and Banking Arrangements L

Debt and Banking Arrangements Long-Term Debt Issuances and Retirements (Details 1) - 7.625% Senior Unsecured Notes Due 2019 [Member] - Williams Companies Inc [Member] $ in Millions	Jul. 15, 2019USD ($)
Debt Instrument [Line Items]
Extinguishment of Debt, Amount	$ 32
Long-term debt interest rate	7.625%

Debt and Banking Arrangements C

Debt and Banking Arrangements Credit Facilities and Commercial Paper (Details 2) - Williams Companies Inc [Member] $ in Millions	Sep. 30, 2019USD ($)
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity	$ 4,500	[1]
Credit facility, loans outstanding	0	[1]
Commercial Paper [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity	4,000
Commercial paper, outstanding	0
Letters Of Credit Under Certain Bilateral Bank Agreements [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, letters of credit outstanding	$ 14
[1]	In managing our available liquidity, we do not expect a maximum outstanding amount in excess of the capacity of our credit facility inclusive of any outstanding amounts under our commercial paper program.

Stockholders' Equity Issuance O

Stockholders' Equity Issuance Of Preferred Shares (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended
	Jul. 31, 2018	Sep. 30, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Preferred Stock, Value, Issued		$ 35	$ 35
Series B Preferred Stock [Member]
Class of Stock [Line Items]
Stock Issued During Period, Shares, New Issues	35,000
Preferred Stock, Value, Issued	$ 35
Preferred Stock, Dividend Rate, Percentage	7.25%
Preferred Stock, Shares Authorized	30,000,000
Preferred Stock, Par or Stated Value Per Share	$ 1

Stockholders' Equity Table Of C

Stockholders' Equity Table Of Changes In AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			$ (270)
Other comprehensive income (loss)	$ (1)	$ 6	4	$ 9
Total, Ending Balance	(266)		(266)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			(270)
Other comprehensive income (loss) before reclassifications			(5)
Amounts reclassified from accumulated other comprehensive income (loss)			9
Other comprehensive income (loss)	(1)	$ 5	4	$ 11
Total, Ending Balance	(266)		(266)
Cash Flow Hedges
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)
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			(1)
Other comprehensive income (loss) before reclassifications			0
Amounts reclassified from accumulated other comprehensive income (loss)			0
Other comprehensive income (loss)			0
Total, Ending Balance	(1)		(1)
Pension and Other Postretirement Benefits
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			(267)
Other comprehensive income (loss) before reclassifications			(5)
Amounts reclassified from accumulated other comprehensive income (loss)			9
Other comprehensive income (loss)			4
Total, Ending Balance	$ (263)		(263)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss)			$ 9

Stockholders' Equity Table Of R

Stockholders' Equity Table Of Reclassifications from AOCI (Details) - Reclassification out of Accumulated Other Comprehensive Income [Member] $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax benefit	$ (3)
Reclassifications during the period	9
Pension and Other Postretirement Benefits
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of actuarial (gain) loss and net actuarial loss from settlements included in net periodic benefit cost (credit)	$ 12

Fair Value Measurements and G_3

Fair Value Measurements and Guarantees Recurring Measurements and Additional (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
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:
Long-term debt, including current portion	(22,257)	$ (22,414)
Guarantees	(42)	(43)
Fair Value [Member]
Additional disclosures:
Long-term debt, including current portion	(25,234)	(23,330)
Guarantees	(29)	(30)
Level 1 [Member]
Additional disclosures:
Long-term debt, including current portion	0	0
Guarantees	0	0
Level 2 [Member]
Additional disclosures:
Long-term debt, including current portion	(25,234)	(23,330)
Guarantees	(13)	(14)
Level 3 [Member]
Additional disclosures:
Long-term debt, including current portion	0	0
Guarantees	(16)	(16)
Fair Value, Recurring [Member] | Carrying Amount [Member]
Measured on a recurring basis:
ARO Trust investments	187	150
Fair Value, Recurring [Member] | Carrying Amount [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	4	3
Energy derivatives liabilities	(5)	(7)
Fair Value, Recurring [Member] | Fair Value [Member]
Measured on a recurring basis:
ARO Trust investments	187	150
Fair Value, Recurring [Member] | Fair Value [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	4	3
Energy derivatives liabilities	(5)	(7)
Fair Value, Recurring [Member] | Level 1 [Member]
Measured on a recurring basis:
ARO Trust investments	187	150
Fair Value, Recurring [Member] | Level 1 [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	4	3
Energy derivatives liabilities	(2)	(4)
Fair Value, Recurring [Member] | Level 2 [Member]
Measured on a recurring basis:
ARO Trust investments	0	0
Fair Value, 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, Recurring [Member] | Level 3 [Member]
Measured on a recurring basis:
ARO Trust investments	0	0
Fair Value, Recurring [Member] | Level 3 [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	0	0
Energy derivatives liabilities	(3)	$ (3)
WilTel Guarantee [Member]
Additional disclosures:
Guarantor Obligations, Maximum Exposure, Undiscounted	28
Indemnification Agreement [Member] | Carrying Amount [Member]
Additional disclosures:
Guarantees	$ 0

Fair Value Measurements and G_4

Fair Value Measurements and Guarantees Nonrecurring Measurements (Details) - USD ($) $ in Millions

Sep. 30, 2019

Aug. 31, 2019

Jun. 30, 2019

[1]

Mar. 31, 2019

[2]

Mar. 17, 2019

Jun. 30, 2018

Sep. 30, 2019

Sep. 30, 2018

Sep. 30, 2019

Sep. 30, 2018

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Tangible Asset Impairment Charges

$ 76

$ 64

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]

Impairment of equity-method investments (Note 13)

$ 114

$ 0

186

0

Impairment Of Certain Assets [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Tangible Asset Impairment Charges

76

66

Fair Value, Nonrecurring [Member] | Impairment Of Certain Assets [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Tangible Asset Impairment Charges

5

$ 0

Fair Value, Nonrecurring [Member] | Level 3 [Member] | Property Plant And Equipment, net [Member] | West [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]

Fair Value of Property, Plant, and Equipment

$ 40

$ 0

Fair Value, Nonrecurring [Member] | Level 3 [Member] | Impairment Of Certain Assets [Member] | West [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Tangible Asset Impairment Charges

$ 59

$ 12

Fair Value, Nonrecurring [Member] | Level 3 [Member] | Impairment Of Equity-Method Investments [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]

Impairment of equity-method investments (Note 13)

(1)

Fair Value, Nonrecurring [Member] | Level 2 [Member] | Property Plant And Equipment, net [Member] | Other [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]

Fair Value of Property, Plant, and Equipment

[3]

$ 25

Fair Value, Nonrecurring [Member] | Level 2 [Member] | Impairment Of Certain Assets [Member] | Other [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Tangible Asset Impairment Charges

[3]

$ 66

Laurel Mountain Midstream, LLC [Member] | Fair Value, Nonrecurring [Member] | Level 3 [Member] | Investments [Member] | Northeast G And P [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Investments, Fair Value Disclosure

[4]

$ 242

$ 242

$ 242

Laurel Mountain Midstream, LLC [Member] | Fair Value, Nonrecurring [Member] | Level 3 [Member] | Impairment Of Equity-Method Investments [Member] | Northeast G And P [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]

Impairment of equity-method investments (Note 13)

[4]

$ 79

Laurel Mountain Midstream, LLC [Member] | Measurement Input, Discount Rate [Member] | Fair Value, Nonrecurring [Member] | Level 3 [Member] | Investments [Member] | Northeast G And P [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Investments Fair Value Inputs

10.20%

10.20%

10.20%

Appalachia Midstream Services, LLC [Member] | Fair Value, Nonrecurring [Member] | Level 3 [Member] | Investments [Member] | Northeast G And P [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Investments, Fair Value Disclosure

[5]

$ 102

$ 102

$ 102

Appalachia Midstream Services, LLC [Member] | Fair Value, Nonrecurring [Member] | Level 3 [Member] | Impairment Of Equity-Method Investments [Member] | Northeast G And P [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]

Impairment of equity-method investments (Note 13)

[5]

$ 17

Appalachia Midstream Services, LLC [Member] | Measurement Input, Discount Rate [Member] | Fair Value, Nonrecurring [Member] | Level 3 [Member] | Investments [Member] | Northeast G And P [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Investments Fair Value Inputs

9.00%

9.00%

9.00%

Pennant Midstream, LLC [Member] | Fair Value, Nonrecurring [Member] | Level 2 [Member] | Investments [Member] | Northeast G And P [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Investments, Fair Value Disclosure

[6]

$ 11

Pennant Midstream, LLC [Member] | Fair Value, Nonrecurring [Member] | Level 2 [Member] | Impairment Of Equity-Method Investments [Member] | Northeast G And P [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]

Impairment of equity-method investments (Note 13)

[6]

$ 17

Utica East Ohio Midstream, LLC [Member] | Fair Value, Nonrecurring [Member] | Level 2 [Member] | Investments [Member] | Northeast G And P [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Investments, Fair Value Disclosure

[7]

$ 1,210

Utica East Ohio Midstream, LLC [Member] | Fair Value, Nonrecurring [Member] | Level 2 [Member] | Impairment Of Equity-Method Investments [Member] | Northeast G And P [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]

Impairment of equity-method investments (Note 13)

[7]

$ 74

[1]

Relates to a gas gathering system in the Eagle Ford region with expected declines in asset utilization and possible idling of the gathering system. The estimated fair value of the Property, plant, and equipment – net was determined using a market approach which incorporated indications of interest from third parties.

[2]

Reflects impairment of Property, plant, and equipment – net that is no longer in use for which the fair value was determined to be lower than the carrying value.

[3]

Relates to certain idle pipelines. The estimated fair value of the Property, plant, and equipment – net was determined by a market approach incorporating information derived from bids received for these assets, which we marketed for sale together with certain other assets. These inputs resulted in a fair value measurement within Level 2 of the fair value hierarchy. We sold these assets in the fourth quarter of 2018.

[4]

Relates to a gas gathering system in the Marcellus region that was adversely impacted by lower sustained forward natural gas price expectations and changes in expected producer activity. The estimated fair value was determined using an income approach. We utilized a discount rate of 10.2 percent in our analysis. This impairment is reported in Other investing income (loss) – net in the Consolidated Statement of Income .

[5]

Relates to a certain gathering system held in Appalachia Midstream Investments that was adversely impacted by changes in the timing of expected producer activity. The estimated fair value was determined using an income approach. We utilized a discount rate of 9.0 percent in our analysis. This impairment is reported in Other investing income (loss) – net in the Consolidated Statement of Income .

[6]

The estimated fair value of Pennant Midstream, LLC (“Pennant”) was determined by a market approach based on recent observable third-party transactions. These inputs resulted in a fair value measurement within Level 2 of the fair value hierarchy. This impairment is reported in Other investing income (loss) – net in the Consolidated Statement of Income .

[7]

The estimated fair value was determined by a market approach based on the transaction price for the purchase of the remaining interest in UEOM as finalized just prior to the signing and closing of the acquisition in March 2019 (see Note 2 – Acquisitions ). These inputs resulted in a fair value measurement within Level 2 of the fair value hierarchy. This impairment is reported in Other investing income (loss) - net in the Consolidated Statement of Income .

Contingent Liabilities (Details

Contingent Liabilities (Details) - USD ($) $ in Millions	May 20, 2016	Sep. 30, 2019
Loss Contingencies [Line Items]
Customer Refund Liability, Current		$ 131
Accrued environmental loss liabilities		33
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		5
Natural Gas Under Ground Storage Facilities [Member]
Loss Contingencies [Line Items]
Accrued environmental loss liabilities		8
Former Operations [Member]
Loss Contingencies [Line Items]
Accrued environmental loss liabilities		20
Maximum [Member] | Former Alaska Refinery [Member]
Loss Contingencies [Line Items]
Loss contingency, range of possible loss		$ 32

Segment Disclosures Reconciliat

Segment Disclosures Reconciliation of Segment Revenues to Consolidated (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment revenues
Revenues	$ 1,999	$ 2,303	$ 6,094	$ 6,482
Intersegment Elimination [Member]
Segment revenues
Revenues	(58)	(147)	(209)	(365)
Operating Segments [Member] | Northeast G And P [Member]
Segment revenues
Revenues	384	322	1,082	963
Operating Segments [Member] | Atlantic Gulf [Member]
Segment revenues
Revenues	814	756	2,397	2,180
Operating Segments [Member] | West [Member]
Segment revenues
Revenues	852	1,362	2,802	3,678
Operating Segments [Member] | Other [Member]
Segment revenues
Revenues	7	10	22	26
Service [Member]
Segment revenues
Revenues	1,495	1,371	4,424	4,062
Service [Member] | Northeast G And P [Member]
Segment revenues
Revenues	340	236	925	677
Service [Member] | Atlantic Gulf [Member]
Segment revenues
Revenues	718	595	2,102	1,769
Service [Member] | West [Member]
Segment revenues
Revenues	433	533	1,384	1,599
Service [Member] | Other [Member]
Segment revenues
Revenues	4	7	13	17
Service [Member] | Intersegment Elimination [Member]
Segment revenues
Revenues	(29)	(26)	(79)	(76)
Service [Member] | Intersegment Elimination [Member] | Northeast G And P [Member]
Segment revenues
Revenues	(13)	(11)	(34)	(30)
Service [Member] | Intersegment Elimination [Member] | Atlantic Gulf [Member]
Segment revenues
Revenues	(13)	(12)	(36)	(37)
Service [Member] | Intersegment Elimination [Member] | West [Member]
Segment revenues
Revenues	0	0	0	0
Service [Member] | Intersegment Elimination [Member] | Other [Member]
Segment revenues
Revenues	(3)	(3)	(9)	(9)
Service [Member] | Operating Segments [Member] | Northeast G And P [Member]
Segment revenues
Revenues	353	247	959	707
Service [Member] | Operating Segments [Member] | Atlantic Gulf [Member]
Segment revenues
Revenues	731	607	2,138	1,806
Service [Member] | Operating Segments [Member] | West [Member]
Segment revenues
Revenues	433	533	1,384	1,599
Service [Member] | Operating Segments [Member] | Other [Member]
Segment revenues
Revenues	7	10	22	26
NonRegulated Service Commodity Consideration [Member]
Segment revenues
Revenues	38	121	158	316
NonRegulated Service Commodity Consideration [Member] | Intersegment Elimination [Member]
Segment revenues
Revenues	0	0	0	0
NonRegulated Service Commodity Consideration [Member] | Operating Segments [Member] | Northeast G And P [Member]
Segment revenues
Revenues	1	6	9	14
NonRegulated Service Commodity Consideration [Member] | Operating Segments [Member] | Atlantic Gulf [Member]
Segment revenues
Revenues	7	18	33	45
NonRegulated Service Commodity Consideration [Member] | Operating Segments [Member] | West [Member]
Segment revenues
Revenues	30	97	116	257
NonRegulated Service Commodity Consideration [Member] | Operating Segments [Member] | Other [Member]
Segment revenues
Revenues	0	0	0	0
Product [Member]
Segment revenues
Revenues	466	811	1,512	2,104
Product [Member] | Northeast G And P [Member]
Segment revenues
Revenues	22	59	87	214
Product [Member] | Atlantic Gulf [Member]
Segment revenues
Revenues	66	46	169	131
Product [Member] | West [Member]
Segment revenues
Revenues	378	706	1,256	1,759
Product [Member] | Other [Member]
Segment revenues
Revenues	0	0	0	0
Product [Member] | Intersegment Elimination [Member]
Segment revenues
Revenues	(29)	(121)	(130)	(289)
Product [Member] | Intersegment Elimination [Member] | Northeast G And P [Member]
Segment revenues
Revenues	(8)	(10)	(27)	(28)
Product [Member] | Intersegment Elimination [Member] | Atlantic Gulf [Member]
Segment revenues
Revenues	(10)	(85)	(57)	(198)
Product [Member] | Intersegment Elimination [Member] | West [Member]
Segment revenues
Revenues	(11)	(26)	(46)	(63)
Product [Member] | Intersegment Elimination [Member] | Other [Member]
Segment revenues
Revenues	0	0	0	0
Product [Member] | Operating Segments [Member] | Northeast G And P [Member]
Segment revenues
Revenues	30	69	114	242
Product [Member] | Operating Segments [Member] | Atlantic Gulf [Member]
Segment revenues
Revenues	76	131	226	329
Product [Member] | Operating Segments [Member] | West [Member]
Segment revenues
Revenues	389	732	1,302	1,822
Product [Member] | Operating Segments [Member] | Other [Member]
Segment revenues
Revenues	$ 0	$ 0	$ 0	$ 0

Segment Disclosures Reconcili_2

Segment Disclosures Reconciliation of Segment Assets to Consolidated (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Segment assets:
Total assets	$ 46,281	$ 45,302
Northeast G And P [Member]
Segment assets:
Total assets	15,445	14,526
Atlantic Gulf [Member]
Segment assets:
Total assets	16,888	16,346
West [Member]
Segment assets:
Total assets	13,550	13,948
Other [Member]
Segment assets:
Total assets	928	849
Intersegment Elimination [Member]
Segment assets:
Total assets	$ (530)	$ (367)

Segment Disclosures Reconcili_3

Segment Disclosures Reconciliation of Segment Modified EBITDA to Consolidated Net Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Reconciliation of Modified EBITDA to Net Income (Loss):
Modified EBITDA Earnings (Loss)	$ 1,253	$ 1,191	$ 3,552	$ 3,369
Accretion expense associated with asset retirement obligations for nonregulated operations	(8)	(8)	(25)	(26)
Depreciation and amortization expenses	(435)	(425)	(1,275)	(1,290)
Equity earnings (losses)	93	105	260	279
Other investing income (loss) - net	(107)	2	(54)	74
Proportional Modified EBITDA of equity-method investments	(181)	(205)	(546)	(552)
Interest expense	(296)	(270)	(888)	(818)
(Provision) benefit for income taxes	(77)	(190)	(244)	(297)
Net income (loss)	242	200	780	739
Operating Segments [Member] | Northeast G And P [Member]
Reconciliation of Modified EBITDA to Net Income (Loss):
Modified EBITDA Earnings (Loss)	345	281	947	786
Operating Segments [Member] | Atlantic Gulf [Member]
Reconciliation of Modified EBITDA to Net Income (Loss):
Modified EBITDA Earnings (Loss)	599	492	1,683	1,418
Operating Segments [Member] | West [Member]
Reconciliation of Modified EBITDA to Net Income (Loss):
Modified EBITDA Earnings (Loss)	311	412	921	1,214
Operating Segments [Member] | Other [Member]
Reconciliation of Modified EBITDA to Net Income (Loss):
Modified EBITDA Earnings (Loss)	$ (2)	$ 6	$ 1	$ (49)

Uncategorized Items - wmb201909

Label	Element	Value
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Contract with Customer, Liability	us-gaap_ContractWithCustomerLiability	$ 126,000,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Contract with Customer, Liability	us-gaap_ContractWithCustomerLiability	70,000,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Contract with Customer, Liability	us-gaap_ContractWithCustomerLiability	103,000,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Contract with Customer, Liability	us-gaap_ContractWithCustomerLiability	167,000,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Contract with Customer, Liability	us-gaap_ContractWithCustomerLiability	1,269,000,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Contract with Customer, Liability	us-gaap_ContractWithCustomerLiability	691,000,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Contract with Customer, Liability	us-gaap_ContractWithCustomerLiability	$ 112,000,000