The Williams Companies, Inc. (WMB) 8-K 25 May 17 Other Events Financial data

Document and Entity Information

Document and Entity Information	12 Months Ended
	Dec. 31, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	Williams Companies Inc
Entity Central Index Key	107,263
Document Type	8-K
Document Period End Date	Dec. 31, 2016
Amendment Flag	false

Consolidated Statement of Opera

Consolidated Statement of Operations - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Revenues:
Service revenues	$ 5,171		$ 5,164		$ 4,116
Product sales	2,328		2,196		3,521
Total revenues	7,499		7,360		7,637
Costs and expenses:
Product costs	1,725		1,779		3,016
Operating and maintenance expenses	1,580		1,655		1,492
Depreciation and amortization expenses	1,763		1,738		1,176
Selling, general, and administrative expenses	723		741		661
Impairment of goodwill (Note 17)	0		1,098		0
Impairment of certain assets (Note 17)	873		209		52
Net insurance recoveries – Geismar Incident	(7)		(126)		(232)
Other (income) expense – net	142		40		(97)
Total costs and expenses	6,799		7,134		6,068
Operating income (loss)	700		226		1,569
Equity earnings (losses)	397		335		144
Gain on remeasurement of equity-method investment (Note 2)	0		0		2,544
Impairment of equity-method investments (Note 17)	(430)		(1,359)		0
Other investing income (loss) – net	63		27		43
Interest incurred	(1,217)		(1,118)		(888)
Interest capitalized	38		74		141
Other income (expense) – net	74		102		31
Income (loss) from continuing operations before income taxes	(375)		(1,713)		3,584
Provision (benefit) for income taxes	(25)		(399)		1,249
Income (loss) from continuing operations	(350)		(1,314)		2,335
Income (loss) from discontinued operations	0		0		4
Net income (loss)	(350)		(1,314)		2,339
Less: Net income (loss) attributable to noncontrolling interests	74		(743)		225
Net income (loss) attributable to The Williams Companies, Inc.	(424)		(571)		2,114
Amounts attributable to The Williams Companies, Inc.:
Income (loss) from continuing operations	(424)		(571)		2,110
Income (loss) from discontinued operations	0		0		4
Net income (loss) attributable to The Williams Companies, Inc.	$ (424)		$ (571)		$ 2,114
Basic earnings (loss) per common share:
Income (loss) from continuing operations	$ (0.57)		$ (0.76)		$ 2.93
Income (loss) from discontinued operations	0		0		0.01
Net income (loss)	$ (0.57)		$ (0.76)		$ 2.94
Weighted-average shares (thousands)	750,673		749,271		719,325
Diluted earnings (loss) per common share:
Income (loss) from continuing operations	$ (0.57)		$ (0.76)		$ 2.91
Income (loss) from discontinued operations	0		0		0.01
Net income (loss)	$ (0.57)		$ (0.76)		$ 2.92
Weighted-average shares (thousands)	750,673	[1]	749,271	[1]	723,641
[1]	For the years ended December 31, 2016 and December 31, 2015, 0.6 million and 1.7 million weighted-average nonvested restricted stock units, and 0.5 million and 1.5 million weighted-average stock options have been excluded from the computation of diluted earnings (loss) per common share as their inclusion would be antidilutive due to our loss from continuing operations attributable to The Williams Companies, Inc.

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Comprehensive income (loss):
Net income (loss)	$ (350)	$ (1,314)	$ 2,339
Cash flow hedging activities:
Net unrealized gain (loss) from derivative instruments, net of taxes of ($1) in 2016	4	6	0
Reclassifications into earnings of net derivative instruments (gain) loss, net of taxes of $1 in 2016 and 2015	(2)	(6)	0
Foreign currency translation activities:
Foreign currency translation adjustments, net of taxes of ($37), $31, and $18 in 2016, 2015, and 2014, respectively	50	(204)	(96)
Reclassification into earnings upon sale of foreign entities, net of taxes of ($36) in 2016	119	0	0
Pension and other postretirement benefits:
Prior service credit (cost) arising during the year (Note 10)	0	0	(1)
Amortization of prior service cost (credit) included in net periodic benefit cost, net of taxes of $2, $3 and $3 in 2016, 2015 and 2014, resepctively	(4)	(3)	(5)
Net actuarial gain (loss) arising during the year, net of taxes of $8, ($5) and $60 in 2016, 2015, and 2014, respectively (Note 10)	(15)	8	(100)
Amortization of actuarial (gain) loss included in net periodic benefit cost, net of taxes of ($12), ($18) and ($15) in 2016, 2015, and 2014, respectively	20	28	26
Other comprehensive income (loss)	172	(171)	(176)
Comprehensive income (loss)	(178)	(1,485)	2,163
Less: Comprehensive income (loss) attributable to noncontrolling interests	143	(813)	206
Comprehensive Income (loss) attributable to The Williams Companies, Inc.	$ (321)	$ (672)	$ 1,957

Consolidated Statement of Comp4

Consolidated Statement of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flow hedging activities:
Other Comprehensive Income, Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	$ (1)	$ 0	$ 0
Other Comprehensive Income Loss Reclassification Adjustment On Derivatives Included In Net Income Tax	1	1	0
Foreign currency translation activities:
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	(37)	31	18
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Tax	(36)	0	0
Pension and other postretirement benefits:
Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans, Benefit Plan Improvement, Tax Effect	0	0	0
Other Comprehensive Income Amortization Of Defined Benefit Plan Net Prior Service Cost Recognized In Net Periodic Pension Cost Tax	2	3	3
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Tax	8	(5)	60
Other Comprehensive Income Loss Reclassification Pension And Other Postretirement Benefit Plans Net Gain Loss Recognized In Net Periodic Benefit Cost Tax	$ (12)	$ (18)	$ (15)

Consolidated Balance Sheet

Consolidated Balance Sheet - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 170	$ 100
Trade accounts and other receivables (net of allowance of $6 at December 31, 2016 and $3 at December 31, 2015)	938	1,041
Inventories	138	127
Other current assets and deferred charges	216	259
Total current assets	1,462	1,527
Investments	6,701	7,336
Property, plant, and equipment – net	28,428	29,579
Intangible assets – net of accumulated amortization	9,663	10,017
Regulatory assets, deferred charges, and other	581	561
Total assets	46,835	49,020
Current liabilities:
Accounts payable	623	744
Accrued liabilities	1,448	1,078
Commercial paper	93	499
Long-term debt due within one year	785	176
Total current liabilities	2,949	2,497
Long-term debt	22,624	23,812
Deferred income tax liabilities	4,238	4,218
Regulatory liabilities, deferred income, and other	2,978	2,268
Contingent liabilities and commitments (Note 18)
Stockholders’ equity:
Common stock (960 million shares authorized at $1 par value; 785 million shares issued at December 31, 2016 and 784 million shares issued at December 31, 2015)	785	784
Capital in excess of par value	14,887	14,807
Retained deficit	(9,649)	(7,960)
Accumulated other comprehensive income (loss)	(339)	(442)
Treasury stock, at cost (35 million shares of common stock)	(1,041)	(1,041)
Total stockholders’ equity	4,643	6,148
Noncontrolling interests in consolidated subsidiaries	9,403	10,077
Total equity	14,046	16,225
Total liabilities and equity	$ 46,835	$ 49,020

Consolidated Balance Sheet (Par

Consolidated Balance Sheet (Parenthetical) - USD ($) shares in Millions, $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Stockholders’ equity:
Common stock, shares authorized	960	960
Common stock, par value per share	$ 1	$ 1
Common Stock, shares issued	785	784
Treasury stock, shares of common stock	35	35
Allowance for trade accounts and other receivables	$ 6	$ 3

Consolidated Statement of Chang

Consolidated Statement of Changes in Equity - USD ($) $ in Millions	Total	Common Stock	Capital in Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Total Stockholders' Equity	Noncontrolling Interests
Beginning balance at Dec. 31, 2013	$ 8,921	$ 718	$ 11,599	$ (6,248)	$ (164)	$ (1,041)	$ 4,864	$ 4,057
Net income (loss)	2,339	0	0	2,114	0	0	2,114	225
Other comprehensive income (loss)	(176)	0	0	0	(157)	0	(157)	(19)
Issuance of common stock for acquisition of business (Note 15)	3,378	61	3,317	0	0	0	3,378	0
Noncontrolling interest resulting from acquisition of business (Note 2)	7,502	0	0	0	0	0	0	7,502
Cash dividends - common stock (Note 15)	(1,412)	0	0	(1,412)	0	0	(1,412)	0
Dividends and distributions to noncontrolling interests	(840)	0	0	0	0	0	0	(840)
Stock-based compensation and related common stock issuances, net of tax	88	3	85	0	0	0	88	0
Sales of limited partner units of Williams Partners L.P.	55	0	0	0	0	0	0	55
Changes in ownership of consolidated subsidiaries, net	44	0	(73)	0	(20)	0	(93)	137
Contributions from noncontrolling interests	340	0	0	0	0	0	0	340
Deconsolidation of Bluegrass Pipeline (Note 6)	(63)	0	0	0	0	0	0	(63)
Other	(4)	0	(3)	(2)	0	0	(5)	1
Net increase (decrease) in equity	11,251	64	3,326	700	(177)	0	3,913	7,338
Ending balance at Dec. 31, 2014	20,172	782	14,925	(5,548)	(341)	(1,041)	8,777	11,395
Net income (loss)	(1,314)	0	0	(571)	0	0	(571)	(743)
Other comprehensive income (loss)	(171)	0	0	0	(101)	0	(101)	(70)
Cash dividends - common stock (Note 15)	(1,836)	0	0	(1,836)	0	0	(1,836)	0
Dividends and distributions to noncontrolling interests	(942)	0	0	0	0	0	0	(942)
Stock-based compensation and related common stock issuances, net of tax	30	2	28	0	0	0	30	0
Sales of limited partner units of Williams Partners L.P.	59	0	0	0	0	0	0	59
Changes in ownership of consolidated subsidiaries, net	94	0	(160)	0	0	0	(160)	254
Contributions from noncontrolling interests	111	0	0	0	0	0	0	111
Other	22	0	14	(5)	0	0	9	13
Net increase (decrease) in equity	(3,947)	2	(118)	(2,412)	(101)	0	(2,629)	(1,318)
Ending balance at Dec. 31, 2015	16,225	784	14,807	(7,960)	(442)	(1,041)	6,148	10,077
Net income (loss)	(350)	0	0	(424)	0	0	(424)	74
Other comprehensive income (loss)	172	0	0	0	103	0	103	69
Cash dividends - common stock (Note 15)	(1,261)	0	0	(1,261)	0	0	(1,261)	0
Dividends and distributions to noncontrolling interests	(940)	0	0	0	0	0	0	(940)
Stock-based compensation and related common stock issuances, net of tax	57	1	56	0	0	0	57	0
Sales of limited partner units of Williams Partners L.P.	114	0	0	0	0	0	0	114
Changes in ownership of consolidated subsidiaries, net	(6)	0	12	0	0	0	12	(18)
Contributions from noncontrolling interests	29	0	0	0	0	0	0	29
Other	6	0	12	(4)	0	0	8	(2)
Net increase (decrease) in equity	(2,179)	1	80	(1,689)	103	0	(1,505)	(674)
Ending balance at Dec. 31, 2016	$ 14,046	$ 785	$ 14,887	$ (9,649)	$ (339)	$ (1,041)	$ 4,643	$ 9,403

Consolidated Statement of Cash

Consolidated Statement of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
OPERATING ACTIVITIES:
Net income (loss)	$ (350)	$ (1,314)	$ 2,339
Adjustments to reconcile to net cash provided (used) by operating activities:
Depreciation and amortization	1,763	1,738	1,176
Provision (benefit) for deferred income taxes	(26)	(337)	1,264
Impairment of goodwill	0	1,098	0
Impairment of equity-method investments	430	1,359	0
Impairment of and net (gain) loss on sale of assets and businesses	918	215	67
Amortization of stock-based awards	73	82	53
Gain on remeasurement of equity-method investment	0	0	(2,544)
Cash provided (used) by changes in current assets and liabilities:
Accounts and notes receivable	82	39	(276)
Inventories	(25)	105	(36)
Other current assets and deferred charges	(4)	4	(44)
Accounts payable	35	(88)	(8)
Accrued liabilities	512	54	(184)
Other, including changes in noncurrent assets and liabilities	272	(247)	327
Net cash provided (used) by operating activities	3,680	2,708	2,134
FINANCING ACTIVITIES:
Proceeds from (payments of) commercial paper – net	(409)	(306)	572
Proceeds from long-term debt	6,528	9,772	7,321
Payments of long-term debt	(7,091)	(6,516)	(1,828)
Proceeds from issuance of common stock	9	27	3,416
Proceeds from sale of limited partner units of consolidated partnership	114	59	55
Dividends paid	(1,261)	(1,836)	(1,412)
Dividends and distributions paid to noncontrolling interests	(940)	(942)	(840)
Contributions from noncontrolling interests	29	111	340
Payments for debt issuance costs	(9)	(35)	(40)
Special distribution from Gulfstream	0	396	0
Contribution to Gulfstream for repayment of debt	(148)	(248)	0
Other – net	(16)	(31)	(2)
Net cash provided (used) by financing activities	(3,194)	451	7,582
INVESTING ACTIVITIES:
Capital expenditures (1)	(2,051)	(3,167)	(4,031)
Net proceeds from dispositions	30	3	34
Proceeds from sale of businesses, net of cash divested	1,020	0	0
Purchases of businesses, net of cash acquired	0	(112)	(5,958)
Purchases of and contributions to equity-method investments	(177)	(595)	(482)
Distributions from unconsolidated affiliates in excess of cumulative earnings	472	404	206
Other – net	290	168	74
Net cash provided (used) by investing activities	(416)	(3,299)	(10,157)
Increase (decrease) in cash and cash equivalents	70	(140)	(441)
Cash and cash equivalents at beginning of year	100	240	681
Cash and cash equivalents at end of year	170	100	240
(1) Increases to property, plant, and equipment	(1,912)	(3,024)	(3,916)
Changes in related accounts payable and accrued liabilities	(139)	(143)	(115)
Capital expenditures (1)	$ (2,051)	$ (3,167)	$ (4,031)

General, Description of Busines

General, Description of Business, Basis of Presentation, and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General, Description of Business, Basis of Presentation and Summary Of Significant Accounting Policies [Text Block]	Note 1 – General, Description of Business, Basis of Presentation, and Summary of Significant Accounting Policies General Unless the context clearly indicates otherwise, references in this report to “Williams,” “we,” “our,” “us,” or like terms refer to The Williams Companies, Inc. and its subsidiaries. Unless the context clearly indicates otherwise, references to “Williams,” “we,” “our,” and “us” include the operations in which we own interests accounted for as equity-method investments that are not consolidated in our financial statements. When we refer to our equity investees by name, we are referring exclusively to their businesses and operations. Financial Repositioning In January 2017, we announced agreements with Williams Partners L.P. (WPZ), wherein we permanently waived the general partner’s incentive distribution rights (IDRs) and converted our 2 percent general partner interest in WPZ to a non-economic interest in exchange for 289 million newly issued WPZ common units. Pursuant to this agreement, we also purchased approximately 277 thousand WPZ common units for $10 million . Additionally, we purchased approximately 59 million common units of WPZ at a price of $36.08586 per unit in a private placement transaction, funded with proceeds from our equity offering (see Note 15 – Stockholders’ Equity). According to the terms of this agreement, following WPZ’s quarterly distribution in February 2017, we paid additional consideration of approximately $50 million to WPZ for these units. Following these transactions, we own a 74 percent limited partner interest in WPZ. Termination of WPZ Merger Agreement On May 12, 2015, we entered into an agreement for a unit-for-stock transaction whereby we would have acquired all of the publicly held outstanding common units of WPZ in exchange for shares of our common stock (WPZ Merger Agreement). On September 28, 2015, we entered into a Termination Agreement and Release (Termination Agreement), terminating the WPZ Merger Agreement. Under the terms of the Termination Agreement, we were required to pay a $428 million termination fee to WPZ, at which time we owned approximately 60 percent , including the interests of the general partner and IDRs. Such termination fee settled through a reduction of quarterly incentive distributions we were entitled to receive from WPZ (such reduction not to exceed $209 million per quarter). The distributions from WPZ in November 2015, February 2016, and May 2016 were reduced by $209 million , $209 million , and $10 million , respectively, related to this termination fee. ACMP Merger On February 2, 2015, Williams Partners L.P. merged with and into Access Midstream Partners, L.P. (ACMP Merger). For the purpose of these financial statements and notes, WPZ refers to the renamed merged partnership, while Pre-merger Access Midstream Partners, L.P. (ACMP) and Pre-merger Williams Partners L.P. (Pre-merger WPZ) refer to the separate partnerships prior to the consummation of the ACMP Merger and subsequent name change. The net assets of Pre-merger WPZ and ACMP were combined at our historical basis. Our basis in ACMP reflected our business combination accounting resulting from acquiring control of ACMP on July 1, 2014. Description of Business We are a Delaware corporation whose common stock is listed and traded on the New York Stock Exchange. Our operations are located principally in the United States. We have one reportable segment, Williams Partners. All remaining business activities are included in Other. For periods after the ACMP Acquisition (see Note 2 – Acquisitions ), the acquired ACMP business is reported within Williams Partners. For periods prior to the ACMP Acquisition, the results associated with our former equity-method investment in ACMP are reported within Other. Williams Partners Williams Partners consists of our consolidated master limited partnership, WPZ, and primarily includes gas pipeline and midstream businesses. WPZ’s gas pipeline businesses primarily consist of two interstate natural gas pipelines, which are Transcontinental Gas Pipe Line Company, LLC ( Transco ) and Northwest Pipeline LLC ( Northwest Pipeline ), and several joint venture investments in interstate and intrastate natural gas pipeline systems, including a 50 percent equity-method investment in Gulfstream Natural Gas System, L.L.C. ( Gulfstream ), and a 41 percent interest in Constitution Pipeline Company, LLC ( Constitution ) (a consolidated entity), which is under development. WPZ’s midstream businesses primarily consist of (1) natural gas gathering, treating, compression, and processing; (2) natural gas liquid (NGL) fractionation, storage, and transportation; (3) crude oil production handling and transportation; and (4) olefins production. The primary service areas are concentrated in major producing basins in Colorado, Texas, Oklahoma, Kansas, New Mexico, Wyoming, the Gulf of Mexico, Louisiana, Pennsylvania, West Virginia, New York, and Ohio which include the Barnett, Eagle Ford, Haynesville, Marcellus, Niobrara, and Utica Shale plays as well as the Mid-Continent region. The midstream businesses include equity-method investments in natural gas gathering and processing assets and NGL fractionation and transportation assets, including a 62 percent equity-method investment in Utica East Ohio Midstream, LLC ( UEOM ), a 50 percent equity-method investment in the Delaware basin gas gathering system (DBJV) in the Mid-Continent region, a 69 percent equity-method investment in Laurel Mountain Midstream, LLC ( Laurel Mountain ), a 58 percent equity-method investment in Caiman Energy II, LLC ( Caiman II ), a 60 percent equity-method investment in Discovery Producer Services, LLC ( Discovery ), a 50 percent equity-method investment in Overland Pass Pipeline, LLC ( OPPL ), and Appalachia Midstream Services, LLC, which owns equity-method investments with an approximate average 41 percent interest in multiple gathering systems in the Marcellus Shale ( Appalachia Midstream Investments ). The midstream businesses also included our Canadian midstream operations, which were comprised of an oil sands offgas processing plant located near Fort McMurray, Alberta, and an NGL/olefin fractionation facility at Redwater, Alberta. In September 2016, we completed the sale of our Canadian operations. (See Note 3 – Divestiture .) Other Our former Williams NGL & Petchem Services segment included certain domestic olefins pipeline assets as well as certain Canadian assets, which included a liquids extraction plant located near Fort McMurray, Alberta, that began operations in March 2016, and a propane dehydrogenation facility which was under development. In September 2016, the Canadian assets were sold. (See Note 3 – Divestiture .) Considering this and in conjunction with an organizational realignment effective January 1, 2017, the remaining assets are now reported in Other. Other also includes minor business activities that are not operating segments, as well as corporate operations. All segment disclosures have been recast for this segment change. Basis of Presentation Canada Dropdown In February 2014, we contributed certain Canadian operations to Pre-merger WPZ (Canada Dropdown) for total consideration of $56 million of cash from Pre-merger WPZ (including a $31 million post-closing adjustment received in the second quarter of 2014), 25,577,521 Pre-merger WPZ Class D limited-partner units, and an increase in the capital account of its general partner to allow us to maintain our 2 percent general partner interest. In lieu of cash distributions, the Class D units received quarterly distributions of additional paid-in-kind Class D units. In October 2014, a purchase price adjustment was finalized whereby we paid $56 million in cash to Pre-merger WPZ in the fourth quarter and waived $2 million in payment of IDRs with respect to the November 2014 distribution. Consolidated master limited partnership As of December 31, 2016 , we owned approximately 60 percent of the interests in WPZ, a variable interest entity (VIE) (see Note 4 – Variable Interest Entities ), including the interests of the general partner, which are wholly owned by us, and IDRs. During 2016, WPZ issued 3,273,601 common units pursuant to an equity distribution agreement between WPZ and certain banks resulting in net proceeds of $115 million . WPZ also implemented a distribution reinvestment program in the third quarter of 2016 resulting in 7,891,414 common units issued associated with reinvested distributions of $260 million , of which $250 million related to our participation. In addition, in August 2016, WPZ completed an equity issuance of 6,975,446 common units sold to us in a private placement transaction for an aggregate purchase price of $250 million . The above transactions, WPZ’s quarterly distribution of additional paid-in-kind Class B units to us, and other equity issuances by WPZ had the combined net impact of decreasing Noncontrolling interests in consolidated subsidiaries by $18 million , and increasing Capital in excess of par value by $12 million and Deferred income tax liabilities by $6 million in the Consolidated Balance Sheet . WPZ is self-funding and maintains separate lines of bank credit and cash management accounts and also has a commercial paper program. (See Note 14 – Debt, Banking Arrangements, and Leases .) Cash distributions from WPZ to all partners, including us, are governed by WPZ’s partnership agreement. Discontinued operations Unless indicated otherwise, the information in the Notes to Consolidated Financial Statements relates to our continuing operations. Significant risks and uncertainties We have announced plans to monetize our olefins production plant in Geismar, Louisiana, as well as other select assets that are not core to our strategy. As we pursue these other select asset monetizations, it is possible that we may incur impairments of certain equity-method investments, property, plant, and equipment, and intangible assets. Such impairments could potentially be caused by indications of fair value implied through the monetization process or, in the case of asset dispositions that are part of a broader asset group, the impact of the loss of future estimated cash flows. Summary of Significant Accounting Policies Principles of consolidation The consolidated financial statements include the accounts of all entities that we control and our proportionate interest in the accounts of certain ventures in which we own an undivided interest. Management’s judgment is required to evaluate whether we control an entity. Key areas of that evaluation include: • Determining whether an entity is a VIE; • Determining whether we are the primary beneficiary of a VIE, including evaluating which activities of the VIE most significantly impact its economic performance and the degree of power that we and our related parties have over those activities through our variable interests; • Identifying events that require reconsideration of whether an entity is a VIE and continuously evaluating whether we are a VIE’s primary beneficiary; • Evaluating whether other owners in entities that are not VIEs are able to effectively participate in significant decisions that would be expected to be made in the ordinary course of business such that we do not have the power to control such entities. We apply the equity method of accounting to investments over which we exercise significant influence but do not control. Equity-method investment basis differences Differences between the cost of our equity-method investments and our underlying equity in the net assets of investees are accounted for as if the investees were consolidated subsidiaries. Equity earnings (losses) in the Consolidated Statement of Operations includes our allocable share of net income (loss) of investees adjusted for any depreciation and amortization, as applicable, associated with basis differences. Use of estimates 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. Significant estimates and assumptions include: • Impairment assessments of investments, property, plant, and equipment, goodwill, and other identifiable intangible assets; • Litigation-related contingencies; • Environmental remediation obligations; • Realization of deferred income tax assets; • Depreciation and/or amortization of equity-method investment basis differences; • Asset retirement obligations; • Pension and postretirement valuation variables; • Acquisition related purchase price allocations. These estimates are discussed further throughout these notes. Regulatory accounting Transco and Northwest Pipeline are regulated by the Federal Energy Regulatory Commission (FERC). Their rates, which are established by the FERC, are designed to recover the costs of providing the regulated services, and their competitive environment makes it probable that such rates can be charged and collected. Therefore, our management has determined that it is appropriate under Accounting Standards Codification (ASC) Topic 980, “Regulated Operations,” to account for and report regulatory assets and liabilities related to these operations consistent with the economic effect of the way in which their rates are established. Accounting for these operations that are regulated can differ from the accounting requirements for nonregulated operations. For example, for regulated operations, allowance for funds used during construction (AFUDC) represents the estimated cost of debt and equity funds applicable to utility plant in process of construction and is capitalized as a cost of property, plant, and equipment because it constitutes an actual cost of construction under established regulatory practices; nonregulated operations are only allowed to capitalize the cost of debt funds related to construction activities, while a component for equity is prohibited. The components of our regulatory assets and liabilities relate to the effects of deferred taxes on equity funds used during construction, asset retirement obligations, fuel cost differentials, levelized incremental depreciation, negative salvage, and pension and other postretirement benefits. Our current and noncurrent regulatory asset and liability balances for the years ended December 31, 2016 and 2015 are as follows: December 31, 2016 2015 (Millions) Current assets reported within Other current assets and deferred charges $ 91 $ 84 Noncurrent assets reported within Regulatory assets, deferred charges, and other 387 370 Total regulated assets $ 478 $ 454 Current liabilities reported within Accrued liabilities $ 11 $ 4 Noncurrent liabilities reported within Regulatory liabilities, deferred income, and other 498 434 Total regulated liabilities $ 509 $ 438 Cash and cash equivalents Cash and cash equivalents in the Consolidated Balance Sheet includes amounts primarily invested in funds with high-quality, short-term securities and instruments that are issued or guaranteed by the U.S. government. These have maturity dates of three months or less when acquired. Accounts receivable Accounts receivable are carried on a gross basis, with no discounting, less an allowance for doubtful accounts. We estimate the allowance for doubtful accounts based on existing economic conditions, the financial condition of our customers, and the amount and age of past due accounts. We consider receivables past due if full payment is not received by the contractual due date. Interest income related to past due accounts receivable is generally recognized at the time full payment is received or collectability is assured. Past due accounts are generally written off against the allowance for doubtful accounts only after all collection attempts have been exhausted. Inventories Inventories in the Consolidated Balance Sheet primarily consist of natural gas liquids, olefins, natural gas in underground storage, and materials and supplies and are stated at the lower of cost or market. The cost of inventories is primarily determined using the average-cost method. Property, plant, and equipment Property, plant, and equipment is recorded at cost. We base the carrying value of these assets on estimates, assumptions, and judgments relative to capitalized costs, useful lives, and salvage values. As regulated entities, Northwest Pipeline and Transco provide for depreciation using the straight-line method at FERC-prescribed rates. Depreciation for nonregulated entities is provided primarily on the straight-line method over estimated useful lives, except for certain offshore facilities that apply an accelerated depreciation method. Gains or losses from the ordinary sale or retirement of property, plant, and equipment for regulated pipelines are credited or charged to accumulated depreciation. Other gains or losses are recorded in Other (income) expense – net included in Operating income (loss) in the Consolidated Statement of Operations . Ordinary maintenance and repair costs are generally expensed as incurred. Costs of major renewals and replacements are capitalized as property, plant, and equipment. We record a liability and increase the basis in the underlying asset for the present value of each expected future asset retirement obligation (ARO) at the time the liability is initially incurred, typically when the asset is acquired or constructed. As regulated entities, Northwest Pipeline and Transco offset the depreciation of the underlying asset that is attributable to capitalized ARO cost to a regulatory asset as management expects to recover these amounts in future rates. We measure changes in the liability due to passage of time by applying an interest rate to the liability balance. This amount is recognized as an increase in the carrying amount of the liability and as a corresponding accretion expense included in Operating and maintenance expenses in the Consolidated Statement of Operations , except for regulated entities, for which the liability is offset by a regulatory asset. The regulatory asset is amortized commensurate with our collection of those costs in rates. Measurements of AROs include, as a component of future expected costs, an estimate of the price that a third party would demand, and could expect to receive, for bearing the uncertainties inherent in the obligations, sometimes referred to as a market-risk premium. Goodwill Goodwill included within Intangible assets – net of accumulated amortization in the Consolidated Balance Sheet represents the excess of the consideration, plus the fair value of any noncontrolling interest or 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. As part of the evaluation, we compare our estimate of the fair value of the reporting unit with its carrying value, including goodwill. If the carrying value of the reporting unit exceeds its fair value, a computation of the implied fair value of the goodwill is compared with its related carrying value. If the carrying value of the reporting unit goodwill exceeds the implied fair value of that goodwill, an impairment loss is recognized in the amount of the excess. Judgments and assumptions are inherent in our management’s estimates of fair value. Other intangible assets Our identifiable intangible assets included within Intangible assets – net of accumulated amortization in the Consolidated Balance Sheet are primarily related to gas gathering, processing, and fractionation contractual customer relationships. Our intangible assets are amortized on a straight-line basis over the period in which these assets contribute to our cash flows. We evaluate these assets for changes in the expected remaining useful lives and would reflect any changes prospectively through amortization over the revised remaining useful life. Impairment of property, plant, and equipment, other identifiable intangible assets, and investments We evaluate our property, plant, and equipment and other identifiable intangible assets for impairment when events or changes in circumstances indicate, in our management’s judgment, that the carrying value of such assets may not be recoverable. When an indicator of impairment has occurred, we compare our management’s estimate of undiscounted future cash flows attributable to the assets to the carrying value of the assets to determine whether an impairment has occurred and we may apply a probability-weighted approach to consider the likelihood of different cash flow assumptions and possible outcomes including selling in the near term or holding for the remaining estimated useful life. If an impairment of the carrying value has occurred, we determine the amount of the impairment recognized in the financial statements by estimating the fair value of the assets and recording a loss for the amount that the carrying value exceeds the estimated fair value. This evaluation is performed at the lowest level for which separately identifiable cash flows exist. For assets identified to be disposed of in the future and considered held for sale, we compare the carrying value to the estimated fair value less the cost to sell to determine if recognition of an impairment is required. Until the assets are disposed of, the estimated fair value, which includes estimated cash flows from operations until the assumed date of sale, is recalculated when related events or circumstances change. We evaluate our investments for impairment when events or changes in circumstances indicate, in our management’s judgment, that the carrying value of such investments may have experienced an other-than-temporary decline in value. When evidence of loss in value has occurred, we compare our estimate of fair value of the investment to the carrying value of the investment to determine whether an impairment has occurred. If the estimated fair value is less than the carrying value and we consider the decline in value to be other-than-temporary, the excess of the carrying value over the fair value is recognized in the consolidated financial statements as an impairment charge. Judgments and assumptions are inherent in our management’s estimate of undiscounted future cash flows and an asset’s or investment’s fair value. Additionally, judgment is used to determine the probability of sale with respect to assets considered for disposal. Deferred income We record a liability for deferred income related to cash received from customers in advance of providing our services. Such amounts are generally recognized in revenue upon satisfying our performance obligations, primarily providing services based on units of production or over remaining contractual service periods ranging from 1 to 25 years. Deferred income is reflected within Accrued liabilities and Regulatory liabilities, deferred income, and other on the Consolidated Balance Sheet . (See Note 13 – Accrued Liabilities .) During 2016, we received cash proceeds totaling $820 million associated with restructuring certain gas gathering contracts in the Barnett Shale and Mid-Continent regions. The proceeds were recorded as deferred income and are being amortized into income in 2016 and future periods. In October 2016, we received $104 million of newly constructed assets as part of a noncash investing transaction with a customer for which we provide production handling and other services. The transaction was recorded in Property, plant, and equipment – net and deferred income in the Consolidated Balance Sheet and is being amortized based on units of production through 2024. Due to the noncash nature of this transaction, it is not presented within the Consolidated Statement of Cash Flows . Contingent liabilities We record liabilities for estimated loss contingencies, including environmental matters, when we assess that a loss is probable and the amount of the loss can be reasonably estimated. These liabilities are calculated based upon our assumptions and estimates with respect to the likelihood or amount of loss and upon advice of legal counsel, engineers, or other third parties regarding the probable outcomes of the matters. These calculations are made without consideration of any potential recovery from third parties. We recognize insurance recoveries or reimbursements from others when realizable. Revisions to these liabilities are generally reflected in income when new or different facts or information become known or circumstances change that affect the previous assumptions or estimates. Cash flows from revolving credit facilities and commercial paper program Proceeds and payments related to borrowings under our credit facilities are reflected in the financing activities in the Consolidated Statement of Cash Flows on a gross basis. Proceeds and payments related to borrowings under our commercial paper program are reflected in the financing activities in the Consolidated Statement of Cash Flows on a net basis, as the outstanding notes generally have maturity dates less than three months from the date of issuance. (See Note 14 – Debt, Banking Arrangements, and Leases .) Treasury stock Treasury stock purchases are accounted for under the cost method whereby the entire cost of the acquired stock is recorded as Treasury stock in the Consolidated Balance Sheet . Gains and losses on the subsequent reissuance of shares are credited or charged to Capital in excess of par value in the Consolidated Balance Sheet using the average-cost method. Derivative instruments and hedging activities We may utilize derivatives to manage a portion of our commodity price risk. These instruments consist primarily of swaps, futures, and forward contracts involving short- and long-term purchases and sales of energy commodities. We report the fair value of derivatives, except those for which the normal purchases and normal sales exception has been elected, in Other current assets and deferred charges ; Regulatory assets, deferred charges, and other ; Accrued liabilities ; or Regulatory liabilities, deferred income, and other in the Consolidated Balance Sheet . We determine the current and noncurrent classification based on the timing of expected future cash flows of individual trades. We report these amounts on a gross basis. Additionally, we report cash collateral receivables and payables with our counterparties on a gross basis. (See Note 17 – Fair Value Measurements, Guarantees, and Concentration of Credit Risk .) The accounting for the changes in fair value of a commodity derivative can be summarized as follows: Derivative Treatment Accounting Method Normal purchases and normal sales exception Accrual accounting Designated in a qualifying hedging relationship Hedge accounting All other derivatives Mark-to-market accounting We may elect the normal purchases and normal sales exception for certain short- and long-term purchases and sales of physical energy commodities. Under accrual accounting, any change in the fair value of these derivatives is not reflected on the balance sheet after the initial election of the exception. We may also designate a hedging relationship for certain commodity derivatives. For a derivative to qualify for designation in a hedging relationship, it must meet specific criteria and we must maintain appropriate documentation. We establish hedging relationships pursuant to our risk management policies. We evaluate the hedging relationships at the inception of the hedge and on an ongoing basis to determine whether the hedging relationship is, and is expected to remain, highly effective in achieving offsetting changes in fair value or cash flows attributable to the underlying risk being hedged. We also regularly assess whether the hedged forecasted transaction is probable of occurring. If a derivative ceases to be or is no longer expected to be highly effective, or if we believe the likelihood of occurrence of the hedged forecasted transaction is no longer probable, hedge accounting is discontinued prospectively, and future changes in the fair value of the derivative are recognized currently in Product sales or Product costs in the Consolidated Statement of Operations . For commodity derivatives designated as a cash flow hedge, the effective portion of the change in fair value of the derivative is reported in Accumulated other comprehensive income (loss) (AOCI) in the Consolidated Balance Sheet and reclassified into earnings in the period in which the hedged item affects earnings. Any ineffective portion of the derivative’s change in fair value is recognized currently in Product sales or Product costs in the Consolidated Statement of Operations . Gains or losses deferred in AOCI associated with terminated derivatives, derivatives that cease to be highly effective hedges, derivatives for which the forecasted transaction is reasonably possible but no longer probable of occurring, and cash flow hedges that have been otherwise discontinued remain in AOCI until the hedged item affects earnings. If it becomes probable that the forecasted transaction designated as the hedged item in a cash flow hedge will not occur, any gain or loss deferred in AOCI is recognized in Product sales or Product costs in the Consolidated Statement of Operations at that time. The change in likelihood of a forecasted transaction is a judgmental decision that includes qualitative assessments made by management. For commodity derivatives that are not designated in a hedging relationship, and for which we have not elected the normal purchases and normal sales exception, we report changes in fair value currently in Product sales or Product costs in the Consolidated Statement of Operations . Certain gains and losses on derivative instruments included in the Consolidated Statement of Operations are netted together to a single net gain or loss, while other gains and losses are reported on a gross basis. Gains and losses recorded on a net basis include unrealized gains and losses on all derivatives that are not designated as hedges and for which we have not elected the normal purchases and normal sales exception. Realized gains and losses on derivatives that require physical delivery, as well as natural gas derivatives for NGL processing activities and which are not held for trading purposes nor were entered into as a pre-contemplated buy/sell arrangement, are recorded on a gross basis. Revenue recognition Revenues As a result of the ratemaking process, certain revenues collected by us may be subject to refunds upon the issuance of final orders by the FERC in pending rate proceedings. We record estimates of rate refund liabilities considering our and other third-party regulatory proceedings, advice of counsel, and other risks. Service revenues Revenues from our interstate natural gas pipeline businesses include services pursuant to long-term firm transportation and storage agreements. These agreements provide for a reservation charge based on the volume of contracted capacity and a commodity charge based on the volume of gas delivered, both at rates specified in our FERC tariffs. We recognize revenues for reservation charges ratably over the contract period regardless of the volume of natural gas that is transported or stored. Revenues for commodity charges, from both firm and interruptible transportation services and storage injection and withdrawal services, are recognized when natural gas is delivered at the agreed upon delivery point or when natural gas is injected or withdrawn from the storage facility. Certain revenues from our midstream operations include those derived from natural gas gathering, processing, treating, and compression services and are performed under volumetric-based fee contracts. These revenues are recorded when services have been performed. Certain of our gas gathering and processing agreements have minimum volume commitments. If a customer under such an agreement fails to meet its minimum volume commitment for a specified period, generally measured on an annual basis, it is obligated to pay a contractually determined fee based upon the shortfall between actual production volumes and the minimum volume commitment for that period. The revenue associated with minimum volume commitments is recognized in th

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2016
Business Combinations [Abstract]
Acquisitions [Text Block]	Note 2 – Acquisitions ACMP On December 20, 2012, we purchased approximately 24 percent of ACMP’s outstanding limited partnership units and 50 percent of the ACMP general partner 2 percent interest which included IDRs for approximately $2.19 billion in cash, including transaction costs. We accounted for these acquired interests as equity-method investments. On July 1, 2014, we acquired control of ACMP (ACMP Acquisition) through the acquisition of an additional 26 percent of ACMP’s outstanding limited partnership units and the remaining 50 percent interest in the general partner for $5.995 billion in cash. The acquisition was funded through the issuance of equity (see Note 15 – Stockholders' Equity ) and debt, credit facility borrowings, and cash on hand. At the time of acquisition, ACMP owned, operated, developed, and acquired natural gas gathering systems and other midstream energy assets. The purpose of the acquisition was to enhance our position in the Marcellus and Utica Shale plays, provide additional diversity via the Eagle Ford, Haynesville, Barnett, Mid-Continent, and Niobrara areas, and to fortify our stable, fee-based business model and support our dividend growth strategy. Our basis in ACMP reflects business combination accounting, which, among other things, requires identifiable assets acquired and liabilities assumed to be measured at their acquisition-date fair values. Prior to the ACMP Acquisition we accounted for our investment in ACMP using the equity method. The acquisition-date fair value of our equity-method investment in ACMP was $4.6 billion . As a result of remeasuring our equity-method investment to fair value, for the year ended December 31, 2014 we recognized a $2.5 billion noncash gain within the Gain on remeasurement of equity-method investment line item in the Consolidated Statement of Operations . The valuation techniques used to measure the acquisition-date fair value of the ACMP Acquisition, including our previous equity-method investment in ACMP, consisted of valuing the limited partner units and general partner interest separately. The limited partner units, consisting of common and Class B units, were valued based on ACMP’s closing common unit price at July 1, 2014. The general partner interest, including IDRs, was valued on a noncontrolling basis using an income approach based on a discounted cash flow analysis and a market comparison analysis based on comparable guideline companies and an implied fair value from our purchase. 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 Williams Partners segment, liabilities assumed, and noncontrolling interest at July 1, 2014. The fair value of accounts receivable acquired equaled contractual amounts receivable. Changes to the preliminary allocation disclosed in Exhibit 99.1 of our Form 8-K dated May 6, 2015, which were recorded in the first quarter of 2015, reflect an increase of $150 million in Property, plant, and equipment and $25 million in Goodwill , and a decrease of $168 million in Other intangible assets and $7 million in Investments . These adjustments during the measurement period were not considered significant to require retrospective revisions of our financial statements. (Millions) Accounts receivable $ 168 Other current assets 63 Investments 5,865 Property, plant, and equipment 7,165 Goodwill 499 Other intangible assets 8,841 Current liabilities (408 ) Debt (4,052 ) Other noncurrent liabilities (9 ) Noncontrolling interest in ACMP’s subsidiaries (958 ) Noncontrolling interest in ACMP (6,544 ) Other intangible assets recognized in the acquisition are related to contractual customer relationships from gas gathering agreements with our customers. The basis for determining the value of these intangible assets was 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 30 years during which contractual customer relationships are expected to contribute to our cash flows. As estimated at the time of acquisition, approximately 56 percent of the expected future revenues from these contractual customer relationships were 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 acquisition), the weighted-average periods to the next renewal or extension of the existing customer contracts were approximately 17 years . The noncash adjustment to record the fair value of the noncontrolling interest in ACMP was determined based on the common units and ACMP’s closing common unit price at July 1, 2014. The following unaudited pro forma Total revenues and Net income (loss) attributable to The Williams Companies, Inc. for the year ended December 31, 2014, are presented as if the ACMP Acquisition had been completed on January 1, 2014. 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 period indicated, nor do they purport to project Total 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 transactions or the potential costs to achieve these cost savings, operating synergies, and revenue enhancements. December 31, 2014 (Millions) Total revenues $ 8,181 Net income (loss) attributable to The Williams Companies, Inc. $ 622 Significant adjustments to pro forma Net income (loss) attributable to The Williams Companies, Inc. include the removal of the previously described $2.5 billion gain on remeasurement of equity-method investment, and include additional depreciation and amortization expense associated with reflecting the acquired investments, property, plant, and equipment, and other intangible assets at fair value. The adjustments assume estimated useful lives of 30 years . Other significant adjustments to pro forma Net income (loss) attributable to The Williams Companies, Inc. include interest expense related to debt financing associated with the acquisition as well as Net income (loss) attributable to noncontrolling interests . During the year ended December 31, 2014, ACMP contributed Total revenues of $781 million and Net income (loss) attributable to The Williams Companies, Inc. of $165 million . Costs related to this acquisition were $16 million in 2014 and are reported within our Williams Partners segment and included in Selling, general, and administrative expenses in the Consolidated Statement of Operations . Direct transaction costs associated with financing commitments were $9 million in 2014 and reported within Interest incurred in the Consolidated Statement of Operations . Equity earnings (losses) within the Consolidated Statement of Operations in 2014 includes $19 million of equity losses associated with certain compensation-related costs at ACMP that were triggered by the acquisition. Eagle Ford Gathering System In May 2015, WPZ acquired a gathering system comprised of approximately 140 miles of pipeline and a sour gas compression facility in the Eagle Ford Shale for $112 million . The acquisition was accounted for as a business combination, and the allocation of the acquisition-date fair value of the major classes of assets acquired includes $80 million of Property, plant, and equipment – net and $32 million of Intangible assets – net of accumulated amortization in the Consolidated Balance Sheet . Changes to the preliminary allocation disclosed in the second quarter of 2015 reflect an increase of $20 million in Property, plant, and equipment – net , and a decrease of $20 million in Intangible assets – net of accumulated amortization . UEOM Equity-Method Investment In June 2015, WPZ acquired an approximate 13 percent additional interest in its equity-method investment, UEOM, for $357 million . Following the acquisition WPZ owns approximately 62 percent of UEOM. However, WPZ continues to account for this as an equity-method investment because WPZ does not control UEOM due to the significant participatory rights of its partner. In connection with the acquisition of the additional interest, we agreed to waive approximately $2 million of our WPZ IDR payments each quarter through 2017. See Note 1 – General, Description of Business, Basis of Presentation, and Summary of Significant Accounting Policies for discussion of agreement with WPZ wherein we permanently waived IDR payment obligations from WPZ.

Divestiture

Divestiture	12 Months Ended
	Dec. 31, 2016
Discontinued Operations and Disposal Groups [Abstract]
Divestiture [Text Block]	Note 3 – Divestiture In September 2016, we completed the sale of subsidiaries conducting Canadian operations, including subsidiaries of WPZ, (such subsidiaries, the disposal group). Consideration received to date totaled $1.020 billion , net of $31 million of cash divested and subject to customary working capital adjustments. In connection with the sale, we waived $150 million of incentive distributions otherwise payable by WPZ to us in the fourth quarter of 2016 in recognition of certain affiliate contracts wherein WPZ’s Canadian operations provided services to certain of our other businesses. The proceeds were primarily used to reduce borrowings on credit facilities. During the second quarter of 2016, we designated these operations as held for sale. As a result, we measured the fair value of the disposal group as of June 30, 2016, resulting in an impairment charge of $747 million , reflected in Impairment of certain assets in the Consolidated Statement of Operations . (See Note 17 – Fair Value Measurements, Guarantees, and Concentration of Credit Risk .) During the second half of 2016 we recorded an additional loss of $66 million upon completion of the sale, primarily reflecting revisions to the sales price and estimated contingent consideration and including a $15 million benefit related to transactions to hedge our foreign currency exchange risk on the Canadian proceeds, reflected in Other (income) expense – net within Costs and expenses in the Consolidated Statement of Operations . The total loss consists of a loss of $34 million at Williams Partners and $32 million at Other. The following table presents the results of operations for the disposal group, excluding the impairment and loss noted above: Years Ended December 31, 2016 2015 (Millions) Income (loss) before income taxes of disposal group $ (98 ) $ 17 Income (loss) before income taxes of disposal group attributable to The Williams Companies, Inc. (95 ) 15

Variable Interest Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2016
Variable Interest Entity Disclosures [Abstract]
Variable Interest Entities [Text Block]	Note 4 – Variable Interest Entities On January 1, 2016, we adopted ASU 2015-02 “Amendments to the Consolidation Analysis," which eliminated certain presumptions related to a general partner interest in a master limited partnership. As a result of adopting this new accounting standard, our consolidated master limited partnership is now a VIE. We are the primary beneficiary of WPZ because we have the power to direct the activities that most significantly impact WPZ’s economic performance. The following table presents amounts included in our Consolidated Balance Sheet that are for the use or obligation of WPZ and/or its subsidiaries, and which comprise a significant portion of our consolidated assets and liabilities: December 31, 2016 2015 Classification (Millions) Assets (liabilities): Cash and cash equivalents $ 145 $ 73 Cash and cash equivalents Trade accounts and other receivables – net 925 1,026 Trade accounts and other receivables Inventories 138 127 Inventories Other current assets 205 190 Other current assets and deferred charges Investments 6,701 7,336 Investments Property, plant, and equipment – net 28,021 28,593 Property, plant, and equipment – net Intangible assets – net 9,662 10,016 Intangible assets – net of accumulated amortization Regulatory assets, deferred charges, and other noncurrent assets 467 479 Regulatory assets, deferred charges, and other Accounts payable (589 ) (625 ) Accounts payable Accrued liabilities including current asset retirement obligations (1,122 ) (757 ) Accrued liabilities Commercial paper (93 ) (499 ) Commercial paper Long-term debt due within one year (785 ) (176 ) Long-term debt due within one year Long-term debt (17,685 ) (19,001 ) Long-term debt Deferred income tax liabilities (20 ) (119 ) Deferred income tax liabilities Noncurrent asset retirement obligations (798 ) (857 ) Regulatory liabilities, deferred income, and other Regulatory liabilities, deferred income, and other noncurrent liabilities (1,860 ) (1,066 ) Regulatory liabilities, deferred income, and other The assets and liabilities presented in the table above also include the consolidated interests of the following individual VIEs within WPZ: Gulfstar One WPZ owns a 51 percent interest in Gulfstar One LLC (Gulfstar One), a subsidiary that, due to certain risk-sharing provisions in its customer contracts, is a VIE. Gulfstar One includes a proprietary floating-production system, Gulfstar FPS, and associated pipelines which provide production handling and gathering services for the Tubular Bells oil and gas discovery in the eastern deepwater Gulf of Mexico. WPZ is the primary beneficiary because it has the power to direct the activities that most significantly impact Gulfstar One’s economic performance. Constitution WPZ owns a 41 percent interest in Constitution, a subsidiary that, due to shipper fixed-payment commitments under its long-term firm transportation contracts, is a VIE. WPZ is the primary beneficiary because it has the power to direct the activities that most significantly impact Constitution’s economic performance. WPZ, as construction manager for Constitution, is responsible for constructing the proposed pipeline connecting its gathering system in Susquehanna County, Pennsylvania, to the Iroquois Gas Transmission and the Tennessee Gas Pipeline systems. The total remaining cost of the project is estimated to be approximately $687 million , which is expected to be funded with capital contributions from WPZ and the other equity partners on a proportional basis. In December 2014, we received approval from the FERC to construct and operate the Constitution pipeline. However, in April 2016, the New York State Department of Environmental Conservation (NYSDEC) denied a necessary water quality certification for the New York portion of the Constitution pipeline. We remain steadfastly committed to the project, and in May 2016, Constitution appealed the NYSDEC's denial of the certification and filed an action in federal court seeking a declaration that the State of New York's authority to exercise permitting jurisdiction over certain other environmental matters is preempted by federal law. The oral argument before the Second Circuit Court of Appeals regarding the NYSDEC’s denial of Constitution’s application for water quality certification under Section 401 of the Clean Water Act was held on November 16, 2016. We anticipate a decision from the Second Circuit Court of Appeals as early as second quarter 2017. In light of the NYSDEC's denial of the water quality certification and the actions taken to challenge the decision, the project in-service date is targeted as early as the second half of 2018, which assumes that the legal challenge process is satisfactorily and promptly concluded. An unfavorable resolution could result in the impairment of a significant portion of the capitalized project costs, which total $381 million on a consolidated basis at December 31, 2016, and are included within Property, plant, and equipment – net in the Consolidated Balance Sheet . Beginning in April 2016, we discontinued capitalization of development costs related to this project. It is also possible that we could incur certain supplier-related costs in the event of a prolonged delay or termination of the project. Cardinal WPZ owns a 66 percent interest in Cardinal Gas Services, L.L.C. (Cardinal), a subsidiary that provides gathering services for the Utica Shale region and is a VIE due to certain risks shared with customers. WPZ is the primary beneficiary because it has the power to direct the activities that most significantly impact Cardinal’s economic performance. Future expansion activity is expected to be funded with capital contributions from WPZ and the other equity partner on a proportional basis. Jackalope WPZ owns a 50 percent interest in Jackalope Gas Gathering Services, L.L.C. (Jackalope), a subsidiary that provides gathering and processing services for the Powder River basin and is a VIE due to certain risks shared with customers. WPZ is the primary beneficiary because it has the power to direct the activities that most significantly impact Jackalope’s economic performance. Future expansion activity is expected to be funded with capital contributions from WPZ and the other equity partner on a proportional basis.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2016
Related Party Transactions [Abstract]
Related Party Transactions [Text Block]	Note 5 – Related Party Transactions Transactions with Equity-Method Investees We have purchases from our equity-method investees included in Product costs in the Consolidated Statement of Operations of $180 million , $187 million , and $197 million for the years ended 2016, 2015, and 2014, respectively. We have $19 million and $12 million included in Accounts payable in the Consolidated Balance Sheet with our equity-method investees at December 31, 2016 and 2015, respectively. WPZ has operating agreements with certain equity-method investees. These operating agreements typically provide for reimbursement or payment to WPZ for certain direct operational payroll and employee benefit costs, materials, supplies, and other charges and also for management services. We supplied a portion of these services, primarily those related to employees since WPZ does not have any employees, to certain equity-method investees. The total charges to equity-method investees for these fees are $66 million , $64 million , and $65 million for the years ended 2016, 2015, and 2014, respectively. Board of Directors A former member of our Board of Directors, who was elected in 2013 and resigned during 2016, is also the current chairman, president, and chief executive officer of an energy services company that is a customer of ours. We recorded $144 million , $111 million , and $115 million in Service revenues in the Consolidated Statement of Operations from this company for transportation and storage of natural gas for the years ended December 31, 2016, 2015, and 2014, respectively.

Investing Activities

Investing Activities	12 Months Ended
	Dec. 31, 2016
Investments [Abstract]
Investing Activities [Text Block]	Note 6 – Investing Activities Impairment of equity-method investments The following table presents other-than-temporary impairment charges related to certain equity-method investments (see Note 17 – Fair Value Measurements, Guarantees, and Concentration of Credit Risk ): Years Ended December 31, 2016 2015 (Millions) Williams Partners Appalachia Midstream Investments $ 294 $ 562 DBJV 59 503 Laurel Mountain 50 45 UEOM — 241 Ranch Westex 24 — Other 3 8 $ 430 $ 1,359 Equity earnings (losses) Equity earnings (losses) in 2015 includes a loss of $19 million associated with WPZ’s share of underlying property impairments at certain of the Appalachia Midstream Investments. This loss is reported within the Williams Partners segment. Equity earnings (losses) in 2014 includes: • Write-offs of capitalized project development costs on our discontinued investments in Bluegrass Pipeline Company LLC (Bluegrass) of $67 million and Moss Lake Fractionation LLC and Moss Lake LPG Terminal LLC (collectively referred to as Moss Lake) of $4 million ; • A $7 million equity loss recognized from our interest in ACMP that was accounted for under the equity-method of accounting for the first six months of the year, including $19 million of equity losses associated with certain compensation-related costs at ACMP that were triggered by the acquisition and $30 million noncash amortization of the difference between the cost of our investment and our underlying share of the net assets for the first six months of the year. Other investing income (loss) – net In 2016, we recognized a $27 million gain from the sale of an equity-method investment interest in a gathering system that was part of the Appalachia Midstream Investments within the Williams Partners segment. Other investing income (loss) – net also includes $36 million , $27 million , and $41 million of interest income for 2016, 2015 and 2014, respectively, associated with a receivable related to the sale of certain former Venezuela assets. Due to changes in circumstances that led to late payments and increased uncertainty regarding the recovery of the receivable, we began accounting for the receivable under a cost recovery model in first quarter 2015. Subsequently, we received payments greater than the remaining carrying amount of the receivable, which resulted in the recognition of interest income. Investments Ownership Interest at December 31, 2016 December 31, 2016 2015 (Millions) Equity-method investments: Appalachia Midstream Investments (1) $ 2,062 $ 2,464 UEOM 62% 1,448 1,525 DBJV 50% 988 977 Discovery 60% 572 602 OPPL 50% 430 445 Caiman II 58% 426 418 Laurel Mountain 69% 324 391 Gulfstream 50% 261 293 Other Various 190 221 $ 6,701 $ 7,336 ___________ (1) Includes equity-method investments in multiple gathering systems in the Marcellus Shale with an approximate average 41 percent interest. We have differences between the carrying value of our equity-method investments and the underlying equity in the net assets of the investees of $1.9 billion at December 31, 2016 and $2.4 billion at December 31, 2015. These differences primarily relate to our investments in Appalachian Midstream Investments, DBJV, and UEOM resulting from property, plant, and equipment, as well as customer-based intangible assets and goodwill. Purchases of and contributions to equity-method investments We generally fund our portion of significant expansion or development projects of these investees through additional capital contributions. These transactions increased the carrying value of our investments and included: Years Ended December 31, 2016 2015 2014 (Millions) DBJV $ 105 $ 57 $ 20 Appalachia Midstream Investments 28 93 84 Caiman II 22 — 175 UEOM — 357 57 Discovery — 35 106 Other 22 53 40 $ 177 $ 595 $ 482 Dividends and distributions The organizational documents of entities in which we have an equity-method interest generally require distribution of available cash to members on at least a quarterly basis. These transactions reduced the carrying value of our investments and included: Years Ended December 31, 2016 2015 2014 (Millions) Appalachia Midstream Investments $ 211 $ 219 $ 130 Discovery 141 116 36 Gulfstream 100 88 81 UEOM 92 42 — OPPL 69 45 27 Caiman II 40 33 13 DBJV 39 33 — Laurel Mountain 28 31 39 ACMP — — 64 Other 22 26 50 $ 742 $ 633 $ 440 In addition, on September 24, 2015, WPZ received a special distribution of $396 million from Gulfstream reflecting its proportional share of the proceeds from new debt issued by Gulfstream. The new debt was issued to refinance Gulfstream’s debt maturities. Subsequently, WPZ contributed $248 million and $148 million to Gulfstream for its proportional share of amounts necessary to fund debt maturities of $500 million due on November 1, 2015, and $300 million due on June 1, 2016, respectively. Summarized Financial Position and Results of Operations of All Equity-Method Investments December 31, 2016 2015 (Millions) Assets (liabilities): Current assets $ 508 $ 773 Noncurrent assets 9,695 9,549 Current liabilities (412 ) (633 ) Noncurrent liabilities (1,484 ) (1,450 ) Years Ended December 31, 2016 2015 2014 (Millions) Gross revenue $ 1,883 $ 1,707 $ 1,623 Operating income 799 690 534 Net income 726 611 460

Other Income and Expenses

Other Income and Expenses	12 Months Ended
	Dec. 31, 2016
Other Income and Expenses [Abstract]
Other Income and Expense [Text Block]	Note 7 – Other Income and Expenses The following table presents certain gains or losses reflected in Other (income) expense – net within Costs and expenses in the Consolidated Statement of Operations : Years Ended December 31, 2016 2015 2014 (Millions) Williams Partners Loss on sale of Canadian operations (Note 3) $ 34 $ — $ — Amortization of regulatory assets associated with asset retirement obligations 33 33 33 Accrual of regulatory liability related to overcollection of certain employee expenses 25 20 14 Project development costs related to Constitution (Note 4) 28 — — Net foreign currency exchange (gains) losses (1) 10 (10 ) (3 ) Contingency gain settlement (2) — — (154 ) Net gain related to partial acreage dedication release — — (12 ) Gain on asset retirement (11 ) — — Loss related to sale of certain assets — — 10 Other Loss on sale of Canadian operations (Note 3) 32 — — Gain on sale of unused pipe (10 ) — — ________________ (1) Primarily relates to gains and losses incurred on foreign currency transactions and the remeasurement of U.S. dollar-denominated current assets and liabilities within our former Canadian operations (see Note 3 – Divestiture ). (2) In November 2014, we settled a claim arising from the resolution of a contingent gain related to claims associated with the purchase of a business in a prior period. Pursuant to the settlement, we received $154 million in cash, all of which was recognized as a gain in the fourth quarter of 2014. ACMP Acquisition, Merger, and Transition Certain ACMP acquisition, merger, and transition costs included in the Consolidated Statement of Operations are as follows: • Selling, general, and administrative expenses includes $26 million in 2015 and $27 million in 2014 (including $16 million of acquisition costs) primarily related to professional advisory fees within the Williams Partners segment. • Selling, general, and administrative expenses includes $9 million in 2015 and $15 million in 2014 of related employee transition costs within the Williams Partners segment and $32 million in 2015 and $10 million in 2014 of general corporate expenses associated with integration and realignment of resources within the Other segment. • Operating and maintenance expenses includes $12 million in 2015 and $15 million in 2014 primarily related to employee transition costs within the Williams Partners segment. • Interest incurred includes transaction-related financing costs of $2 million in 2015 from the merger and $9 million in 2014 from the acquisition. Additional Items Certain additional items included in the Consolidated Statement of Operations are as follows: • Service revenues includes $173 million associated with the amortization of deferred income related to the restructuring of certain gas gathering contracts in the Barnett Shale and Mid-Continent regions within the Williams Partners segment. Service revenues also includes $58 million , $239 million , and $167 million recognized in the fourth quarter of 2016, 2015, and 2014, respectively, from minimum volume commitment fees in the Barnett Shale and Mid-Continent regions within the Williams Partners segment. • Selling, general, and administrative expenses and Operating and maintenance expenses include $42 million in 2016 of severance and other related costs. • Other income (expense) – net below Operating income (loss) includes $89 million , $95 million , and $44 million for equity AFUDC for 2016, 2015, and 2014, respectively, primarily within the Williams Partners segment. • Other income (expense) – net below Operating income (loss) includes a $14 million gain in 2015 resulting from the early retirement of certain debt within the Williams Partners segment.

Provision (Benefit) for Income

Provision (Benefit) for Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Provision (Benefit) for Income Taxes [Text Block]	Note 8 – Provision (Benefit) for Income Taxes The Provision (benefit) for income taxes includes: Years Ended December 31, 2016 2015 2014 (Millions) Current: Federal $ — $ — $ (9 ) State 2 (7 ) 2 Foreign (1 ) (55 ) 10 1 (62 ) 3 Deferred: Federal (6 ) (317 ) 1,108 State 61 (25 ) 119 Foreign (81 ) 5 19 (26 ) (337 ) 1,246 Provision (benefit) for income taxes $ (25 ) $ (399 ) $ 1,249 Reconciliations from the Provision (benefit) at statutory rate to recorded Provision (benefit) for income taxes are as follows: Years Ended December 31, 2016 2015 2014 (Millions) Provision (benefit) at statutory rate $ (131 ) $ (600 ) $ 1,255 Increases (decreases) in taxes resulting from: Impact of nontaxable noncontrolling interests (22 ) 263 (75 ) State income taxes (net of federal benefit) 3 (21 ) 82 State deferred income tax rate change 43 — — Foreign operations – net (Including tax effect of Canadian Sale) 78 8 (11 ) Taxes on undistributed earnings of foreign subsidiaries – net — — (37 ) Translation adjustment of certain unrecognized tax benefits (1 ) (71 ) — Other – net 5 22 35 Provision (benefit) for income taxes $ (25 ) $ (399 ) $ 1,249 Income (loss) from continuing operations before income taxes includes $885 million of foreign loss in 2016 , and $20 million and $102 million of foreign income in 2015 and 2014 , respectively. Foreign operations – net (Including tax effect of Canadian Sale) increased in 2016 due to a valuation allowance associated with impairments and losses on the sale of our Canadian operations (see Note 3 – Divestiture ) and the reversal of anticipatory foreign tax credits, partially offset by the tax effect of the impairments associated with our Canadian disposition. The Translation adjustment of certain unrecognized tax benefits in 2016 and 2015 reflects the impact of changes in foreign currency exchange rates on the remeasurement of a foreign currency denominated unrecognized tax benefit, including associated penalties and interest. The 2015 federal and state income tax provisions include the tax effect of a $2.7 billion impairment loss associated with certain goodwill, equity-method investments, and other assets. (See Note 17 – Fair Value Measurements, Guarantees, and Concentration of Credit Risk .) The 2014 federal and state income tax provisions include the tax effect of a $2.5 billion gain associated with remeasuring our equity-method investment to fair value as a result of the ACMP Acquisition. (See Note 2 – Acquisitions .) Taxes on undistributed earnings of foreign subsidiaries - net decreased in 2014 due to revisions of our estimate of the undistributed earnings, partially offset by an increase of tax expense, which decreased our share of the foreign tax credit due to the Canada Dropdown. During the course of audits of our business by domestic and foreign tax authorities, we frequently face challenges regarding the amount of taxes due. These challenges include questions regarding the timing and amount of deductions and the allocation of income among various tax jurisdictions. In evaluating the liability associated with our various filing positions, we apply the two-step process of recognition and measurement. In association with this liability, we record an estimate of related interest and tax exposure as a component of our tax provision. The impact of this accrual is included within Other – net in our reconciliation of the Provision (benefit) at statutory rate to recorded Provision (benefit) for income taxes . Significant components of Deferred income tax liabilities and Deferred income tax assets are as follows: December 31, 2016 2015 (Millions) Deferred income tax liabilities: Property, plant, and equipment $ — $ 4 Investments 5,300 5,272 Other 29 15 Total deferred income tax liabilities 5,329 5,291 Deferred income tax assets: Accrued liabilities 145 150 Minimum tax credits 139 139 Foreign tax credit 140 193 Federal loss carryovers 651 485 State losses and credits 313 296 Other 37 42 Total deferred income tax assets 1,425 1,305 Less valuation allowance 334 190 Net deferred income tax assets 1,091 1,115 Overall net deferred income tax liabilities $ 4,238 $ 4,176 The valuation allowance at December 31, 2016 and 2015 serves to reduce the available deferred income tax assets to an amount that will, more likely than not, be realized. We consider all available positive and negative evidence, including projected future taxable income and management’s estimate of future reversals of existing taxable temporary differences, and have determined that a portion of our deferred income tax assets related to State losses and credits and Federal loss carryovers may not be realized. The change in Valuation allowance is partially due to this evaluation. The amounts presented in the table above are, with respect to state items, before any federal benefit. The change from prior year for the State losses and credits is primarily due to increases in losses and credits generated in the current and prior years less losses and/or credits utilized in the current year. We have loss and credit carryovers in multiple state taxing jurisdictions. These attributes generally expire between 2017 and 2036 with some carryovers having indefinite carryforward periods. Federal loss carryovers includes the tax effect of a capital loss carryover of $364 million , incurred with the sale of our Canadian operations, which, if unused, will expire in 2021. The Valuation allowance change from prior year is primarily due to a valuation allowance on the deferred tax asset associated with this capital loss carryover. We reasonably anticipate that this valuation allowance could be released in the near future due to tax impacts of the potential monetization of certain assets as previously announced by management. The federal tax Minimum tax credits of $139 million currently has no expiration date. Foreign tax credit of $ 140 million is expected to be utilized prior to expiration in 2026. Federal net operating loss carryovers and charitable contribution carryovers of $1.6 billion at the end of 2016 are expected to be utilized by us prior to expiration between 2018 and 2036. Employee share-based compensation attributable to the exercise of stock options and vesting of restricted stock is deductible by us for tax purposes. To the extent these tax deductions exceed the previously accrued deferred income tax benefit for these items, the additional tax benefit is not recognized until the deduction reduces current income taxes payable. Since the additional tax benefit does not reduce our current income taxes payable for 2014 through 2016, these tax benefits are not included in our Federal loss carryovers deferred income tax assets. The additional tax benefits deductible for tax purposes but not included in our Federal loss carryovers deferred income tax assets were $38 million through 2016. Cash payments for income taxes (net of refunds) were $5 million and $29 million in 2016 and 2014, respectively. Cash refunds for income taxes (net of payments and discontinued operations) were $136 million in 2015. As of December 31, 2016 , we had approximately $50 million of unrecognized tax benefits. If recognized, income tax expense would be reduced by $49 million and $51 million for 2016 and 2015, respectively, including the effect of these changes on other tax attributes, with state income tax amounts included net of federal tax effect. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows: 2016 2015 (Millions) Balance at beginning of period $ 55 $ 89 Additions for tax positions of prior years — 2 Reductions for tax positions of prior years (4 ) — Changes due to currency translation (1 ) (36 ) Balance at end of period $ 50 $ 55 We recognize related interest and penalties as a component of Provision (benefit) for income taxes . Total interest and penalties recognized as part of income tax provision were expenses of $300 thousand and $8 million for 2016 and 2014, respectively, and a benefit of $22 million for 2015, including a $35 million benefit due to currency fluctuation. Approximately $3 million and $2 million of interest and penalties primarily relating to uncertain tax positions have been accrued as of December 31, 2016 and 2015 , respectively. Changes due to currency translation in 2015 reflects the unrecognized tax benefit portion of the previously described impact of changes in foreign currency exchange rates on the remeasurement of a foreign currency denominated balance. 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. Consolidated U.S Federal income tax returns are open to Internal Revenue Service (IRS) examination for years after 2010. As of December 31, 2016, examinations of tax returns for 2011 through 2013 are currently in process. We do not expect material changes in our financial position resulting from these examinations. The statute of limitations for most states expires one year after expiration of the IRS statute. Generally, tax returns for our Canadian entities are open to audit for tax years after 2011. Tax years 2013 and 2014 are currently under examination. We have indemnified the purchaser of our Canadian operations for any adjustments to Canadian tax returns for periods prior to the sale of our Canadian operations in September 2016. In November 2015, the FASB issued ASU 2015-17 “Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes” (ASU 2015-17). The standard requires that deferred income tax liabilities and assets, along with any related valuation allowance, be presented as noncurrent in a classified statement of financial position. The standard is effective for interim and annual periods beginning after December 15, 2016 and early adoption is permitted. We have elected to early adopt ASU 2015-17 prospectively as of December 31, 2016. The Consolidated Balance Sheet as of December 31, 2015 was not retrospectively adjusted. On September 13, 2013, the IRS issued final regulations providing guidance on the treatment of amounts paid to acquire, produce, or improve tangible property. On August 18, 2014, the IRS issued final regulations providing guidance on the dispositions of such property. The implementation date for these regulations was January 1, 2014. The IRS is expected to issue additional procedural guidance regarding how the requirements may be implemented for the gas transmission and distribution industry. Pending the issuance of this additional procedural guidance from the IRS, we cannot at this time estimate the impact of implementing the regulations for our gas transmission business, although we anticipate that it will result in an immaterial balance sheet only impact.

Earnings (Loss) Per Common Shar

Earnings (Loss) Per Common Share from Continuing Operations	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Earnings (Loss) Per Common Share from Continuing Operations [Text Block]	Note 9 – Earnings (Loss) Per Common Share from Continuing Operations Years Ended December 31, 2016 2015 2014 (Dollars in millions, except per-share amounts; shares in thousands) Income (loss) from continuing operations attributable to The Williams Companies, Inc. available to common stockholders for basic and diluted earnings (loss) per common share $ (424 ) $ (571 ) $ 2,110 Basic weighted-average shares 750,673 749,271 719,325 Effect of dilutive securities: Nonvested restricted stock units — — 2,234 Stock options — — 2,064 Convertible debentures — — 18 Diluted weighted-average shares (1) 750,673 749,271 723,641 Earnings (loss) per common share from continuing operations: Basic $ (.57 ) $ (.76 ) $ 2.93 Diluted $ (.57 ) $ (.76 ) $ 2.91 (1) For the years ended December 31, 2016 and December 31, 2015, 0.6 million and 1.7 million weighted-average nonvested restricted stock units, and 0.5 million and 1.5 million weighted-average stock options have been excluded from the computation of diluted earnings (loss) per common share as their inclusion would be antidilutive due to our loss from continuing operations attributable to The Williams Companies, Inc.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2016
Compensation and Retirement Disclosure [Abstract]
Employee Benefit Plans [Text Block]	Note 10 – Employee Benefit Plans We have noncontributory defined benefit pension plans in which all eligible employees participate. Currently, eligible employees earn benefits primarily based on a cash balance formula. Various other formulas, as defined in the plan documents, are utilized to calculate the retirement benefits for plan participants not covered by the cash balance formula. At the time of retirement, participants may elect, to the extent they are eligible for the various options, to receive annuity payments, a lump sum payment, or a combination of a lump sum and annuity payments. In addition to our pension plans, we currently provide subsidized retiree medical and life insurance benefits (other postretirement benefits) to certain eligible participants. Generally, employees hired after December 31, 1991, are not eligible for the subsidized retiree medical benefits, except for participants that were employees or retirees of Transco Energy Company on December 31, 1995, and other miscellaneous defined participant groups. Subsidized retiree medical benefits for eligible participants age 65 and older are paid through contributions to health reimbursement accounts. Subsidized retiree medical benefits for eligible participants under age 65 are provided through a self-insured medical plan sponsored by us. The self-insured retiree medical plan provides for retiree contributions and contains other cost-sharing features such as deductibles, co-payments, and co-insurance. The accounting for these plans anticipates estimated future increases to our contribution levels to the health reimbursement accounts for participants age 65 and older, as well as future cost-sharing that is consistent with our expressed intent to increase the retiree contribution level generally in line with health care cost increases for participants under age 65. Funded Status The following table presents the changes in benefit obligations and plan assets for pension benefits and other postretirement benefits for the years indicated: Pension Benefits Other Postretirement Benefits 2016 2015 2016 2015 (Millions) Change in benefit obligation: Benefit obligation at beginning of year $ 1,464 $ 1,544 $ 202 $ 233 Service cost 54 59 1 2 Interest cost 62 58 8 9 Plan participants’ contributions — — 2 2 Benefits paid (130 ) (101 ) (15 ) (13 ) Actuarial loss (gain) 20 (91 ) (1 ) (31 ) Settlements (4 ) (5 ) — — Net increase (decrease) in benefit obligation 2 (80 ) (5 ) (31 ) Benefit obligation at end of year 1,466 1,464 197 202 Change in plan assets: Fair value of plan assets at beginning of year 1,241 1,293 201 208 Actual return on plan assets 82 (11 ) 13 (1 ) Employer contributions 65 65 7 5 Plan participants’ contributions — — 2 2 Benefits paid (130 ) (101 ) (15 ) (13 ) Settlements (4 ) (5 ) — — Net increase (decrease) in fair value of plan assets 13 (52 ) 7 (7 ) Fair value of plan assets at end of year 1,254 1,241 208 201 Funded status — overfunded (underfunded) $ (212 ) $ (223 ) $ 11 $ (1 ) Accumulated benefit obligation $ 1,440 $ 1,432 The overfunded (underfunded) status of our pension plans and other postretirement benefit plans presented in the previous table are recognized in the Consolidated Balance Sheet within the following accounts: December 31, 2016 2015 (Millions) Underfunded pension plans: Current liabilities $ (2 ) $ (2 ) Noncurrent liabilities (210 ) (221 ) Overfunded (underfunded) other postretirement benefit plans: Current liabilities (7 ) (7 ) Noncurrent assets (liabilities) 18 6 The plan assets within our other postretirement benefit plans are intended to be used for the payment of benefits for certain groups of participants. The Current liabilities for the other postretirement benefit plans represent the current portion of benefits expected to be payable in the subsequent year for the groups of participants whose benefits are not expected to be paid from plan assets. The pension plans’ benefit obligation Actuarial loss (gain) of $ 20 million in 2016 is primarily due to the impact of a decrease in the discount rates utilized to calculate the benefit obligation. The pension plans’ benefit obligation Actuarial loss (gain) of $(91) million in 2015 is primarily due to the impact of a decrease in the assumed future interest crediting rate for the cash balance pension formula and an increase in the discount rates utilized to calculate the benefit obligation. The 2015 benefit obligation Actuarial loss (gain) of $(31) million for our other postretirement benefit plans is primarily due to an increase in the discount rate used to calculate the benefit obligation, tax law changes, and other assumption changes. At December 31, 2016 and 2015 , all of our pension plans had a projected benefit obligation and accumulated benefit obligation in excess of plan assets. Pre-tax amounts not yet recognized in Net periodic benefit cost at December 31 are as follows: Pension Benefits Other Postretirement Benefits 2016 2015 2016 2015 (Millions) Amounts included in Accumulated other comprehensive income (loss) : Prior service credit $ — $ — $ 5 $ 11 Net actuarial loss (535 ) (544 ) (18 ) (18 ) Amounts included in regulatory liabilities associated with Transco and Northwest Pipeline: Prior service credit N/A N/A $ 10 $ 19 Net actuarial gain N/A N/A 8 6 In addition to the regulatory liabilities included in the previous table, differences in the amount of actuarially determined Net periodic benefit cost for our other postretirement benefit plans and the other postretirement benefit costs recovered in rates for Transco and Northwest Pipeline are deferred as a regulatory asset or liability. We have regulatory liabilities of $94 million at December 31, 2016 and $78 million at December 31, 2015 , related to these deferrals. Additionally, Transco recognizes a regulatory liability for rate collections in excess of its amount funded to the tax-qualified pension plans. At December 31, 2016 and 2015 , these regulatory liabilities were $21 million and $8 million , respectively. These pension and other postretirement plans amounts will be reflected in future rates based on the rate structures of these gas pipelines. Net Periodic Benefit Cost Net periodic benefit cost for the years ended December 31 consist of the following: Pension Benefits Other Postretirement Benefits 2016 2015 2014 2016 2015 2014 (Millions) Components of net periodic benefit cost: Service cost $ 54 $ 59 $ 40 $ 1 $ 2 $ 2 Interest cost 62 58 62 8 9 10 Expected return on plan assets (85 ) (75 ) (76 ) (12 ) (12 ) (12 ) Amortization of prior service credit — — — (15 ) (17 ) (20 ) Amortization of net actuarial loss 30 42 39 — 2 — Net actuarial (gain) loss from settlements and curtailments 2 2 1 — — (1 ) Reclassification to regulatory liability — — — 4 3 4 Net periodic benefit cost $ 63 $ 86 $ 66 $ (14 ) $ (13 ) $ (17 ) Items Recognized in Other Comprehensive Income (Loss) and Regulatory Assets/Liabilities Other changes in plan assets and benefit obligations recognized in Other comprehensive income (loss) before taxes for the years ended December 31 consist of the following: Pension Benefits Other Postretirement Benefits 2016 2015 2014 2016 2015 2014 (Millions) Other changes in plan assets and benefit obligations recognized in Other comprehensive income (loss) : Net actuarial gain (loss) $ (23 ) $ 5 $ (142 ) $ — $ 8 $ (18 ) Prior service (cost) credit — — — — — (1 ) Amortization of prior service credit — — — (6 ) (6 ) (8 ) Amortization of net actuarial loss 30 42 39 — 2 — Loss from settlements and curtailments 2 2 1 — — 1 Other changes in plan assets and benefit obligations recognized in Other comprehensive income (loss) $ 9 $ 49 $ (102 ) $ (6 ) $ 4 $ (26 ) Other changes in plan assets and benefit obligations for our other postretirement benefit plans associated with Transco and Northwest Pipeline are recognized in regulatory assets/liabilities. Amounts recognized in regulatory assets/ liabilities for the years ended December 31 consist of the following: 2016 2015 2014 (Millions) Other changes in plan assets and benefit obligations recognized in regulatory (assets) liabilities: Net actuarial gain (loss) $ 2 $ 10 $ (2 ) Amortization of prior service credit (9 ) (11 ) (12 ) Pre-tax amounts expected to be amortized in Net periodic benefit cost in 2017 are as follows: Pension Benefits Other Postretirement Benefits (Millions) Amounts included in Accumulated other comprehensive income (loss) : Prior service credit $ — $ (5 ) Net actuarial loss 28 — Amounts included in regulatory liabilities associated with Transco and Northwest Pipeline: Prior service credit N/A $ (8 ) Net actuarial loss N/A — Key Assumptions The weighted-average assumptions utilized to determine benefit obligations as of December 31 are as follows: Pension Benefits Other Postretirement Benefits 2016 2015 2016 2015 Discount rate 4.17 % 4.38 % 4.27 % 4.50 % Rate of compensation increase 4.87 4.88 N/A N/A The weighted-average assumptions utilized to determine Net periodic benefit cost for the years ended December 31 are as follows: Pension Benefits Other Postretirement Benefits 2016 2015 2014 2016 2015 2014 Discount rate 4.37 % 3.96 % 4.68 % 4.50 % 4.12 % 4.80 % Expected long-term rate of return on plan assets 6.85 6.38 6.85 6.11 5.70 6.11 Rate of compensation increase 4.88 4.62 4.56 N/A N/A N/A The mortality assumptions used to determine the benefit obligations for our pension and other postretirement benefit plans reflect generational projection mortality tables. The assumed health care cost trend rate for 2017 is 7.5 percent. This rate decreases to 4.5 percent by 2025 . A one-percentage-point change in assumed health care cost trend rates would have the following effects: Point increase Point decrease (Millions) Effect on total of service and interest cost components $ — $ — Effect on other postretirement benefit obligation 6 (5 ) Plan Assets Plan assets for our pension and other postretirement benefit plans consist primarily of equity and fixed income securities including mutual funds and commingled investment funds invested in equity and fixed income securities. The plans’ investment policy provides for a strategy in accordance with the Employee Retirement Income Security Act (ERISA), which governs the investment of the assets in a diversified portfolio. The plans follow a policy of diversifying the investments across various asset classes and investment managers. Additionally, the investment returns on approximately 38 percent of the other postretirement benefit plan assets are subject to income tax; therefore, certain investments are managed in a tax efficient manner. The investment policy for the pension plans includes a general target asset allocation at December 31, 2016 of 60 percent equity securities and 40 percent fixed income securities. The target allocation includes the investments in equity and fixed income mutual funds and commingled investment funds. The investment policy allows for a broad range of asset allocations that permit the plans to de-risk in response to changes in the plans’ funded status. Equity securities may include U.S. equities and non-U.S. equities. Investment in Williams’ securities or an entity in which Williams has a majority ownership is prohibited except where these securities may be owned in a commingled investment fund in which the plans’ trusts invest. No more than 5 percent of the total stock portfolio valued at market may be invested in the common stock of any one corporation. Fixed income securities may consist of U.S. as well as international instruments, including emerging markets. The fixed income strategies may invest in government, corporate, asset-backed securities, and mortgage-backed obligations. The weighted-average credit rating of the fixed income strategies must be at least “investment grade” including ratings by Moody’s and/or Standard & Poor’s. No more than 5 percent of the total fixed income portfolio may be invested in the fixed income securities of any one issuer with the exception of bond index funds and U.S. government guaranteed and agency securities. The following securities and transactions are not authorized: unregistered securities, commodities or commodity contracts, short sales or margin transactions, or other leveraging strategies. Investment strategies using direct investments in derivative securities require approval and, historically, have not been used; however, these instruments may be used in mutual funds and commingled investment funds held by the plans’ trusts. Additionally, real estate equity, natural resource property, venture capital, leveraged buyouts, and other high-return, high-risk investments are generally restricted. There are no significant concentrations of risk within the plans’ investment securities because of the diversity of the types of investments, diversity of the various industries, and the diversity of the fund managers and investment strategies. Generally, the investments held in the plans are publicly traded, therefore, minimizing liquidity risk in the portfolio. The fair values of our pension plan assets at December 31, 2016 and 2015 by asset class are as follows: 2016 Quoted Prices Significant Significant Total (Millions) Pension assets: Cash management fund $ 14 $ — $ — $ 14 Equity securities: U.S. large cap 87 — — 87 U.S. small cap 77 — — 77 Fixed income securities (1): U.S. Treasury securities 68 — — 68 Government and municipal bonds — 10 — 10 Mortgage and asset-backed securities — 80 — 80 Corporate bonds — 148 — 148 Insurance company investment contracts and other — 5 — 5 $ 246 $ 243 $ — 489 Commingled investment funds measured at net asset value practical expedient (3): Equities — U.S. large cap 369 Equities — International small cap 27 Equities — International emerging markets 50 Equities — International developed markets 149 Fixed income — U.S. long duration 88 Fixed income — Corporate bonds 82 Total assets at fair value at December 31, 2016 $ 1,254 2015 Quoted Prices Significant Significant Total (Millions) Pension assets: Cash management fund $ 8 $ — $ — $ 8 Equity securities: U.S. large cap 83 — — 83 U.S. small cap 64 — — 64 Fixed income securities (1): U.S. Treasury securities 65 — — 65 Government and municipal bonds — 8 — 8 Mortgage and asset-backed securities — 87 — 87 Corporate bonds — 145 — 145 Insurance company investment contracts and other — 5 — 5 $ 220 $ 245 $ — 465 Commingled investment funds measured at net asset value practical expedient (3): Equities — U.S. large cap 367 Equities — International small cap 27 Equities — International emerging markets 50 Equities — International developed markets 153 Fixed income — U.S. long duration 95 Fixed income — Corporate bonds 84 Total assets at fair value at December 31, 2015 $ 1,241 The fair values of our other postretirement benefits plan assets at December 31, 2016 and 2015 by asset class are as follows: 2016 Quoted Prices Significant Significant Total (Millions) Other postretirement benefit assets: Cash management funds $ 11 $ — $ — $ 11 Equity securities: U.S. large cap 24 — — 24 U.S. small cap 15 — — 15 International developed markets large cap growth — 5 — 5 Fixed income securities (2): U.S. Treasury securities 7 — — 7 Government and municipal bonds — 1 — 1 Mortgage and asset-backed securities — 8 — 8 Corporate bonds — 15 — 15 Mutual fund — Municipal bonds 42 — — 42 $ 99 $ 29 $ — 128 Commingled investment funds measured at net asset value practical expedient (3): Equities — U.S. large cap 38 Equities — International small cap 3 Equities — International emerging markets 5 Equities — International developed markets 16 Fixed income — U.S. long duration 9 Fixed income — Corporate bonds 9 Total assets at fair value at December 31, 2016 $ 208 2015 Quoted Prices Significant Significant Total (Millions) Other postretirement benefit assets: Cash management funds $ 11 $ — $ — $ 11 Equity securities: U.S. large cap 37 — — 37 U.S. small cap 20 — — 20 International developed markets large cap growth 1 9 — 10 Emerging markets growth — 1 — 1 Fixed income securities (2): U.S. Treasury securities 7 — — 7 Government and municipal bonds — 12 — 12 Mortgage and asset-backed securities — 9 — 9 Corporate bonds — 15 — 15 $ 76 $ 46 $ — 122 Commingled investment funds measured at net asset value practical expedient (3): Equities — U.S. large cap 37 Equities — International small cap 3 Equities — International emerging markets 5 Equities — International developed markets 16 Fixed income — U.S. long duration 10 Fixed income — Corporate bonds 8 Total assets at fair value at December 31, 2015 $ 201 ____________ (1) The weighted-average credit quality rating of the pension assets fixed income security portfolio is investment grade with a weighted-average duration of approximately 8 years for 2016 and 2015 . (2) The weighted-average credit quality rating of the other postretirement benefit assets fixed income security portfolio is investment grade with a weighted-average duration of approximately 8 years for 2016 and 7 years for 2015 . (3) The stated intents of the funds vary based on each commingled fund’s investment objective. These objectives generally include strategies to replicate or outperform various market indices. Certain standard withdrawal restrictions generally apply, which may include redemption notification period restrictions ranging from 10 to 30 days. Additionally, the fund managers retain the right to restrict withdrawals from and/or purchases into the funds so as not to disadvantage other investors in the funds. Generally, the funds also reserve the right to make all or a portion of the redemption in-kind rather than in cash or a combination of cash and in-kind. The fair value measurement level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement of an asset. Shares of the cash management funds and mutual funds are valued at fair value based on published market prices as of the close of business on the last business day of the year, which represents the net asset values of the shares held. The fair values of equity securities traded on U.S. exchanges are derived from quoted market prices as of the close of business on the last business day of the year. The fair values of equity securities traded on foreign exchanges are also derived from quoted market prices as of the close of business on an active foreign exchange on the last business day of the year. However, the valuation requires translation of the foreign currency to U.S. dollars and this translation is considered an observable input to the valuation. The fair values of all commingled investment funds are determined based on the net asset values per unit of each of the funds. The net asset values per unit represent the aggregate values of the funds’ assets at fair value less liabilities, divided by the number of units outstanding. The fair values of fixed income securities, except U.S. Treasury securities, are determined using pricing models. These pricing models incorporate observable inputs such as benchmark yields, reported trades, broker/dealer quotes, and issuer spreads for similar securities to determine fair value. The U.S. Treasury securities are valued at fair value based on closing prices on the last business day of the year reported in the active market in which the security is traded. The investment contracts with insurance companies are valued at fair value by discounting the cash flow of a bond using a yield to maturity based on an investment grade index or comparable index with a similar maturity value, maturity period, and nominal coupon rate. There have been no significant changes in the preceding valuation methodologies used at December 31, 2016 and 2015 . Additionally, there were no transfers or reclassifications of investments between Level 1 and Level 2 from December 2015 to December 2016 . If transfers between levels had occurred, the transfers would have been recognized as of the end of the period. Plan Benefit Payments and Employer Contributions Following are the expected benefits to be paid by the plans. These estimates are based on the same assumptions previously discussed and reflect future service as appropriate. The actuarial assumptions are based on long-term expectations and include, but are not limited to, assumptions as to average expected retirement age and form of benefit payment. Actual benefit payments could differ significantly from expected benefit payments if near-term participant behaviors differ significantly from the actuarial assumptions. Pension Benefits Other Postretirement Benefits (Millions) 2017 $ 99 $ 13 2018 103 13 2019 103 13 2020 106 13 2021 111 13 2022-2026 562 62 In 2017 , we expect to contribute approximately $60 million to our tax-qualified pension plans and approximately $2 million to our nonqualified pension plans, for a total of approximately $62 million , and approximately $7 million to our other postretirement benefit plans. Defined Contribution Plans We also maintain defined contribution plans for the benefit of substantially all of our employees. Generally, plan participants may contribute a portion of their compensation on a pre-tax and after-tax basis in accordance with the plans’ guidelines. We match employees’ contributions up to certain limits. Our matching contributions charged to expense were $36 million in 2016 , $39 million in 2015 , and $39 million in 2014 .

Property, Plant, and Equipment

Property, Plant, and Equipment	12 Months Ended
	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment [Text Block]	Note 11 – Property, Plant, and Equipment The following table presents nonregulated and regulated Property, plant, and equipment – net as presented on the Consolidated Balance Sheet for the years ended: Estimated Useful Life (1) (Years) Depreciation Rates (1) (%) December 31, 2016 2015 (Millions) Nonregulated: Natural gas gathering and processing facilities 5 - 40 $ 20,413 $ 20,789 Construction in progress Not applicable 412 1,366 Other 2 - 45 2,202 2,170 Regulated: Natural gas transmission facilities 1.20 - 6.97 12,692 12,189 Construction in progress Not applicable Not applicable 1,603 941 Other 5 - 45 1.35 - 33.33 1,590 1,584 Total property, plant, and equipment, at cost 38,912 39,039 Accumulated depreciation and amortization (10,484 ) (9,460 ) Property, plant, and equipment — net $ 28,428 $ 29,579 __________ (1) Estimated useful life and depreciation rates are presented as of December 31, 2016 . Depreciation rates and estimated useful lives for regulated assets are prescribed by the FERC. Depreciation and amortization expense for Property, plant, and equipment – net was $1,407 million , $1,382 million , and $967 million in 2016 , 2015 , and 2014 , respectively. Regulated Property, plant, and equipment – net includes approximately $665 million and $706 million at December 31, 2016 and 2015 , respectively, related to amounts in excess of the original cost of the regulated facilities within our gas pipeline businesses as a result of our prior acquisitions. This amount is being amortized over 40 years using the straight-line amortization method. Current FERC policy does not permit recovery through rates for amounts in excess of original cost of construction. Asset Retirement Obligations Our accrued obligations relate to underground storage caverns, offshore platforms and pipelines, fractionation and compression facilities, gas gathering well connections and pipelines, and gas transmission pipelines and facilities. At the end of the useful life of each respective asset, we are legally obligated to plug storage caverns and remove any related surface equipment, to restore land and remove surface equipment at gas processing, fractionation, and compression facilities, to dismantle offshore platforms and appropriately abandon offshore pipelines, to cap certain gathering pipelines at the wellhead connection and remove any related surface equipment, and to remove certain components of gas transmission facilities from the ground. The following table presents the significant changes to our ARO, of which $801 million and $858 million are included in Regulatory liabilities, deferred income, and other with the remaining current portion in Accrued liabilities at December 31, 2016 and 2015 , respectively. December 31, 2016 2015 (Millions) Beginning balance $ 915 $ 831 Liabilities incurred 24 42 Liabilities settled (8 ) (3 ) Accretion expense 69 60 Revisions (1) (138 ) (15 ) Ending balance $ 862 $ 915 ___________ (1) Several factors are considered in the annual review process, including inflation rates, current estimates for removal cost, market risk premiums, discount rates, and the estimated remaining useful life of the assets. The 2016 revisions reflect changes in removal cost estimates, increases in the estimated remaining useful life of certain assets, and decreases in the inflation rate and discount rates used in the annual review process. The 2015 revisions reflect changes in removal cost estimates and the estimated remaining useful life of assets, a decrease in the inflation rate, and increases in the discount rates used in the annual review process. The funds Transco collects through a portion of its rates to fund its ARO are deposited into an external trust account dedicated to funding its ARO (ARO Trust). (See Note 17 – Fair Value Measurements, Guarantees, and Concentration of Credit Risk .) Under its current rate settlement, Transco’s annual funding obligation is approximately $36 million , with installments to be deposited monthly.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets [Text Block]	Note 12 – Goodwill and Other Intangible Assets Goodwill Changes in the carrying amount of goodwill, included in Intangible assets – net of accumulated amortization , by reportable segment for the periods indicated are as follows: Williams Partners (Millions) December 31, 2014 $ 1,120 Purchase accounting adjustment 25 Impairment (1,098 ) December 31, 2015 $ 47 December 31, 2016 $ 47 Our goodwill is not subject to amortization, but is evaluated at least annually for impairment or more frequently if impairment indicators are present. We did not identify or recognize any impairments to goodwill in connection with our annual evaluation of goodwill for impairment (performed as of October 1) during the years ended December 31, 2016 and 2014 . During 2015, we performed an interim assessment and an annual assessment as of September 30, 2015 and October 1, 2015, respectively, of certain goodwill within the Williams Partners segment. The estimated fair value of the reporting units evaluated exceeded their carrying amounts, and thus no impairment was identified. We performed an additional goodwill impairment evaluation as of December 31, 2015 , of the goodwill recorded within the Williams Partners segment. As a result of this evaluation, we recorded goodwill impairment charges totaling $1.098 billion . (See Note 17 – Fair Value Measurements, Guarantees, and Concentration of Credit Risk .) Other Intangible Assets The gross carrying amount and accumulated amortization of other intangible assets, included in Intangible assets – net of accumulated amortization , at December 31 are as follows: 2016 2015 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization (Millions) Contractual customer relationships $ 10,635 $ (1,019 ) $ 10,633 $ (663 ) Other intangible assets primarily relate to gas gathering, processing, and fractionation contractual customer relationships recognized in the ACMP and Eagle Ford acquisitions (see Note 2 – Acquisitions ) as well as previous acquisitions. Other intangible assets are being amortized on a straight-line basis over an initial period of 30 years which represents a portion of the term over which the contractual customer relationships are expected to contribute to our cash flows. 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 contract periods (as estimated at the time of the respective acquisition), the weighted-average periods prior to the next renewal or extension of the contractual customer relationships associated with the ACMP and Eagle Ford acquisitions were approximately 17 years and 10 years , respectively. Although a significant portion of the expected future cash flows associated with these contractual customer relationships are dependent on our ability to renew or extend the arrangements beyond the initial contract periods, these expected future cash flows are significantly influenced by the scope and pace of our producer customers’ drilling programs. Once producer customers’ wells are connected to our gathering infrastructure, their likelihood of switching to another provider before the wells are abandoned is reduced due to the significant capital investment required. The amortization expense related to other intangible assets was $356 million , $353 million , and $209 million in 2016 , 2015 , and 2014 , respectively. The estimated amortization expense for each of the next five succeeding fiscal years is approximately $356 million.

Accrued Liabilities

Accrued Liabilities	12 Months Ended
	Dec. 31, 2016
Accrued Liabilities, Current [Abstract]
Accrued Liabilities [Text Block]	Note 13 – Accrued Liabilities December 31, 2016 2015 (Millions) Deferred income $ 338 $ 94 Interest on debt 310 284 Employee costs 223 215 Refundable deposits 160 — Special distribution repayable to Gulfstream (See Note 6 - Investing Activities) — 149 Asset retirement obligations 61 57 Other, including other loss contingencies 356 279 $ 1,448 $ 1,078 Deferred income in 2016 includes cash proceeds associated with restructuring certain gas gathering contracts in the Barnett Shale and Mid-Continent regions. (See Note 1 – General, Description of Business, Basis of Presentation, and Summary of Significant Accounting Policies .) Refundable deposits in 2016 includes receipts related to an agreement to resolve several matters in relation to Transco’s Hillabee Expansion Project. In accordance with the agreement, the member–sponsors of Sabal Trail will pay WPZ an aggregate amount of $240 million in three equal installments as certain milestones of the project are met, of which $160 million was received in 2016. WPZ expects to recognize income associated with these receipts over the term of an underlying contract once the project is in service.

Debt, Banking Arrangements, and

Debt, Banking Arrangements, and Leases	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Debt, Banking Arrangements, and Leases [Text Block]	Note 14 – Debt, Banking Arrangements, and Leases Long-Term Debt December 31, 2016 2015 (Millions) Unsecured: Transco: 6.4% Notes due 2016 (1) $ — $ 200 6.05% Notes due 2018 250 250 7.08% Debentures due 2026 8 8 7.25% Debentures due 2026 200 200 7.85% Notes due 2026 1,000 — 5.4% Notes due 2041 375 375 4.45% Notes due 2042 400 400 Northwest Pipeline: 7% Notes due 2016 — 175 5.95% Notes due 2017 185 185 6.05% Notes due 2018 250 250 7.125% Debentures due 2025 85 85 WPZ: 7.25% Notes due 2017 600 600 5.25% Notes due 2020 1,500 1,500 4.125% Notes due 2020 600 600 4% Notes due 2021 500 500 3.6% Notes due 2022 1,250 1,250 3.35% Notes due 2022 750 750 6.125% Notes due 2022 750 750 4.5% Notes due 2023 600 600 4.875% Notes due 2023 1,400 1,400 4.3% Notes due 2024 1,000 1,000 4.875% Notes due 2024 750 750 3.9% Notes due 2025 750 750 4% Notes due 2025 750 750 6.3% Notes due 2040 1,250 1,250 5.8% Notes due 2043 400 400 5.4% Notes due 2044 500 500 4.9% Notes due 2045 500 500 5.1% Notes due 2045 1,000 1,000 Term Loan, variable interest rate, due 2018 850 850 Credit facility loans — 1,310 WMB: 7.875% Notes due 2021 371 371 3.7% Notes due 2023 850 850 4.55% Notes due 2024 1,250 1,250 7.5% Debentures due 2031 339 339 December 31, 2016 2015 (Millions) 7.75% Notes due 2031 252 252 8.75% Notes due 2032 445 445 5.75% Notes due 2044 650 650 Various — 5.5% to 10.25% Notes and Debentures due 2019 to 2033 55 55 Credit facility loans 775 650 Capital lease obligations — 1 Debt issuance costs (119 ) (123 ) Net unamortized debt premium (discount) 88 110 Total long-term debt, including current portion 23,409 23,988 Long-term debt due within one year (785 ) (176 ) Long-term debt $ 22,624 $ 23,812 ___________ (1) Presented as long-term debt at December 31, 2015, due to Transco’s intent and ability to refinance. Certain of our debt agreements contain covenants that restrict or limit, among other things, our ability to create liens supporting indebtedness, sell assets, and incur additional debt. Default of these agreements could also restrict our ability to make certain distributions or repurchase equity. The following table presents aggregate minimum maturities of long-term debt, excluding net unamortized debt premium (discount), debt issuance costs, and capital lease obligations, for each of the next five years: December 31, 2016 (Millions) 2017 $ 785 2018 1,350 2019 32 2020 2,896 2021 871 Issuances and retirements WPZ retired $600 million of 7.25 percent senior unsecured notes that matured on February 1, 2017. Northwest Pipeline retired $175 million of 7 percent senior unsecured notes that matured on June 15, 2016. Transco retired $200 million of 6.4 percent senior unsecured notes that matured on April 15, 2016. On January 22, 2016, Transco issued $1 billion of 7.85 percent senior unsecured notes due 2026 to investors in a private debt placement. In January 2017, Transco completed an exchange of these notes for substantially identical new notes that are registered under the Securities Act of 1933, as amended. Transco used the net proceeds to repay debt and to fund capital expenditures. In December 2015, WPZ borrowed $850 million on a variable interest rate loan with certain lenders due 2018. At December 31, 2016, the interest rate was 2.50 percent . WPZ used the proceeds for working capital, capital expenditures, and for general partnership purposes. On April 15, 2015, WPZ paid $783 million , including a redemption premium, to early retire $750 million of 5.875 percent senior notes due 2021 with a carrying value of $797 million . On March 3, 2015, WPZ completed a public offering of $1.25 billion of 3.6 percent senior unsecured notes due 2022, $750 million of 4 percent senior unsecured notes due 2025, and $1 billion of 5.1 percent senior unsecured notes due 2045. WPZ used the net proceeds to repay amounts outstanding under its commercial paper program and credit facility, to fund capital expenditures, and for general partnership purposes. WPZ retired $750 million of 3.8 percent senior unsecured notes that matured on February 15, 2015. Credit Facilities December 31, 2016 Available Outstanding (Millions) WMB Long-term credit facility $ 1,500 $ 775 Letters of credit under certain bilateral bank agreements 13 WPZ Long-term credit facility (1) 3,500 — Letters of credit under certain bilateral bank agreements 1 ________________ (1) In managing our available liquidity, we do not expect a maximum outstanding amount in excess of the capacity of our credit facility inclusive of any outstanding amounts under our commercial paper program. WMB long-term credit facility On February 2, 2015, we entered into the Second Amended and Restated Credit Agreement. The aggregate commitments available remained at $1.5 billion , with up to an additional $500 million increase in aggregate commitments available under certain circumstances. The maturity date of the credit facility was extended to February 2, 2020. However, we may request up to two extensions of the maturity date each for an additional one year period to allow a maturity date as late as February 2, 2022, under certain circumstances. The agreement also allows for swing line loans up to an aggregate amount of $50 million , subject to available capacity under the credit facility, and the letters of credit up to $675 million . The agreements governing the credit facilities contain the following terms and conditions: • Various covenants may limit, among other things, a borrower’s and its material subsidiaries’ ability to grant certain liens supporting indebtedness, merge or consolidate, sell all or substantially all of its assets, enter into certain affiliate transactions, make certain distributions during an event of default, make investments, and allow any material change in the nature of its business. • If an event of default with respect to a borrower occurs under its respective credit facility, the lenders will be able to terminate the commitments for the respective borrowers and accelerate the maturity of any loans of the defaulting borrower under the respective credit facility agreement and exercise other rights and remedies. • Each time funds are borrowed under our credit facility, the borrower may choose from two methods of calculating interest: a fluctuating base rate equal to the bank’s alternate base rate plus an applicable margin or a periodic fixed rate equal to LIBOR plus an applicable margin. The borrower is required to pay a commitment fee based on the unused portion of its respective credit facility. The applicable margin and the commitment fee are determined for us by reference to a pricing schedule based on our senior unsecured long-term debt ratings. Significant financial covenants under the agreement require the ratio of debt to EBITDA (each as defined in the credit agreement) be no greater than 5 to 1, except for the fiscal quarter and the two following fiscal quarters in which one or more acquisitions has been executed, in which case the ratio of debt to EBITDA is to be no greater than 5.5 to 1. We are in compliance with these financial covenants as measured at December 31, 2016. As of February 20, 2017, $235 million is outstanding under our long-term credit facility. WPZ long-term credit facilities Prior to their merger both WPZ and ACMP had separate credit facilities that terminated on February 2, 2015. On February 2, 2015, WPZ along with Transco, Northwest Pipeline, the lenders named therein, and an administrative agent entered into the Second Amended & Restated Credit Agreement with aggregate commitments available of $3.5 billion , with up to an additional $500 million increase in aggregate commitments available under certain circumstances. The maturity date of the credit facility is February 2, 2020. However, the co-borrowers may request up to two extensions of the maturity date each for an additional one year period to allow a maturity date as late as February 2, 2022, under certain circumstances. The agreement allows for swing line loans up to an aggregate amount of $150 million , subject to available capacity under the credit facility, and letters of credit commitments of $1.125 billion . Transco and Northwest Pipeline are each able to borrow up to $500 million under this credit facility to the extent not otherwise utilized by the other co-borrowers. On December 18, 2015, WPZ along with Transco, Northwest Pipeline, the lenders named therein and an administrative agent entered into the Amendment No. 1 to Second Amended & Restated Credit Agreement modifying the thresholds specified in the covenant related to the maximum ratio of WPZ’s debt to EBITDA. The agreement governing this credit facility contains the following terms and conditions: • Various covenants may limit, among other things, a borrower’s and its material subsidiaries’ ability to grant certain liens supporting indebtedness, merge or consolidate, sell all or substantially all of its assets, enter into certain affiliate transactions, make certain distributions during an event of default, enter into certain restrictive agreements, and allow any material change in the nature of its business. • If an event of default with respect to a borrower occurs under the credit facility, the lenders will be able to terminate the commitments for all borrowers and accelerate the maturity of any loans of the defaulting borrower under the credit facility agreement and exercise other rights and remedies. • Other than swing line loans, each time funds are borrowed, the borrower must choose whether such borrowing will be an alternate base rate borrowing or a Eurodollar borrowing. If such borrowing is an alternate base rate borrowing, interest is calculated on the basis of the greater of (a) the Prime Rate, (b) the Federal Funds Effective Rate plus one half of 1 percent and (c) a periodic fixed rate equal to the London Interbank Offered Rate (LIBOR) plus 1 percent , plus, in the case of each of (a), (b) and (c), an applicable margin. If the borrowing is a Eurodollar borrowing, interest is calculated on the basis of LIBOR for the relevant period plus an applicable margin. Interest on swing line loans is calculated as the sum of the alternate base rate plus an applicable margin. The borrower is required to pay a commitment fee based on the unused portion of the credit facility. The applicable margin and the commitment fee are determined for each borrower by reference to a pricing schedule based on such borrower’s senior unsecured long-term debt ratings. Significant financial covenants under the agreement require the ratio of debt to EBITDA, each as defined in the credit facility, be no greater than: • 5.75 to 1, for the quarters ending December 31, 2015, March 31, 2016 and June 30, 2016; • 5.50 to 1, for the quarters ending September 30, 2016 and December 31, 2016; • 5.00 to 1, for the quarter ending March 31, 2017 and each subsequent fiscal quarter, except for the fiscal quarter and the two following fiscal quarters in which one or more acquisitions has been executed, in which case the ratio of debt to EBITDA is to be no greater than 5.5 to 1.00. The ratio of debt to capitalization (defined as net worth plus debt) must be no greater than 65 percent for each Transco and Northwest Pipeline. WPZ is in compliance with these financial covenants as measured at December 31, 2016. As of February 20, 2017, there are no amounts outstanding under the long-term credit facility. WPZ short-term credit facilities On August 26, 2015, WPZ entered into a $1.0 billion short-term credit facility. On December 23, 2015, WPZ’s short-term credit facility capacity decreased to $150 million in conjunction with entering into the $850 million term loan. The $150 million short-term credit facility is no longer available as it expired August 24, 2016. Commercial Paper Program On February 2, 2015, WPZ amended and restated the commercial paper program for the ACMP Merger and to allow a maximum outstanding amount of unsecured commercial paper notes of $3 billion . The maturities of the commercial paper notes vary but may not exceed 397 days from the date of issuance. The commercial paper notes are sold under customary terms in the commercial paper market and are issued at a discount from par, or, alternatively, are sold at par and bear varying interest rates on a fixed or floating basis. Proceeds from these notes are used for general partnership purposes, including funding capital expenditures, working capital, and partnership distributions. We classify WPZ’s commercial paper outstanding in Current liabilities in the Consolidated Balance Sheet , as the outstanding notes at December 31, 2016 and December 31, 2015 , have maturity dates less than three months from the date of issuance. At December 31, 2016 , WPZ had $93 million in Commercial paper outstanding at a weighted-average interest rate of 1.06 percent and at December 31, 2015 , WPZ had $499 million in Commercial paper outstanding at a weighted-average interest rate of 0.92 percent . Cash Payments for Interest (Net of Amounts Capitalized) Cash payments for interest (net of amounts capitalized) were $1.152 billion in 2016, $1.023 billion in 2015, and $681 million in 2014. Restricted Net Assets of Subsidiaries We have considered the guidance in the Securities and Exchange Commission’s Regulation S-X related to restricted net assets of subsidiaries. In accordance with Rule 4-08(e) of Regulation S-X, we have determined that certain net assets of our subsidiaries are considered restricted under this guidance and exceed 25 percent of our consolidated net assets. As of December 31, 2016, substantially all of these restricted net assets relate to the net assets of WPZ, which are technically considered restricted under this accounting rule due to terms within WPZ’s partnership agreement that govern the partnerships’ assets. Our interest in WPZ’s net assets that are considered to be restricted at December 31, 2016, was $13 billion . Leases-Lessee The future minimum annual rentals under noncancelable operating leases, are payable as follows: December 31, 2016 (Millions) 2017 $ 62 2018 58 2019 51 2020 46 2021 35 Thereafter 90 Total $ 342 Total rent expense was $64 million in 2016, $69 million in 2015, and $62 million in 2014 and primarily included in Operating and maintenance expenses and Selling, general, and administrative expenses in the Consolidated Statement of Operations . Other On January 25, 2017, WPZ announced that it will redeem all of its $750 million 6.125 percent senior notes due 2022 on February 23, 2017.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2016
Stockholders' Equity Note [Abstract]
Stockholders' Equity [Text Block]	Note 15 – Stockholders' Equity Cash dividends declared per common share were $1.68 , $2.45 , and $1.9575 for 2016 , 2015 , and 2014 , respectively. On February 20, 2017, our board of directors approved a regular quarterly dividend of $0.30 per share payable on March 27, 2017. In January 2017, we issued 65 million shares of common stock in a public offering at a price of $29.00 per share. In February 2017, we issued 9.75 million shares of common stock pursuant to the full exercise of the underwriter’s option to purchase additional shares. The net proceeds of approximately $2.1 billion were used to purchase newly issued common units in WPZ as part of our Financial Repositioning. (See Note 1 - General, Description of Business, Basis of Presentation and Summary of Significant Accounting Policies.) On June 23, 2014, we issued 61 million shares of common stock in a public offering at a price of $57.00 per share. That amount includes 8 million shares purchased pursuant to the full exercise of the underwriter’s option to purchase additional shares. The net proceeds of $3.378 billion were used in July 2014 to finance a portion of the ACMP Acquisition. (See Note 2 - Acquisitions.) AOCI The following table presents the changes in AOCI by component, net of income taxes: Cash Flow Hedges Foreign Currency Translation Pension and Other Post Retirement Benefits Total (Millions) Balance at December 31, 2015 $ (1 ) $ (103 ) $ (338 ) $ (442 ) Other comprehensive income (loss) before reclassifications 2 25 (15 ) 12 Amounts reclassified from accumulated other comprehensive income (loss) (1 ) 76 16 91 Other comprehensive income (loss) 1 101 1 103 Balance at December 31, 2016 $ — $ (2 ) $ (337 ) $ (339 ) Reclassifications out of AOCI are presented in the following table by component for the year ended December 31, 2016 : Component Reclassifications Classification (Millions) Cash flow hedges: Energy commodity contracts $ (3 ) Product sales Total cash flow hedges (3 ) Pension and other postretirement benefits: Amortization of prior service cost (credit) included in net periodic benefit cost (6 ) Note 10 – Employee Benefit Plans Amortization of actuarial (gain) loss included in net periodic benefit cost 32 Note 10 – Employee Benefit Plans Total pension and other postretirement benefits 26 Foreign currency translation: Reclassification of cumulative foreign currency translation adjustment upon sale of foreign entities 155 Other (income) expense - net Total before tax 178 Income tax benefit (45 ) Provision (benefit) for income taxes Net of income tax 133 Noncontrolling interest (42 ) Net income (loss) attributable to noncontrolling interests Reclassifications during the period $ 91

Equity-Based Compensation

Equity-Based Compensation	12 Months Ended
	Dec. 31, 2016
Share-based Compensation [Abstract]
Equity-Based Compensation [Text Block]	Note 16 – Equity-Based Compensation Williams’ Plan Information On May 17, 2007, our stockholders approved The Williams Companies, Inc. 2007 Incentive Plan (the Plan) that provides common-stock-based awards to both employees and nonmanagement directors and reserved 19 million new shares for issuance. On May 20, 2010 and May 22, 2014, our stockholders approved amendments and restatements of the Plan to increase by 11 million and 10 million , respectively, the number of new shares authorized for making awards under the Plan, among other changes. The Plan permits the granting of various types of awards including, but not limited to, restricted stock units and stock options. At December 31, 2016 , 27 million shares of our common stock were reserved for issuance pursuant to existing and future stock awards, of which 17 million shares were available for future grants. Additionally, on May 17, 2007, our stockholders approved an Employee Stock Purchase Plan (ESPP) which authorized up to 2 million new shares of our common stock to be available for sale under the ESPP. On May 22, 2014, our stockholders approved an amendment and restatement of the ESPP to increase by 1.6 million the number of new shares authorized for sale under the ESPP. The ESPP enables eligible participants to purchase our common stock through payroll deductions not exceeding an annual amount of $15,000 per participant. The ESPP provides for offering periods during which shares may be purchased and continues until the earliest of (1) the Board of Directors terminates the ESPP, (2) the sale of all shares available under the ESPP, or (3) the tenth anniversary of the date the amended and restated ESPP was approved by the stockholders. Offering periods are from January through June and from July through December. Generally, all employees are eligible to participate in the ESPP, with the exception of executives and international employees. The number of shares eligible for an employee to purchase during each offering period is limited to 750 shares. The purchase price of the stock is 85 percent of the lower closing price of either the first or the last day of the offering period. The ESPP requires a one -year holding period before the stock can be sold. The plan was suspended during the period from January 1, 2016 to August 31, 2016, and was reinstated effective September 1, 2016. Employees purchased 111 thousand shares at an average price of $23.93 per share during the period from September 1, 2016 to December 31, 2016. Approximately 1.4 million shares were available for purchase under the ESPP at December 31, 2016 . Operating and maintenance expenses and Selling, general and administrative expenses include equity-based compensation expense for the years ended December 31, 2016 , 2015 , and 2014 of $53 million , $56 million , and $44 million , respectively. Income tax benefit recognized related to the stock-based compensation expense for the years ended December 31, 2016 , 2015 , and 2014 was $20 million , $21 million , and $17 million , respectively. Measured but unrecognized stock-based compensation expense at December 31, 2016 , was $67 million , which does not include the effect of estimated forfeitures of $2 million . Unrecognized stock-based compensation expense is comprised of $5 million related to stock options and $62 million related to restricted stock units. These amounts are expected to be recognized over a weighted-average period of 1.9 years. Stock Options Stock options are valued at the date of award, which does not precede the approval date. The purchase price per share for stock options may not be less than the market price of the underlying stock on the date of grant. Stock options generally become exercisable over a three -year period from the date of grant. Stock options generally expire ten years after the grant. The following summary reflects stock option activity and related information for the year ended December 31, 2016 : Stock Options Options Weighted- Average Exercise Price Aggregate Intrinsic Value (Millions) (Millions) Outstanding at December 31, 2015 5.7 $ 31.51 Granted 0.9 $ 24.99 Exercised (0.3 ) $ 17.84 Cancelled (0.1 ) $ 24.04 Outstanding at December 31, 2016 6.2 $ 31.32 $ 28 Exercisable at December 31, 2016 5.0 $ 29.75 $ 23 The following table summarizes additional information related to stock option activity during each of the last three years: Years Ended December 31, 2016 2015 2014 (Millions) Total intrinsic value of options exercised $ 2 $ 37 $ 48 Tax benefits realized on options exercised $ 1 $ 13 $ 18 Cash received from the exercise of options $ 4 $ 20 $ 31 The weighted-average remaining contractual life for stock options outstanding and exercisable at December 31, 2016 , was 5.5 years and 4.2 years, respectively. The estimated fair value at date of grant of options for our common stock granted in each respective year, using the Black-Scholes option pricing model, is as follows: 2016 2015 2014 Weighted-average grant date fair value of options for our common stock granted during the year, per share $ 7.90 $ 7.61 $ 7.50 Weighted-average assumptions: Dividend yield 3.2 % 4.8 % 4.2 % Volatility 44.7 % 27.8 % 28.0 % Risk-free interest rate 1.2 % 1.8 % 2.2 % Expected life (years) 6.0 6.0 6.5 The 2016 expected dividend yield is based on the 2016 dividend forecast and the grant-date market price of our stock. Expected volatility is based on the average of our peer group 10 -year historical volatility adjusted by a ratio of our implied volatility to the adjusted average of our peer group’s implied volatility. The adjustment is made because the difference in implied volatility between our peer group and us may indicate that we are expected to be more volatile than our peer group average. The risk-free interest rate is based on the U.S. Treasury Constant Maturity rates as of the grant date. The expected life of the option is based on historical exercise behavior and expected future experience. Nonvested Restricted Stock Units The following summary reflects nonvested restricted stock unit activity and related information for the year ended December 31, 2016 : Restricted Stock Units Outstanding Shares Weighted- Average Fair Value (1) (Millions) Nonvested at December 31, 2015 3.4 $ 39.38 Granted 1.5 $ 26.51 Forfeited (0.1 ) $ 38.18 Vested (0.9 ) $ 35.49 Nonvested at December 31, 2016 3.9 $ 35.19 ______________ (1) Performance-based restricted stock units are valued utilizing a Monte Carlo valuation method using measures of total shareholder return. Certain of the performance-based restricted stock units are subject to a holding period of up to two years after the vesting date. Discounts for the restrictions of liquidity were applied to the estimated fair value at the date of certain awards and ranged from 5.83 percent to 15.58 percent . The discounts were developed using the Chaffe model and the Finnerty model. All other restricted stock units are valued at the grant-date market price. Restricted stock units generally vest after three years . Value of Restricted Stock Units 2016 2015 2014 Weighted-average grant date fair value of restricted stock units granted during the year, per share $ 26.51 $ 40.15 $ 42.79 Total fair value of restricted stock units vested during the year ($’s in millions) $ 32 $ 42 $ 27 Performance-based restricted stock units granted under the Plan represent 40 percent of nonvested restricted stock units outstanding at December 31, 2016 . These grants may be earned at the end of the vesting period based on actual performance against a performance target. Based on the extent to which certain financial targets are achieved, vested shares may range from zero percent to 500 percent of the original grant amount. WPZ’s Plan Information During 2014, certain employees of ACMP’s general partner received equity-based compensation through ACMP’s equity-based compensation program. The fair value of the awards issued was based on the fair market value of the common units on the date of grant. This value is being amortized over the vesting period, which is one to four years from the date of grant. These awards were converted to WPZ equity-based awards in accordance with the terms of the ACMP Merger. No additional grants of restricted common units were awarded through WPZ’s equity-based compensation programs in 2016 or 2015, and no additional grants are expected in the future. Equity-based compensation expense of $20 million , $29 million , and $11 million related to WPZ’s equity-based compensation program is included in Operating and maintenance expenses and Selling, general, and administrative expenses for the years ended December 31, 2016, 2015, and 2014, respectively. As of December 31, 2016, there was $11 million of unrecognized compensation expense attributable to the outstanding awards, which does not include the effect of estimated forfeitures of $1 million . These amounts are expected to be recognized over a weighted average period of 1.2 years . The following summary reflects nonvested WPZ restricted common unit activity and related information for the year ended December 31, 2016 : Restricted Common Units Outstanding Units Weighted- Average Fair Value (Millions) Nonvested at December 31, 2015 1.2 $ 55.93 Forfeited (0.1 ) $ 52.85 Vested (0.5 ) $ 59.09 Nonvested at December 31, 2016 0.6 $ 52.97

Fair Value Measurements, Guaran

Fair Value Measurements, Guarantees, and Concentration of Credit Risk	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements, Guarantees, and Concentration of Credit Risk [Text Block]	Note 17 – Fair Value Measurements, Guarantees, and Concentration of Credit Risk The following table presents, by level within the fair value hierarchy, certain of our financial assets and liabilities. The carrying values of cash and cash equivalents, accounts receivable, commercial paper, and accounts payable approximate fair value because of the short-term nature of these instruments. Therefore, these assets and liabilities are not presented in the following table. Fair Value Measurements Using Carrying Amount Fair Value Quoted Prices In Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (Millions) Assets (liabilities) at December 31, 2016: Measured on a recurring basis: ARO Trust investments $ 96 $ 96 $ 96 $ — $ — Energy derivatives assets designated as hedging instruments 2 2 — 2 — Energy derivatives assets not designated as hedging instruments 1 1 — — 1 Energy derivatives liabilities not designated as hedging instruments (6 ) (6 ) — — (6 ) Additional disclosures: Other receivables 15 15 15 — — Long-term debt, including current portion (23,409 ) (24,090 ) — (24,090 ) — Guarantees (44 ) (30 ) — (14 ) (16 ) Assets (liabilities) at December 31, 2015: Measured on a recurring basis: ARO Trust investments $ 67 $ 67 $ 67 $ — $ — Energy derivatives assets not designated as hedging instruments 5 5 — 3 2 Energy derivatives liabilities not designated as hedging instruments (2 ) (2 ) — — (2 ) Additional disclosures: Other receivables 12 30 10 2 18 Long-term debt, including current portion (1) (23,987 ) (19,606 ) — (19,606 ) — Guarantee (29 ) (16 ) — (16 ) — ___________ (1) Excludes capital leases. 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 that is specifically designated to fund future asset retirement obligations. The ARO Trust invests in a portfolio of actively traded mutual funds that are measured at fair value on a recurring basis based on quoted prices in an active market, is classified as available-for-sale, and is reported in Regulatory assets, deferred charges, and other in the Consolidated Balance Sheet. Both realized and unrealized gains and losses are ultimately recorded as regulatory assets or liabilities. Energy derivatives : Energy derivatives include commodity based exchange-traded contracts and over-the-counter contracts, which consist of physical forwards, futures, and swaps that are measured at fair value on a recurring basis. The fair value amounts are presented on a gross basis and do not reflect the netting of asset and liability positions permitted under the terms of our master netting arrangements. Further, the amounts do not include cash held on deposit in margin accounts that we have received or remitted to collateralize certain derivative positions. Energy derivatives assets are reported in Other current assets and deferred charges and Regulatory assets, deferred charges, and other in the Consolidated Balance Sheet. Energy derivatives liabilities are reported in Accrued liabilities and Regulatory liabilities, deferred income, and other in the Consolidated Balance Sheet. Reclassifications of fair value between Level 1, Level 2, and Level 3 of the fair value hierarchy, if applicable, are made at the end of each quarter. No transfers between Level 1 and Level 2 occurred during the years ended December 31, 2016 or 2015 . Additional fair value disclosures Other receivables: Other receivables primarily consist of margin deposits, which are reported in Other current assets and deferred charges in the Consolidated Balance Sheet. The disclosed fair value of our margin deposits is considered to approximate the carrying value generally due to the short-term nature of these items. Other receivables also include a receivable related to the sale of certain former Venezuela assets. The disclosed fair value of this receivable is determined by an income approach. We calculated the net present value of a probability-weighted set of cash flows utilizing assumptions based on contractual terms, historical payment patterns by the counterparty, future probabilities of default, our likelihood of using arbitration if the counterparty does not perform, and discount rates. We determined the fair value of the receivable to be $18 million at December 31, 2015. We received two payments in 2016. The carrying value of this receivable is zero at December 31, 2016 and December 31, 2015. Long-term debt : The disclosed fair value of our long-term debt is determined by a market approach using broker quoted indicative period-end bond prices. The quoted prices are based on observable transactions in less active markets for our debt or similar instruments. Guarantees : Guarantees primarily consist of a guarantee we have provided in the event of nonpayment by our previously owned communications subsidiary, Williams Communications Group (WilTel), on a lease performance obligation that extends through 2042. Guarantees also include an indemnification related to a disposed operation. To estimate the disclosed fair value of the WilTel guarantee, an estimated default rate is applied to the sum of the future contractual lease payments using an income approach. The estimated default rate is determined by obtaining the average cumulative issuer-weighted corporate default rate based on the credit rating of WilTel’s current owner and the term of the underlying obligation. The default rate is published by Moody’s Investors Service. The carrying value of the WilTel guarantee is reported in Accrued liabilities in the Consolidated Balance Sheet. The maximum potential undiscounted exposure is approximately $32 million at December 31, 2016 . Our exposure declines systematically through the remaining term of WilTel’s obligation. The fair value of the guarantee associated with the indemnification related to a disposed operation was estimated using an income approach that considered probability-weighted scenarios of potential levels of future performance. The terms of the indemnification do not limit the maximum potential future payments associated with the guarantee. The carrying value of this guarantee is reported in Regulatory liabilities, deferred income, and other in the Consolidated Balance Sheet. We are required by our revolving credit agreements to indemnify lenders for certain taxes required to be withheld from payments due to the lenders and for certain tax payments made by the lenders. The maximum potential amount of future payments under these indemnifications is based on the related borrowings and such future payments cannot currently be determined. These indemnifications generally continue indefinitely unless limited by the underlying tax regulations and have no carrying value. We have never been called upon to perform under these indemnifications and have no current expectation of a future claim. Nonrecurring fair value measurements We performed an interim assessment of the goodwill associated with our former Central and Northeast G&P reporting units as of September 30, 2015, and the annual assessment of goodwill associated with our Northeast G&P and West reporting units as of October 1, 2015. No impairment charges were required following these evaluations. During the fourth quarter of 2015, we observed a significant decline in the market values of WPZ and comparable midstream companies within the industry. This served to reduce our estimate of enterprise value and increased our estimates of discount rates. As a result, we performed an impairment assessment as of December 31, 2015, of the goodwill associated with these reporting units, all within the Williams Partners segment. We estimated the fair value of each reporting unit based on an income approach utilizing discount rates specific to the underlying businesses of each reporting unit. These discount rates considered variables unique to each business area, including equity yields of comparable midstream businesses, expectations for future growth, and customer performance considerations. Weighted-average discount rates utilized ranged from approximately 10 percent to 13 percent across the three reporting units. As a result of the increases in discount rates during the fourth quarter of 2015, coupled with certain reductions in estimated future cash flows determined during the same period, the fair values of the Central and Northeast G&P reporting units were determined to be below their respective carrying values. For these measurements, the book basis of each reporting unit was reduced by the associated deferred tax liabilities. We then calculated the implied fair value of goodwill by performing a hypothetical application of the acquisition method wherein the estimated fair value was allocated to the underlying assets and liabilities of each reporting unit. As a result of these Level 3 measurements, we determined that the previously recorded goodwill associated with each reporting unit was fully impaired, resulting in a fourth-quarter 2015 noncash charge of $1,098 million , reflected in Impairment of goodwill in the Consolidated Statement of Operations . For the West reporting unit, the estimated fair value exceeded the carrying value and no impairment was recorded. The following table presents impairments of assets and investments associated with certain nonrecurring fair value measurements within Level 3 of the fair value hierarchy. Impairments Years Ended December 31, Classification Segment Date of Measurement Fair Value 2016 2015 2014 (Millions) Surplus equipment (1) Property, plant, and equipment – net Williams Partners June 30, 2014 $ 46 $ 17 Surplus equipment (1) Property, plant, and equipment – net Williams Partners December 31, 2014 32 13 Surplus equipment (1) Property, plant, and equipment – net Williams Partners June 30, 2015 17 $ 20 Surplus equipment (1) Assets held for sale Williams Partners December 31, 2014 1 12 Previously capitalized project development costs (2) Property, plant, and equipment – net Williams Partners December 31, 2015 13 94 Previously capitalized project development costs (3) Property, plant, and equipment – net Other December 31, 2015 40 64 Canadian operations (4) Assets held for sale Williams Partners June 30, 2016 924 $ 341 Canadian operations (4) Assets held for sale Other June 30, 2016 206 406 Certain gathering operations (5) Property, plant, and equipment – net Williams Partners June 30, 2016 18 48 Certain idle assets Property, plant, and equipment – net Other December 31, 2016 73 8 Level 3 fair value measurements of certain assets 803 178 42 Other impairments and write-downs (6) 70 31 10 Impairment of certain assets $ 873 $ 209 $ 52 Equity-method investments (7) Investments Williams Partners September 30, 2015 $ 1,203 $ 461 Equity-method investments (8) Investments Williams Partners December 31, 2015 4,017 890 Equity-method investments (9) Investments Williams Partners March 31, 2016 1,294 $ 109 Equity-method investments (10) Investments Williams Partners December 31, 2016 1,295 318 Other equity-method investment Investments Williams Partners December 31, 2015 58 8 Other equity-method investment Investments Williams Partners March 31, 2016 — 3 Impairment of equity-method investments $ 430 $ 1,359 ______________ (1) Relates to certain surplus equipment. The estimated fair value was determined by a market approach based on our analysis of observable inputs in the principal market. (2) Relates to a gas processing plant, the completion of which is considered remote due to unfavorable impact of low natural gas prices on customer drilling activities. The assessed fair value primarily represents the estimated salvage value of certain equipment measured using a market approach based on our analysis of observable inputs in the principal market. (3) Relates to an olefins pipeline project, the completion of which is considered remote due to lack of customer interest. The assessed fair value primarily represents the estimated fair value of unused pipeline measured using a market approach based on our analysis of observable inputs in the principal market. (4) Relates to our Canadian operations. We designated these operations as held for sale as of June 30, 2016. As a result, we measured the fair value of the disposal group, resulting in an impairment charge. The estimated fair value was determined by a market approach based primarily on inputs received in the marketing process and reflected our estimate of the potential assumed proceeds. We disposed of our Canadian operations through a sale during the third quarter of 2016. See Note 3 – Divestiture . (5) Relates to certain gathering assets within the Mid-Continent region. The estimated fair value was determined by a market approach based on our analysis of observable inputs in the principal market. (6) Reflects multiple individually insignificant impairments and write-downs of other certain assets that may no longer be in use or are surplus in nature for which the fair value was determined to be zero or an insignificant salvage value. (7) Relates to equity-method investments in DBJV and certain of the Appalachia Midstream Investments. The historical carrying value of these investments was initially recorded based on estimated fair value during the third quarter of 2014 in conjunction with the acquisition of ACMP. We estimated the fair value of these investments using an income approach based on expected future cash flows and appropriate discount rates. The determination of estimated future cash flows involved significant assumptions regarding gathering volumes and related capital spending. Discount rates utilized were 11.8 percent and 8.8 percent for DBJV and certain of the Appalachia Midstream Investments, respectively, and reflected our cost of capital as impacted by market conditions, and risks associated with the underlying businesses. (8) Relates to equity-method investments in DBJV, certain of the Appalachia Midstream Investments, UEOM, and Laurel Mountain. We estimated the fair value of these investments using an income approach based on expected future cash flows and appropriate discount rates. The determination of estimated future cash flows involved significant assumptions regarding gathering volumes and related capital spending. Discount rates utilized ranged from 10.8 percent to 14.4 percent and reflected further fourth-quarter 2015 increases in our cost of capital, revised estimates of expected future cash flows, and risks associated with the underlying businesses. (9) Relates to equity-method investments in DBJV and Laurel Mountain. Our carrying values in these equity-method investments had been written down to fair value at December 31, 2015. Our first-quarter 2016 analysis reflected higher discount rates for both of these investments, along with lower natural gas prices for Laurel Mountain. We estimated the fair value of these investments using an income approach based on expected future cash flows and appropriate discount rates. The determination of estimated future cash flows involved significant assumptions regarding gathering volumes and related capital spending. Discount rates utilized ranged from 13.0 percent to 13.3 percent and reflected increases in our cost of capital, revised estimates of expected future cash flows, and risks associated with the underlying businesses. (10) Relates to equity-method investments in Ranch Westex and multiple Appalachia Midstream Investments. The historical carrying value of these investments was initially recorded based on estimated fair value during the third quarter of 2014 in conjunction with the acquisition of ACMP. We estimated the fair value of these Appalachia Midstream Investments using an income approach based on expected future cash flows and appropriate discount rates. The determination of estimated future cash flows involved significant assumptions regarding gathering volumes, rates, and related capital spending. The discount rate utilized for the Appalachia Midstream Investments evaluation was 10.2 percent and reflected our cost of capital as impacted by market conditions and risks associated with the underlying businesses. In addition to utilizing an income approach, we also considered a market approach for certain Appalachia Midstream Investments and Ranch Westex based on an agreement reached in February 2017 to exchange our interests in DBJV and Ranch Westex for additional interests in certain Appalachia Midstream Investments and cash. Concentration of Credit Risk Cash equivalents Our cash equivalents are primarily invested in funds with high-quality, short-term securities and instruments that are issued or guaranteed by the U.S. government. Trade accounts and other receivables The following table summarizes concentration of receivables, net of allowances: December 31, 2016 2015 (Millions) NGLs, natural gas, and related products and services $ 736 $ 823 Transportation of natural gas and related products 187 202 Other 15 16 Total $ 938 $ 1,041 Customers include producers, distribution companies, industrial users, gas marketers, and pipelines primarily located in the continental United States. As a general policy, collateral is not required for receivables, but customers’ financial condition and credit worthiness are evaluated regularly. Based upon this evaluation, we may obtain collateral to support receivables. As of December 31, 2016 and 2015, Chesapeake Energy Corporation, and its affiliates (Chesapeake), a customer within our Williams Partners segment, accounted for $133 million and $364 million , respectively, of the consolidated Trade accounts and other receivables balances. Revenues In 2016 and 2015, Chesapeake accounted for 14 percent and 18 percent , respectively, of our consolidated revenues.

Contingent Liabilities and Comm

Contingent Liabilities and Commitments	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Contingent Liabilities and Commitments [Text Block]	Note 18 – Contingent Liabilities and Commitments Reporting of Natural Gas-Related Information to Trade Publications Direct and indirect purchasers of natural gas in various states filed an individual and class actions against us, our former affiliate WPX and its subsidiaries, and others alleging the manipulation of published gas price indices and seeking unspecified amounts of damages. Such actions were transferred to the Nevada federal district court for consolidation of discovery and pre-trial issues. We have agreed to indemnify WPX and its subsidiaries related to this matter. In the individual action, filed by Farmland Industries Inc. (Farmland), the court issued an order on May 24, 2016, granting one of our co-defendant’s motion for summary judgment as to Farmland’s claims. On January 5, 2017, the court extended such ruling to us, entering final judgment in our favor. Farmland has appealed. Because of the uncertainty around the remaining pending unresolved issues, including an insufficient description of the purported classes and other related matters, we cannot reasonably estimate a range of potential exposure at this time. However, it is reasonably possible that the ultimate resolution of these actions and our related indemnification obligation could result in a potential loss that may be material to our results of operations. In connection with this indemnification, we have an accrued liability balance associated with this matter, and as a result, have exposure to future developments in this matter. Geismar Incident On June 13, 2013, an explosion and fire occurred at our Geismar olefins plant and rendered the facility temporarily inoperable (Geismar Incident). As a result, there were two fatalities and numerous individuals (including employees and contractors) reported injuries. We are addressing the following contingent liabilities in connection with the Geismar Incident. On October 21, 2013, the U.S. Environmental Protection Agency (EPA) issued an Inspection Report pursuant to the Clean Air Act’s Risk Management Program following its inspection of the facility on June 24 through June 28, 2013. The report notes the EPA’s preliminary determinations about the facility’s documentation regarding process safety, process hazard analysis, as well as operating procedures, employee training, and other matters. On June 16, 2014, we received a request for information related to the Geismar Incident from the EPA under Section 114 of the Clean Air Act to which we responded on August 13, 2014. The EPA could issue penalties pertaining to final determinations. Multiple lawsuits, including class actions for alleged offsite impacts, property damage, customer claims, and personal injury, have been filed against us. To date, we have settled certain of the personal injury claims for an aggregate immaterial amount that we have recovered from our insurers. The first two trials, for nine plaintiffs claiming personal injury, were held in Louisiana state court in Iberville Parish, Louisiana in September and November 2016. The juries returned adverse verdicts against us, our subsidiary Williams Olefins, LLC, and other defendants. The defendants, including us, intend to appeal the verdicts. Trial dates for additional plaintiffs are scheduled in April 2017 and August 2017. We believe it is probable that additional losses will be incurred on some lawsuits, while for others we believe it is only reasonably possible that losses will be incurred. However, due to ongoing litigation involving defenses to liability, the number of individual plaintiffs, limited information as to the nature and extent of all plaintiffs’ damages, and the ultimate outcome of all appeals, we are unable to reliably estimate any such losses at this time. We believe that it is probable that any ultimate losses incurred will be covered by our general liability insurance policy, which has an aggregate limit of $610 million applicable to this event and retention (deductible) of $2 million per occurrence. Alaska Refinery Contamination Litigation In 2010, James West filed a class action lawsuit in state court in Fairbanks, Alaska on behalf of individual property owners whose water contained sulfolane contamination allegedly emanating from the Flint Hills Oil Refinery in North Pole, Alaska. The suit named our subsidiary, Williams Alaska Petroleum Inc. (WAPI), and Flint Hills Resources Alaska, LLC (FHRA), a subsidiary of Koch Industries, Inc., as defendants. We owned and operated the refinery until 2004 when we sold it to FHRA. We and FHRA made claims under the pollution liability insurance policy issued in connection with the sale of the North Pole refinery to FHRA. We and FHRA also filed claims against each other seeking, among other things, contractual indemnification alleging that the other party caused the sulfolane contamination. In 2011, we and FHRA settled the James West claim. We and FHRA subsequently filed motions for summary judgment on the other’s claims. On July 8, 2014, the court dismissed all FHRA’s claims and entered judgment for us. On August 6, 2014, FHRA appealed the court’s decision to the Alaska Supreme Court, which heard oral arguments in October of 2015, and issued a decision on August 26, 2016. The Alaska Supreme Court affirmed dismissal of FHRA’s equitable claims and statutory claims for damages related to sulfolane located on the refinery property. The Alaska Supreme Court remanded FHRA’s claims against us for contractual indemnification and statutory claims for damages related to off-site sulfolane for further resolution by the trial court. We currently estimate that our reasonably possible loss exposure in this matter 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. On March 6, 2014, the State of Alaska filed suit against FHRA, WAPI, and us in state court in Fairbanks seeking injunctive relief and damages in connection with sulfolane contamination of the water supply near the Flint Hills Oil Refinery in North Pole, Alaska. On May 5, 2014, FHRA filed cross-claims against us in the State of Alaska suit. FHRA also seeks injunctive relief and damages. On November 26, 2014, the City of North Pole (North Pole) filed suit in Alaska state court in Fairbanks against FHRA, WAPI, and us alleging nuisance and violations of municipal and state statutes based upon the same alleged sulfolane contamination of the water supply. North Pole claims an unspecified amount of past and future damages as well as punitive damages against WAPI. FHRA filed cross-claims against us. In October of 2015, the court consolidated the State of Alaska and North Pole cases. On February 29, 2016, we and WAPI filed Amended Answers in the consolidated cases. Both we and WAPI asserted counter claims against both the State of Alaska and North Pole, and cross claims against FHRA. A trial is scheduled to commence May 30, 2017. All or a portion of the exposure in this consolidated State of Alaska and North Pole action may duplicate exposure in the James West case. As such, on February 9, 2017, the remanded claims in the James West case were consolidated into the State of Alaska and North Pole action. 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 for the consolidated action at this time. Independent of the litigation matter described in the preceding paragraphs, in 2013, the Alaska Department of Environmental Conservation indicated that it views FHRA and us as responsible parties, and that it intended to enter a compliance order to address the environmental remediation of sulfolane and other possible contaminants including cleanup work outside the refinery’s boundaries. Due to the ongoing assessment of the level and extent of sulfolane contamination and the ultimate cost of remediation and division of costs among the potentially responsible parties, we are unable to estimate a range of exposure at this time. Royalty Matters Certain of our customers, including one major customer, have been named in various lawsuits alleging underpayment of royalties and claiming, among other things, violations of anti-trust laws and the Racketeer Influenced and Corrupt Organizations Act. We have also been named as a defendant in certain of these cases in Texas, Pennsylvania, and Ohio based on allegations that we improperly participated with that major customer in causing the alleged royalty underpayments. We have also received subpoenas from the United States Department of Justice and the Pennsylvania Attorney General requesting documents relating to the agreements between us and our major customer and calculations of the major customer’s royalty payments. On December 9, 2015, the Pennsylvania Attorney General filed a civil suit against one of our major customers and us alleging breaches of the Pennsylvania Unfair Trade Practices and Consumer Protection Law, and on February 8, 2016, the Pennsylvania Attorney General filed an amended complaint in such civil suit, which omitted us as a party. We believe that the claims asserted are subject to indemnity obligations owed to us by that major customer. Our customer and plaintiffs in the Texas cases reached a settlement, and therefore all claims asserted (or possibly asserted) by any such plaintiffs against us in the Texas cases have been fully dismissed with prejudice. On February 7, 2017, the plaintiffs in the Ohio case voluntarily dismissed the case without prejudice. Due to the preliminary status of the remaining cases, we are unable to estimate a range of potential loss at this time. Shareholder Litigation Between October 2015 and December 2015, purported shareholders of us filed six putative class action lawsuits in the Delaware Court of Chancery that were consolidated into a single suit on January 13, 2016. This consolidated putative class action lawsuit relates to our terminated merger with Energy Transfer Equity, L.P. (Energy Transfer). The complaint asserts various claims against the individual members of our Board of Directors, including that they breached their fiduciary duties by agreeing to sell us through an allegedly unfair process and for an allegedly unfair price and by allegedly failing to disclose allegedly material information about the merger. The complaint seeks, among other things, an injunction against the merger and an award of costs and attorneys’ fees. On March 22, 2016, the court granted the parties’ proposed order in the consolidated action to stay the proceedings pending the close of the transaction with Energy Transfer. The plaintiffs have not filed an amended complaint. A purported shareholder filed a separate class action lawsuit in the Delaware Court of Chancery on January 15, 2016. The putative class action complaint alleged that the individual members of our Board of Directors breached their fiduciary duties by, among other things, agreeing to the WPZ Merger Agreement, which purportedly reduced the merger consideration to have been received in the subsequently proposed but now terminated merger with Energy Transfer. The plaintiff filed a motion to voluntarily dismiss, which the court granted on January 13, 2017. On September 2, 2016, the same purported shareholder filed a derivative action claiming that the members of our Board of Directors breached their fiduciary duties by executing the WPZ Merger Agreement as a defensive measure against Energy Transfer. On September 28, 2016, we requested the court dismiss this action also. On March 7, 2016, a purported unitholder of WPZ filed a putative class action on behalf of certain purchasers of WPZ units in U.S. District Court in Oklahoma. The action names as defendants us, WPZ, Williams Partners GP LLC, Alan S. Armstrong, and Donald R. Chappel and alleges violations of certain federal securities laws for failure to disclose Energy Transfer’s intention to pursue a purchase of us conditioned on us not closing the WPZ Merger Agreement when announcing the WPZ Merger Agreement. The complaint seeks, among other things, damages and an award of costs and attorneys’ fees. The plaintiff filed an amended complaint on August 31, 2016. On October 17, 2016, we requested the court dismiss the action. We cannot reasonably estimate a range of potential loss at this time. Litigation against Energy Transfer and related parties On April 6, 2016, we filed suit in Delaware Chancery Court against Energy Transfer and LE GP, LLC (the general partner for Energy Transfer) alleging willful and material breaches of the Agreement and Plan of Merger (Merger Agreement) with Energy Transfer resulting from the private offering by Energy Transfer on March 8, 2016, of Series A Convertible Preferred Units (Special Offering) to certain Energy Transfer insiders and other accredited investors. The suit seeks, among other things, an injunction ordering the defendants to unwind the Special Offering and to specifically perform their obligations under the Merger Agreement. On April 19, 2016, we filed an amended complaint seeking the same relief. On May 3, 2016, Energy Transfer and LE GP, LLC filed an answer and counterclaims. On May 13, 2016, we filed a separate complaint in Delaware Chancery Court against Energy Transfer, LE GP, LLC, and the other Energy Transfer affiliates that are parties to the Merger Agreement, alleging material breaches of the Merger Agreement for failing to cooperate and use necessary efforts to obtain a tax opinion required under the Merger Agreement (Tax Opinion) and for otherwise failing to use necessary efforts to consummate the merger under the Merger Agreement wherein we would be merged with and into the newly formed Energy Transfer Corp LP (ETC) (ETC Merger). The suit sought, among other things, a declaratory judgment and injunction preventing Energy Transfer from terminating or otherwise avoiding its obligations under the Merger Agreement due to any failure to obtain the Tax Opinion. The Court of Chancery coordinated the Special Offering and Tax Opinion suits. On May 20, 2016, the Energy Transfer defendants filed amended affirmative defenses and verified counterclaims in the Special Offering and Tax Opinion suits, alleging certain breaches of the Merger Agreement by us and seeking, among other things, a declaration that we were not entitled to specific performance, that Energy Transfer could terminate the ETC Merger, and that Energy Transfer is entitled to a $1.48 billion termination fee. On June 24, 2016, following a two-day trial, the court issued a Memorandum Opinion and Order denying our requested relief in the Tax Opinion suit. The court did not rule on the substance of our claims related to the Special Offering or on the substance of Energy Transfer’s counterclaims. On June 27, 2016, we filed an appeal of the court’s decision with the Supreme Court of Delaware, seeking reversal and remand to pursue damages. The appeal has been fully briefed for consideration by the Supreme Court of Delaware, and oral argument occurred on January 11, 2017. On September 16, 2016, we filed an amended complaint with the Court of Chancery seeking damages for breaches of the Merger Agreement by defendants. On September 23, 2016, Energy Transfer filed a second amended and supplemental affirmative defenses and verified counterclaim with the Court of Chancery seeking, among other things, payment of the $1.48 billion termination fee due to our alleged breaches of the Merger Agreement. We filed a motion to dismiss Energy Transfer’s counterclaims, which was fully briefed on November 14, 2016, and oral argument occurred on November 30, 2016. Environmental Matters We are a participant in certain environmental activities in various stages including assessment studies, cleanup operations, and remedial processes at certain sites, some of which we currently do not own. We are monitoring these sites in a coordinated effort with other potentially responsible parties, the EPA, and other governmental authorities. We are jointly and severally liable along with unrelated third parties in some of these activities and solely responsible in others. Certain of our subsidiaries have been identified as potentially responsible parties at various Superfund and state waste disposal sites. In addition, these subsidiaries have incurred, or are alleged to have incurred, various other hazardous materials removal or remediation obligations under environmental laws. As of December 31, 2016 , we have accrued liabilities totaling $38 million for these matters, as discussed below. Our accrual reflects the most likely costs of cleanup, which are generally based on completed assessment studies, preliminary results of studies, or our experience with other similar cleanup operations. Certain assessment studies are still in process for which the ultimate outcome may yield significantly different estimates of most likely costs. Any incremental amount in excess of amounts currently accrued cannot be reasonably estimated at this time due to uncertainty about the actual number of contaminated sites ultimately identified, the actual amount and extent of contamination discovered, and the final cleanup standards mandated by the EPA and other governmental authorities. The EPA and various state regulatory agencies routinely promulgate and propose new rules, and issue updated guidance to existing rules. More recent rules and rulemakings include, but are not limited to, rules for reciprocating internal combustion engine maximum achievable control technology, new air quality standards for one hour nitrogen dioxide emissions, and volatile organic compound and methane new source performance standards impacting design and operation of storage vessels, pressure valves, and compressors. On October 1, 2015, the EPA issued its new rule regarding National Ambient Air Quality Standards for ground-level ozone, setting a new standard of 70 parts per billion. We are monitoring the rule’s implementation and evaluating potential impacts to our operations. For these and other new regulations, we are unable to estimate the costs of asset additions or modifications necessary to comply due to uncertainty created by the various legal challenges to these regulations and the need for further specific regulatory guidance. Continuing operations Our interstate gas pipelines are involved in remediation activities related to certain facilities and locations for polychlorinated biphenyls, mercury, and other hazardous substances. These activities have involved the EPA and various state environmental authorities, resulting in our identification as a potentially responsible party at various Superfund waste sites. At December 31, 2016 , we have accrued liabilities of $9 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 December 31, 2016 , we have accrued liabilities totaling $7 million for these costs. Former operations, including operations classified as discontinued We have potential obligations in connection with assets and businesses we no longer operate. These potential obligations include remediation activities at the direction of federal and state environmental authorities and the indemnification of the purchasers of certain of these assets and businesses for environmental and other liabilities existing at the time the sale was consummated. Our responsibilities relate to the operations of the assets and businesses described below. • Former agricultural fertilizer and chemical operations and former retail petroleum and refining operations; • Former petroleum products and natural gas pipelines; • Former petroleum refining facilities; • Former exploration and production and mining operations; • Former electricity and natural gas marketing and trading operations. At December 31, 2016 , we have accrued environmental liabilities of $22 million related to these matters. Other Divestiture Indemnifications Pursuant to various purchase and sale agreements relating to divested businesses and assets, we have indemnified certain purchasers against liabilities that they may incur with respect to the businesses and assets acquired from us. The indemnities provided to the purchasers are customary in sale transactions and are contingent upon the purchasers incurring liabilities that are not otherwise recoverable from third parties. The indemnities generally relate to breach of warranties, tax, historic litigation, personal injury, property damage, environmental matters, right of way, and other representations that we have provided. At December 31, 2016 , 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. 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. Commitments Commitments for construction and acquisition of property, plant, and equipment are approximately $244 million at December 31, 2016 .

Segment Disclosures

Segment Disclosures	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Segment Disclosures [Text Block]	Note 19 – Segment Disclosures We have one reportable segment, Williams Partners. All remaining business activities are included in Other. (See Note 1 – General, Description of Business, Basis of Presentation, and Summary of Significant Accounting Policies .) Our segment presentation of Williams Partners, which includes our consolidated master limited partnership, is reflective of the parent-level focus by our chief operating decision-maker, considering the resource allocation and governance provisions associated with the master limited partnership structure. This partnership maintains capital and cash management structures that are separate from ours. It is self-funding and maintains its own lines of bank credit and cash management accounts. These factors, coupled with different costs of capital from our other businesses, serve to differentiate the management of this entity as a whole. Performance Measurement We evaluate segment operating performance based upon Modified EBITDA (earnings before interest, taxes, depreciation, and amortization). This measure represents the basis of our internal financial reporting and is the primary performance measure used by our chief operating decision maker in measuring performance and allocating resources among our reportable segments. We define Modified EBITDA as follows: • Net income (loss) before: ◦ Income (loss) from discontinued operations; ◦ Provision (benefit) for income taxes; ◦ Interest incurred, net of interest capitalized; ◦ Equity earnings (losses); ◦ Gain on remeasurement of equity-method investment; ◦ Impairment of equity-method investments; ◦ Other investing income (loss) – net; ◦ Impairment of goodwill; ◦ Depreciation and amortization expenses; ◦ Accretion expense associated with asset retirement obligations for nonregulated operations. • This measure is further adjusted to include our proportionate share (based on ownership interest) of Modified EBITDA from our equity-method investments calculated consistently with the definition described above. The following geographic area data includes Revenues from external customers based on product shipment origin and Long-lived assets based upon physical location: United States Canada Total (Millions) Revenues from external customers: 2016 $ 7,425 $ 74 $ 7,499 2015 7,247 113 7,360 2014 7,229 408 7,637 Long-lived assets: 2016 $ 38,091 $ — $ 38,091 2015 38,016 1,580 39,596 2014 38,290 1,364 39,654 Long-lived assets are comprised of property, plant, and equipment, goodwill, and other intangible assets. The following table reflects the reconciliation of Segment revenues to Total revenues as reported in the Consolidated Statement of Operations and Other financial information : Williams Partners Other Eliminations Total (Millions) 2016 Segment revenues: Service revenues External $ 5,140 $ 31 $ — $ 5,171 Internal 33 19 (52 ) — Total service revenues 5,173 50 (52 ) 5,171 Product sales External 2,318 10 — 2,328 Internal — 16 (16 ) — Total product sales 2,318 26 (16 ) 2,328 Total revenues $ 7,491 $ 76 $ (68 ) $ 7,499 Other financial information: Additions to long-lived assets $ 2,102 $ 44 $ (1 ) $ 2,145 Proportional Modified EBITDA of equity-method investments 754 — — 754 2015 Segment revenues: Service revenues External $ 5,134 $ 30 $ — $ 5,164 Internal 1 91 (92 ) — Total service revenues 5,135 121 (92 ) 5,164 Product sales External 2,196 — — 2,196 Internal — — — — Total product sales 2,196 — — 2,196 Total revenues $ 7,331 $ 121 $ (92 ) $ 7,360 Other financial information: Additions to long-lived assets $ 2,960 $ 388 $ (12 ) $ 3,336 Proportional Modified EBITDA of equity-method investments 699 — — 699 2014 Segment revenues: Service revenues External $ 3,887 $ 229 $ — $ 4,116 Internal 1 19 (20 ) — Total service revenues 3,888 248 (20 ) 4,116 Product sales External 3,521 — — 3,521 Internal — — — — Total product sales 3,521 — — 3,521 Total revenues $ 7,409 $ 248 $ (20 ) $ 7,637 Other financial information: Additions to long-lived assets (1) $ 20,413 $ 345 $ (2 ) $ 20,756 Proportional Modified EBITDA of equity-method investments 431 7 — 438 _______________ (1) 2014 Additions to long-lived assets within our Williams Partners segment primarily includes the acquisition-date fair value of long-lived assets from the ACMP Acquisition. (See Note 2 - Acquisitions.) The following table reflects the reconciliation of Modified EBITDA to Net income (loss) as reported in the Consolidated Statement of Operations : Years Ended December 31, 2016 2015 2014 (Millions) Modified EBITDA by segment: Williams Partners $ 3,864 $ 4,003 $ 3,244 Other (542 ) (112 ) (12 ) 3,322 3,891 3,232 Accretion expense associated with asset retirement obligations for nonregulated operations (31 ) (28 ) (18 ) Depreciation and amortization expenses (1,763 ) (1,738 ) (1,176 ) Impairment of goodwill — (1,098 ) — Equity earnings (losses) 397 335 144 Gain on remeasurement of equity-method investment — — 2,544 Impairment of equity-method investments (430 ) (1,359 ) — Other investing income (loss) – net 63 27 43 Proportional Modified EBITDA of equity-method investments (754 ) (699 ) (438 ) Interest expense (1,179 ) (1,044 ) (747 ) (Provision) benefit for income taxes 25 399 (1,249 ) Income (loss) from discontinued operations, net of tax — — 4 Net income (loss) $ (350 ) $ (1,314 ) $ 2,339 The following table reflects Total assets and Equity-method investments by reportable segments: Total Assets Equity-Method Investments December 31, 2016 December 31, 2015 December 31, 2016 December 31, 2015 (Millions) Williams Partners $ 46,265 $ 47,870 $ 6,701 $ 7,336 Other 685 1,351 — — Eliminations (115 ) (201 ) — — Total $ 46,835 $ 49,020 $ 6,701 $ 7,336

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2016
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Note 20 – Subsequent Events Debt Items As of May 24, 2017, there was no commercial paper outstanding and $175 million outstanding under our long-term credit facility. Issuances and retirements On April 3, 2017, Northwest Pipeline issued $250 million of 4.0 percent senior unsecured notes due 2027 to investors in a private debt placement. Northwest Pipeline used the net proceeds to retire $185 million of 5.95 percent senior unsecured notes that matured on April 15, 2017. On February 23, 2017, utilizing proceeds received from the Financial Repositioning (see Note 1 – General, Description of Business, Basis of Presentation, and Summary of Significant Accounting Policies ) , WPZ early retired $750 million of 6.125 percent senior unsecured notes that were due in 2022. Acquisition of Additional Interests in Appalachia Midstream Investments In March 2017, WPZ exchanged all of its 50 percent interest in DBJV for an increased interest in two natural gas gathering systems that are part of the Appalachia Midstream Investments and $155 million in cash. This transaction was recorded based on our estimate of the fair value of the interests received as we have more insight to this value as we operate the underlying assets. Following this exchange, we have an approximate average 66 percent interest in the Appalachia Midstream Investments. We continue to account for this investment under the equity-method due to the significant participatory rights of our partners such that we do not exercise control. WPZ also sold all of its interest in Ranch Westex JV LLC for $45 million . These transactions resulted in a total gain of $269 million in the first quarter of 2017. Geismar Olefins Sale Agreement On April 17, 2017, WPZ announced that it agreed to sell Williams Olefins, L.L.C., a wholly owned subsidiary which owns an interest in the Geismar, Louisiana, olefins plant for $2.1 billion in cash, subject to customary closing conditions and regulatory approvals. Upon closing of the sale, WPZ will enter into a long-term supply and transportation agreement with the purchaser to provide feedstock to the plant via its Bayou Ethane pipeline system. WPZ expects that the sale will close during the summer of 2017. Dividends We paid a cash dividend of $0.30 per common share on March 27, 2017. On May 18, 2017, our Board of Directors declared a cash dividend of $0.30 per common share, payable on June 26, 2017, to holders of record at the close of business on June 9, 2017.

Schedule I Condensed Financial

Schedule I Condensed Financial Information Of Registrant	12 Months Ended
	Dec. 31, 2016
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Financial Information of Parent Company Only Disclosure [Text Block]	The Williams Companies, Inc. Schedule I — Condensed Financial Information of Registrant Statement of Comprehensive Income (Loss) (Parent) Years Ended December 31, 2016 2015 2014 (Millions, except per-share amounts) Equity in earnings of consolidated subsidiaries $ 522 $ 232 $ 1,799 Equity earnings (losses) from investment in Access Midstream Partners — — (7 ) Interest incurred — external (268 ) (255 ) (206 ) Interest incurred — affiliate (568 ) (828 ) (797 ) Interest income — affiliate — 6 10 Gain on remeasurement of equity-method investment — — 2,544 Other income (expense) — net (53 ) (75 ) (13 ) Income (loss) from continuing operations before income taxes (367 ) (920 ) 3,330 Provision (benefit) for income taxes 57 (349 ) 1,220 Income (loss) from continuing operations (424 ) (571 ) 2,110 Income (loss) from discontinued operations — — 4 Net income (loss) $ (424 ) $ (571 ) $ 2,114 Basic earnings (loss) per common share: Income (loss) from continuing operations $ (.57 ) $ (.76 ) $ 2.93 Income (loss) from discontinued operations — — .01 Net income (loss) $ (.57 ) $ (.76 ) $ 2.94 Weighted-average shares (thousands) 750,673 749,271 719,325 Diluted earnings (loss) per common share: Income (loss) from continuing operations $ (.57 ) $ (.76 ) $ 2.91 Income (loss) from discontinued operations — — .01 Net income (loss) $ (.57 ) $ (.76 ) $ 2.92 Weighted-average shares (thousands) 750,673 749,271 723,641 Other comprehensive income (loss): Equity in other comprehensive income (loss) of consolidated subsidiaries $ 171 $ (204 ) $ (96 ) Other comprehensive income (loss) attributable to The Williams Companies, Inc. 1 33 (80 ) Other comprehensive income (loss) 172 (171 ) (176 ) Less: Other comprehensive income (loss) attributable to noncontrolling interests 69 (70 ) (19 ) Comprehensive income (loss) attributable to The Williams Companies, Inc. $ (321 ) $ (672 ) $ 1,957 See accompanying notes. The Williams Companies, Inc. Schedule I — Condensed Financial Information of Registrant – (Continued) Balance Sheet (Parent) December 31, 2016 2015 (Millions) ASSETS Current assets: Cash and cash equivalents $ 14 $ 12 Other current assets and deferred charges 16 62 Total current assets 30 74 Investments in and advances to consolidated subsidiaries 22,359 30,927 Property, plant, and equipment — net 77 99 Other noncurrent assets 8 12 Total assets $ 22,474 $ 31,112 LIABILITIES AND STOCKHOLDERS’ EQUITY Current liabilities: Accounts payable $ 27 $ 27 Other current liabilities 169 163 Total current liabilities 196 190 Long-term debt 4,939 4,811 Notes payable — affiliates 8,171 15,506 Pension, other postretirement, and other noncurrent liabilities 287 336 Deferred income tax liabilities 4,238 4,121 Contingent liabilities and commitments Equity: Common stock 785 784 Other stockholders’ equity 3,858 5,364 Total stockholders’ equity 4,643 6,148 Total liabilities and stockholders’ equity $ 22,474 $ 31,112 See accompanying notes. The Williams Companies, Inc. Schedule I — Condensed Financial Information of Registrant – (Continued) Statement of Cash Flows (Parent) Years Ended December 31, 2016 2015 2014 (Millions) NET CASH FLOWS PROVIDED (USED) BY OPERATING ACTIVITIES $ (827 ) $ (1,181 ) $ (481 ) FINANCING ACTIVITIES: Proceeds from long-term debt 2,280 2,097 2,935 Payments of long-term debt (2,155 ) (1,817 ) (671 ) Changes in notes payable to affiliates 9 2,211 2,465 Tax benefit of stock-based awards — — 25 Proceeds from issuance of common stock 9 27 3,416 Dividends paid (1,261 ) (1,836 ) (1,412 ) Other — net (6 ) (30 ) (36 ) Net cash provided (used) by financing activities (1,124 ) 652 6,722 INVESTING ACTIVITIES: Capital expenditures (13 ) (29 ) (54 ) Purchase of Access Midstream Partners — — (5,995 ) Changes in investments in and advances to consolidated subsidiaries 1,966 521 (450 ) Other — net — — 25 Net cash provided (used) by investing activities 1,953 492 (6,474 ) Increase (decrease) in cash and cash equivalents 2 (37 ) (233 ) Cash and cash equivalents at beginning of year 12 49 282 Cash and cash equivalents at end of year $ 14 $ 12 $ 49 See accompanying notes. Note 1. Guarantees In addition to the guarantees disclosed in the accompanying consolidated financial statements in Item 8, we have financially guaranteed the performance of certain consolidated subsidiaries. The duration of these guarantees varies, and we estimate the maximum undiscounted potential future payment obligation related to these guarantees as of December 31, 2016, is approximately $305 million . Note 2. Cash Dividends Received We receive dividends and distributions either directly from our subsidiaries or indirectly through dividends received by subsidiaries and subsequent transfers of cash to us through our corporate cash management system. The total of such receipts ultimately related to dividends and distributions for the years ended December 31, 2016, 2015, and 2014 was approximately $1.7 billion , $1.8 billion , and $1.9 billion , respectively.

Schedule II Valuation and Quali

Schedule II Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2016
Valuation and Qualifying Accounts [Abstract]
Schedule II Valuation and Qualifying Accounts [Text Block]	The Williams Companies, Inc. Schedule II — Valuation and Qualifying Accounts Additions Beginning Balance Charged (Credited) To Costs and Expenses Other Deductions Ending Balance (Millions) 2016 Allowance for doubtful accounts — accounts and notes receivable (1) $ 3 $ 6 $ — $ 3 $ 6 Deferred tax asset valuation allowance (1) 190 144 — — 334 2015 Allowance for doubtful accounts — accounts and notes receivable (1) — 3 — — 3 Deferred tax asset valuation allowance (1) 206 (16 ) — — 190 2014 Allowance for doubtful accounts — accounts and notes receivable (1) — — — — — Deferred tax asset valuation allowance (1) 181 25 — — 206 __________ (1) Deducted from related assets.

General, Description of Busin31

General, Description of Business, Basis of Presentation, and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Principles of consolidation [Policy Text Block]	Principles of consolidation The consolidated financial statements include the accounts of all entities that we control and our proportionate interest in the accounts of certain ventures in which we own an undivided interest. Management’s judgment is required to evaluate whether we control an entity. Key areas of that evaluation include: • Determining whether an entity is a VIE; • Determining whether we are the primary beneficiary of a VIE, including evaluating which activities of the VIE most significantly impact its economic performance and the degree of power that we and our related parties have over those activities through our variable interests; • Identifying events that require reconsideration of whether an entity is a VIE and continuously evaluating whether we are a VIE’s primary beneficiary; • Evaluating whether other owners in entities that are not VIEs are able to effectively participate in significant decisions that would be expected to be made in the ordinary course of business such that we do not have the power to control such entities. We apply the equity method of accounting to investments over which we exercise significant influence but do not control.
Equity-method investment basis differences [Policy Text Block]	Equity-method investment basis differences Differences between the cost of our equity-method investments and our underlying equity in the net assets of investees are accounted for as if the investees were consolidated subsidiaries. Equity earnings (losses) in the Consolidated Statement of Operations includes our allocable share of net income (loss) of investees adjusted for any depreciation and amortization, as applicable, associated with basis differences.
Use of estimates [Policy Text Block]	Use of estimates 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. Significant estimates and assumptions include: • Impairment assessments of investments, property, plant, and equipment, goodwill, and other identifiable intangible assets; • Litigation-related contingencies; • Environmental remediation obligations; • Realization of deferred income tax assets; • Depreciation and/or amortization of equity-method investment basis differences; • Asset retirement obligations; • Pension and postretirement valuation variables; • Acquisition related purchase price allocations. These estimates are discussed further throughout these notes.
Regulatory Accounting [Policy Text Block]	Regulatory accounting Transco and Northwest Pipeline are regulated by the Federal Energy Regulatory Commission (FERC). Their rates, which are established by the FERC, are designed to recover the costs of providing the regulated services, and their competitive environment makes it probable that such rates can be charged and collected. Therefore, our management has determined that it is appropriate under Accounting Standards Codification (ASC) Topic 980, “Regulated Operations,” to account for and report regulatory assets and liabilities related to these operations consistent with the economic effect of the way in which their rates are established. Accounting for these operations that are regulated can differ from the accounting requirements for nonregulated operations. For example, for regulated operations, allowance for funds used during construction (AFUDC) represents the estimated cost of debt and equity funds applicable to utility plant in process of construction and is capitalized as a cost of property, plant, and equipment because it constitutes an actual cost of construction under established regulatory practices; nonregulated operations are only allowed to capitalize the cost of debt funds related to construction activities, while a component for equity is prohibited. The components of our regulatory assets and liabilities relate to the effects of deferred taxes on equity funds used during construction, asset retirement obligations, fuel cost differentials, levelized incremental depreciation, negative salvage, and pension and other postretirement benefits. Our current and noncurrent regulatory asset and liability balances for the years ended December 31, 2016 and 2015 are as follows: December 31, 2016 2015 (Millions) Current assets reported within Other current assets and deferred charges $ 91 $ 84 Noncurrent assets reported within Regulatory assets, deferred charges, and other 387 370 Total regulated assets $ 478 $ 454 Current liabilities reported within Accrued liabilities $ 11 $ 4 Noncurrent liabilities reported within Regulatory liabilities, deferred income, and other 498 434 Total regulated liabilities $ 509 $ 438
Cash and cash equivalents [Policy Text Block]	Cash and cash equivalents Cash and cash equivalents in the Consolidated Balance Sheet includes amounts primarily invested in funds with high-quality, short-term securities and instruments that are issued or guaranteed by the U.S. government. These have maturity dates of three months or less when acquired.
Accounts receivable [Policy Text Block]	Accounts receivable Accounts receivable are carried on a gross basis, with no discounting, less an allowance for doubtful accounts. We estimate the allowance for doubtful accounts based on existing economic conditions, the financial condition of our customers, and the amount and age of past due accounts. We consider receivables past due if full payment is not received by the contractual due date. Interest income related to past due accounts receivable is generally recognized at the time full payment is received or collectability is assured. Past due accounts are generally written off against the allowance for doubtful accounts only after all collection attempts have been exhausted.
Inventories [Policy Text Block]	Inventories Inventories in the Consolidated Balance Sheet primarily consist of natural gas liquids, olefins, natural gas in underground storage, and materials and supplies and are stated at the lower of cost or market. The cost of inventories is primarily determined using the average-cost method.
Property, plant, and equipment [Policy Text Block]	Property, plant, and equipment Property, plant, and equipment is recorded at cost. We base the carrying value of these assets on estimates, assumptions, and judgments relative to capitalized costs, useful lives, and salvage values. As regulated entities, Northwest Pipeline and Transco provide for depreciation using the straight-line method at FERC-prescribed rates. Depreciation for nonregulated entities is provided primarily on the straight-line method over estimated useful lives, except for certain offshore facilities that apply an accelerated depreciation method. Gains or losses from the ordinary sale or retirement of property, plant, and equipment for regulated pipelines are credited or charged to accumulated depreciation. Other gains or losses are recorded in Other (income) expense – net included in Operating income (loss) in the Consolidated Statement of Operations . Ordinary maintenance and repair costs are generally expensed as incurred. Costs of major renewals and replacements are capitalized as property, plant, and equipment. We record a liability and increase the basis in the underlying asset for the present value of each expected future asset retirement obligation (ARO) at the time the liability is initially incurred, typically when the asset is acquired or constructed. As regulated entities, Northwest Pipeline and Transco offset the depreciation of the underlying asset that is attributable to capitalized ARO cost to a regulatory asset as management expects to recover these amounts in future rates. We measure changes in the liability due to passage of time by applying an interest rate to the liability balance. This amount is recognized as an increase in the carrying amount of the liability and as a corresponding accretion expense included in Operating and maintenance expenses in the Consolidated Statement of Operations , except for regulated entities, for which the liability is offset by a regulatory asset. The regulatory asset is amortized commensurate with our collection of those costs in rates. Measurements of AROs include, as a component of future expected costs, an estimate of the price that a third party would demand, and could expect to receive, for bearing the uncertainties inherent in the obligations, sometimes referred to as a market-risk premium.
Goodwill [Policy Text Block]	Goodwill Goodwill included within Intangible assets – net of accumulated amortization in the Consolidated Balance Sheet represents the excess of the consideration, plus the fair value of any noncontrolling interest or 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. As part of the evaluation, we compare our estimate of the fair value of the reporting unit with its carrying value, including goodwill. If the carrying value of the reporting unit exceeds its fair value, a computation of the implied fair value of the goodwill is compared with its related carrying value. If the carrying value of the reporting unit goodwill exceeds the implied fair value of that goodwill, an impairment loss is recognized in the amount of the excess. Judgments and assumptions are inherent in our management’s estimates of fair value.
Other intangibles assets [Policy Text Block]	Other intangible assets Our identifiable intangible assets included within Intangible assets – net of accumulated amortization in the Consolidated Balance Sheet are primarily related to gas gathering, processing, and fractionation contractual customer relationships. Our intangible assets are amortized on a straight-line basis over the period in which these assets contribute to our cash flows. We evaluate these assets for changes in the expected remaining useful lives and would reflect any changes prospectively through amortization over the revised remaining useful life.
Impairment of property, plant, and equipment, other identifiable intangible assets, and investments [Policy Text Block]	Impairment of property, plant, and equipment, other identifiable intangible assets, and investments We evaluate our property, plant, and equipment and other identifiable intangible assets for impairment when events or changes in circumstances indicate, in our management’s judgment, that the carrying value of such assets may not be recoverable. When an indicator of impairment has occurred, we compare our management’s estimate of undiscounted future cash flows attributable to the assets to the carrying value of the assets to determine whether an impairment has occurred and we may apply a probability-weighted approach to consider the likelihood of different cash flow assumptions and possible outcomes including selling in the near term or holding for the remaining estimated useful life. If an impairment of the carrying value has occurred, we determine the amount of the impairment recognized in the financial statements by estimating the fair value of the assets and recording a loss for the amount that the carrying value exceeds the estimated fair value. This evaluation is performed at the lowest level for which separately identifiable cash flows exist. For assets identified to be disposed of in the future and considered held for sale, we compare the carrying value to the estimated fair value less the cost to sell to determine if recognition of an impairment is required. Until the assets are disposed of, the estimated fair value, which includes estimated cash flows from operations until the assumed date of sale, is recalculated when related events or circumstances change. We evaluate our investments for impairment when events or changes in circumstances indicate, in our management’s judgment, that the carrying value of such investments may have experienced an other-than-temporary decline in value. When evidence of loss in value has occurred, we compare our estimate of fair value of the investment to the carrying value of the investment to determine whether an impairment has occurred. If the estimated fair value is less than the carrying value and we consider the decline in value to be other-than-temporary, the excess of the carrying value over the fair value is recognized in the consolidated financial statements as an impairment charge. Judgments and assumptions are inherent in our management’s estimate of undiscounted future cash flows and an asset’s or investment’s fair value. Additionally, judgment is used to determine the probability of sale with respect to assets considered for disposal.
Deferred income [Policy Text Block]	Deferred income We record a liability for deferred income related to cash received from customers in advance of providing our services. Such amounts are generally recognized in revenue upon satisfying our performance obligations, primarily providing services based on units of production or over remaining contractual service periods ranging from 1 to 25 years. Deferred income is reflected within Accrued liabilities and Regulatory liabilities, deferred income, and other on the Consolidated Balance Sheet . (See Note 13 – Accrued Liabilities .) During 2016, we received cash proceeds totaling $820 million associated with restructuring certain gas gathering contracts in the Barnett Shale and Mid-Continent regions. The proceeds were recorded as deferred income and are being amortized into income in 2016 and future periods. In October 2016, we received $104 million of newly constructed assets as part of a noncash investing transaction with a customer for which we provide production handling and other services. The transaction was recorded in Property, plant, and equipment – net and deferred income in the Consolidated Balance Sheet and is being amortized based on units of production through 2024. Due to the noncash nature of this transaction, it is not presented within the Consolidated Statement of Cash Flows .
Contingent liabilities [Policy Text Block]	Contingent liabilities We record liabilities for estimated loss contingencies, including environmental matters, when we assess that a loss is probable and the amount of the loss can be reasonably estimated. These liabilities are calculated based upon our assumptions and estimates with respect to the likelihood or amount of loss and upon advice of legal counsel, engineers, or other third parties regarding the probable outcomes of the matters. These calculations are made without consideration of any potential recovery from third parties. We recognize insurance recoveries or reimbursements from others when realizable. Revisions to these liabilities are generally reflected in income when new or different facts or information become known or circumstances change that affect the previous assumptions or estimates.
Cash flows from revolving credit facilities and commercial paper program [Policy Text Block]	Cash flows from revolving credit facilities and commercial paper program Proceeds and payments related to borrowings under our credit facilities are reflected in the financing activities in the Consolidated Statement of Cash Flows on a gross basis. Proceeds and payments related to borrowings under our commercial paper program are reflected in the financing activities in the Consolidated Statement of Cash Flows on a net basis, as the outstanding notes generally have maturity dates less than three months from the date of issuance. (See Note 14 – Debt, Banking Arrangements, and Leases .)
Treasury stock [Policy Text Block]	Treasury stock Treasury stock purchases are accounted for under the cost method whereby the entire cost of the acquired stock is recorded as Treasury stock in the Consolidated Balance Sheet . Gains and losses on the subsequent reissuance of shares are credited or charged to Capital in excess of par value in the Consolidated Balance Sheet using the average-cost method.
Derivative instruments and hedging activities [Policy Text Block]	Derivative instruments and hedging activities We may utilize derivatives to manage a portion of our commodity price risk. These instruments consist primarily of swaps, futures, and forward contracts involving short- and long-term purchases and sales of energy commodities. We report the fair value of derivatives, except those for which the normal purchases and normal sales exception has been elected, in Other current assets and deferred charges ; Regulatory assets, deferred charges, and other ; Accrued liabilities ; or Regulatory liabilities, deferred income, and other in the Consolidated Balance Sheet . We determine the current and noncurrent classification based on the timing of expected future cash flows of individual trades. We report these amounts on a gross basis. Additionally, we report cash collateral receivables and payables with our counterparties on a gross basis. (See Note 17 – Fair Value Measurements, Guarantees, and Concentration of Credit Risk .) The accounting for the changes in fair value of a commodity derivative can be summarized as follows: Derivative Treatment Accounting Method Normal purchases and normal sales exception Accrual accounting Designated in a qualifying hedging relationship Hedge accounting All other derivatives Mark-to-market accounting We may elect the normal purchases and normal sales exception for certain short- and long-term purchases and sales of physical energy commodities. Under accrual accounting, any change in the fair value of these derivatives is not reflected on the balance sheet after the initial election of the exception. We may also designate a hedging relationship for certain commodity derivatives. For a derivative to qualify for designation in a hedging relationship, it must meet specific criteria and we must maintain appropriate documentation. We establish hedging relationships pursuant to our risk management policies. We evaluate the hedging relationships at the inception of the hedge and on an ongoing basis to determine whether the hedging relationship is, and is expected to remain, highly effective in achieving offsetting changes in fair value or cash flows attributable to the underlying risk being hedged. We also regularly assess whether the hedged forecasted transaction is probable of occurring. If a derivative ceases to be or is no longer expected to be highly effective, or if we believe the likelihood of occurrence of the hedged forecasted transaction is no longer probable, hedge accounting is discontinued prospectively, and future changes in the fair value of the derivative are recognized currently in Product sales or Product costs in the Consolidated Statement of Operations . For commodity derivatives designated as a cash flow hedge, the effective portion of the change in fair value of the derivative is reported in Accumulated other comprehensive income (loss) (AOCI) in the Consolidated Balance Sheet and reclassified into earnings in the period in which the hedged item affects earnings. Any ineffective portion of the derivative’s change in fair value is recognized currently in Product sales or Product costs in the Consolidated Statement of Operations . Gains or losses deferred in AOCI associated with terminated derivatives, derivatives that cease to be highly effective hedges, derivatives for which the forecasted transaction is reasonably possible but no longer probable of occurring, and cash flow hedges that have been otherwise discontinued remain in AOCI until the hedged item affects earnings. If it becomes probable that the forecasted transaction designated as the hedged item in a cash flow hedge will not occur, any gain or loss deferred in AOCI is recognized in Product sales or Product costs in the Consolidated Statement of Operations at that time. The change in likelihood of a forecasted transaction is a judgmental decision that includes qualitative assessments made by management. For commodity derivatives that are not designated in a hedging relationship, and for which we have not elected the normal purchases and normal sales exception, we report changes in fair value currently in Product sales or Product costs in the Consolidated Statement of Operations . Certain gains and losses on derivative instruments included in the Consolidated Statement of Operations are netted together to a single net gain or loss, while other gains and losses are reported on a gross basis. Gains and losses recorded on a net basis include unrealized gains and losses on all derivatives that are not designated as hedges and for which we have not elected the normal purchases and normal sales exception. Realized gains and losses on derivatives that require physical delivery, as well as natural gas derivatives for NGL processing activities and which are not held for trading purposes nor were entered into as a pre-contemplated buy/sell arrangement, are recorded on a gross basis.
Revenue recognition [Policy Text Block]	Revenue recognition Revenues As a result of the ratemaking process, certain revenues collected by us may be subject to refunds upon the issuance of final orders by the FERC in pending rate proceedings. We record estimates of rate refund liabilities considering our and other third-party regulatory proceedings, advice of counsel, and other risks. Service revenues Revenues from our interstate natural gas pipeline businesses include services pursuant to long-term firm transportation and storage agreements. These agreements provide for a reservation charge based on the volume of contracted capacity and a commodity charge based on the volume of gas delivered, both at rates specified in our FERC tariffs. We recognize revenues for reservation charges ratably over the contract period regardless of the volume of natural gas that is transported or stored. Revenues for commodity charges, from both firm and interruptible transportation services and storage injection and withdrawal services, are recognized when natural gas is delivered at the agreed upon delivery point or when natural gas is injected or withdrawn from the storage facility. Certain revenues from our midstream operations include those derived from natural gas gathering, processing, treating, and compression services and are performed under volumetric-based fee contracts. These revenues are recorded when services have been performed. Certain of our gas gathering and processing agreements have minimum volume commitments. If a customer under such an agreement fails to meet its minimum volume commitment for a specified period, generally measured on an annual basis, it is obligated to pay a contractually determined fee based upon the shortfall between actual production volumes and the minimum volume commitment for that period. The revenue associated with minimum volume commitments is recognized in the period that the actual shortfall is determined and is no longer subject to future reduction or offset, which is generally at the end of the annual period or fourth quarter. Crude oil gathering and transportation revenues and offshore production handling fees are recognized when the services have been performed. Certain offshore production handling contracts contain fixed payment terms that result in the deferral of revenues until such services have been performed or such capacity has been made available. Storage revenues from our midstream operations associated with prepaid contracted storage capacity contracts are recognized on a straight-line basis over the life of the contract as services are provided. Product sales In the course of providing transportation services to customers of our interstate natural gas pipeline businesses, we may receive different quantities of gas from shippers than the quantities delivered on behalf of those shippers. The resulting imbalances are primarily settled through the purchase and sale of gas with our customers under terms provided for in our FERC tariffs. Revenue is recognized from the sale of gas upon settlement of the transportation and exchange imbalances. We market NGLs, crude oil, natural gas, and olefins that we purchase from our producer customers as part of the overall service provided to producers. Revenues from marketing NGLs are recognized when the products have been sold and delivered. Under our keep-whole and percent-of-liquids processing contracts, we retain the rights to all or a portion of the NGLs extracted from the producers’ natural gas stream and recognize revenues when the extracted NGLs are sold and delivered. Our domestic olefins business produces olefins from purchased or produced feedstock and we recognize revenues when the olefins are sold and delivered. Our Canadian businesses that were sold in September 2016 had processing and fractionation operations where we retained certain NGLs and olefins from an upgrader’s offgas stream and we recognized revenues when the fractionated products were sold and delivered.
Interest capitalized [Policy Text Block]	Interest capitalized We capitalize interest during construction on major projects with construction periods of at least 3 months and a total project cost in excess of $1 million . Interest is capitalized on borrowed funds and, where regulation by the FERC exists, on internally generated funds (equity AFUDC). The latter is included in Other income (expense) – net below Operating income (loss) in the Consolidated Statement of Operations . The rates used by regulated companies are calculated in accordance with FERC rules. Rates used by nonregulated companies are based on our average interest rate on debt.
Employee stock-based awards [Policy Text Block]	Employee stock-based awards We recognize compensation expense on employee stock-based awards, net of estimated forfeitures, on a straight-line basis. (See Note 16 – Equity-Based Compensation .)
Pension and other postretirement benefits [Policy Text Block]	Pension and other postretirement benefits The funded status of each of the pension and other postretirement benefit plans is recognized separately in the Consolidated Balance Sheet as either an asset or liability. The funded status is the difference between the fair value of plan assets and the plan’s benefit obligation. The plans’ benefit obligations and net periodic benefit costs are actuarially determined and impacted by various assumptions and estimates. (See Note 10 – Employee Benefit Plans .) The discount rates are determined separately for each of our pension and other postretirement benefit plans based on an approach specific to our plans. The year-end discount rates are determined considering a yield curve comprised of high-quality corporate bonds and the timing of the expected benefit cash flows of each plan. The expected long-term rates of return on plan assets are determined by combining a review of the historical returns within the portfolio, the investment strategy included in the plans’ investment policy statement, and capital market projections for the asset classes in which the portfolio is invested, as well as the weighting of each asset class. Unrecognized actuarial gains and losses and unrecognized prior service costs and credits are deferred and recorded in AOCI or, for Transco and Northwest Pipeline, as a regulatory asset or liability, until amortized as a component of net periodic benefit cost. Unrecognized actuarial gains and losses in excess of 10 percent of the greater of the benefit obligation or the market-related value of plan assets are amortized over the participants’ average remaining future years of service, which is approximately 13 years for our pension plans and approximately 7 years for our other postretirement benefit plans. Unrecognized prior service costs and credits for the other postretirement benefit plans are amortized on a straight line basis over the average remaining years of service to eligibility for eligible plan participants, which is approximately 4 years . The expected return on plan assets component of net periodic benefit cost is calculated using the market-related value of plan assets. For our pension plans, the market-related value of plan assets is equal to the fair value of plan assets adjusted to reflect the amortization of gains or losses associated with the difference between the expected and actual return on plan assets over a 5 -year period. Additionally, the market-related value of assets may be no more than 110 percent or less than 90 percent of the fair value of plan assets at the beginning of the year. The market-related value of plan assets for our other postretirement benefit plans is equal to the unadjusted fair value of plan assets at the beginning of the year.
Income taxes [Policy Text Block]	Income taxes We include the operations of our domestic corporate subsidiaries and income from our subsidiary partnerships in our consolidated federal income tax return and also file tax returns in various foreign and state jurisdictions as required. Deferred income taxes are computed using the liability method and are provided on all temporary differences between the financial basis and the tax basis of our assets and liabilities. Our management’s judgment and income tax assumptions are used to determine the levels, if any, of valuation allowances associated with deferred tax assets.
Earnings (loss) per common share [Policy Text Block]	Earnings (loss) per common share Basic earnings (loss) per common share in the Consolidated Statement of Operations is based on the sum of the weighted-average number of common shares outstanding and vested restricted stock units. Diluted earnings (loss) per common share in the Consolidated Statement of Operations includes any dilutive effect of stock options, nonvested restricted stock units, and convertible debt, unless otherwise noted. Diluted earnings (loss) per common share are calculated using the treasury-stock method.
Foreign currency translation [Policy Text Block]	Foreign currency translation Certain of our foreign subsidiaries that used the Canadian dollar as their functional currency were sold in 2016. The assets and liabilities of such foreign subsidiaries were translated at the spot rate in effect at the applicable reporting date, and the combined statements of operations were translated into the U.S. dollar at the average exchange rates in effect during the applicable period. The resulting cumulative translation adjustment was recorded as a separate component of AOCI in the Consolidated Balance Sheet . Transactions denominated in currencies other than the functional currency were recorded based on exchange rates at the time such transactions arose. Subsequent changes in exchange rates when the transactions were settled resulted in transaction gains and losses which were reflected in Other (income) expense – net within Costs and expenses in the Consolidated Statement of Operations . Substantially all of our Canadian operations were sold in September 2016.

General, Description of Busin32

General, Description of Business, Basis of Presentation, and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Regulatory Assets and Liabilities [Table Text Block]	Our current and noncurrent regulatory asset and liability balances for the years ended December 31, 2016 and 2015 are as follows: December 31, 2016 2015 (Millions) Current assets reported within Other current assets and deferred charges $ 91 $ 84 Noncurrent assets reported within Regulatory assets, deferred charges, and other 387 370 Total regulated assets $ 478 $ 454 Current liabilities reported within Accrued liabilities $ 11 $ 4 Noncurrent liabilities reported within Regulatory liabilities, deferred income, and other 498 434 Total regulated liabilities $ 509 $ 438

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2016
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 Williams Partners segment, liabilities assumed, and noncontrolling interest at July 1, 2014. The fair value of accounts receivable acquired equaled contractual amounts receivable. Changes to the preliminary allocation disclosed in Exhibit 99.1 of our Form 8-K dated May 6, 2015, which were recorded in the first quarter of 2015, reflect an increase of $150 million in Property, plant, and equipment and $25 million in Goodwill , and a decrease of $168 million in Other intangible assets and $7 million in Investments . These adjustments during the measurement period were not considered significant to require retrospective revisions of our financial statements. (Millions) Accounts receivable $ 168 Other current assets 63 Investments 5,865 Property, plant, and equipment 7,165 Goodwill 499 Other intangible assets 8,841 Current liabilities (408 ) Debt (4,052 ) Other noncurrent liabilities (9 ) Noncontrolling interest in ACMP’s subsidiaries (958 ) Noncontrolling interest in ACMP (6,544 )
Business Acquisition, Pro Forma Information [Table Text Block]	The following unaudited pro forma Total revenues and Net income (loss) attributable to The Williams Companies, Inc. for the year ended December 31, 2014, are presented as if the ACMP Acquisition had been completed on January 1, 2014. 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 period indicated, nor do they purport to project Total 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 transactions or the potential costs to achieve these cost savings, operating synergies, and revenue enhancements. December 31, 2014 (Millions) Total revenues $ 8,181 Net income (loss) attributable to The Williams Companies, Inc. $ 622

Divestiture (Tables)

Divestiture (Tables)	12 Months Ended
	Dec. 31, 2016
Discontinued Operations and Disposal Groups [Abstract]
Schedule of Disposal Group's Income Statement Disclosures [Table Text Block]	The following table presents the results of operations for the disposal group, excluding the impairment and loss noted above: Years Ended December 31, 2016 2015 (Millions) Income (loss) before income taxes of disposal group $ (98 ) $ 17 Income (loss) before income taxes of disposal group attributable to The Williams Companies, Inc. (95 ) 15

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	12 Months Ended
	Dec. 31, 2016
Variable Interest Entity Disclosures [Abstract]
Schedule of Variable Interest Entities [Table Text Block]	The following table presents amounts included in our Consolidated Balance Sheet that are for the use or obligation of WPZ and/or its subsidiaries, and which comprise a significant portion of our consolidated assets and liabilities: December 31, 2016 2015 Classification (Millions) Assets (liabilities): Cash and cash equivalents $ 145 $ 73 Cash and cash equivalents Trade accounts and other receivables – net 925 1,026 Trade accounts and other receivables Inventories 138 127 Inventories Other current assets 205 190 Other current assets and deferred charges Investments 6,701 7,336 Investments Property, plant, and equipment – net 28,021 28,593 Property, plant, and equipment – net Intangible assets – net 9,662 10,016 Intangible assets – net of accumulated amortization Regulatory assets, deferred charges, and other noncurrent assets 467 479 Regulatory assets, deferred charges, and other Accounts payable (589 ) (625 ) Accounts payable Accrued liabilities including current asset retirement obligations (1,122 ) (757 ) Accrued liabilities Commercial paper (93 ) (499 ) Commercial paper Long-term debt due within one year (785 ) (176 ) Long-term debt due within one year Long-term debt (17,685 ) (19,001 ) Long-term debt Deferred income tax liabilities (20 ) (119 ) Deferred income tax liabilities Noncurrent asset retirement obligations (798 ) (857 ) Regulatory liabilities, deferred income, and other Regulatory liabilities, deferred income, and other noncurrent liabilities (1,860 ) (1,066 ) Regulatory liabilities, deferred income, and other

Investing Activities (Tables)

Investing Activities (Tables)	12 Months Ended
	Dec. 31, 2016
Investments [Abstract]
Impairments [Table Text Block]	Impairment of equity-method investments The following table presents other-than-temporary impairment charges related to certain equity-method investments (see Note 17 – Fair Value Measurements, Guarantees, and Concentration of Credit Risk ): Years Ended December 31, 2016 2015 (Millions) Williams Partners Appalachia Midstream Investments $ 294 $ 562 DBJV 59 503 Laurel Mountain 50 45 UEOM — 241 Ranch Westex 24 — Other 3 8 $ 430 $ 1,359
Investments [Table Text Block]	Investments Ownership Interest at December 31, 2016 December 31, 2016 2015 (Millions) Equity-method investments: Appalachia Midstream Investments (1) $ 2,062 $ 2,464 UEOM 62% 1,448 1,525 DBJV 50% 988 977 Discovery 60% 572 602 OPPL 50% 430 445 Caiman II 58% 426 418 Laurel Mountain 69% 324 391 Gulfstream 50% 261 293 Other Various 190 221 $ 6,701 $ 7,336 ___________ (1) Includes equity-method investments in multiple gathering systems in the Marcellus Shale with an approximate average 41 percent interest.
Contributions [Table Text Block]	Purchases of and contributions to equity-method investments We generally fund our portion of significant expansion or development projects of these investees through additional capital contributions. These transactions increased the carrying value of our investments and included: Years Ended December 31, 2016 2015 2014 (Millions) DBJV $ 105 $ 57 $ 20 Appalachia Midstream Investments 28 93 84 Caiman II 22 — 175 UEOM — 357 57 Discovery — 35 106 Other 22 53 40 $ 177 $ 595 $ 482
Dividends and distributions [Table Text Block]	Dividends and distributions The organizational documents of entities in which we have an equity-method interest generally require distribution of available cash to members on at least a quarterly basis. These transactions reduced the carrying value of our investments and included: Years Ended December 31, 2016 2015 2014 (Millions) Appalachia Midstream Investments $ 211 $ 219 $ 130 Discovery 141 116 36 Gulfstream 100 88 81 UEOM 92 42 — OPPL 69 45 27 Caiman II 40 33 13 DBJV 39 33 — Laurel Mountain 28 31 39 ACMP — — 64 Other 22 26 50 $ 742 $ 633 $ 440
Summarized Financial Position and Results of Operations of Equity Method Investments [Table Text Block]	Summarized Financial Position and Results of Operations of All Equity-Method Investments December 31, 2016 2015 (Millions) Assets (liabilities): Current assets $ 508 $ 773 Noncurrent assets 9,695 9,549 Current liabilities (412 ) (633 ) Noncurrent liabilities (1,484 ) (1,450 ) Years Ended December 31, 2016 2015 2014 (Millions) Gross revenue $ 1,883 $ 1,707 $ 1,623 Operating income 799 690 534 Net income 726 611 460

Other Income and Expenses (Tabl

Other Income and Expenses (Tables)	12 Months Ended
	Dec. 31, 2016
Other Income and Expenses [Abstract]
Other Income and Expenses [Table Text Block]	The following table presents certain gains or losses reflected in Other (income) expense – net within Costs and expenses in the Consolidated Statement of Operations : Years Ended December 31, 2016 2015 2014 (Millions) Williams Partners Loss on sale of Canadian operations (Note 3) $ 34 $ — $ — Amortization of regulatory assets associated with asset retirement obligations 33 33 33 Accrual of regulatory liability related to overcollection of certain employee expenses 25 20 14 Project development costs related to Constitution (Note 4) 28 — — Net foreign currency exchange (gains) losses (1) 10 (10 ) (3 ) Contingency gain settlement (2) — — (154 ) Net gain related to partial acreage dedication release — — (12 ) Gain on asset retirement (11 ) — — Loss related to sale of certain assets — — 10 Other Loss on sale of Canadian operations (Note 3) 32 — — Gain on sale of unused pipe (10 ) — — ________________ (1) Primarily relates to gains and losses incurred on foreign currency transactions and the remeasurement of U.S. dollar-denominated current assets and liabilities within our former Canadian operations (see Note 3 – Divestiture ). (2) In November 2014, we settled a claim arising from the resolution of a contingent gain related to claims associated with the purchase of a business in a prior period. Pursuant to the settlement, we received $154 million in cash, all of which was recognized as a gain in the fourth quarter of 2014.

Provision (Benefit) for Incom38

Provision (Benefit) for Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Schedule of Components of Provision (benefit) for income taxes [Table Text Block]	The Provision (benefit) for income taxes includes: Years Ended December 31, 2016 2015 2014 (Millions) Current: Federal $ — $ — $ (9 ) State 2 (7 ) 2 Foreign (1 ) (55 ) 10 1 (62 ) 3 Deferred: Federal (6 ) (317 ) 1,108 State 61 (25 ) 119 Foreign (81 ) 5 19 (26 ) (337 ) 1,246 Provision (benefit) for income taxes $ (25 ) $ (399 ) $ 1,249
Provision for income taxes at federal statutory rate [Table Text Block]	Reconciliations from the Provision (benefit) at statutory rate to recorded Provision (benefit) for income taxes are as follows: Years Ended December 31, 2016 2015 2014 (Millions) Provision (benefit) at statutory rate $ (131 ) $ (600 ) $ 1,255 Increases (decreases) in taxes resulting from: Impact of nontaxable noncontrolling interests (22 ) 263 (75 ) State income taxes (net of federal benefit) 3 (21 ) 82 State deferred income tax rate change 43 — — Foreign operations – net (Including tax effect of Canadian Sale) 78 8 (11 ) Taxes on undistributed earnings of foreign subsidiaries – net — — (37 ) Translation adjustment of certain unrecognized tax benefits (1 ) (71 ) — Other – net 5 22 35 Provision (benefit) for income taxes $ (25 ) $ (399 ) $ 1,249
Deferred tax liabilities and Deferred tax assets [Table Text Block]	Significant components of Deferred income tax liabilities and Deferred income tax assets are as follows: December 31, 2016 2015 (Millions) Deferred income tax liabilities: Property, plant, and equipment $ — $ 4 Investments 5,300 5,272 Other 29 15 Total deferred income tax liabilities 5,329 5,291 Deferred income tax assets: Accrued liabilities 145 150 Minimum tax credits 139 139 Foreign tax credit 140 193 Federal loss carryovers 651 485 State losses and credits 313 296 Other 37 42 Total deferred income tax assets 1,425 1,305 Less valuation allowance 334 190 Net deferred income tax assets 1,091 1,115 Overall net deferred income tax liabilities $ 4,238 $ 4,176
Reconciliation of unrecognized tax benefits [Table Bext Block]	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows: 2016 2015 (Millions) Balance at beginning of period $ 55 $ 89 Additions for tax positions of prior years — 2 Reductions for tax positions of prior years (4 ) — Changes due to currency translation (1 ) (36 ) Balance at end of period $ 50 $ 55

Earnings (Loss) Per Common Sh39

Earnings (Loss) Per Common Share from Continuing Operations (Tables)	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Earnings (loss) per common share from continuing operations [Table Text Block]	Years Ended December 31, 2016 2015 2014 (Dollars in millions, except per-share amounts; shares in thousands) Income (loss) from continuing operations attributable to The Williams Companies, Inc. available to common stockholders for basic and diluted earnings (loss) per common share $ (424 ) $ (571 ) $ 2,110 Basic weighted-average shares 750,673 749,271 719,325 Effect of dilutive securities: Nonvested restricted stock units — — 2,234 Stock options — — 2,064 Convertible debentures — — 18 Diluted weighted-average shares (1) 750,673 749,271 723,641 Earnings (loss) per common share from continuing operations: Basic $ (.57 ) $ (.76 ) $ 2.93 Diluted $ (.57 ) $ (.76 ) $ 2.91 (1) For the years ended December 31, 2016 and December 31, 2015, 0.6 million and 1.7 million weighted-average nonvested restricted stock units, and 0.5 million and 1.5 million weighted-average stock options have been excluded from the computation of diluted earnings (loss) per common share as their inclusion would be antidilutive due to our loss from continuing operations attributable to The Williams Companies, Inc.

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2016
Compensation and Retirement Disclosure [Abstract]
Changes in benefit obligations and plan assets [Table Text Block]	The following table presents the changes in benefit obligations and plan assets for pension benefits and other postretirement benefits for the years indicated: Pension Benefits Other Postretirement Benefits 2016 2015 2016 2015 (Millions) Change in benefit obligation: Benefit obligation at beginning of year $ 1,464 $ 1,544 $ 202 $ 233 Service cost 54 59 1 2 Interest cost 62 58 8 9 Plan participants’ contributions — — 2 2 Benefits paid (130 ) (101 ) (15 ) (13 ) Actuarial loss (gain) 20 (91 ) (1 ) (31 ) Settlements (4 ) (5 ) — — Net increase (decrease) in benefit obligation 2 (80 ) (5 ) (31 ) Benefit obligation at end of year 1,466 1,464 197 202 Change in plan assets: Fair value of plan assets at beginning of year 1,241 1,293 201 208 Actual return on plan assets 82 (11 ) 13 (1 ) Employer contributions 65 65 7 5 Plan participants’ contributions — — 2 2 Benefits paid (130 ) (101 ) (15 ) (13 ) Settlements (4 ) (5 ) — — Net increase (decrease) in fair value of plan assets 13 (52 ) 7 (7 ) Fair value of plan assets at end of year 1,254 1,241 208 201 Funded status — overfunded (underfunded) $ (212 ) $ (223 ) $ 11 $ (1 ) Accumulated benefit obligation $ 1,440 $ 1,432
Overfunded (underfunded) status of our pension plans and other postretirement benefit plans [Table Text Block]	The overfunded (underfunded) status of our pension plans and other postretirement benefit plans presented in the previous table are recognized in the Consolidated Balance Sheet within the following accounts: December 31, 2016 2015 (Millions) Underfunded pension plans: Current liabilities $ (2 ) $ (2 ) Noncurrent liabilities (210 ) (221 ) Overfunded (underfunded) other postretirement benefit plans: Current liabilities (7 ) (7 ) Noncurrent assets (liabilities) 18 6
Pre-tax amounts not yet recognized in net periodic benefit cost [Table Text Block]	Pre-tax amounts not yet recognized in Net periodic benefit cost at December 31 are as follows: Pension Benefits Other Postretirement Benefits 2016 2015 2016 2015 (Millions) Amounts included in Accumulated other comprehensive income (loss) : Prior service credit $ — $ — $ 5 $ 11 Net actuarial loss (535 ) (544 ) (18 ) (18 ) Amounts included in regulatory liabilities associated with Transco and Northwest Pipeline: Prior service credit N/A N/A $ 10 $ 19 Net actuarial gain N/A N/A 8 6
Schedule of Net Benefit Costs [Table Text Block]	Net periodic benefit cost for the years ended December 31 consist of the following: Pension Benefits Other Postretirement Benefits 2016 2015 2014 2016 2015 2014 (Millions) Components of net periodic benefit cost: Service cost $ 54 $ 59 $ 40 $ 1 $ 2 $ 2 Interest cost 62 58 62 8 9 10 Expected return on plan assets (85 ) (75 ) (76 ) (12 ) (12 ) (12 ) Amortization of prior service credit — — — (15 ) (17 ) (20 ) Amortization of net actuarial loss 30 42 39 — 2 — Net actuarial (gain) loss from settlements and curtailments 2 2 1 — — (1 ) Reclassification to regulatory liability — — — 4 3 4 Net periodic benefit cost $ 63 $ 86 $ 66 $ (14 ) $ (13 ) $ (17 )
Other changes in plan assets and benefit obligations recognized in other comprehensive income (loss) [Table Text Block]	Other changes in plan assets and benefit obligations recognized in Other comprehensive income (loss) before taxes for the years ended December 31 consist of the following: Pension Benefits Other Postretirement Benefits 2016 2015 2014 2016 2015 2014 (Millions) Other changes in plan assets and benefit obligations recognized in Other comprehensive income (loss) : Net actuarial gain (loss) $ (23 ) $ 5 $ (142 ) $ — $ 8 $ (18 ) Prior service (cost) credit — — — — — (1 ) Amortization of prior service credit — — — (6 ) (6 ) (8 ) Amortization of net actuarial loss 30 42 39 — 2 — Loss from settlements and curtailments 2 2 1 — — 1 Other changes in plan assets and benefit obligations recognized in Other comprehensive income (loss) $ 9 $ 49 $ (102 ) $ (6 ) $ 4 $ (26 )
Schedule of Regulatory Assets / Liabilities [Table Text Block]	Other changes in plan assets and benefit obligations for our other postretirement benefit plans associated with Transco and Northwest Pipeline are recognized in regulatory assets/liabilities. Amounts recognized in regulatory assets/ liabilities for the years ended December 31 consist of the following: 2016 2015 2014 (Millions) Other changes in plan assets and benefit obligations recognized in regulatory (assets) liabilities: Net actuarial gain (loss) $ 2 $ 10 $ (2 ) Amortization of prior service credit (9 ) (11 ) (12 )
Pre-tax amounts expected to be amortized in net periodic benefit cost [Table Text Block]	Pre-tax amounts expected to be amortized in Net periodic benefit cost in 2017 are as follows: Pension Benefits Other Postretirement Benefits (Millions) Amounts included in Accumulated other comprehensive income (loss) : Prior service credit $ — $ (5 ) Net actuarial loss 28 — Amounts included in regulatory liabilities associated with Transco and Northwest Pipeline: Prior service credit N/A $ (8 ) Net actuarial loss N/A —
Schedule of Assumptions Used [Table Text Block]	The weighted-average assumptions utilized to determine benefit obligations as of December 31 are as follows: Pension Benefits Other Postretirement Benefits 2016 2015 2016 2015 Discount rate 4.17 % 4.38 % 4.27 % 4.50 % Rate of compensation increase 4.87 4.88 N/A N/A The weighted-average assumptions utilized to determine Net periodic benefit cost for the years ended December 31 are as follows: Pension Benefits Other Postretirement Benefits 2016 2015 2014 2016 2015 2014 Discount rate 4.37 % 3.96 % 4.68 % 4.50 % 4.12 % 4.80 % Expected long-term rate of return on plan assets 6.85 6.38 6.85 6.11 5.70 6.11 Rate of compensation increase 4.88 4.62 4.56 N/A N/A N/A
One percentage point change in assumed health care cost trend rates effects [Table Text Block]	A one-percentage-point change in assumed health care cost trend rates would have the following effects: Point increase Point decrease (Millions) Effect on total of service and interest cost components $ — $ — Effect on other postretirement benefit obligation 6 (5 )
Fair values of plan assets [Table Text Block]	The fair values of our pension plan assets at December 31, 2016 and 2015 by asset class are as follows: 2016 Quoted Prices Significant Significant Total (Millions) Pension assets: Cash management fund $ 14 $ — $ — $ 14 Equity securities: U.S. large cap 87 — — 87 U.S. small cap 77 — — 77 Fixed income securities (1): U.S. Treasury securities 68 — — 68 Government and municipal bonds — 10 — 10 Mortgage and asset-backed securities — 80 — 80 Corporate bonds — 148 — 148 Insurance company investment contracts and other — 5 — 5 $ 246 $ 243 $ — 489 Commingled investment funds measured at net asset value practical expedient (3): Equities — U.S. large cap 369 Equities — International small cap 27 Equities — International emerging markets 50 Equities — International developed markets 149 Fixed income — U.S. long duration 88 Fixed income — Corporate bonds 82 Total assets at fair value at December 31, 2016 $ 1,254 2015 Quoted Prices Significant Significant Total (Millions) Pension assets: Cash management fund $ 8 $ — $ — $ 8 Equity securities: U.S. large cap 83 — — 83 U.S. small cap 64 — — 64 Fixed income securities (1): U.S. Treasury securities 65 — — 65 Government and municipal bonds — 8 — 8 Mortgage and asset-backed securities — 87 — 87 Corporate bonds — 145 — 145 Insurance company investment contracts and other — 5 — 5 $ 220 $ 245 $ — 465 Commingled investment funds measured at net asset value practical expedient (3): Equities — U.S. large cap 367 Equities — International small cap 27 Equities — International emerging markets 50 Equities — International developed markets 153 Fixed income — U.S. long duration 95 Fixed income — Corporate bonds 84 Total assets at fair value at December 31, 2015 $ 1,241 The fair values of our other postretirement benefits plan assets at December 31, 2016 and 2015 by asset class are as follows: 2016 Quoted Prices Significant Significant Total (Millions) Other postretirement benefit assets: Cash management funds $ 11 $ — $ — $ 11 Equity securities: U.S. large cap 24 — — 24 U.S. small cap 15 — — 15 International developed markets large cap growth — 5 — 5 Fixed income securities (2): U.S. Treasury securities 7 — — 7 Government and municipal bonds — 1 — 1 Mortgage and asset-backed securities — 8 — 8 Corporate bonds — 15 — 15 Mutual fund — Municipal bonds 42 — — 42 $ 99 $ 29 $ — 128 Commingled investment funds measured at net asset value practical expedient (3): Equities — U.S. large cap 38 Equities — International small cap 3 Equities — International emerging markets 5 Equities — International developed markets 16 Fixed income — U.S. long duration 9 Fixed income — Corporate bonds 9 Total assets at fair value at December 31, 2016 $ 208 2015 Quoted Prices Significant Significant Total (Millions) Other postretirement benefit assets: Cash management funds $ 11 $ — $ — $ 11 Equity securities: U.S. large cap 37 — — 37 U.S. small cap 20 — — 20 International developed markets large cap growth 1 9 — 10 Emerging markets growth — 1 — 1 Fixed income securities (2): U.S. Treasury securities 7 — — 7 Government and municipal bonds — 12 — 12 Mortgage and asset-backed securities — 9 — 9 Corporate bonds — 15 — 15 $ 76 $ 46 $ — 122 Commingled investment funds measured at net asset value practical expedient (3): Equities — U.S. large cap 37 Equities — International small cap 3 Equities — International emerging markets 5 Equities — International developed markets 16 Fixed income — U.S. long duration 10 Fixed income — Corporate bonds 8 Total assets at fair value at December 31, 2015 $ 201 ____________ (1) The weighted-average credit quality rating of the pension assets fixed income security portfolio is investment grade with a weighted-average duration of approximately 8 years for 2016 and 2015 . (2) The weighted-average credit quality rating of the other postretirement benefit assets fixed income security portfolio is investment grade with a weighted-average duration of approximately 8 years for 2016 and 7 years for 2015 . (3) The stated intents of the funds vary based on each commingled fund’s investment objective. These objectives generally include strategies to replicate or outperform various market indices. Certain standard withdrawal restrictions generally apply, which may include redemption notification period restrictions ranging from 10 to 30 days. Additionally, the fund managers retain the right to restrict withdrawals from and/or purchases into the funds so as not to disadvantage other investors in the funds. Generally, the funds also reserve the right to make all or a portion of the redemption in-kind rather than in cash or a combination of cash and in-kind.
Expected benefit payments [Table Text Block]	Following are the expected benefits to be paid by the plans. These estimates are based on the same assumptions previously discussed and reflect future service as appropriate. The actuarial assumptions are based on long-term expectations and include, but are not limited to, assumptions as to average expected retirement age and form of benefit payment. Actual benefit payments could differ significantly from expected benefit payments if near-term participant behaviors differ significantly from the actuarial assumptions. Pension Benefits Other Postretirement Benefits (Millions) 2017 $ 99 $ 13 2018 103 13 2019 103 13 2020 106 13 2021 111 13 2022-2026 562 62

Property, Plant, and Equipment

Property, Plant, and Equipment (Tables)	12 Months Ended
	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Property, Plant, and Equipment [Table Text Block]	The following table presents nonregulated and regulated Property, plant, and equipment – net as presented on the Consolidated Balance Sheet for the years ended: Estimated Useful Life (1) (Years) Depreciation Rates (1) (%) December 31, 2016 2015 (Millions) Nonregulated: Natural gas gathering and processing facilities 5 - 40 $ 20,413 $ 20,789 Construction in progress Not applicable 412 1,366 Other 2 - 45 2,202 2,170 Regulated: Natural gas transmission facilities 1.20 - 6.97 12,692 12,189 Construction in progress Not applicable Not applicable 1,603 941 Other 5 - 45 1.35 - 33.33 1,590 1,584 Total property, plant, and equipment, at cost 38,912 39,039 Accumulated depreciation and amortization (10,484 ) (9,460 ) Property, plant, and equipment — net $ 28,428 $ 29,579 __________ (1) Estimated useful life and depreciation rates are presented as of December 31, 2016 . Depreciation rates and estimated useful lives for regulated assets are prescribed by the FERC.
Asset Retirement Obligation [Table Text Block]	The following table presents the significant changes to our ARO, of which $801 million and $858 million are included in Regulatory liabilities, deferred income, and other with the remaining current portion in Accrued liabilities at December 31, 2016 and 2015 , respectively. December 31, 2016 2015 (Millions) Beginning balance $ 915 $ 831 Liabilities incurred 24 42 Liabilities settled (8 ) (3 ) Accretion expense 69 60 Revisions (1) (138 ) (15 ) Ending balance $ 862 $ 915 ___________ (1) Several factors are considered in the annual review process, including inflation rates, current estimates for removal cost, market risk premiums, discount rates, and the estimated remaining useful life of the assets. The 2016 revisions reflect changes in removal cost estimates, increases in the estimated remaining useful life of certain assets, and decreases in the inflation rate and discount rates used in the annual review process. The 2015 revisions reflect changes in removal cost estimates and the estimated remaining useful life of assets, a decrease in the inflation rate, and increases in the discount rates used in the annual review process.

Goodwill and Other Intangible42

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill [Table Text Block]	Goodwill Changes in the carrying amount of goodwill, included in Intangible assets – net of accumulated amortization , by reportable segment for the periods indicated are as follows: Williams Partners (Millions) December 31, 2014 $ 1,120 Purchase accounting adjustment 25 Impairment (1,098 ) December 31, 2015 $ 47 December 31, 2016 $ 47
Schedule of Finite-Lived Intangible Assets [Table Text Block]	Other Intangible Assets The gross carrying amount and accumulated amortization of other intangible assets, included in Intangible assets – net of accumulated amortization , at December 31 are as follows: 2016 2015 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization (Millions) Contractual customer relationships $ 10,635 $ (1,019 ) $ 10,633 $ (663 )

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	12 Months Ended
	Dec. 31, 2016
Accrued Liabilities, Current [Abstract]
Accrued Liabilities [Table Text Block]	December 31, 2016 2015 (Millions) Deferred income $ 338 $ 94 Interest on debt 310 284 Employee costs 223 215 Refundable deposits 160 — Special distribution repayable to Gulfstream (See Note 6 - Investing Activities) — 149 Asset retirement obligations 61 57 Other, including other loss contingencies 356 279 $ 1,448 $ 1,078

Debt, Banking Arrangements, a44

Debt, Banking Arrangements, and Leases (Tables)	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments [Table Text Block]	Long-Term Debt December 31, 2016 2015 (Millions) Unsecured: Transco: 6.4% Notes due 2016 (1) $ — $ 200 6.05% Notes due 2018 250 250 7.08% Debentures due 2026 8 8 7.25% Debentures due 2026 200 200 7.85% Notes due 2026 1,000 — 5.4% Notes due 2041 375 375 4.45% Notes due 2042 400 400 Northwest Pipeline: 7% Notes due 2016 — 175 5.95% Notes due 2017 185 185 6.05% Notes due 2018 250 250 7.125% Debentures due 2025 85 85 WPZ: 7.25% Notes due 2017 600 600 5.25% Notes due 2020 1,500 1,500 4.125% Notes due 2020 600 600 4% Notes due 2021 500 500 3.6% Notes due 2022 1,250 1,250 3.35% Notes due 2022 750 750 6.125% Notes due 2022 750 750 4.5% Notes due 2023 600 600 4.875% Notes due 2023 1,400 1,400 4.3% Notes due 2024 1,000 1,000 4.875% Notes due 2024 750 750 3.9% Notes due 2025 750 750 4% Notes due 2025 750 750 6.3% Notes due 2040 1,250 1,250 5.8% Notes due 2043 400 400 5.4% Notes due 2044 500 500 4.9% Notes due 2045 500 500 5.1% Notes due 2045 1,000 1,000 Term Loan, variable interest rate, due 2018 850 850 Credit facility loans — 1,310 WMB: 7.875% Notes due 2021 371 371 3.7% Notes due 2023 850 850 4.55% Notes due 2024 1,250 1,250 7.5% Debentures due 2031 339 339 December 31, 2016 2015 (Millions) 7.75% Notes due 2031 252 252 8.75% Notes due 2032 445 445 5.75% Notes due 2044 650 650 Various — 5.5% to 10.25% Notes and Debentures due 2019 to 2033 55 55 Credit facility loans 775 650 Capital lease obligations — 1 Debt issuance costs (119 ) (123 ) Net unamortized debt premium (discount) 88 110 Total long-term debt, including current portion 23,409 23,988 Long-term debt due within one year (785 ) (176 ) Long-term debt $ 22,624 $ 23,812 ___________ (1) Presented as long-term debt at December 31, 2015, due to Transco’s intent and ability to refinance.
Schedule of Maturities of Long-term Debt [Table Text Block]	The following table presents aggregate minimum maturities of long-term debt, excluding net unamortized debt premium (discount), debt issuance costs, and capital lease obligations, for each of the next five years: December 31, 2016 (Millions) 2017 $ 785 2018 1,350 2019 32 2020 2,896 2021 871
Schedule of Line of Credit Facilities [Table Text Block]	Credit Facilities December 31, 2016 Available Outstanding (Millions) WMB Long-term credit facility $ 1,500 $ 775 Letters of credit under certain bilateral bank agreements 13 WPZ Long-term credit facility (1) 3,500 — Letters of credit under certain bilateral bank agreements 1 ________________ (1) In managing our available liquidity, we do not expect a maximum outstanding amount in excess of the capacity of our credit facility inclusive of any outstanding amounts under our commercial paper program.
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	The future minimum annual rentals under noncancelable operating leases, are payable as follows: December 31, 2016 (Millions) 2017 $ 62 2018 58 2019 51 2020 46 2021 35 Thereafter 90 Total $ 342

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2016
Stockholders' Equity Note [Abstract]
Accumulated Other Comprehensive Income (Loss) [Table Text Block]	The following table presents the changes in AOCI by component, net of income taxes: Cash Flow Hedges Foreign Currency Translation Pension and Other Post Retirement Benefits Total (Millions) Balance at December 31, 2015 $ (1 ) $ (103 ) $ (338 ) $ (442 ) Other comprehensive income (loss) before reclassifications 2 25 (15 ) 12 Amounts reclassified from accumulated other comprehensive income (loss) (1 ) 76 16 91 Other comprehensive income (loss) 1 101 1 103 Balance at December 31, 2016 $ — $ (2 ) $ (337 ) $ (339 )
Reclassifications Out Of Accumulated Other Comprehensive Income [Table Text Block]	Reclassifications out of AOCI are presented in the following table by component for the year ended December 31, 2016 : Component Reclassifications Classification (Millions) Cash flow hedges: Energy commodity contracts $ (3 ) Product sales Total cash flow hedges (3 ) Pension and other postretirement benefits: Amortization of prior service cost (credit) included in net periodic benefit cost (6 ) Note 10 – Employee Benefit Plans Amortization of actuarial (gain) loss included in net periodic benefit cost 32 Note 10 – Employee Benefit Plans Total pension and other postretirement benefits 26 Foreign currency translation: Reclassification of cumulative foreign currency translation adjustment upon sale of foreign entities 155 Other (income) expense - net Total before tax 178 Income tax benefit (45 ) Provision (benefit) for income taxes Net of income tax 133 Noncontrolling interest (42 ) Net income (loss) attributable to noncontrolling interests Reclassifications during the period $ 91

Equity-Based Compensation (Tabl

Equity-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2016
Williams Companies Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Option Rollfoward and related information [Table Text Block]	The following summary reflects stock option activity and related information for the year ended December 31, 2016 : Stock Options Options Weighted- Average Exercise Price Aggregate Intrinsic Value (Millions) (Millions) Outstanding at December 31, 2015 5.7 $ 31.51 Granted 0.9 $ 24.99 Exercised (0.3 ) $ 17.84 Cancelled (0.1 ) $ 24.04 Outstanding at December 31, 2016 6.2 $ 31.32 $ 28 Exercisable at December 31, 2016 5.0 $ 29.75 $ 23
Schedule of Cash Proceeds Received from Share-based Payment Awards [Table Text Block]	The following table summarizes additional information related to stock option activity during each of the last three years: Years Ended December 31, 2016 2015 2014 (Millions) Total intrinsic value of options exercised $ 2 $ 37 $ 48 Tax benefits realized on options exercised $ 1 $ 13 $ 18 Cash received from the exercise of options $ 4 $ 20 $ 31
Stock Options Schedule of Valuation Assumptions [Table Text Block]	The estimated fair value at date of grant of options for our common stock granted in each respective year, using the Black-Scholes option pricing model, is as follows: 2016 2015 2014 Weighted-average grant date fair value of options for our common stock granted during the year, per share $ 7.90 $ 7.61 $ 7.50 Weighted-average assumptions: Dividend yield 3.2 % 4.8 % 4.2 % Volatility 44.7 % 27.8 % 28.0 % Risk-free interest rate 1.2 % 1.8 % 2.2 % Expected life (years) 6.0 6.0 6.5
Nonvested Restricted Stock Unit Rollforward and related information [Table Text Block]	The following summary reflects nonvested restricted stock unit activity and related information for the year ended December 31, 2016 : Restricted Stock Units Outstanding Shares Weighted- Average Fair Value (1) (Millions) Nonvested at December 31, 2015 3.4 $ 39.38 Granted 1.5 $ 26.51 Forfeited (0.1 ) $ 38.18 Vested (0.9 ) $ 35.49 Nonvested at December 31, 2016 3.9 $ 35.19 ______________ (1) Performance-based restricted stock units are valued utilizing a Monte Carlo valuation method using measures of total shareholder return. Certain of the performance-based restricted stock units are subject to a holding period of up to two years after the vesting date. Discounts for the restrictions of liquidity were applied to the estimated fair value at the date of certain awards and ranged from 5.83 percent to 15.58 percent . The discounts were developed using the Chaffe model and the Finnerty model. All other restricted stock units are valued at the grant-date market price. Restricted stock units generally vest after three years .
Other restricted stock unit information [Table Text Block]	Value of Restricted Stock Units 2016 2015 2014 Weighted-average grant date fair value of restricted stock units granted during the year, per share $ 26.51 $ 40.15 $ 42.79 Total fair value of restricted stock units vested during the year ($’s in millions) $ 32 $ 42 $ 27
Williams Partners Long Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested Restricted Stock Unit Rollforward and related information [Table Text Block]	The following summary reflects nonvested WPZ restricted common unit activity and related information for the year ended December 31, 2016 : Restricted Common Units Outstanding Units Weighted- Average Fair Value (Millions) Nonvested at December 31, 2015 1.2 $ 55.93 Forfeited (0.1 ) $ 52.85 Vested (0.5 ) $ 59.09 Nonvested at December 31, 2016 0.6 $ 52.97

Fair Value Measurements, Guar47

Fair Value Measurements, Guarantees, and Concentration of Credit Risk (Tables)	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Assets and Liabilities Measured On Recurring Basis [Table Text Block]	The following table presents, by level within the fair value hierarchy, certain of our financial assets and liabilities. The carrying values of cash and cash equivalents, accounts receivable, commercial paper, and accounts payable approximate fair value because of the short-term nature of these instruments. Therefore, these assets and liabilities are not presented in the following table. Fair Value Measurements Using Carrying Amount Fair Value Quoted Prices In Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (Millions) Assets (liabilities) at December 31, 2016: Measured on a recurring basis: ARO Trust investments $ 96 $ 96 $ 96 $ — $ — Energy derivatives assets designated as hedging instruments 2 2 — 2 — Energy derivatives assets not designated as hedging instruments 1 1 — — 1 Energy derivatives liabilities not designated as hedging instruments (6 ) (6 ) — — (6 ) Additional disclosures: Other receivables 15 15 15 — — Long-term debt, including current portion (23,409 ) (24,090 ) — (24,090 ) — Guarantees (44 ) (30 ) — (14 ) (16 ) Assets (liabilities) at December 31, 2015: Measured on a recurring basis: ARO Trust investments $ 67 $ 67 $ 67 $ — $ — Energy derivatives assets not designated as hedging instruments 5 5 — 3 2 Energy derivatives liabilities not designated as hedging instruments (2 ) (2 ) — — (2 ) Additional disclosures: Other receivables 12 30 10 2 18 Long-term debt, including current portion (1) (23,987 ) (19,606 ) — (19,606 ) — Guarantee (29 ) (16 ) — (16 ) — ___________ (1) Excludes capital leases.
Fair Value Measurements, Nonrecurring [Table Text Block]	The following table presents impairments of assets and investments associated with certain nonrecurring fair value measurements within Level 3 of the fair value hierarchy. Impairments Years Ended December 31, Classification Segment Date of Measurement Fair Value 2016 2015 2014 (Millions) Surplus equipment (1) Property, plant, and equipment – net Williams Partners June 30, 2014 $ 46 $ 17 Surplus equipment (1) Property, plant, and equipment – net Williams Partners December 31, 2014 32 13 Surplus equipment (1) Property, plant, and equipment – net Williams Partners June 30, 2015 17 $ 20 Surplus equipment (1) Assets held for sale Williams Partners December 31, 2014 1 12 Previously capitalized project development costs (2) Property, plant, and equipment – net Williams Partners December 31, 2015 13 94 Previously capitalized project development costs (3) Property, plant, and equipment – net Other December 31, 2015 40 64 Canadian operations (4) Assets held for sale Williams Partners June 30, 2016 924 $ 341 Canadian operations (4) Assets held for sale Other June 30, 2016 206 406 Certain gathering operations (5) Property, plant, and equipment – net Williams Partners June 30, 2016 18 48 Certain idle assets Property, plant, and equipment – net Other December 31, 2016 73 8 Level 3 fair value measurements of certain assets 803 178 42 Other impairments and write-downs (6) 70 31 10 Impairment of certain assets $ 873 $ 209 $ 52 Equity-method investments (7) Investments Williams Partners September 30, 2015 $ 1,203 $ 461 Equity-method investments (8) Investments Williams Partners December 31, 2015 4,017 890 Equity-method investments (9) Investments Williams Partners March 31, 2016 1,294 $ 109 Equity-method investments (10) Investments Williams Partners December 31, 2016 1,295 318 Other equity-method investment Investments Williams Partners December 31, 2015 58 8 Other equity-method investment Investments Williams Partners March 31, 2016 — 3 Impairment of equity-method investments $ 430 $ 1,359 ______________ (1) Relates to certain surplus equipment. The estimated fair value was determined by a market approach based on our analysis of observable inputs in the principal market. (2) Relates to a gas processing plant, the completion of which is considered remote due to unfavorable impact of low natural gas prices on customer drilling activities. The assessed fair value primarily represents the estimated salvage value of certain equipment measured using a market approach based on our analysis of observable inputs in the principal market. (3) Relates to an olefins pipeline project, the completion of which is considered remote due to lack of customer interest. The assessed fair value primarily represents the estimated fair value of unused pipeline measured using a market approach based on our analysis of observable inputs in the principal market. (4) Relates to our Canadian operations. We designated these operations as held for sale as of June 30, 2016. As a result, we measured the fair value of the disposal group, resulting in an impairment charge. The estimated fair value was determined by a market approach based primarily on inputs received in the marketing process and reflected our estimate of the potential assumed proceeds. We disposed of our Canadian operations through a sale during the third quarter of 2016. See Note 3 – Divestiture . (5) Relates to certain gathering assets within the Mid-Continent region. The estimated fair value was determined by a market approach based on our analysis of observable inputs in the principal market. (6) Reflects multiple individually insignificant impairments and write-downs of other certain assets that may no longer be in use or are surplus in nature for which the fair value was determined to be zero or an insignificant salvage value. (7) Relates to equity-method investments in DBJV and certain of the Appalachia Midstream Investments. The historical carrying value of these investments was initially recorded based on estimated fair value during the third quarter of 2014 in conjunction with the acquisition of ACMP. We estimated the fair value of these investments using an income approach based on expected future cash flows and appropriate discount rates. The determination of estimated future cash flows involved significant assumptions regarding gathering volumes and related capital spending. Discount rates utilized were 11.8 percent and 8.8 percent for DBJV and certain of the Appalachia Midstream Investments, respectively, and reflected our cost of capital as impacted by market conditions, and risks associated with the underlying businesses. (8) Relates to equity-method investments in DBJV, certain of the Appalachia Midstream Investments, UEOM, and Laurel Mountain. We estimated the fair value of these investments using an income approach based on expected future cash flows and appropriate discount rates. The determination of estimated future cash flows involved significant assumptions regarding gathering volumes and related capital spending. Discount rates utilized ranged from 10.8 percent to 14.4 percent and reflected further fourth-quarter 2015 increases in our cost of capital, revised estimates of expected future cash flows, and risks associated with the underlying businesses. (9) Relates to equity-method investments in DBJV and Laurel Mountain. Our carrying values in these equity-method investments had been written down to fair value at December 31, 2015. Our first-quarter 2016 analysis reflected higher discount rates for both of these investments, along with lower natural gas prices for Laurel Mountain. We estimated the fair value of these investments using an income approach based on expected future cash flows and appropriate discount rates. The determination of estimated future cash flows involved significant assumptions regarding gathering volumes and related capital spending. Discount rates utilized ranged from 13.0 percent to 13.3 percent and reflected increases in our cost of capital, revised estimates of expected future cash flows, and risks associated with the underlying businesses. (10) Relates to equity-method investments in Ranch Westex and multiple Appalachia Midstream Investments. The historical carrying value of these investments was initially recorded based on estimated fair value during the third quarter of 2014 in conjunction with the acquisition of ACMP. We estimated the fair value of these Appalachia Midstream Investments using an income approach based on expected future cash flows and appropriate discount rates. The determination of estimated future cash flows involved significant assumptions regarding gathering volumes, rates, and related capital spending. The discount rate utilized for the Appalachia Midstream Investments evaluation was 10.2 percent and reflected our cost of capital as impacted by market conditions and risks associated with the underlying businesses. In addition to utilizing an income approach, we also considered a market approach for certain Appalachia Midstream Investments and Ranch Westex based on an agreement reached in February 2017 to exchange our interests in DBJV and Ranch Westex for additional interests in certain Appalachia Midstream Investments and cash.
Concentration of receivables, net of allowances, by product or service [Table Text Block]	Trade accounts and other receivables The following table summarizes concentration of receivables, net of allowances: December 31, 2016 2015 (Millions) NGLs, natural gas, and related products and services $ 736 $ 823 Transportation of natural gas and related products 187 202 Other 15 16 Total $ 938 $ 1,041

Segment Disclosures (Tables)

Segment Disclosures (Tables)	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block]	The following geographic area data includes Revenues from external customers based on product shipment origin and Long-lived assets based upon physical location: United States Canada Total (Millions) Revenues from external customers: 2016 $ 7,425 $ 74 $ 7,499 2015 7,247 113 7,360 2014 7,229 408 7,637 Long-lived assets: 2016 $ 38,091 $ — $ 38,091 2015 38,016 1,580 39,596 2014 38,290 1,364 39,654 Long-lived assets are comprised of property, plant, and equipment, goodwill, and other intangible assets.
Reconciliation of revenue from segment to consolidated [Table Text Block]	The following table reflects the reconciliation of Segment revenues to Total revenues as reported in the Consolidated Statement of Operations and Other financial information : Williams Partners Other Eliminations Total (Millions) 2016 Segment revenues: Service revenues External $ 5,140 $ 31 $ — $ 5,171 Internal 33 19 (52 ) — Total service revenues 5,173 50 (52 ) 5,171 Product sales External 2,318 10 — 2,328 Internal — 16 (16 ) — Total product sales 2,318 26 (16 ) 2,328 Total revenues $ 7,491 $ 76 $ (68 ) $ 7,499 Other financial information: Additions to long-lived assets $ 2,102 $ 44 $ (1 ) $ 2,145 Proportional Modified EBITDA of equity-method investments 754 — — 754 2015 Segment revenues: Service revenues External $ 5,134 $ 30 $ — $ 5,164 Internal 1 91 (92 ) — Total service revenues 5,135 121 (92 ) 5,164 Product sales External 2,196 — — 2,196 Internal — — — — Total product sales 2,196 — — 2,196 Total revenues $ 7,331 $ 121 $ (92 ) $ 7,360 Other financial information: Additions to long-lived assets $ 2,960 $ 388 $ (12 ) $ 3,336 Proportional Modified EBITDA of equity-method investments 699 — — 699 2014 Segment revenues: Service revenues External $ 3,887 $ 229 $ — $ 4,116 Internal 1 19 (20 ) — Total service revenues 3,888 248 (20 ) 4,116 Product sales External 3,521 — — 3,521 Internal — — — — Total product sales 3,521 — — 3,521 Total revenues $ 7,409 $ 248 $ (20 ) $ 7,637 Other financial information: Additions to long-lived assets (1) $ 20,413 $ 345 $ (2 ) $ 20,756 Proportional Modified EBITDA of equity-method investments 431 7 — 438 _______________ (1) 2014 Additions to long-lived assets within our Williams Partners segment primarily includes the acquisition-date fair value of long-lived assets from the ACMP Acquisition. (See Note 2 - Acquisitions.)
Reconciliation of Modified EBITDA to Net income (loss) [Table Text Block]	The following table reflects the reconciliation of Modified EBITDA to Net income (loss) as reported in the Consolidated Statement of Operations : Years Ended December 31, 2016 2015 2014 (Millions) Modified EBITDA by segment: Williams Partners $ 3,864 $ 4,003 $ 3,244 Other (542 ) (112 ) (12 ) 3,322 3,891 3,232 Accretion expense associated with asset retirement obligations for nonregulated operations (31 ) (28 ) (18 ) Depreciation and amortization expenses (1,763 ) (1,738 ) (1,176 ) Impairment of goodwill — (1,098 ) — Equity earnings (losses) 397 335 144 Gain on remeasurement of equity-method investment — — 2,544 Impairment of equity-method investments (430 ) (1,359 ) — Other investing income (loss) – net 63 27 43 Proportional Modified EBITDA of equity-method investments (754 ) (699 ) (438 ) Interest expense (1,179 ) (1,044 ) (747 ) (Provision) benefit for income taxes 25 399 (1,249 ) Income (loss) from discontinued operations, net of tax — — 4 Net income (loss) $ (350 ) $ (1,314 ) $ 2,339
Total assets and equity method investments by reporting segment [Table Text Block]	The following table reflects Total assets and Equity-method investments by reportable segments: Total Assets Equity-Method Investments December 31, 2016 December 31, 2015 December 31, 2016 December 31, 2015 (Millions) Williams Partners $ 46,265 $ 47,870 $ 6,701 $ 7,336 Other 685 1,351 — — Eliminations (115 ) (201 ) — — Total $ 46,835 $ 49,020 $ 6,701 $ 7,336

Schedule I Condensed Financia49

Schedule I Condensed Financial Information of Registrant (Tables)	12 Months Ended
	Dec. 31, 2016
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Income Statement [Table Text Block]	The Williams Companies, Inc. Schedule I — Condensed Financial Information of Registrant Statement of Comprehensive Income (Loss) (Parent) Years Ended December 31, 2016 2015 2014 (Millions, except per-share amounts) Equity in earnings of consolidated subsidiaries $ 522 $ 232 $ 1,799 Equity earnings (losses) from investment in Access Midstream Partners — — (7 ) Interest incurred — external (268 ) (255 ) (206 ) Interest incurred — affiliate (568 ) (828 ) (797 ) Interest income — affiliate — 6 10 Gain on remeasurement of equity-method investment — — 2,544 Other income (expense) — net (53 ) (75 ) (13 ) Income (loss) from continuing operations before income taxes (367 ) (920 ) 3,330 Provision (benefit) for income taxes 57 (349 ) 1,220 Income (loss) from continuing operations (424 ) (571 ) 2,110 Income (loss) from discontinued operations — — 4 Net income (loss) $ (424 ) $ (571 ) $ 2,114 Basic earnings (loss) per common share: Income (loss) from continuing operations $ (.57 ) $ (.76 ) $ 2.93 Income (loss) from discontinued operations — — .01 Net income (loss) $ (.57 ) $ (.76 ) $ 2.94 Weighted-average shares (thousands) 750,673 749,271 719,325 Diluted earnings (loss) per common share: Income (loss) from continuing operations $ (.57 ) $ (.76 ) $ 2.91 Income (loss) from discontinued operations — — .01 Net income (loss) $ (.57 ) $ (.76 ) $ 2.92 Weighted-average shares (thousands) 750,673 749,271 723,641 Other comprehensive income (loss): Equity in other comprehensive income (loss) of consolidated subsidiaries $ 171 $ (204 ) $ (96 ) Other comprehensive income (loss) attributable to The Williams Companies, Inc. 1 33 (80 ) Other comprehensive income (loss) 172 (171 ) (176 ) Less: Other comprehensive income (loss) attributable to noncontrolling interests 69 (70 ) (19 ) Comprehensive income (loss) attributable to The Williams Companies, Inc. $ (321 ) $ (672 ) $ 1,957 See accompanying notes.
Condensed Balance Sheet [Table Text Block]	The Williams Companies, Inc. Schedule I — Condensed Financial Information of Registrant – (Continued) Balance Sheet (Parent) December 31, 2016 2015 (Millions) ASSETS Current assets: Cash and cash equivalents $ 14 $ 12 Other current assets and deferred charges 16 62 Total current assets 30 74 Investments in and advances to consolidated subsidiaries 22,359 30,927 Property, plant, and equipment — net 77 99 Other noncurrent assets 8 12 Total assets $ 22,474 $ 31,112 LIABILITIES AND STOCKHOLDERS’ EQUITY Current liabilities: Accounts payable $ 27 $ 27 Other current liabilities 169 163 Total current liabilities 196 190 Long-term debt 4,939 4,811 Notes payable — affiliates 8,171 15,506 Pension, other postretirement, and other noncurrent liabilities 287 336 Deferred income tax liabilities 4,238 4,121 Contingent liabilities and commitments Equity: Common stock 785 784 Other stockholders’ equity 3,858 5,364 Total stockholders’ equity 4,643 6,148 Total liabilities and stockholders’ equity $ 22,474 $ 31,112 See accompanying notes.
Condensed Cash Flow Statement [Table Text Block]	The Williams Companies, Inc. Schedule I — Condensed Financial Information of Registrant – (Continued) Statement of Cash Flows (Parent) Years Ended December 31, 2016 2015 2014 (Millions) NET CASH FLOWS PROVIDED (USED) BY OPERATING ACTIVITIES $ (827 ) $ (1,181 ) $ (481 ) FINANCING ACTIVITIES: Proceeds from long-term debt 2,280 2,097 2,935 Payments of long-term debt (2,155 ) (1,817 ) (671 ) Changes in notes payable to affiliates 9 2,211 2,465 Tax benefit of stock-based awards — — 25 Proceeds from issuance of common stock 9 27 3,416 Dividends paid (1,261 ) (1,836 ) (1,412 ) Other — net (6 ) (30 ) (36 ) Net cash provided (used) by financing activities (1,124 ) 652 6,722 INVESTING ACTIVITIES: Capital expenditures (13 ) (29 ) (54 ) Purchase of Access Midstream Partners — — (5,995 ) Changes in investments in and advances to consolidated subsidiaries 1,966 521 (450 ) Other — net — — 25 Net cash provided (used) by investing activities 1,953 492 (6,474 ) Increase (decrease) in cash and cash equivalents 2 (37 ) (233 ) Cash and cash equivalents at beginning of year 12 49 282 Cash and cash equivalents at end of year $ 14 $ 12 $ 49 See accompanying notes.

General, Description of Busin50

General, Description of Business, Basis of Presentation, and Summary of Significant Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Millions

Feb. 10, 2017

Jan. 09, 2017

Sep. 28, 2015

Feb. 10, 2017

Feb. 03, 2017

Jan. 31, 2017

Nov. 30, 2016

Aug. 31, 2016

May 31, 2016

Feb. 29, 2016

Nov. 30, 2015

Jun. 30, 2015

Oct. 31, 2014

Feb. 28, 2014

Jun. 30, 2014

Dec. 31, 2016

Dec. 31, 2015

Dec. 31, 2014

Dec. 20, 2012

Mar. 31, 2017

Basis Of Presentation [Abstract]

Master limited partnership, general partner ownership percentage

2.00%

Changes in ownership of consolidated subsidiaries, net

$ (6)

$ 94

$ 44

Income Tax Effects Allocated Directly to Equity, Other

6

WPZ Merger Agreement [Member]

General and Description Of Business [Abstract]

Termination Fee

$ 428

Maximum Reduction Of Quarterly Incentive Distributions

$ 209

Basis Of Presentation [Abstract]

Reduction in incentive distribution rights payment

$ 10

$ 209

$ 209

Canada Dropdown [Member]

Basis Of Presentation [Abstract]

Proceeds from Divestiture of Businesses

$ 56

$ 31

Number Of Limited Partner Units Received1

25,577,521

Payments for Previous Acquisition

$ 56

Reduction in incentive distribution rights payment

$ 2

Financial Repositioning [Member] | Subsequent Event [Member]

Basis Of Presentation [Abstract]

Sale Of Stock Number Of Shares Issued In Transaction

277,000

59,000,000

289,000,000

Payments to Acquire Limited Partnership Interests

$ 50

$ 10

Sale of Stock, Price Per Share

$ 36.08586

Noncontrolling Interest [Member]

Basis Of Presentation [Abstract]

Changes in ownership of consolidated subsidiaries, net

(18)

254

137

Capital in excess of par value [Member]

Basis Of Presentation [Abstract]

Changes in ownership of consolidated subsidiaries, net

$ 12

(160)

(73)

Gulfstream Natural Gas System, L.L.C.[Member]

General and Description Of Business [Abstract]

Equity Method Investment, Ownership Percentage

50.00%

Utica East Ohio Midstream, LLC [Member]

General and Description Of Business [Abstract]

Equity Method Investment, Ownership Percentage

62.00%

Delaware Basin Gas Gathering System [Member]

General and Description Of Business [Abstract]

Equity Method Investment, Ownership Percentage

50.00%

Laurel Mountain Midstream, LLC [Member]

General and Description Of Business [Abstract]

Equity Method Investment, Ownership Percentage

69.00%

Caiman Energy II [Member]

General and Description Of Business [Abstract]

Equity Method Investment, Ownership Percentage

58.00%

Discovery Producer Services LLC [Member]

General and Description Of Business [Abstract]

Equity Method Investment, Ownership Percentage

60.00%

Overland Pass Pipeline Company LLC [Member]

General and Description Of Business [Abstract]

Equity Method Investment, Ownership Percentage

50.00%

Williams Partners L.P. [Member]

Basis Of Presentation [Abstract]

Master limited partnership, general partner ownership percentage

2.00%

Williams Partners L.P. [Member] | Financial Repositioning [Member] | Subsequent Event [Member]

General and Description Of Business [Abstract]

Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest

74.00%

Basis Of Presentation [Abstract]

Master limited partnership, general partner ownership percentage

2.00%

Williams Partners L.P. [Member] | General and Limited Partner [Member]

General and Description Of Business [Abstract]

Master limited partnership ownership percentage

60.00%

Williams Partners [Member]

General and Description Of Business [Abstract]

Number Of Interstate Natural Gas Pipelines

2

Basis Of Presentation [Abstract]

Goodwill

$ 47

$ 47

$ 1,120

Williams Partners [Member] | Private Placement [Member]

Basis Of Presentation [Abstract]

Sale Of Stock Number Of Shares Issued In Transaction

6,975,446

Payments to Acquire Limited Partnership Interests

$ 250

Williams Partners [Member] | Dividend Reinvestment Program [Member]

Basis Of Presentation [Abstract]

Sale Of Stock Number Of Shares Issued In Transaction

7,891,414

Payments to Acquire Limited Partnership Interests

$ 250

Sale of Stock, Consideration Received on Transaction

$ 260

Williams Partners [Member] | Equity Distribution Agreement [Member]

Basis Of Presentation [Abstract]

Sale Of Stock Number Of Shares Issued In Transaction

3,273,601

Sale of Stock, Consideration Received on Transaction

$ 115

Williams Partners [Member] | Gulfstream Natural Gas System, L.L.C.[Member]

General and Description Of Business [Abstract]

Equity Method Investment, Ownership Percentage

50.00%

Williams Partners [Member] | Utica East Ohio Midstream, LLC [Member]

General and Description Of Business [Abstract]

Equity Method Investment, Ownership Percentage

62.00%

Basis Of Presentation [Abstract]

Reduction in incentive distribution rights payment

$ 2

Williams Partners [Member] | Delaware Basin Gas Gathering System [Member]

General and Description Of Business [Abstract]

Equity Method Investment, Ownership Percentage

50.00%

Williams Partners [Member] | Delaware Basin Gas Gathering System [Member] | Subsequent Event [Member]

General and Description Of Business [Abstract]

Equity Method Investment, Ownership Percentage

50.00%

Williams Partners [Member] | Laurel Mountain Midstream, LLC [Member]

General and Description Of Business [Abstract]

Equity Method Investment, Ownership Percentage

69.00%

Williams Partners [Member] | Caiman Energy II [Member]

General and Description Of Business [Abstract]

Equity Method Investment, Ownership Percentage

58.00%

Williams Partners [Member] | Discovery Producer Services LLC [Member]

General and Description Of Business [Abstract]

Equity Method Investment, Ownership Percentage

60.00%

Williams Partners [Member] | Overland Pass Pipeline Company LLC [Member]

General and Description Of Business [Abstract]

Equity Method Investment, Ownership Percentage

50.00%

Williams Partners [Member] | Appalachia Midstream Services, LLC [Member]

General and Description Of Business [Abstract]

Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest

41.00%

Williams Partners [Member] | Appalachia Midstream Services, LLC [Member] | Subsequent Event [Member]

General and Description Of Business [Abstract]

Equity Method Investment, Ownership Percentage

66.00%

Williams Partners [Member] | Constitution Pipeline Company LLC [Member]

General and Description Of Business [Abstract]

Variable Interest Entity Ownership Percentage

41.00%

Summary of Significant Accounti

Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Regulatory Assets and Liabilities Disclosure [Abstract]
Regulatory Assets, Current	$ 91	$ 84
Regulatory Assets, Noncurrent	387	370
Total regulatory assets	478	454
Regulatory Liabilities, Current	11	4
Regulatory Liabilities, Noncurrent	498	434
Total regulatory liabilities	$ 509	$ 438
Interest Capitalized [Abstract]
Minimum period of construction for capitalization of interest	3 months
Minimum total project cost for capitalization of interest	$ 1
General Discussion of Pension and Other Postretirement Benefits [Abstract]
Threshold For Amortization Of Unrecognized Actuarial Gains Losses	10.00%
Pension Benefits [Member]
General Discussion of Pension and Other Postretirement Benefits [Abstract]
Approximate Amortization Period Of Net Actuarial Gain Loss	13 years
Amortization Period Of Difference Between Expected And Actual Return On Plan Assets	5 years
Other Postretirement Benefits [Member]
General Discussion of Pension and Other Postretirement Benefits [Abstract]
Approximate Amortization Period Of Net Actuarial Gain Loss	7 years
Amortization Period Of Unrecognized Prior Service Costs Credits	4 years
Maximum [Member] | Pension Benefits [Member]
General Discussion of Pension and Other Postretirement Benefits [Abstract]
Threshold For Market Related Value	110.00%
Minimum [Member] | Pension Benefits [Member]
General Discussion of Pension and Other Postretirement Benefits [Abstract]
Threshold For Market Related Value	90.00%

General, Description of Busin52

General, Description of Business, Basis of Presentation, and Summary of Significant Accounting Policies Deferred Revenue Arrangement, by Type [Table] (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Oct. 31, 2016	Dec. 31, 2016
Newly constructed assets [Member]
Deferred Revenue Arrangement [Line Items]
Deferred Revenue, Additions	$ 104
Contracts in Barnett Shale and Mid-Continent regions [Member]
Deferred Revenue Arrangement [Line Items]
Deferred Revenue, Additions		$ 820
Maximum [Member]
Deferred Revenue Arrangement [Line Items]
Duration Of Period For Deferred Revenue Recognition		25 years
Minimum [Member]
Deferred Revenue Arrangement [Line Items]
Duration Of Period For Deferred Revenue Recognition		1 year

Acquisitions (Details)

Acquisitions (Details) $ in Millions	1 Months Ended		3 Months Ended		6 Months Ended	12 Months Ended
	Jun. 30, 2015USD ($)	May 31, 2015USD ($)	Sep. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Jul. 02, 2014USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 20, 2012USD ($)	Jul. 01, 2014USD ($)
Equity Method Investments and Joint Ventures [Abstract]
Payments to Acquire Equity Method Investments						$ 177	$ 595	$ 482
Business Combination, Consideration Transferred [Abstract]
Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest									2.00%
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain						0	0	2,544
Business Acquisition, Pro Forma Information [Abstract]
Gain on remeasurement of equity-method investment (Note 2)						0	0	2,544
Williams Partners [Member]
Business Acquisition [Line Items]
Goodwill, Purchase Accounting Adjustments							25
Business Acquisition, Purchase Price Allocation [Abstract]
Goodwill						$ 47	47	1,120
Access Midstream [Member]
Equity Method Investments and Joint Ventures [Abstract]
Payments to Acquire Equity Method Investments									$ 2,190
Business Combination, Consideration Transferred [Abstract]
Business Combination, Step Acquisition, Equity Interest in Acquiree, Fair Value					$ 4,600
Utica East Ohio Midstream, LLC [Member]
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investment, Ownership Percentage						62.00%
Payments to Acquire Equity Method Investments						$ 0	$ 357	57
Utica East Ohio Midstream, LLC [Member] | Williams Partners [Member]
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investment, Ownership Percentage						62.00%
Payments to Acquire Equity Method Investments	$ 357
Reduction in incentive distribution rights payment	$ 2
Access Midstream Partners Acquisition [Member]
Business Acquisition [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Property, Plant, and Equipment				$ 150
Goodwill, Purchase Accounting Adjustments				25
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles				(168)
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Investments				$ (7)
Business Combination, Consideration Transferred [Abstract]
Payments to Acquire Businesses, Gross					$ 5,995
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain								2,544
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life					30 years
Percentage Of Finite Lived Intangible Assets Impacted By Our Intent Or Ability To Renew Or Extend Arrangement										56.00%
Acquired Finite-lived Intangible Asset, Weighted-Average Period before Renewal or Extension					17 years
Business Acquisition, Pro Forma Information [Abstract]
Business Acquisition, Pro Forma Revenue								8,181
Business Acquisition, Pro Forma Net Income (Loss)								622
Gain on remeasurement of equity-method investment (Note 2)								2,544
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual								781
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual								165
Access Midstream Partners Acquisition [Member] | Selling, General and Administrative Expenses [Member]
Business Combination, Consideration Transferred [Abstract]
Business Combination, Acquisition Related Costs								16
Access Midstream Partners Acquisition [Member] | Interest Incurred [Member]
Business Combination, Consideration Transferred [Abstract]
Business Combination, Acquisition Related Costs								9
Access Midstream Partners Acquisition [Member] | Income Loss From Equity Method Investment [Member]
Business Combination, Consideration Transferred [Abstract]
Business Combination, Integration Related Costs								$ 19
Access Midstream Partners Acquisition [Member] | Pro Forma [Member]
Business Combination, Consideration Transferred [Abstract]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life								30 years
Access Midstream Partners Acquisition [Member] | Williams Partners [Member]
Business Acquisition, Purchase Price Allocation [Abstract]
Accounts receivable										$ 168
Other current assets										63
Investments										5,865
Property, plant, and equipment										7,165
Goodwill										499
Other intangible assets										8,841
Current liabilities										(408)
Debt										(4,052)
Other noncurrent liabilities										$ (9)
Access Midstream Partners Acquisition [Member] | Access Midstream Partners L.P. [Member]
Business Combination, Consideration Transferred [Abstract]
Business Combination, Step Acquisition, Equity Interest in Acquiree, Including Subsequent Acquisition, Percentage										26.00%
Access Midstream Partners Acquisition [Member] | Access Midstream Partners L.P. [Member] | Williams Partners [Member]
Business Acquisition, Purchase Price Allocation [Abstract]
Noncontrolling interest										$ (6,544)
Access Midstream Partners Acquisition [Member] | ACMP's subsidiaries [Member] | Williams Partners [Member]
Business Acquisition, Purchase Price Allocation [Abstract]
Noncontrolling interest										$ (958)
Eagle Ford Gathering System [Member]
Business Combination, Consideration Transferred [Abstract]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		30 years
Acquired Finite-lived Intangible Asset, Weighted-Average Period before Renewal or Extension		10 years
Business Acquisition, Purchase Price Allocation [Abstract]
Other intangible assets		$ 32
Eagle Ford Gathering System [Member] | Williams Partners [Member]
Business Acquisition [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Property, Plant, and Equipment			$ 20
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles			$ (20)
Number Of Miles Of Pipeline Acquired		140
Business Combination, Consideration Transferred [Abstract]
Payments to Acquire Businesses, Gross		$ 112
Business Acquisition, Purchase Price Allocation [Abstract]
Property, plant, and equipment		$ 80
Limited Partner [Member] | Access Midstream Partners L.P. [Member]
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investment, Ownership Percentage									24.00%
General Partner [Member] | Access Midstream [Member]
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investment, Ownership Percentage									50.00%
General Partner [Member] | Access Midstream Partners Acquisition [Member]
Business Combination, Consideration Transferred [Abstract]
Business Acquisition, Percentage of Voting Interests Acquired										50.00%
Additional Investment [Member] | Utica East Ohio Midstream, LLC [Member]
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investment, Ownership Percentage	13.00%

Divestiture (Details)

Divestiture (Details) - Canadian Operations [Member] - USD ($) $ in Millions		3 Months Ended	12 Months Ended
		Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Impairment Of Certain Assets [Member] | Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Williams Partners [Member]
Income Statement and Additional Disclosures by Disposal Groups [Line Items]
Disposal Group, Not Discontinued Operation, Loss (Gain) on Write-down	[1]	$ 341
Impairment Of Certain Assets [Member] | Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Corporate and Other [Member]
Income Statement and Additional Disclosures by Disposal Groups [Line Items]
Disposal Group, Not Discontinued Operation, Loss (Gain) on Write-down	[1]	406
Disposal Group, Not Discontinued Operations [Member]
Income Statement and Additional Disclosures by Disposal Groups [Line Items]
Disposal Group, Consideration			$ 1,020
Divested cash of disposal group			31
Reduction in incentive distribution rights payment			150
Income (Loss) from Individually Significant Component Disposed of, Attributable to Parent, before Income Tax [Abstract]
Income (Loss) before Income Taxes of Disposal Group			(98)	$ 17
Income (Loss) before Income Taxes of Disposal Group Attributable to the Williams Companies, Inc.			(95)	15
Disposal Group, Not Discontinued Operations [Member] | Other income (expense) - net [Member]
Income Statement and Additional Disclosures by Disposal Groups [Line Items]
Loss on sale of Canadian operations (Note 3)			66
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments			15
Disposal Group, Not Discontinued Operations [Member] | Other income (expense) - net [Member] | Williams Partners [Member]
Income Statement and Additional Disclosures by Disposal Groups [Line Items]
Loss on sale of Canadian operations (Note 3)			34	0	$ 0
Disposal Group, Not Discontinued Operations [Member] | Other income (expense) - net [Member] | Corporate and Other [Member]
Income Statement and Additional Disclosures by Disposal Groups [Line Items]
Loss on sale of Canadian operations (Note 3)			$ 32	$ 0	$ 0
Disposal Group, Not Discontinued Operations [Member] | Impairment Of Certain Assets [Member] | Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member]
Income Statement and Additional Disclosures by Disposal Groups [Line Items]
Disposal Group, Not Discontinued Operation, Loss (Gain) on Write-down		$ 747
[1]	Relates to our Canadian operations. We designated these operations as held for sale as of June 30, 2016. As a result, we measured the fair value of the disposal group, resulting in an impairment charge. The estimated fair value was determined by a market approach based primarily on inputs received in the marketing process and reflected our estimate of the potential assumed proceeds. We disposed of our Canadian operations through a sale during the third quarter of 2016. See Note 3 – Divestiture.

Variable Interest Entities (Det

Variable Interest Entities (Details) - Variable Interest Entity, Primary Beneficiary [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Cash and cash equivalents [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	$ 145	$ 73
Accounts receivable [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	925	1,026
Inventories [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	138	127
Other current assets [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	205	190
Investments [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	6,701	7,336
Property, plant, and equipment, net [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	28,021	28,593
Intangible Assets [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	9,662	10,016
Regulatory assets, deferred charges, and other noncurrent assets [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	467	479
Accounts payable [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	(589)	(625)
Accrued liabilities [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	(1,122)	(757)
Commercial Paper [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	(93)	(499)
Long-term debt due within one year [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	(785)	(176)
Long-term Debt [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	(17,685)	(19,001)
Deferred Income Tax Liabilities [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	(20)	(119)
Noncurrent asset retirement obligations [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	(798)	(857)
Regulatory liabilities, deferred income, and other noncurrent liabilities [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	$ (1,860)	$ (1,066)
Gulfstar One [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	51.00%
Constitution Pipeline Company Llc [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	41.00%
Constitution Pipeline Company Llc [Member] | Property, plant, and equipment, net [Member]
Variable Interest Entity [Line Items]
Capitalized project development costs, Cumulative	$ 381
Constitution Pipeline Company Llc [Member] | Estimated Remaining Construction Costs For Variable Interest Entity [Member]
Variable Interest Entity [Line Items]
Estimated remaining construction costs	$ 687
Cardinal Gas Services LLC [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	66.00%
Jackalope Gas Gathering Services LLC [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	50.00%

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Related Party Transaction [Line Items]
Product costs	$ 180	$ 187	$ 197
Equity Method Investee [Member]
Related Party Transaction [Line Items]
Accounts payable	19	12
Management Fees Revenue	66	64	65
Common Management Transaction [Member]
Related Party Transaction [Line Items]
Service revenues	$ 144	$ 111	$ 115

Investing Activities (Details)

Investing Activities (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 20, 2012
Schedule of Investments [Line Items]
Impairment of equity-method investments		$ 430	$ 1,359	$ 0
Equity earnings (losses)		397	335	144
Investment income, nonoperating		63	27	43
Equity-method investments		6,701	7,336
Equity-method investment, difference between carrying amount and underlying equity		1,900	2,400
Equity-method investment, payments to purchase or contributions		177	595	482
Equity-method investment, dividends or distributions		742	633	440
Special distribution from equity-method investment		0	396	0
Summarized Financial Position of Equity Method Investments
Current assets		508	773
Noncurrent assets		9,695	9,549
Current liabilities		(412)	(633)
Noncurrent liabilities		(1,484)	(1,450)
Summarized Results of Operations of Equity Method Investments
Gross revenue		1,883	1,707	1,623
Operating income		799	690	534
Net income		726	611	460
Caiman Energy II [Member]
Schedule of Investments [Line Items]
Equity-method investments		$ 426	418
Equity-method investment, ownership percentage		58.00%
Equity-method investment, payments to purchase or contributions		$ 22	0	175
Equity-method investment, dividends or distributions		40	33	13
Delaware Basin Gas Gathering System [Member]
Schedule of Investments [Line Items]
Impairment of equity-method investments		59	503
Equity-method investments		$ 988	977
Equity-method investment, ownership percentage		50.00%
Equity-method investment, payments to purchase or contributions		$ 105	57	20
Equity-method investment, dividends or distributions		39	33	0
Appalachia Midstream Investments [Member]
Schedule of Investments [Line Items]
Impairment of equity-method investments		294	562
Equity earnings (losses)		(19)
Gain on sale of equity-method investment		27
Equity-method investments	[1]	$ 2,062	2,464
Equity-method investment, ownership percentage		41.00%
Equity-method investment, payments to purchase or contributions		$ 28	93	84
Equity-method investment, dividends or distributions		211	219	130
Utica East Ohio Midstream, LLC [Member]
Schedule of Investments [Line Items]
Impairment of equity-method investments		0	241
Equity-method investments		$ 1,448	1,525
Equity-method investment, ownership percentage		62.00%
Equity-method investment, payments to purchase or contributions		$ 0	357	57
Equity-method investment, dividends or distributions		92	42	0
Discovery Producer Services LLC [Member]
Schedule of Investments [Line Items]
Equity-method investments		$ 572	602
Equity-method investment, ownership percentage		60.00%
Equity-method investment, payments to purchase or contributions		$ 0	35	106
Equity-method investment, dividends or distributions		141	116	36
Laurel Mountain Midstream, LLC [Member]
Schedule of Investments [Line Items]
Impairment of equity-method investments		50	45
Equity-method investments		$ 324	391
Equity-method investment, ownership percentage		69.00%
Equity-method investment, dividends or distributions		$ 28	31	39
Overland Pass Pipeline Company LLC [Member]
Schedule of Investments [Line Items]
Equity-method investments		$ 430	445
Equity-method investment, ownership percentage		50.00%
Equity-method investment, dividends or distributions		$ 69	45	27
Gulfstream Natural Gas System, L.L.C.[Member]
Schedule of Investments [Line Items]
Equity-method investments		$ 261	293
Equity-method investment, ownership percentage		50.00%
Equity-method investment, dividends or distributions		$ 100	88	81
Special distribution from equity-method investment			396
Contribution to equity-method investment for repayment of debt		148	248
Access Midstream Partners [Member]
Schedule of Investments [Line Items]
Equity earnings (losses)				(7)
Equity-method investment, payments to purchase or contributions					$ 2,190
Equity-method investment, dividends or distributions		0	0	64
Access Midstream Partners [Member] | Adjustment for amortization of difference between carrying amount and underlying equity [Member]
Schedule of Investments [Line Items]
Equity earnings (losses)				(30)
Ranch Westex JV LLC [Member]
Schedule of Investments [Line Items]
Impairment of equity-method investments		24	0
Other [Member]
Schedule of Investments [Line Items]
Impairment of equity-method investments		3	8
Equity-method investments		190	221
Equity-method investment, payments to purchase or contributions		22	53	40
Equity-method investment, dividends or distributions		22	26	50
Bluegrass Pipeline [Member]
Schedule of Investments [Line Items]
Equity earnings (losses)				(67)
Moss Lake [Member]
Schedule of Investments [Line Items]
Equity earnings (losses)				(4)
Former Venezuela Operations [Member]
Schedule of Investments [Line Items]
Investment income, nonoperating		36	27	41
Equity-Method Investment Debt Due November 1, 2015 [Member] | Gulfstream Natural Gas System, L.L.C.[Member]
Schedule of Investments [Line Items]
Equity-method investment debt			$ 500
Equity-Method Investment Debt Due June 1, 2016 [Member] | Gulfstream Natural Gas System, L.L.C.[Member]
Schedule of Investments [Line Items]
Equity-method investment debt		$ 300
Access Midstream Partners Acquisition [Member] | Income Loss From Equity-Method Investment [Member]
Schedule of Investments [Line Items]
Business Combination, Integration Related Costs				$ 19
[1]	Includes equity-method investments in multiple gathering systems in the Marcellus Shale with an approximate average 41 percent interest.

Other Income and Expenses (Deta

Other Income and Expenses (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Gain on asset retirement	[1]	$ 138	$ 15
Other income (expense) - net [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Amortization of regulatory assets associated with asset retirement obligations		33	33	$ 33
Accrual of regulatory liability related to overcollection of certain employee expenses		25	20	14
Project development costs related to Constitution (Note 4)		28	0	0
Net foreign currency exchange (gains) losses (1)	[2]	10	(10)	(3)
Contingency gain settlement (2)	[3]	0	0	(154)
Net gain related to partial acreage dedication release		0	0	(12)
Gain on asset retirement		(11)	0	0
Loss related to sale of certain assets		0	0	10
Other income (expense) - net [Member] | Other [Member]
Segment Reporting Information [Line Items]
Gain on sale of unused pipe		(10)	0	0
Selling, general and administrative expenses [Member] | Williams Partners [Member] | Acquisition and Merger [Member]
Segment Reporting Information [Line Items]
Business combination, acquisition related costs			26	27
Selling, general and administrative expenses [Member] | Williams Partners [Member] | Acquisition [Member]
Segment Reporting Information [Line Items]
Business combination, acquisition related costs				16
Selling, general and administrative expenses [Member] | Williams Partners [Member] | Transition [Member]
Segment Reporting Information [Line Items]
Business combination, integration related costs			9	15
Selling, general and administrative expenses [Member] | Other [Member] | Other Restructuring [Member]
Segment Reporting Information [Line Items]
Business combination, integration related costs			32	10
Operation and maintenance expenses [Member] | Williams Partners [Member] | Transition [Member]
Segment Reporting Information [Line Items]
Business combination, integration related costs			12	15
Interest incurred [Member] | Acquisition [Member]
Segment Reporting Information [Line Items]
Business combination, acquisition related costs				9
Interest incurred [Member] | Merger [Member]
Segment Reporting Information [Line Items]
Business combination, acquisition related costs			2
Service revenues [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Deferred Revenue, Revenue Recognized		173
Minimum volume commitment fees		58	239	167
Selling, general, and administrative expenses and Operating and maintenance expenses [Member]
Segment Reporting Information [Line Items]
Severance and other related costs		42
Other income (expense) - net [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Allowance for funds used during construction, capitalized cost of equity		89	95	44
Gain on extinguishment of debt			14
Disposal Group, Not Discontinued Operations [Member] | Canadian Operations [Member] | Other income (expense) - net [Member]
Segment Reporting Information [Line Items]
Loss on sale of Canadian operations (Note 3)		66
Disposal Group, Not Discontinued Operations [Member] | Canadian Operations [Member] | Other income (expense) - net [Member] | Williams Partners [Member]
Segment Reporting Information [Line Items]
Loss on sale of Canadian operations (Note 3)		34	0	0
Disposal Group, Not Discontinued Operations [Member] | Canadian Operations [Member] | Other income (expense) - net [Member] | Other [Member]
Segment Reporting Information [Line Items]
Loss on sale of Canadian operations (Note 3)		$ 32	$ 0	$ 0
[1]	Several factors are considered in the annual review process, including inflation rates, current estimates for removal cost, market risk premiums, discount rates, and the estimated remaining useful life of the assets. The 2016 revisions reflect changes in removal cost estimates, increases in the estimated remaining useful life of certain assets, and decreases in the inflation rate and discount rates used in the annual review process. The 2015 revisions reflect changes in removal cost estimates and the estimated remaining useful life of assets, a decrease in the inflation rate, and increases in the discount rates used in the annual review process.
[2]	Primarily relates to gains and losses incurred on foreign currency transactions and the remeasurement of U.S. dollar-denominated current assets and liabilities within our former Canadian operations (see Note 3 – Divestiture).
[3]	In November 2014, we settled a claim arising from the resolution of a contingent gain related to claims associated with the purchase of a business in a prior period. Pursuant to the settlement, we received $154 million in cash, all of which was recognized as a gain in the fourth quarter of 2014.

Provision (Benefit) for Incom59

Provision (Benefit) for Income Taxes Tax Provison (Benefit) Table (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current :
Federal	$ 0	$ 0	$ (9)
State	2	(7)	2
Foreign	(1)	(55)	10
Total	1	(62)	3
Deferred:
Federal	(6)	(317)	1,108
State	61	(25)	119
Foreign	(81)	5	19
Total	(26)	(337)	1,246
Provision (benefit) for income taxes	$ (25)	$ (399)	$ 1,249

Provision (Benefit) for Incom60

Provision (Benefit) for Income Taxes Reconciliations to Recorded Tax Provision (Benefit) Table (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Effective Income Tax Rate Reconciliation [Abstract]
Provision (benefit) at statutory rate	$ (131)	$ (600)	$ 1,255
Increases (decreases) in taxes resulting from:
Impact of nontaxable noncontrolling interests	(22)	263	(75)
State income taxes (net of federal benefit)	3	(21)	82
State deferred income tax rate change	43	0	0
Foreign operations – net (Including tax effect of Canadian Sale)	78	8	(11)
Taxes on undistributed earnings of foreign subsidiaries - net	0	0	(37)
Translation adjustment of certain unrecognized tax benefits	(1)	(71)	0
Other – net	5	22	35
Provision (benefit) for income taxes	$ (25)	$ (399)	$ 1,249

Provision (Benefit) for Incom61

Provision (Benefit) for Income Taxes Deferred Tax Table (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Deferred income tax liabilities:
Property, plant, and equipment	$ 0	$ 4
Investments	5,300	5,272
Other	29	15
Total deferred income tax liabilities	5,329	5,291
Deferred income tax assets:
Accrued liabilities	145	150
Minimum tax credits	139	139
Foreign tax credit	140	193
Federal loss carryovers	651	485
State losses and credits	313	296
Other	37	42
Total deferred income tax assets	1,425	1,305
Less valuation allowance	334	190
Net deferred income tax assets	1,091	1,115
Overall net deferred income tax liabilities	$ 4,238	$ 4,176

Provision (Benefit) for Incom62

Provision (Benefit) for Income Taxes Reconciliation of Unrecognized Tax Benefits Table (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of period	$ 55	$ 89
Additions for tax positions of prior years	0	2
Reductions for tax positions of prior years	(4)	0
Changes due to currency translation	(1)	(36)
Balance at end of period	$ 50	$ 55

Provision (Benefit) for Incom63

Provision (Benefit) for Income Taxes Textuals (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Contingency [Line Items]
Foreign income (loss) in Income from continuing operations before income taxes	$ (885,000)	$ 20,000	$ 102,000
Impairment Loss		2,700,000
Gain on remeasurement of equity-method investment (Note 2)	0	0	2,544,000
Deferred Tax Assets, Capital Loss Carryforwards	364,000
Minimum tax credits	139,000	139,000
Deferred Tax Assets, Tax Credit Carryforwards, Foreign	140,000	193,000
Employee Share-based Compensation Tax Benefit Excluded From Deferred Income Tax Assets	38,000
Cash payments for income taxes (net of refunds and including discontinued operations)	5,000	(136,000)	29,000
Unrecognized tax benefits	50,000	55,000	89,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	49,000	51,000
Total interest and penalties recognized as part of income tax provision	300	(22,000)	$ 8,000
Total interest and penalties accrued as uncertain tax positions	3,000	2,000
Unrecognized Tax Benefits Income Tax Penalties And Interest Expense Due To Currency Fluctuations [Member]
Income Tax Contingency [Line Items]
Total interest and penalties recognized as part of income tax provision		$ (35,000)
Federal [Member] | Federal Net Operating Loss And Charitable Contribution Carryforwards [Member]
Income Tax Contingency [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Domestic	$ 1,600,000

Earnings (Loss) Per Common Sh64

Earnings (Loss) Per Common Share from Continuing Operations (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Earnings (loss) per common share from continuing operations
Income (loss) from continuing operations attributable to The Williams Companies, Inc. available to common stockholders for basic and diluted earnings (loss) per common share	$ (424)		$ (571)		$ 2,110
Basic weighted-average shares	750,673		749,271		719,325
Effect of dilutive securities:
Diluted weighted-average shares	750,673	[1]	749,271	[1]	723,641
Earnings (loss) per common share from continuing operations:
Basic	$ (0.57)		$ (0.76)		$ 2.93
Diluted	$ (0.57)		$ (0.76)		$ 2.91
Nonvested restricted stock units [Member]
Effect of dilutive securities:
Incremental common shares attributable to share-based payment arrangements under effects of dilutive securities item	0		0		2,234
Earnings (loss) per common share from continuing operations (Textuals) [Abstract]
Number of weighted-average shares excluded from computation of diluted earnings per common share	600		1,700
Stock options [Member]
Effect of dilutive securities:
Incremental common shares attributable to share-based payment arrangements under effects of dilutive securities item	0		0		2,064
Earnings (loss) per common share from continuing operations (Textuals) [Abstract]
Number of weighted-average shares excluded from computation of diluted earnings per common share	500		1,500
Convertible debentures [Member]
Effect of dilutive securities:
Incremental dilutive shares, Convertible debt	0		0		18
[1]	For the years ended December 31, 2016 and December 31, 2015, 0.6 million and 1.7 million weighted-average nonvested restricted stock units, and 0.5 million and 1.5 million weighted-average stock options have been excluded from the computation of diluted earnings (loss) per common share as their inclusion would be antidilutive due to our loss from continuing operations attributable to The Williams Companies, Inc.

EBPs Obligation Rollforward (De

EBPs Obligation Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Pension Plan, Defined Benefit [Member]
Change in benefit obligation:
Benefit obligation at beginning of year	$ 1,464	$ 1,544
Service cost	54	59	$ 40
Interest cost	62	58	62
Plan participants' contributions	0	0
Benefits paid	(130)	(101)
Actuarial loss (gain)	20	(91)
Settlements	(4)	(5)
Net increase (decrease) in benefit obligation	2	(80)
Benefit obligation at end of year	1,466	1,464	1,544
Other Postretirement Benefits [Member]
Change in benefit obligation:
Benefit obligation at beginning of year	202	233
Service cost	1	2	2
Interest cost	8	9	10
Plan participants' contributions	2	2
Benefits paid	(15)	(13)
Actuarial loss (gain)	(1)	(31)
Settlements	0	0
Net increase (decrease) in benefit obligation	(5)	(31)
Benefit obligation at end of year	$ 197	$ 202	$ 233

EBP Asset rollforward and B.S.

EBP Asset rollforward and B.S. classification (Details 1) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Pension Benefits [Member]
Change in plan assets:
Fair value of plan assets at beginning of year	$ 1,241	$ 1,293
Actual return on plan assets	82	(11)
Employer contributions	65	65
Plan participants' contributions	0	0
Benefits paid	(130)	(101)
Settlements	(4)	(5)
Net increase (decrease) in fair value of plan assets	13	(52)
Fair value of plan asets at end of year	1,254	1,241
Funded status - overfunded (underfunded)	(212)	(223)
Accumulated benefit obligation	1,440	1,432
Overfunded/(underfunded) status of our pension plans and other postretirement benefit plans
Current liabilities	(2)	(2)
Noncurrent liabilities	(210)	(221)
Amounts included in accumulated other comprehensive income (loss):
Prior service credit	0	0
Net actuarial loss	(535)	(544)
Amounts included in regulatory liabilities associated with Transco and Northwest Pipeline
Net regulatory assets (liabilities)	(21)	(8)
Other Postretirement Benefits [Member]
Change in plan assets:
Fair value of plan assets at beginning of year	201	208
Actual return on plan assets	13	(1)
Employer contributions	7	5
Plan participants' contributions	2	2
Benefits paid	(15)	(13)
Settlements	0	0
Net increase (decrease) in fair value of plan assets	7	(7)
Fair value of plan asets at end of year	208	201
Funded status - overfunded (underfunded)	11	(1)
Overfunded/(underfunded) status of our pension plans and other postretirement benefit plans
Current liabilities	(7)	(7)
Noncurrent assets	18	6
Amounts included in accumulated other comprehensive income (loss):
Prior service credit	5	11
Net actuarial loss	(18)	(18)
Amounts included in regulatory liabilities associated with Transco and Northwest Pipeline
Prior service credit	10	19
Net actuarial gain (loss)	8	6
Net regulatory assets (liabilities)	$ (94)	$ (78)

EBP Net Periodic Benefit Cost &

EBP Net Periodic Benefit Cost & OCI (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Pension Benefits [Member]
Components of net periodic benefit cost:
Service cost	$ 54	$ 59	$ 40
Interest cost	62	58	62
Expected return on plan assets	(85)	(75)	(76)
Amortization of prior service cost (credit)	0	0	0
Amortization of net actuarial loss	30	42	39
Net actuarial (gain) loss from settlements and curtailments	2	2	1
Reclassification to regulatory liability	0	0	0
Net periodic benefit cost	63	86	66
Other changes in plan assets and benefit obligations recognized in other comprehensive income (loss):
Net actuarial gain (loss)	(23)	5	(142)
Prior service (cost) credit	0	0	0
Amortization of prior service cost (credit) included in net periodic benefit cost	0	0	0
Amortization of net actuarial loss	30	42	39
Loss from settlements and curtailments	2	2	1
Other changes in plan assets and benefit obligations recognized in other comprehensive income (loss)	9	49	(102)
Amounts included in accumulated other comprehensive income (loss):
Prior service cost (credit) expected to be amortized in next fiscal year	0
Net actuarial (gain) loss expected to be amortized in next fiscal year	28
Other Postretirement Benefits [Member]
Components of net periodic benefit cost:
Service cost	1	2	2
Interest cost	8	9	10
Expected return on plan assets	(12)	(12)	(12)
Amortization of prior service cost (credit)	(15)	(17)	(20)
Amortization of net actuarial loss	0	2	0
Net actuarial (gain) loss from settlements and curtailments	0	0	(1)
Reclassification to regulatory liability	4	3	4
Net periodic benefit cost	(14)	(13)	(17)
Other changes in plan assets and benefit obligations recognized in other comprehensive income (loss):
Net actuarial gain (loss)	0	8	(18)
Prior service (cost) credit	0	0	(1)
Amortization of prior service cost (credit) included in net periodic benefit cost	(6)	(6)	(8)
Amortization of net actuarial loss	0	2	0
Loss from settlements and curtailments	0	0	1
Other changes in plan assets and benefit obligations recognized in other comprehensive income (loss)	(6)	4	(26)
Other changes in plan assets and benefit obligations recognized in regulatory (assets) liabilities:
Net actuarial gain (loss) recognized in regulatory liabilities (assets)	2	10	(2)
Amortization of prior service cost (credit) from regulatory assets (liabilities)	(9)	$ (11)	$ (12)
Amounts included in accumulated other comprehensive income (loss):
Prior service cost (credit) expected to be amortized in next fiscal year	(5)
Net actuarial (gain) loss expected to be amortized in next fiscal year	0
Amounts included in regulatory liabilities associated with Transco and Northwest Pipeline
Prior service cost (credit) expected to be amortized in next fiscal year	(8)
Net actuarial (gain) loss expected to be amortized in next fiscal year	$ 0

EBP Key Assumptions (Details 3)

EBP Key Assumptions (Details 3) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Pension Benefits [Member]
Weighted average assumptions utilized to determine benefit obligations
Discount rate	4.17%	4.38%
Rate of compensation increase	4.87%	4.88%
Weighted average assumptions utilized to determine net periodic benefit cost
Discount rate	4.37%	3.96%	4.68%
Expected long-term rate of return on plan assets	6.85%	6.38%	6.85%
Rate of compensation increase	4.88%	4.62%	4.56%
Other Postretirement Benefits [Member]
Weighted average assumptions utilized to determine benefit obligations
Discount rate	4.27%	4.50%
Weighted average assumptions utilized to determine net periodic benefit cost
Discount rate	4.50%	4.12%	4.80%
Expected long-term rate of return on plan assets	6.11%	5.70%	6.11%
One percentage point change in assumed health care cost trend rates effects
Effect on total of service and interest cost components, Point increase	$ 0
Effect on total of service and interest cost components, Point decrease	0
Effect on other postretirement benefit obligation, Point increase	6
Effect on other postretirement benefit obligation, Point decrease	$ (5)
Health care cost trend rate assumed for next fiscal year	7.50%
Direction and pattern of change for assumed health care cost trend rate	decreases
Ultimate health care cost trend rate	4.50%
Year that rate reaches ultimate trend rate	2,025

EBP Plan Assets (Details 4)

EBP Plan Assets (Details 4) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Maximum percentage of total stock portfolio invested in the common stock of any one corporation	5.00%
Maximum percentage of portfolio invested in fixed income securities of any one issuer with exception of bond index funds and U. S. government guaranteed and agency securities	5.00%
Fair value, plan assets, Level 1 to Level 2 transfers, amount	$ 0	$ 0
Fair value, plan assets, Level 2 to Level 1 transfers, amount	$ 0	0
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period	30 days
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period	10 days
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value, plan assets, Level 1 to Level 2 transfers, amount	$ 0
Fair value, plan assets, Level 2 to Level 1 transfers, amount	0
Fair values of plan assets
Total assets at fair value	$ 1,254	$ 1,241	$ 1,293
Pension Benefits [Member] | Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan asset target allocation	60.00%
Pension Benefits [Member] | Fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan asset target allocation	40.00%
Weighted average duration of fixed income security portfolio	8 years	8 years
Pension Benefits [Member] | Plan assets within fair value hierarchy [Member]
Fair values of plan assets
Total assets at fair value	$ 489	$ 465
Pension Benefits [Member] | Cash management fund [Member]
Fair values of plan assets
Total assets at fair value	14	8
Pension Benefits [Member] | U.S. large cap [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value	87	83
Pension Benefits [Member] | U.S. small cap [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value	77	64
Pension Benefits [Member] | U.S. Treasury securities [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	68	65
Pension Benefits [Member] | Government and municipal bonds [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	10	8
Pension Benefits [Member] | Mortgage and asset-backed securities [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	80	87
Pension Benefits [Member] | Corporate bonds [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	148	145
Pension Benefits [Member] | Insurance company investment contracts and other [Member]
Fair values of plan assets
Total assets at fair value	5	5
Pension Benefits [Member] | Equities - U.S. large cap [Member] | Commingled investment funds - equities [Member]
Fair values of plan assets
Total assets at fair value	369	367
Pension Benefits [Member] | Equities - International small cap [Member] | Commingled investment funds - equities [Member]
Fair values of plan assets
Total assets at fair value	27	27
Pension Benefits [Member] | Equities - International emerging markets [Member] | Commingled investment funds - equities [Member]
Fair values of plan assets
Total assets at fair value	50	50
Pension Benefits [Member] | Equities - International developed markets [Member] | Commingled investment funds - equities [Member]
Fair values of plan assets
Total assets at fair value	149	153
Pension Benefits [Member] | Fixed income - U.S. long duration [Member] | Commingled investment funds - fixed income [Member]
Fair values of plan assets
Total assets at fair value	88	95
Pension Benefits [Member] | Fixed income - Corporate bonds [Member] | Commingled investment funds - fixed income [Member]
Fair values of plan assets
Total assets at fair value	82	84
Pension Benefits [Member] | Level 1 [Member]
Fair values of plan assets
Total assets at fair value	246	220
Pension Benefits [Member] | Level 1 [Member] | Cash management fund [Member]
Fair values of plan assets
Total assets at fair value	14	8
Pension Benefits [Member] | Level 1 [Member] | U.S. large cap [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value	87	83
Pension Benefits [Member] | Level 1 [Member] | U.S. small cap [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value	77	64
Pension Benefits [Member] | Level 1 [Member] | U.S. Treasury securities [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	68	65
Pension Benefits [Member] | Level 1 [Member] | Government and municipal bonds [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Pension Benefits [Member] | Level 1 [Member] | Mortgage and asset-backed securities [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Pension Benefits [Member] | Level 1 [Member] | Corporate bonds [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Pension Benefits [Member] | Level 1 [Member] | Insurance company investment contracts and other [Member]
Fair values of plan assets
Total assets at fair value	0	0
Pension Benefits [Member] | Level 2 [Member]
Fair values of plan assets
Total assets at fair value	243	245
Pension Benefits [Member] | Level 2 [Member] | Cash management fund [Member]
Fair values of plan assets
Total assets at fair value	0	0
Pension Benefits [Member] | Level 2 [Member] | U.S. large cap [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Pension Benefits [Member] | Level 2 [Member] | U.S. small cap [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Pension Benefits [Member] | Level 2 [Member] | U.S. Treasury securities [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Pension Benefits [Member] | Level 2 [Member] | Government and municipal bonds [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	10	8
Pension Benefits [Member] | Level 2 [Member] | Mortgage and asset-backed securities [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	80	87
Pension Benefits [Member] | Level 2 [Member] | Corporate bonds [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	148	145
Pension Benefits [Member] | Level 2 [Member] | Insurance company investment contracts and other [Member]
Fair values of plan assets
Total assets at fair value	5	5
Pension Benefits [Member] | Level 3 [Member]
Fair values of plan assets
Total assets at fair value	0	0
Pension Benefits [Member] | Level 3 [Member] | Cash management fund [Member]
Fair values of plan assets
Total assets at fair value	0	0
Pension Benefits [Member] | Level 3 [Member] | U.S. large cap [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Pension Benefits [Member] | Level 3 [Member] | U.S. small cap [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Pension Benefits [Member] | Level 3 [Member] | U.S. Treasury securities [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Pension Benefits [Member] | Level 3 [Member] | Government and municipal bonds [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Pension Benefits [Member] | Level 3 [Member] | Mortgage and asset-backed securities [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Pension Benefits [Member] | Level 3 [Member] | Corporate bonds [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Pension Benefits [Member] | Level 3 [Member] | Insurance company investment contracts and other [Member]
Fair values of plan assets
Total assets at fair value	$ 0	0
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Proportion of assets subjected to income tax	38.00%
Fair values of plan assets
Total assets at fair value	$ 208	$ 201	$ 208
Other Postretirement Benefits [Member] | Fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Weighted average duration of fixed income security portfolio	8 years	7 years
Other Postretirement Benefits [Member] | Plan assets within fair value hierarchy [Member]
Fair values of plan assets
Total assets at fair value	$ 128	$ 122
Other Postretirement Benefits [Member] | Cash management fund [Member]
Fair values of plan assets
Total assets at fair value	11	11
Other Postretirement Benefits [Member] | U.S. large cap [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value	24	37
Other Postretirement Benefits [Member] | U.S. small cap [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value	15	20
Other Postretirement Benefits [Member] | International developed markets large cap growth [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value	5	10
Other Postretirement Benefits [Member] | Emerging markets growth [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value		1
Other Postretirement Benefits [Member] | U.S. Treasury securities [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	7	7
Other Postretirement Benefits [Member] | Government and municipal bonds [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	1	12
Other Postretirement Benefits [Member] | Mortgage and asset-backed securities [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	8	9
Other Postretirement Benefits [Member] | Corporate bonds [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	15	15
Other Postretirement Benefits [Member] | Equities - U.S. large cap [Member] | Commingled investment funds - equities [Member]
Fair values of plan assets
Total assets at fair value	38	37
Other Postretirement Benefits [Member] | Equities - International small cap [Member] | Commingled investment funds - equities [Member]
Fair values of plan assets
Total assets at fair value	3	3
Other Postretirement Benefits [Member] | Equities - International emerging markets [Member] | Commingled investment funds - equities [Member]
Fair values of plan assets
Total assets at fair value	5	5
Other Postretirement Benefits [Member] | Equities - International developed markets [Member] | Commingled investment funds - equities [Member]
Fair values of plan assets
Total assets at fair value	16	16
Other Postretirement Benefits [Member] | Fixed income - U.S. long duration [Member] | Commingled investment funds - fixed income [Member]
Fair values of plan assets
Total assets at fair value	9	10
Other Postretirement Benefits [Member] | Fixed income - Corporate bonds [Member] | Commingled investment funds - fixed income [Member]
Fair values of plan assets
Total assets at fair value	9	8
Other Postretirement Benefits [Member] | Mutual fund - Municipal bonds [Member]
Fair values of plan assets
Total assets at fair value	42
Other Postretirement Benefits [Member] | Level 1 [Member]
Fair values of plan assets
Total assets at fair value	99	76
Other Postretirement Benefits [Member] | Level 1 [Member] | Cash management fund [Member]
Fair values of plan assets
Total assets at fair value	11	11
Other Postretirement Benefits [Member] | Level 1 [Member] | U.S. large cap [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value	24	37
Other Postretirement Benefits [Member] | Level 1 [Member] | U.S. small cap [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value	15	20
Other Postretirement Benefits [Member] | Level 1 [Member] | International developed markets large cap growth [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value	0	1
Other Postretirement Benefits [Member] | Level 1 [Member] | Emerging markets growth [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value		0
Other Postretirement Benefits [Member] | Level 1 [Member] | U.S. Treasury securities [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	7	7
Other Postretirement Benefits [Member] | Level 1 [Member] | Government and municipal bonds [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Other Postretirement Benefits [Member] | Level 1 [Member] | Mortgage and asset-backed securities [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Other Postretirement Benefits [Member] | Level 1 [Member] | Corporate bonds [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Other Postretirement Benefits [Member] | Level 1 [Member] | Mutual fund - Municipal bonds [Member]
Fair values of plan assets
Total assets at fair value	42
Other Postretirement Benefits [Member] | Level 2 [Member]
Fair values of plan assets
Total assets at fair value	29	46
Other Postretirement Benefits [Member] | Level 2 [Member] | Cash management fund [Member]
Fair values of plan assets
Total assets at fair value	0	0
Other Postretirement Benefits [Member] | Level 2 [Member] | U.S. large cap [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Other Postretirement Benefits [Member] | Level 2 [Member] | U.S. small cap [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Other Postretirement Benefits [Member] | Level 2 [Member] | International developed markets large cap growth [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value	5	9
Other Postretirement Benefits [Member] | Level 2 [Member] | Emerging markets growth [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value		1
Other Postretirement Benefits [Member] | Level 2 [Member] | U.S. Treasury securities [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Other Postretirement Benefits [Member] | Level 2 [Member] | Government and municipal bonds [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	1	12
Other Postretirement Benefits [Member] | Level 2 [Member] | Mortgage and asset-backed securities [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	8	9
Other Postretirement Benefits [Member] | Level 2 [Member] | Corporate bonds [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	15	15
Other Postretirement Benefits [Member] | Level 2 [Member] | Mutual fund - Municipal bonds [Member]
Fair values of plan assets
Total assets at fair value	0
Other Postretirement Benefits [Member] | Level 3 [Member]
Fair values of plan assets
Total assets at fair value	0	0
Other Postretirement Benefits [Member] | Level 3 [Member] | Cash management fund [Member]
Fair values of plan assets
Total assets at fair value	0	0
Other Postretirement Benefits [Member] | Level 3 [Member] | U.S. large cap [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Other Postretirement Benefits [Member] | Level 3 [Member] | U.S. small cap [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Other Postretirement Benefits [Member] | Level 3 [Member] | International developed markets large cap growth [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Other Postretirement Benefits [Member] | Level 3 [Member] | Emerging markets growth [Member] | Equity securities [Member]
Fair values of plan assets
Total assets at fair value		0
Other Postretirement Benefits [Member] | Level 3 [Member] | U.S. Treasury securities [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Other Postretirement Benefits [Member] | Level 3 [Member] | Government and municipal bonds [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Other Postretirement Benefits [Member] | Level 3 [Member] | Mortgage and asset-backed securities [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	0	0
Other Postretirement Benefits [Member] | Level 3 [Member] | Corporate bonds [Member] | Fixed income securities [Member]
Fair values of plan assets
Total assets at fair value	0	$ 0
Other Postretirement Benefits [Member] | Level 3 [Member] | Mutual fund - Municipal bonds [Member]
Fair values of plan assets
Total assets at fair value	$ 0

EBP Benefit Pymts & Defined Con

EBP Benefit Pymts & Defined Contribution Plans (Details 5) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Benefit Plan Disclosure [Line Items]
Employer's contributions charged to expense under defined contribution plans	$ 36	$ 39	$ 39
Other Postretirement Benefits [Member]
Benefit Plan Disclosure [Line Items]
Expected total plans contribution, approximate	7
Expected benefit payments
2,017	13
2,018	13
2,019	13
2,020	13
2,021	13
2022-2026	62
Pension Benefits [Member]
Benefit Plan Disclosure [Line Items]
Expected total plans contribution, approximate	62
Expected benefit payments
2,017	99
2,018	103
2,019	103
2,020	106
2,021	111
2022-2026	562
Nonqualified Pension Benefits - Supplemental Employee Retirement Benefits [Member]
Benefit Plan Disclosure [Line Items]
Expected total plans contribution, approximate	2
Tax-qualified Pension Benefits [Member]
Benefit Plan Disclosure [Line Items]
Expected total plans contribution, approximate	$ 60

Property, Plant, and Equipmen71

Property, Plant, and Equipment (Details PPE) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant, and Equipment
Property, plant, and equipment, at cost		$ 38,912	$ 39,039
Accumulated depreciation and amortization		(10,484)	(9,460)
Property, plant, and equipment - net		28,428	29,579
Depreciation and amortization expenses		1,407	1,382	$ 967
Nonregulated [Member] | Natural gas gathering and processing facilities [Member]
Property, Plant, and Equipment
Property, plant, and equipment, at cost		$ 20,413	20,789
Nonregulated [Member] | Natural gas gathering and processing facilities [Member] | Minimum [Member]
Property, Plant, and Equipment
Property, Plant and Equipment, Useful Life	[1]	5 years
Nonregulated [Member] | Natural gas gathering and processing facilities [Member] | Maximum [Member]
Property, Plant, and Equipment
Property, Plant and Equipment, Useful Life	[1]	40 years
Nonregulated [Member] | Construction in Progress [Member]
Property, Plant, and Equipment
Property, plant, and equipment, at cost		$ 412	1,366
Nonregulated [Member] | Other Capitalized Property Plant and Equipment [Member]
Property, Plant, and Equipment
Property, plant, and equipment, at cost		$ 2,202	2,170
Nonregulated [Member] | Other Capitalized Property Plant and Equipment [Member] | Minimum [Member]
Property, Plant, and Equipment
Property, Plant and Equipment, Useful Life	[1]	2 years
Nonregulated [Member] | Other Capitalized Property Plant and Equipment [Member] | Maximum [Member]
Property, Plant, and Equipment
Property, Plant and Equipment, Useful Life	[1]	45 years
Regulated [Member] | Natural gas transmission facilities [Member]
Property, Plant, and Equipment
Property, plant, and equipment, at cost		$ 12,692	12,189
Regulated [Member] | Natural gas transmission facilities [Member] | Minimum [Member]
Property, Plant, and Equipment
Property, Plant, and Equipment, Depreciation Rate	[1]	1.20%
Regulated [Member] | Natural gas transmission facilities [Member] | Maximum [Member]
Property, Plant, and Equipment
Property, Plant, and Equipment, Depreciation Rate	[1]	6.97%
Regulated [Member] | Construction in Progress [Member]
Property, Plant, and Equipment
Property, plant, and equipment, at cost		$ 1,603	941
Regulated [Member] | Other Capitalized Property Plant and Equipment [Member]
Property, Plant, and Equipment
Property, plant, and equipment, at cost		$ 1,590	1,584
Regulated [Member] | Other Capitalized Property Plant and Equipment [Member] | Minimum [Member]
Property, Plant, and Equipment
Property, Plant and Equipment, Useful Life	[1]	5 years
Property, Plant, and Equipment, Depreciation Rate	[1]	1.35%
Regulated [Member] | Other Capitalized Property Plant and Equipment [Member] | Maximum [Member]
Property, Plant, and Equipment
Property, Plant and Equipment, Useful Life	[1]	45 years
Property, Plant, and Equipment, Depreciation Rate	[1]	33.33%
Regulated [Member] | Acquisition Adjustment Of Regulated Facilities [Member]
Property, Plant, and Equipment
Property, Plant and Equipment, Plant Acquisition Adjustments for Intangible Utility Plants		$ 665	$ 706
Period of straight-line amortization		40 years
[1]	Estimated useful life and depreciation rates are presented as of December 31, 2016. Depreciation rates and estimated useful lives for regulated assets are prescribed by the FERC.

Property, Plant, and Equipmen72

Property, Plant, and Equipment (Details ARO) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015
Asset Retirement Obligations
Asset Retirement Obligations, Noncurrent		$ 801	$ 858
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning balance		915	831
Liabilities incurred		24	42
Liabilities settled		(8)	(3)
Accretion expense		69	60
Revisions (1)	[1]	(138)	(15)
Ending balance		862	$ 915
Asset Retirement Obligation Costs [Member]
Unusual or Infrequent Item [Line Items]
Transco's annual funding commitment for ARO		$ 36
[1]	Several factors are considered in the annual review process, including inflation rates, current estimates for removal cost, market risk premiums, discount rates, and the estimated remaining useful life of the assets. The 2016 revisions reflect changes in removal cost estimates, increases in the estimated remaining useful life of certain assets, and decreases in the inflation rate and discount rates used in the annual review process. The 2015 revisions reflect changes in removal cost estimates and the estimated remaining useful life of assets, a decrease in the inflation rate, and increases in the discount rates used in the annual review process.

Goodwill (Details)

Goodwill (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Goodwill [Line Items]
Impairment of goodwill	$ (1,098)	$ 0	$ (1,098)	$ 0
Williams Partners [Member]
Goodwill [Line Items]
Goodwill	$ 47	$ 47	47	$ 1,120
Goodwill, purchase accounting adjustments			25
Impairment of goodwill			$ (1,098)

Other Intangible Assets (Detail

Other Intangible Assets (Details) - USD ($) $ in Millions	1 Months Ended	6 Months Ended	12 Months Ended
	May 31, 2015	Jul. 02, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets			$ 356	$ 353	$ 209
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months			356
Finite-Lived Intangible Assets, Amortization Expense, Year Two			356
Finite-Lived Intangible Assets, Amortization Expense, Year Three			356
Finite-Lived Intangible Assets, Amortization Expense, Year Four			356
Finite-Lived Intangible Assets, Amortization Expense, Year Five			356
Contractual customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross			10,635	10,633
Finite-Lived Intangible Assets, Accumulated Amortization			$ (1,019)	$ (663)
Access Midstream Partners Acquisition [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		30 years
Acquired Finite-lived Intangible Asset, Weighted-Average Period before Renewal or Extension		17 years
Eagle Ford Gathering System [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	30 years
Acquired Finite-lived Intangible Asset, Weighted-Average Period before Renewal or Extension	10 years

Accrued Liabilities Table (Deta

Accrued Liabilities Table (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Accrued Liabilities, Current [Abstract]
Deferred income	$ 338	$ 94
Interest on debt	310	284
Employee costs	223	215
Refundable deposits	160	0
Special distribution repayable to Gulfstream (See Note 6 - Investing Activities)	0	149
Asset retirement obligations	61	57
Other, including other loss contingencies	356	279
Other accrued liabilities	$ 1,448	$ 1,078

Accrued Liabilities Accrued Lia

Accrued Liabilities Accrued Liabilities Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)
Accrued Liabilities, Current [Abstract]
Refundable deposits, contracted	$ 240
Refundable deposits, proceeds	$ 160

Long-Term Debt (Details)

Long-Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2016		Jun. 15, 2016	Apr. 15, 2016	Jan. 22, 2016	Dec. 31, 2015		Apr. 15, 2015	Mar. 03, 2015
Long-term Debt
Capital lease obligations	$ 0					$ 1
Debt issuance costs	(119)					(123)
Net unamortized debt premium (discount)	88					110
Total long-term debt, including current portion	23,409					23,988
Long-term debt due within one year	(785)					(176)
Long-term debt	22,624					23,812
Transcontinental Gas Pipe Line Company, LLC [Member] | 6.4% Senior Unsecured Notes due 2016 [Member]
Long-term Debt
Long-term debt	0					$ 200	[1]
Long-term debt interest rate				6.40%		6.40%
Transcontinental Gas Pipe Line Company, LLC [Member] | 6.05% Senior Unsecured Notes due 2018 [Member]
Long-term Debt
Long-term debt	$ 250					$ 250
Long-term debt interest rate	6.05%
Transcontinental Gas Pipe Line Company, LLC [Member] | 7.08% Debentures due 2026 [Member]
Long-term Debt
Long-term debt	$ 8					8
Long-term debt interest rate	7.08%
Transcontinental Gas Pipe Line Company, LLC [Member] | 7.25% Debentures due 2026 [Member]
Long-term Debt
Long-term debt	$ 200					200
Long-term debt interest rate	7.25%
Transcontinental Gas Pipe Line Company, LLC [Member] | 7.85% Senior Unsecured Notes Due 2026 [Member]
Long-term Debt
Long-term debt	$ 1,000					0
Long-term debt interest rate	7.85%				7.85%
Transcontinental Gas Pipe Line Company, LLC [Member] | 5.4% Senior Unsecured Notes due 2041 [Member]
Long-term Debt
Long-term debt	$ 375					375
Long-term debt interest rate	5.40%
Transcontinental Gas Pipe Line Company, LLC [Member] | 4.45% Senior Unsecured Notes due 2042 [Member]
Long-term Debt
Long-term debt	$ 400					400
Long-term debt interest rate	4.45%
Northwest Pipeline LLC [Member] | 7% Senior Unsecured Notes due 2016 [Member]
Long-term Debt
Long-term debt	$ 0					$ 175
Long-term debt interest rate			7.00%			7.00%
Northwest Pipeline LLC [Member] | 5.95% Senior Unsecured Notes due 2017 [Member]
Long-term Debt
Long-term debt	$ 185					$ 185
Long-term debt interest rate	5.95%
Northwest Pipeline LLC [Member] | 6.05% Senior Unsecured Notes due 2018 [Member]
Long-term Debt
Long-term debt	$ 250					250
Long-term debt interest rate	6.05%
Northwest Pipeline LLC [Member] | 7.125% Debentures due 2025 [Member]
Long-term Debt
Long-term debt	$ 85					85
Long-term debt interest rate	7.125%
Williams Partners L.P. [Member]
Long-term Debt
Credit facility loans	$ 0	[2]				1,310
Williams Partners L.P. [Member] | 7.25% Senior Unsecured Notes due 2017 [Member]
Long-term Debt
Long-term debt	$ 600					600
Long-term debt interest rate	7.25%
Williams Partners L.P. [Member] | 5.25% Senior Unsecured Notes due 2020 [Member]
Long-term Debt
Long-term debt	$ 1,500					1,500
Long-term debt interest rate	5.25%
Williams Partners L.P. [Member] | 4.125% Senior Unsecured Notes due 2020 [Member]
Long-term Debt
Long-term debt	$ 600					600
Long-term debt interest rate	4.125%
Williams Partners L.P. [Member] | 4% Senior Unsecured Notes due 2021 [Member]
Long-term Debt
Long-term debt	$ 500					500
Long-term debt interest rate	4.00%
Williams Partners L.P. [Member] | 3.6% Senior Unsecured Notes due 2022 [Member]
Long-term Debt
Long-term debt	$ 1,250					1,250
Long-term debt interest rate	3.60%								3.60%
Williams Partners L.P. [Member] | 5.875% Senior Unsecured Notes due 2021 [Member]
Long-term Debt
Long-term debt interest rate								5.875%
Williams Partners L.P. [Member] | 3.35% Senior Unsecured Notes due 2022 [Member]
Long-term Debt
Long-term debt	$ 750					750
Long-term debt interest rate	3.35%
Williams Partners L.P. [Member] | 6.125% Senior Unsecured Notes due 2022 [Member]
Long-term Debt
Long-term debt	$ 750					750
Long-term debt interest rate	6.125%
Williams Partners L.P. [Member] | 4.5% Senior Unsecured Notes due 2023 [Member]
Long-term Debt
Long-term debt	$ 600					600
Long-term debt interest rate	4.50%
Williams Partners L.P. [Member] | 4.875% Senior Unsecured Notes due 2023 [Member]
Long-term Debt
Long-term debt	$ 1,400					1,400
Long-term debt interest rate	4.875%
Williams Partners L.P. [Member] | 4.3% Senior Unsecured Notes Due 2024 [Member]
Long-term Debt
Long-term debt	$ 1,000					1,000
Long-term debt interest rate	4.30%
Williams Partners L.P. [Member] | 4.875% Senior Unsecured Notes due 2024 [Member]
Long-term Debt
Long-term debt	$ 750					750
Long-term debt interest rate	4.875%
Williams Partners L.P. [Member] | 3.9% Senior Unsecured Notes due 2025 [Member]
Long-term Debt
Long-term debt	$ 750					750
Long-term debt interest rate	3.90%
Williams Partners L.P. [Member] | 4% Senior Unsecured Notes due 2025 [Member]
Long-term Debt
Long-term debt	$ 750					750
Long-term debt interest rate	4.00%								4.00%
Williams Partners L.P. [Member] | 6.3% Senior Unsecured Notes due 2040 [Member]
Long-term Debt
Long-term debt	$ 1,250					1,250
Long-term debt interest rate	6.30%
Williams Partners L.P. [Member] | 5.8% Senior Unsecured Notes due 2043 [Member]
Long-term Debt
Long-term debt	$ 400					400
Long-term debt interest rate	5.80%
Williams Partners L.P. [Member] | 5.4% Senior Unsecured Notes Due 2044 [Member]
Long-term Debt
Long-term debt	$ 500					500
Long-term debt interest rate	5.40%
Williams Partners L.P. [Member] | 4.9% Senior Unsecured Notes due 2045 [Member]
Long-term Debt
Long-term debt	$ 500					500
Long-term debt interest rate	4.90%
Williams Partners L.P. [Member] | 5.1% Senior Unsecured Notes due 2045 [Member]
Long-term Debt
Long-term debt	$ 1,000					1,000
Long-term debt interest rate	5.10%								5.10%
Williams Partners L.P. [Member] | Variable Interest Term Loan due 2018 [Member]
Long-term Debt
Long-term debt	$ 850					850
Long-term debt interest rate	2.50%
The Williams Companies, Inc. [Member]
Long-term Debt
Credit facility loans	$ 775					650
The Williams Companies, Inc. [Member] | 7.875% Senior Unsecured Notes due 2021 [Member]
Long-term Debt
Long-term debt	$ 371					371
Long-term debt interest rate	7.875%
The Williams Companies, Inc. [Member] | 3.7% Senior Unsecured Notes due 2023 [Member]
Long-term Debt
Long-term debt	$ 850					850
Long-term debt interest rate	3.70%
The Williams Companies, Inc. [Member] | 4.55% Senior Unsecured Notes due 2024 [Member]
Long-term Debt
Long-term debt	$ 1,250					1,250
Long-term debt interest rate	4.55%
The Williams Companies, Inc. [Member] | 7.5% Debentures due 2031 [Member]
Long-term Debt
Long-term debt	$ 339					339
Long-term debt interest rate	7.50%
The Williams Companies, Inc. [Member] | 7.75% Senior Unsecured Notes due 2031 [Member]
Long-term Debt
Long-term debt	$ 252					252
Long-term debt interest rate	7.75%
The Williams Companies, Inc. [Member] | 8.75% Senior Unsecured Notes due 2032 [Member]
Long-term Debt
Long-term debt	$ 445					445
Long-term debt interest rate	8.75%
The Williams Companies, Inc. [Member] | 5.75% Senior Unsecured Notes due 2044 [Member]
Long-term Debt
Long-term debt	$ 650					650
Long-term debt interest rate	5.75%
The Williams Companies, Inc. [Member] | Various - 5.5% to 10.25% Senior Unsecured Notes and Debentures due 2019 to 2033 [Member]
Long-term Debt
Long-term debt	$ 55					$ 55
The Williams Companies, Inc. [Member] | Various - 5.5% to 10.25% Senior Unsecured Notes and Debentures due 2019 to 2033 Minimum Interest Rate [Member]
Long-term Debt
Long-term debt interest rate	5.50%
The Williams Companies, Inc. [Member] | Various - 5.5% to 10.25% Senior Unsecured Notes and Debentures due 2019 to 2033 Maximum Interest Rate [Member]
Long-term Debt
Long-term debt interest rate	10.25%
[1]	Presented as long-term debt at December 31, 2015, due to Transco’s intent and ability to refinance.
[2]	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.

Long-Term Debt Maturities (Deta

Long-Term Debt Maturities (Details) $ in Millions	Dec. 31, 2016USD ($)
Aggregate minimum maturities of long-term debt
2,017	$ 785
2,018	1,350
2,019	32
2,020	2,896
2,021	$ 871

Long-Term Debt Issuances and Re

Long-Term Debt Issuances and Retirements (Details) - USD ($) $ in Millions

Feb. 23, 2017

Feb. 01, 2017

Jun. 15, 2016

Apr. 15, 2016

Apr. 15, 2015

Feb. 15, 2015

Jan. 25, 2017

Dec. 31, 2016

Dec. 31, 2015

Dec. 31, 2014

Jan. 22, 2016

Dec. 23, 2015

Mar. 03, 2015

Debt Instrument [Line Items]

Repayments of Long-term Debt

$ 7,091

$ 6,516

$ 1,828

The Williams Companies, Inc. [Member] | 4.55% Senior Unsecured Notes due 2024 [Member]

Debt Instrument [Line Items]

Long-term debt interest rate

4.55%

The Williams Companies, Inc. [Member] | 5.75% Senior Unsecured Notes due 2044 [Member]

Debt Instrument [Line Items]

Long-term debt interest rate

5.75%

Williams Partners L.P. [Member] | Variable interest Rate [Member]

Debt Instrument [Line Items]

Long-term debt face amount

$ 850

Long-term debt interest rate

2.50%

Williams Partners L.P. [Member] | 3.8% Senior Unsecured Notes due 2015 [Member]

Debt Instrument [Line Items]

Long-term debt retired

$ 750

Long-term debt interest rate

3.80%

Williams Partners L.P. [Member] | 3.9% Senior Unsecured Notes due 2025 [Member]

Debt Instrument [Line Items]

Long-term debt interest rate

3.90%

Williams Partners L.P. [Member] | 4.9% Senior Unsecured Notes due 2045 [Member]

Debt Instrument [Line Items]

Long-term debt interest rate

4.90%

Williams Partners L.P. [Member] | 4.3% Senior Unsecured Notes Due 2024 [Member]

Debt Instrument [Line Items]

Long-term debt interest rate

4.30%

Williams Partners L.P. [Member] | 5.4% Senior Unsecured Notes Due 2044 [Member]

Debt Instrument [Line Items]

Long-term debt interest rate

5.40%

Williams Partners L.P. [Member] | 4.5% Senior Unsecured Notes due 2023 [Member]

Debt Instrument [Line Items]

Long-term debt interest rate

4.50%

Williams Partners L.P. [Member] | 5.8% Senior Unsecured Notes due 2043 [Member]

Debt Instrument [Line Items]

Long-term debt interest rate

5.80%

Williams Partners L.P. [Member] | 5.875% Senior Unsecured Notes due 2021 [Member]

Debt Instrument [Line Items]

Long-term debt retired

$ 750

Long-term debt interest rate

5.875%

Long-term Debt, Current Maturities

$ 797

Repayments of Long-term Debt

$ 783

Williams Partners L.P. [Member] | 3.6% Senior Unsecured Notes due 2022 [Member]

Debt Instrument [Line Items]

Long-term debt face amount

$ 1,250

Long-term debt interest rate

3.60%

3.60%

Williams Partners L.P. [Member] | 4% Senior Unsecured Notes due 2025 [Member]

Debt Instrument [Line Items]

Long-term debt face amount

$ 750

Long-term debt interest rate

4.00%

4.00%

Williams Partners L.P. [Member] | 5.1% Senior Unsecured Notes due 2045 [Member]

Debt Instrument [Line Items]

Long-term debt face amount

$ 1,000

Long-term debt interest rate

5.10%

5.10%

Williams Partners L.P. [Member] | 6.125% Senior Unsecured Notes due 2022 [Member]

Debt Instrument [Line Items]

Long-term debt interest rate

6.125%

Williams Partners L.P. [Member] | 6.125% Senior Unsecured Notes due 2022 [Member] | Subsequent Event [Member]

Debt Instrument [Line Items]

Long-term debt retired

$ 750

$ 750

Long-term debt interest rate

6.125%

6.125%

Williams Partners L.P. [Member] | 7.25% Senior Unsecured Notes due 2017 [Member]

Debt Instrument [Line Items]

Long-term debt interest rate

7.25%

Williams Partners L.P. [Member] | 7.25% Senior Unsecured Notes due 2017 [Member] | Subsequent Event [Member]

Debt Instrument [Line Items]

Long-term debt retired

$ 600

Long-term debt interest rate

7.25%

Northwest Pipeline LLC [Member] | 7% Senior Unsecured Notes due 2016 [Member]

Debt Instrument [Line Items]

Long-term debt retired

$ 175

Long-term debt interest rate

7.00%

7.00%

Transcontinental Gas Pipe Line Company, LLC [Member] | 7.85% Senior Unsecured Notes Due 2026 [Member]

Debt Instrument [Line Items]

Long-term debt face amount

$ 1,000

Long-term debt interest rate

7.85%

7.85%

Transcontinental Gas Pipe Line Company, LLC [Member] | 6.4% Senior Unsecured Notes due 2016 [Member]

Debt Instrument [Line Items]

Long-term debt retired

$ 200

Long-term debt interest rate

6.40%

6.40%

Credit Facilities and Commercia

Credit Facilities and Commercial Paper (Details) $ in Millions	Dec. 18, 2015	Feb. 02, 2015USD ($)	Dec. 31, 2016USD ($)		May 24, 2017USD ($)	Feb. 20, 2017USD ($)	Dec. 31, 2015USD ($)	Dec. 23, 2015USD ($)	Aug. 26, 2015USD ($)
Credit Facility and Commercial Paper [Line Items]
Commercial paper, outstanding			$ 93				$ 499
Williams Companies, Inc. [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity		$ 1,500	1,500
Credit facility, loans outstanding			775				650
Additional amount by which credit facility can be increased		$ 500
Maximum ratio of debt to EBITDA		5
Maximum ratio of debt to EBITDA after acquisition		5.5
Williams Companies, Inc. [Member] | Subsequent Event [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, loans outstanding					$ 175	$ 235
Williams Companies, Inc. [Member] | Swingline Loan [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity		$ 50
Williams Companies, Inc. [Member] | Letters of credit [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity		675
Williams Companies, Inc. [Member] | Letters Of Credit Under Certain Bilateral Bank Agreements [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, letters of credit outstanding			13
Williams Partners L.P. [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity		3,500	3,500	[1]
Credit facility, loans outstanding			0	[1]			1,310
Additional amount by which credit facility can be increased		500
Williams Partners L.P. [Member] | Subsequent Event [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, loans outstanding						$ 0
Williams Partners L.P. [Member] | Rate addition to federal funds effective rate [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, basis spread on variable rate	0.50%
Williams Partners L.P. [Member] | Rate addition to London interbank offered rate (LIBOR) [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, basis spread on variable rate	1.00%
Williams Partners L.P. [Member] | Swingline Loan [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity		150
Williams Partners L.P. [Member] | Commercial paper [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity		3,000
Commercial paper, outstanding			$ 93				$ 499
Commercial paper, weighted average interest rate			1.06%				0.92%
Commercial paper, maximum maturity			397 days
Williams Partners L.P. [Member] | Commercial paper [Member] | Subsequent Event [Member]
Credit Facility and Commercial Paper [Line Items]
Commercial paper, outstanding					$ 0
Williams Partners L.P. [Member] | Letters of credit [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity		1,125
Williams Partners L.P. [Member] | Letters Of Credit Under Certain Bilateral Bank Agreements [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, letters of credit outstanding			$ 1
Williams Partners L.P. [Member] | Short-term facility [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity								$ 150	$ 1,000
Transcontinental Gas Pipe Line Company, LLC [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity		500
Maximum ratio of debt to capitalization	65.00%
Northwest Pipeline LLC [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity		$ 500
Maximum ratio of debt to capitalization	65.00%
Acquisition [Member] | Williams Partners L.P. [Member]
Credit Facility and Commercial Paper [Line Items]
Maximum ratio of debt to EBITDA	5.5
Mar 2017 & Subsequent Quarters [Member] | Williams Partners L.P. [Member]
Credit Facility and Commercial Paper [Line Items]
Maximum ratio of debt to EBITDA	5
Sep & Dec 2016 [Member] | Williams Partners L.P. [Member]
Credit Facility and Commercial Paper [Line Items]
Maximum ratio of debt to EBITDA	5.50
Dec 2015, Mar & Jun 2016 [Member] | Williams Partners L.P. [Member]
Credit Facility and Commercial Paper [Line Items]
Maximum ratio of debt to EBITDA	5.75
Variable Interest Term Loan due 2018 [Member] | Williams Partners L.P. [Member]
Credit Facility and Commercial Paper [Line Items]
Debt Instrument, Face Amount								$ 850
[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.

Cash Payments For Interest (Net

Cash Payments For Interest (Net of Amounts Capitalized) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Debt Disclosure [Abstract]
Cash payments for interest (net of amounts capitalized)	$ 1,152	$ 1,023	$ 681

Restricted Net Assets of Subsid

Restricted Net Assets of Subsidiaries (Details) $ in Billions	Dec. 31, 2016USD ($)
Debt Disclosure [Abstract]
Amount of restricted net assets for consolidated and unconsolidated subsidiaries	$ 13
Restricted net assets threshold	25.00%

Leases-Lessee (Details)

Leases-Lessee (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Future minimum annual rentals under noncancelable operating leases
2,017	$ 62
2,018	58
2,019	51
2,020	46
2,021	35
Thereafter	90
Total	342
Operating leases [Abstract]
Total rent expense	$ 64	$ 69	$ 62

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	May 18, 2017	Feb. 20, 2017	Feb. 01, 2017	Jun. 23, 2014	Jan. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jan. 13, 2017
Stockholders' Equity (Textuals) [Abstract]
Common Stock, Dividends, Per Share, Declared						$ 1.6800	$ 2.45	$ 1.9575
Stock Issued During Period, Shares, New Issues				61,000
Equity Issuance, Per Share Amount				$ 57
Common Units Sold In Offering				8,000
Proceeds from Issuance of Common Stock				$ 3,378		$ 9	$ 27	$ 3,416
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance					$ (339)	(442)
Other comprehensive income (loss)						172	(171)	(176)
Total, Ending Balance						(339)	(442)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance					(339)	(442)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax						12
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax						91
Other comprehensive income (loss)						103	(101)	$ (157)
Total, Ending Balance						(339)	(442)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance					0	(1)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax						2
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax						(1)
Other comprehensive income (loss)						1
Total, Ending Balance						0	(1)
Foreign currency translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance					(2)	(103)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax						25
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax						76
Other comprehensive income (loss)						101
Total, Ending Balance						(2)	(103)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance					$ (337)	(338)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax						(15)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax						16
Other comprehensive income (loss)						1
Total, Ending Balance						$ (337)	$ (338)
Subsequent Event [Member]
Stockholders' Equity (Textuals) [Abstract]
Common Stock, Dividends, Per Share, Declared	$ 0.30	$ 0.30
Stock Issued During Period, Shares, New Issues			9,750		65,000
Equity Issuance, Per Share Amount									$ 29
Proceeds from Issuance of Common Stock			$ 2,100

Stockholders' Equity Stockholde

Stockholders' Equity Stockholders' Equity Reclassifications from AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Product sales	$ 2,328	$ 2,196	$ 3,521
Total cash flow hedges, energy commodity contract reclassifications	(375)	(1,713)	3,584
Provision (benefit) for income taxes	(25)	(399)	1,249
Net Of Tax Reclassifications Of Pension And Foreign Currency Adjustments	(350)	(1,314)	2,339
Net Income (Loss) Attributable to Noncontrolling Interest	74	$ (743)	$ 225
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(1)
Accumulated Defined Benefit Plans Adjustment [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	16
Foreign currency translation [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	76
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	178
Provision (benefit) for income taxes	(45)
Net Of Tax Reclassifications Of Pension And Foreign Currency Adjustments	133
Net Income (Loss) Attributable to Noncontrolling Interest	(42)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	91
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total cash flow hedges, energy commodity contract reclassifications	(3)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service (credit) inlcuded in net periodic benefit cost	(6)
Amortization of actuarial (gain) loss included in net periodic benefit cost	32
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, before Tax	26
Reclassification out of Accumulated Other Comprehensive Income [Member] | Foreign currency translation [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, before Tax	155
Reclassification out of Accumulated Other Comprehensive Income [Member] | Energy Commodity Contract [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Product sales	$ (3)

Equity-Based Compensation (Deta

Equity-Based Compensation (Details) - USD ($)		12 Months Ended
		Dec. 31, 2016		Dec. 31, 2015	Dec. 31, 2014	May 22, 2014	May 20, 2010	May 17, 2007
Williams Companies Incentive Plan [Member]
Equity-Based Compensation (Textuals) [Abstract]
Shares reserved for issuance		27,000,000				10,000,000	11,000,000	19,000,000
Shares available for future grants		17,000,000
Equity-based compensation expense		$ 53,000,000		$ 56,000,000	$ 44,000,000
Tax benefit from equity-based compensation expense		20,000,000		$ 21,000,000	17,000,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Abstract]
Unrecognized equity-based compensation expense		67,000,000
Estimated forfeitures under employee equity-based awards		$ 2,000,000
Unrecognized equity-based compensation expense, Weighted-average period of recognition in years		1 year 11 months
Williams Companies Incentive Plan [Member] | Stock options [Member]
Equity-Based Compensation (Textuals) [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period		10 years
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Abstract]
Unrecognized equity-based compensation expense - Stock Options		$ 5,000,000
Rollforward of stock option activity and related information
Options Outstanding, Beginning Balance		5,700,000
Options, Granted		900,000
Options, Exercised		(300,000)
Options, Cancelled		(100,000)
Options Outstanding, Ending Balance		6,200,000		5,700,000
Options Exercisable at Period End		5,000,000
Options, Aggregate Intrinsic Value, Ending Balance		$ 28,000,000
Options, Aggregate Intrinsic Value, Exercisable at Period End		23,000,000
Total intrinsic value of options exercised		2,000,000		$ 37,000,000	48,000,000
Tax benefits realized on options exercised		1,000,000		13,000,000	18,000,000
Cash received from the exercise of options		$ 4,000,000		$ 20,000,000	$ 31,000,000
Stock Options Outstanding, Weighted Average Remaining Contractual Life		5 years 6 months
Stock Options Exercisable, Weighted Average Remaining Contractual Life		4 years 2 months
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Options, Weighted Average Exercise Price, Beginning Balance		$ 31.51
Options, Weighted Average Exercise Price, Granted		24.99
Options, Weighted Average Exercise Price, Exercised		17.84
Options, Weighted Average Exercise Price, Cancelled		24.04
Options, Weighted Average Exercise Price, Ending Balance		31.32		$ 31.51
Options, Weighted Average Exercise Price, Exercisable at Period End		29.75
Estimated fair value at date of grant of options for common stock granted
Weighted-average grant date fair value of options for our common stock granted during the year, per share		$ 7.90		$ 7.61	$ 7.50
Weighted-average assumptions:
Dividend yield		3.20%		4.80%	4.20%
Volatility		44.70%		27.80%	28.00%
Risk-free interest rate		1.20%		1.80%	2.20%
Expected life (years)		6 years		6 years	6 years 6 months
Duration Of Base Term For Peer Group Historical Volatility Measurement		10 years
Williams Companies Incentive Plan [Member] | Nonvested Restricted Stock Units [Member]
Equity-Based Compensation (Textuals) [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Abstract]
Unrecognized equity-based compensation expense - Restricted Stock Units		$ 62,000,000
Rollforward of nonvested restricted stock unit activity and related information
Restricted Stock Units, Nonvested shares, Beginning Balance		3,400,000
Restricted Stock Units, Granted		1,500,000
Restricted Stock Units, Forfeited		(100,000)
Restricted Stock Units, Vested		(900,000)
Restricted Stock Units, Nonvested shares, Ending Balance		3,900,000		3,400,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Restricted Stock Units, Nonvested, Weighted-Average Fair Value, Beginning Balance	[1]	$ 39.38
Weighted-average grant date fair value of restricted stock units granted during the year, per share		26.51	[1]	$ 40.15	$ 42.79
Restricted Stock Units, Forfeited, Weighted-Average Fair Value	[1]	38.18
Restricted Stock Units, Vested, Weighted-Average Fair Value	[1]	35.49
Restricted Stock Units, Nonvested, Weighted-Average Fair Value, Ending Balance	[1]	$ 35.19		$ 39.38
Restricted Stock Units, Vested in Period, Fair Value		$ 32,000,000		$ 42,000,000	$ 27,000,000
Williams Companies Incentive Plan [Member] | Performance Shares [Member]
Equity-Based Compensation (Textuals) [Abstract]
Share Based Compensation Arrangement By Share Based Payment Award Duration Of Postvesting Restriction On Sale		2 years
Rollforward of nonvested restricted stock unit activity and related information
Performance based nonvested restricted stock units as a percent of total nonvested restricted stock units outstanding		40.00%
Williams Companies Incentive Plan [Member] | Performance Shares [Member] | Minimum [Member]
Rollforward of nonvested restricted stock unit activity and related information
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Discount for Postvesting Restrictions		5.83%
Range of vested shares based on extent to which certain financial targets are achieved		0.00%
Williams Companies Incentive Plan [Member] | Performance Shares [Member] | Maximum [Member]
Rollforward of nonvested restricted stock unit activity and related information
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Discount for Postvesting Restrictions		15.58%
Range of vested shares based on extent to which certain financial targets are achieved		500.00%
Employee Stock Purchase Plan [Member]
Equity-Based Compensation (Textuals) [Abstract]
Shares reserved for issuance						1,600,000		2,000,000
Shares available for future grants		1,400,000
Maximum annual amount for purchase of common stock per participant under employee stock purchase plan		$ 15,000
Number of shares eligible for employee to purchase per offering period		750
Percentage of purchase price is the lower of closing price of either the first or the last day of the offering period		85.00%
No. of shares purchases by employees		111,000
Average price of shares purchased		$ 23.93
Share Based Compensation Arrangement By Share Based Payment Award Duration Of Postvesting Restriction On Sale		1 year
Williams Partners Long Term Incentive Plan [Member] | Nonvested Restricted Stock Units [Member]
Equity-Based Compensation (Textuals) [Abstract]
Equity-based compensation expense		$ 20,000,000		$ 29,000,000	$ 11,000,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Abstract]
Unrecognized equity-based compensation expense - Restricted Stock Units		11,000,000
Estimated forfeitures under employee equity-based awards		$ 1,000,000
Unrecognized equity-based compensation expense, Weighted-average period of recognition in years		1 year 2 months
Rollforward of nonvested restricted stock unit activity and related information
Restricted Stock Units, Nonvested shares, Beginning Balance		1,200,000
Restricted Stock Units, Granted		0		0
Restricted Stock Units, Forfeited		(100,000)
Restricted Stock Units, Vested		(500,000)
Restricted Stock Units, Nonvested shares, Ending Balance		600,000		1,200,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Restricted Stock Units, Nonvested, Weighted-Average Fair Value, Beginning Balance		$ 55.93
Restricted Stock Units, Forfeited, Weighted-Average Fair Value		52.85
Restricted Stock Units, Vested, Weighted-Average Fair Value		59.09
Restricted Stock Units, Nonvested, Weighted-Average Fair Value, Ending Balance		$ 52.97		$ 55.93
Williams Partners Long Term Incentive Plan [Member] | Nonvested Restricted Stock Units [Member] | Minimum [Member]
Equity-Based Compensation (Textuals) [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		1 year
Williams Partners Long Term Incentive Plan [Member] | Nonvested Restricted Stock Units [Member] | Maximum [Member]
Equity-Based Compensation (Textuals) [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		4 years
[1]	Performance-based restricted stock units are valued utilizing a Monte Carlo valuation method using measures of total shareholder return. Certain of the performance-based restricted stock units are subject to a holding period of up to two years after the vesting date. Discounts for the restrictions of liquidity were applied to the estimated fair value at the date of certain awards and ranged from 5.83 percent to 15.58 percent. The discounts were developed using the Chaffe model and the Finnerty model. All other restricted stock units are valued at the grant-date market price. Restricted stock units generally vest after three years.

Fair Value Measurements Recurri

Fair Value Measurements Recurring Measurements and Additional (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Additional disclosures:
Fair Value, Level 1 to level 2 Transfers, Amount	$ 0	$ 0
Fair Value, Level 2 to level 1 Transfers, Amount	0	0
Wiltel Guarantee [Member]
Additional disclosures:
Guarantor Obligations, Maximum Exposure, Undiscounted	32
Carrying Amount [Member]
Additional disclosures:
Other receivables	15	12
Long-term debt, including current portion	(23,409)	(23,987)	[1]
Guarantees	(44)	(29)
Carrying Amount [Member] | Former Venezuela Operations [Member]
Additional disclosures:
Notes Receivable, Fair Value Disclosure	0	0
Fair Value [Member]
Additional disclosures:
Other receivables	15	30
Long-term debt, including current portion	(24,090)	(19,606)	[1]
Guarantees	(30)	(16)
Fair Value [Member] | Former Venezuela Operations [Member]
Additional disclosures:
Notes Receivable, Fair Value Disclosure		18
Level 1 [Member]
Additional disclosures:
Other receivables	15	10
Long-term debt, including current portion	0	0	[1]
Guarantees	0	0
Level 2 [Member]
Additional disclosures:
Other receivables	0	2
Long-term debt, including current portion	(24,090)	(19,606)	[1]
Guarantees	(14)	(16)
Level 3 [Member]
Additional disclosures:
Other receivables	0	18
Long-term debt, including current portion	0	0	[1]
Guarantees	(16)	0
Fair Value, Measurements, Recurring [Member] | Carrying Amount [Member]
Measured on a recurring basis:
ARO Trust investments	96	67
Fair Value, Measurements, Recurring [Member] | Carrying Amount [Member] | Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	2
Fair Value, Measurements, Recurring [Member] | Carrying Amount [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	1	5
Energy derivatives liabilities	(6)	(2)
Fair Value, Measurements, Recurring [Member] | Fair Value [Member]
Measured on a recurring basis:
ARO Trust investments	96	67
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	2
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	1	5
Energy derivatives liabilities	(6)	(2)
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Measured on a recurring basis:
ARO Trust investments	96	67
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	0	0
Energy derivatives liabilities	0	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Measured on a recurring basis:
ARO Trust investments	0	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	2
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	0	3
Energy derivatives liabilities	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Measured on a recurring basis:
ARO Trust investments	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	1	2
Energy derivatives liabilities	$ (6)	$ (2)
[1]	Excludes capital leases.

Fair Value Measurements Nonrecu

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

3 Months Ended

9 Months Ended

12 Months Ended

Dec. 31, 2016

Jun. 30, 2016

Mar. 31, 2016

Dec. 31, 2015

Sep. 30, 2015

Jun. 30, 2015

[3]

Dec. 31, 2014

Jun. 30, 2014

[3]

Sep. 30, 2015

Dec. 31, 2016

Dec. 31, 2015

Dec. 31, 2014

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Impairment of goodwill

$ 1,098

$ 0

$ 1,098

$ 0

Impairment of certain assets

873

209

52

Impairment of equity-method investments

430

1,359

0

Delaware Basin Gas Gathering System [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Impairment of equity-method investments

59

503

Appalachia Midstream Investments [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Impairment of equity-method investments

294

562

Williams Partners [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Impairment of goodwill

1,098

Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Williams Partners [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Impairment of goodwill

$ 0

Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Williams Partners [Member] | Minimum [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Discount rate

10.00%

Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Williams Partners [Member] | Maximum [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Discount rate

13.00%

Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | West [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Impairment of goodwill

$ 0

Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Property, plant, and equipment, net [Member] | Williams Partners [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Fair value of property, plant, and equipment

$ 18

[1]

13

[2]

$ 17

$ 32

[3]

$ 46

13

[2]

32

[3]

Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Property, plant, and equipment, net [Member] | Other [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Fair value of property, plant, and equipment

$ 73

40

[4]

73

40

[4]

Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Assets Held For Sale [Member] | Williams Partners [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Assets Held-for-sale, Long Lived, Fair Value Disclosure

[3]

1

1

Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Investments [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Fair value of investment

$ 0

58

58

Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Investments [Member] | Williams Partners [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Fair value of investment

$ 1,295

[5]

$ 1,294

[6]

$ 4,017

[7]

$ 1,203

[8]

$ 1,203

[8]

1,295

[5]

4,017

[7]

Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Investments [Member] | Williams Partners [Member] | Minimum [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Discount rate

13.00%

[6]

10.80%

[7]

Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Investments [Member] | Williams Partners [Member] | Maximum [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Discount rate

13.30%

[6]

14.40%

[7]

Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Investments [Member] | Williams Partners [Member] | Delaware Basin Gas Gathering System [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Discount rate

[8]

11.80%

Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Investments [Member] | Williams Partners [Member] | Appalachia Midstream Investments [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Discount rate

10.20%

[5]

8.80%

[8]

Canadian Operations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Assets Held For Sale [Member] | Williams Partners [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Assets Held-for-sale, Long Lived, Fair Value Disclosure

[9]

924

Canadian Operations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Assets Held For Sale [Member] | Other [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Assets Held-for-sale, Long Lived, Fair Value Disclosure

[9]

206

Impairment Of Goodwill [Member] | Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Williams Partners [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Impairment of goodwill

$ 1,098

Impairment Of Certain Assets [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Impairment of certain assets

873

209

52

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

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Impairment of certain assets

[10]

70

31

10

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

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Impairment of certain assets

803

178

$ 42

Impairment Of Certain Assets [Member] | Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Williams Partners [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Impairment of certain assets

48

[1]

94

[2]

$ 20

13

[3]

$ 17

Impairment of Long-Lived Assets to be Disposed of

[3]

$ 12

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

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Impairment of certain assets

$ 8

64

[4]

Impairment Of Certain Assets [Member] | Canadian Operations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Williams Partners [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Disposal Group, Not Discontinued Operation, Loss (Gain) on Write-down

[9]

341

Impairment Of Certain Assets [Member] | Canadian Operations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Other [Member]

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Disposal Group, Not Discontinued Operation, Loss (Gain) on Write-down

[9]

$ 406

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

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Impairment of equity-method investments

$ 430

$ 1,359

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

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Impairment of equity-method investments

$ 3

8

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

Fair Value Assets Measured On Nonrecurring Basis [Abstract]

Impairment of equity-method investments

$ 318

[5]

$ 109

[6]

$ 890

[7]

$ 461

[8]

[1]

Relates to certain gathering assets within the Mid-Continent region. The estimated fair value was determined by a market approach based on our analysis of observable inputs in the principal market.

[2]

Relates to a gas processing plant, the completion of which is considered remote due to unfavorable impact of low natural gas prices on customer drilling activities. The assessed fair value primarily represents the estimated salvage value of certain equipment measured using a market approach based on our analysis of observable inputs in the principal market.

[3]

Relates to certain surplus equipment. The estimated fair value was determined by a market approach based on our analysis of observable inputs in the principal market.

[4]

Relates to an olefins pipeline project, the completion of which is considered remote due to lack of customer interest. The assessed fair value primarily represents the estimated fair value of unused pipeline measured using a market approach based on our analysis of observable inputs in the principal market.

[5]

Relates to equity-method investments in Ranch Westex and multiple Appalachia Midstream Investments. The historical carrying value of these investments was initially recorded based on estimated fair value during the third quarter of 2014 in conjunction with the acquisition of ACMP. We estimated the fair value of these Appalachia Midstream Investments using an income approach based on expected future cash flows and appropriate discount rates. The determination of estimated future cash flows involved significant assumptions regarding gathering volumes, rates, and related capital spending. The discount rate utilized for the Appalachia Midstream Investments evaluation was 10.2 percent and reflected our cost of capital as impacted by market conditions and risks associated with the underlying businesses. In addition to utilizing an income approach, we also considered a market approach for certain Appalachia Midstream Investments and Ranch Westex based on an agreement reached in February 2017 to exchange our interests in DBJV and Ranch Westex for additional interests in certain Appalachia Midstream Investments and cash.

[6]

Relates to equity-method investments in DBJV and Laurel Mountain. Our carrying values in these equity-method investments had been written down to fair value at December 31, 2015. Our first-quarter 2016 analysis reflected higher discount rates for both of these investments, along with lower natural gas prices for Laurel Mountain. We estimated the fair value of these investments using an income approach based on expected future cash flows and appropriate discount rates. The determination of estimated future cash flows involved significant assumptions regarding gathering volumes and related capital spending. Discount rates utilized ranged from 13.0 percent to 13.3 percent and reflected increases in our cost of capital, revised estimates of expected future cash flows, and risks associated with the underlying businesses.

[7]

Relates to equity-method investments in DBJV, certain of the Appalachia Midstream Investments, UEOM, and Laurel Mountain. We estimated the fair value of these investments using an income approach based on expected future cash flows and appropriate discount rates. The determination of estimated future cash flows involved significant assumptions regarding gathering volumes and related capital spending. Discount rates utilized ranged from 10.8 percent to 14.4 percent and reflected further fourth-quarter 2015 increases in our cost of capital, revised estimates of expected future cash flows, and risks associated with the underlying businesses.

[8]

Relates to equity-method investments in DBJV and certain of the Appalachia Midstream Investments. The historical carrying value of these investments was initially recorded based on estimated fair value during the third quarter of 2014 in conjunction with the acquisition of ACMP. We estimated the fair value of these investments using an income approach based on expected future cash flows and appropriate discount rates. The determination of estimated future cash flows involved significant assumptions regarding gathering volumes and related capital spending. Discount rates utilized were 11.8 percent and 8.8 percent for DBJV and certain of the Appalachia Midstream Investments, respectively, and reflected our cost of capital as impacted by market conditions, and risks associated with the underlying businesses.

[9]

Relates to our Canadian operations. We designated these operations as held for sale as of June 30, 2016. As a result, we measured the fair value of the disposal group, resulting in an impairment charge. The estimated fair value was determined by a market approach based primarily on inputs received in the marketing process and reflected our estimate of the potential assumed proceeds. We disposed of our Canadian operations through a sale during the third quarter of 2016. See Note 3 – Divestiture.

[10]

Reflects multiple individually insignificant impairments and write-downs of other certain assets that may no longer be in use or are surplus in nature for which the fair value was determined to be zero or an insignificant salvage value.

Fair Value Measurements Concent

Fair Value Measurements Concentration of Credit Risk (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Concentration Risk [Line Items]
Trade accounts and other receivables	$ 938	$ 1,041
NGLs, natural gas, and related products and services [Member]
Concentration Risk [Line Items]
Trade accounts and other receivables	736	823
Transportation of natural gas and related products [Member]
Concentration Risk [Line Items]
Trade accounts and other receivables	187	202
Other Receivable [Member]
Concentration Risk [Line Items]
Trade accounts and other receivables	15	16
Chesapeake Energy Corporation [Member] | Customer Concentration Risk [Member] | Accounts receivable [Member] | Williams Partners [Member]
Concentration Risk [Line Items]
Trade accounts and other receivables	$ 133	$ 364
Chesapeake Energy Corporation [Member] | Customer Concentration Risk [Member] | Sales Revenue, Net [Member] | Williams Partners [Member]
Concentration Risk [Line Items]
Consolidated revenue, major customer, percentage	14.00%	18.00%

Contingent Liabilities and Co90

Contingent Liabilities and Commitments (Details) - USD ($) $ in Millions	May 20, 2016	Dec. 31, 2016
Loss Contingencies [Line Items]
Accrued environmental loss liabilities		$ 38
Capital Addition Purchase Commitments [Member]
Loss Contingencies [Line Items]
Commitments for construction and acquisition of property, plant, and equipment		244
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		9
Natural gas underground storage facilities [Member]
Loss Contingencies [Line Items]
Accrued environmental loss liabilities		7
Former Operations [Member]
Loss Contingencies [Line Items]
Accrued environmental loss liabilities		22
Williams Partners [Member] | General Liability [Member] | Geismar Incident [Member]
Loss Contingencies [Line Items]
Aggregate limit of insurance		610
Insurance deductibles		2
Maximum [Member] | Former Alaska Refinery [Member]
Loss Contingencies [Line Items]
Loss contingency, range of possible loss, maximum		$ 32

Segment Disclosures Geographic

Segment Disclosures Geographic Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues from external customers:
Revenues from external customers	$ 7,499	$ 7,360	$ 7,637
Long-lived assets:
Long-lived assets	38,091	39,596	39,654
United States [Member]
Revenues from external customers:
Revenues from external customers	7,425	7,247	7,229
Long-lived assets:
Long-lived assets	38,091	38,016	38,290
Canada [Member]
Revenues from external customers:
Revenues from external customers	74	113	408
Long-lived assets:
Long-lived assets	$ 0	$ 1,580	$ 1,364

Segment Disclosures Recon from

Segment Disclosures Recon from Segment to Consolidated - Revenues (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment revenues [Line Items]
Service revenues	$ 5,171	$ 5,164	$ 4,116
Product sales	2,328	2,196	3,521
Total revenues	7,499	7,360	7,637
Other financial information:
Additions to long-lived assets	2,145	3,336	20,756
Proportional Modified Ebitda Equity Method Investments	754	699	438
Williams Partners [Member]
Segment revenues [Line Items]
Service revenues	5,140	5,134	3,887
Product sales	2,318	2,196	3,521
Other [Member]
Segment revenues [Line Items]
Service revenues	31	30	229
Product sales	10	0	0
Intersegment Eliminations [Member]
Segment revenues [Line Items]
Service revenues	(52)	(92)	(20)
Product sales	(16)	0	0
Total revenues	(68)	(92)	(20)
Other financial information:
Additions to long-lived assets	(1)	(12)	(2)
Proportional Modified Ebitda Equity Method Investments	0	0	0
Intersegment Eliminations [Member] | Williams Partners [Member]
Segment revenues [Line Items]
Service revenues	(33)	(1)	(1)
Product sales	0	0	0
Intersegment Eliminations [Member] | Other [Member]
Segment revenues [Line Items]
Service revenues	(19)	(91)	(19)
Product sales	(16)	0	0
Operating Segments [Member] | Williams Partners [Member]
Segment revenues [Line Items]
Service revenues	5,173	5,135	3,888
Product sales	2,318	2,196	3,521
Total revenues	7,491	7,331	7,409
Other financial information:
Additions to long-lived assets	2,102	2,960	20,413	[1]
Proportional Modified Ebitda Equity Method Investments	754	699	431
Operating Segments [Member] | Other [Member]
Segment revenues [Line Items]
Service revenues	50	121	248
Product sales	26	0	0
Total revenues	76	121	248
Other financial information:
Additions to long-lived assets	44	388	345
Proportional Modified Ebitda Equity Method Investments	$ 0	$ 0	$ 7
[1]	2014 Additions to long-lived assets within our Williams Partners segment primarily includes the acquisition-date fair value of long-lived assets from the ACMP Acquisition. (See Note 2 - Acquisitions.)

Segment Disclosures Recon fro93

Segment Disclosures Recon from Modified EBITDA to Net Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of Modified EBITDA to Net Income (Loss)
Modified EBITDA		$ 3,322	$ 3,891	$ 3,232
Accretion expense associated with asset retirement obligations for nonregulated operations		(31)	(28)	(18)
Depreciation and amortization expenses		(1,763)	(1,738)	(1,176)
Impairment of goodwill	$ (1,098)	0	(1,098)	0
Equity earnings (losses)		397	335	144
Gain on remeasurement of equity-method investment (Note 2)		0	0	2,544
Impairment of equity-method investments		(430)	(1,359)	0
Other investing income (loss) – net		63	27	43
Proportional Modified Ebitda Equity Method Investments		(754)	(699)	(438)
Interest Expense		(1,179)	(1,044)	(747)
(Provision) benefit for income taxes		25	399	(1,249)
Income (loss) from discontinued operations, net of tax		0	0	4
Net income (loss)		(350)	(1,314)	2,339
Williams Partners [Member]
Reconciliation of Modified EBITDA to Net Income (Loss)
Impairment of goodwill			(1,098)
Intersegment Eliminations [Member]
Reconciliation of Modified EBITDA to Net Income (Loss)
Proportional Modified Ebitda Equity Method Investments		0	0	0
Operating Segments [Member] | Williams Partners [Member]
Reconciliation of Modified EBITDA to Net Income (Loss)
Modified EBITDA		3,864	4,003	3,244
Proportional Modified Ebitda Equity Method Investments		(754)	(699)	(431)
Operating Segments [Member] | Other [Member]
Reconciliation of Modified EBITDA to Net Income (Loss)
Modified EBITDA		(542)	(112)	(12)
Proportional Modified Ebitda Equity Method Investments		$ 0	$ 0	$ (7)

Segment Disclosures Recon fro94

Segment Disclosures Recon from Segment to Consolidated - Assets and Investments (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 46,835	$ 49,020
Equity-method investments	6,701	7,336
Operating Segments [Member] | Williams Partners [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	46,265	47,870
Equity-method investments	6,701	7,336
Operating Segments [Member] | Other [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	685	1,351
Equity-method investments	0	0
Intersegment Eliminations [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	(115)	(201)
Equity-method investments	$ 0	$ 0

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Millions

May 18, 2017

Apr. 15, 2017

Feb. 23, 2017

Feb. 20, 2017

Jan. 25, 2017

Mar. 31, 2017

Dec. 31, 2016

Dec. 31, 2015

Dec. 31, 2014

May 24, 2017

Apr. 17, 2017

Apr. 03, 2017

Subsequent Event [Line Items]

Commercial paper, outstanding

$ 93

$ 499

Common Stock, Dividends, Per Share, Declared

$ 1.6800

$ 2.45

$ 1.9575

Williams Companies, Inc. [Member]

Subsequent Event [Line Items]

Credit facility, loans outstanding

$ 775

$ 650

Williams Partners L.P. [Member]

Subsequent Event [Line Items]

Credit facility, loans outstanding

$ 0

[1]

1,310

Delaware Basin Gas Gathering System [Member]

Subsequent Event [Line Items]

Equity Method Investment, Ownership Percentage

50.00%

Williams Partners [Member] | Delaware Basin Gas Gathering System [Member]

Subsequent Event [Line Items]

Equity Method Investment, Ownership Percentage

50.00%

Commercial Paper [Member] | Williams Partners L.P. [Member]

Subsequent Event [Line Items]

Commercial paper, outstanding

$ 93

$ 499

5.95% Senior Unsecured Notes due 2017 [Member] | Northwest Pipeline LLC [Member]

Subsequent Event [Line Items]

Long-term debt interest rate

5.95%

6.125% Senior Unsecured Notes due 2022 [Member] | Williams Partners L.P. [Member]

Subsequent Event [Line Items]

Long-term debt interest rate

6.125%

Subsequent Event [Member]

Subsequent Event [Line Items]

Common Stock, Dividends, Per Share, Cash Paid

$ 0.30

Common Stock, Dividends, Per Share, Declared

$ 0.30

$ 0.30

Subsequent Event [Member] | Williams Olefins, L.L.C. [Member]

Subsequent Event [Line Items]

Disposal Group, Consideration

$ 2,100

Subsequent Event [Member] | Williams Companies, Inc. [Member]

Subsequent Event [Line Items]

Credit facility, loans outstanding

$ 235

$ 175

Subsequent Event [Member] | Williams Partners L.P. [Member]

Subsequent Event [Line Items]

Credit facility, loans outstanding

$ 0

Subsequent Event [Member] | Williams Partners [Member] | Delaware Basin Gas Gathering System [Member]

Subsequent Event [Line Items]

Equity Method Investment, Ownership Percentage

50.00%

Proceeds from Sale of Equity Method Investments

$ 155

Gain from sale of an equity-method investment interest

$ 269

Subsequent Event [Member] | Williams Partners [Member] | Appalachia Midstream Services, LLC [Member]

Subsequent Event [Line Items]

Equity Method Investment, Ownership Percentage

66.00%

Subsequent Event [Member] | Williams Partners [Member] | Ranch Westex JV LLC [Member]

Subsequent Event [Line Items]

Proceeds from Sale of Equity Method Investments

$ 45

Subsequent Event [Member] | Commercial Paper [Member] | Williams Partners L.P. [Member]

Subsequent Event [Line Items]

Commercial paper, outstanding

$ 0

Subsequent Event [Member] | 4% Senior Unsecured Notes Due 2027 [Member] | Northwest Pipeline LLC [Member]

Subsequent Event [Line Items]

Debt Instrument, Face Amount

$ 250

Long-term debt interest rate

4.00%

Subsequent Event [Member] | 5.95% Senior Unsecured Notes due 2017 [Member] | Northwest Pipeline LLC [Member]

Subsequent Event [Line Items]

Long-term debt interest rate

5.95%

Long-term debt retired

$ 185

Subsequent Event [Member] | 6.125% Senior Unsecured Notes due 2022 [Member] | Williams Partners L.P. [Member]

Subsequent Event [Line Items]

Long-term debt interest rate

6.125%

6.125%

Long-term debt retired

$ 750

$ 750

[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.

Schedule I Condensed Financia96

Schedule I Condensed Financial Information Of Registrant (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	Jun. 23, 2014	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2016	Dec. 31, 2015
Condensed Statement Of Comprehensive Income Parent Company Only [Abstract]
Equity earnings (losses)		$ 397		$ 335		$ 144
Interest incurred - external		(1,217)		(1,118)		(888)
Gain on remeasurement of equity-method investment (Note 2)		0		0		2,544
Other income (expense) – net		74		102		31
Income (loss) from continuing operations before income taxes		(375)		(1,713)		3,584
Provision (benefit) for income taxes		(25)		(399)		1,249
Income (loss) from continuing operations		(424)		(571)		2,110
Income (loss) from discontinued operations		0		0		4
Net income (loss) attributable to The Williams Companies, Inc.		$ (424)		$ (571)		$ 2,114
Basic earnings (loss) per common share:
Income (loss) from continuing operations		$ (0.57)		$ (0.76)		$ 2.93
Income (loss) from discontinued operations		0		0		0.01
Net income (loss)		$ (0.57)		$ (0.76)		$ 2.94
Weighted-average shares (thousands)		750,673		749,271		719,325
Diluted earnings (loss) per common share:
Income (loss) from continuing operations		$ (0.57)		$ (0.76)		$ 2.91
Income (loss) from discontinued operations		0		0		0.01
Net income (loss)		$ (0.57)		$ (0.76)		$ 2.92
Weighted-average shares (thousands)		750,673	[1]	749,271	[1]	723,641
Other comprehensive income (loss):
Other comprehensive income (loss)		$ 172		$ (171)		$ (176)
Comprehensive Income (loss) attributable to The Williams Companies, Inc.		(321)		(672)		1,957
Assets, Current [Abstract]
Cash and cash equivalents		100		240		681	$ 170	$ 100
Other current assets and deferred charges							216	259
Total current assets							1,462	1,527
Property, plant, and equipment – net							28,428	29,579
Other noncurrent assets							581	561
Total assets							46,835	49,020
Liabilities, Current [Abstract]
Accounts payable							623	744
Total current liabilities							2,949	2,497
Long-term debt							22,624	23,812
Deferred income taxes							4,238	4,218
Contingent liabilities and commitments
Equity: [Abstract]
Common stock							785	784
Total stockholders’ equity							4,643	6,148
Total liabilities and stockholders' equity							46,835	49,020
Condensed Statement Of Cash Flows Parent Company Only [Abstract]
Net Cash Provided (Used) by Operating Activities		3,680		2,708		2,134
FINANCING ACTIVITIES:
Proceeds from long-term debt		6,528		9,772		7,321
Payments of long-term debt		(7,091)		(6,516)		(1,828)
Proceeds from issuance of common stock	$ 3,378	9		27		3,416
Dividends paid		(1,261)		(1,836)		(1,412)
Other – net		(16)		(31)		(2)
Net cash provided (used) by financing activities		(3,194)		451		7,582
INVESTING ACTIVITIES:
Capital expenditures		(2,145)		(3,336)		(20,756)
Other – net		290		168		74
Net cash provided (used) by investing activities		(416)		(3,299)		(10,157)
Increase (decrease) in cash and cash equivalents		70		(140)		(441)
Cash and cash equivalents at beginning of year		100		240		681
Cash and cash equivalents at end of year		170		100		240
Parent Company [Member]
Condensed Statement Of Comprehensive Income Parent Company Only [Abstract]
Equity in earnings of consolidated subsidiaries		522		232		1,799
Equity earnings (losses)		0		0		(7)
Interest incurred - external		(268)		(255)		(206)
Interest incurred - affiliate		(568)		(828)		(797)
Interest income - affiliate		0		6		10
Gain on remeasurement of equity-method investment (Note 2)		0		0		2,544
Other income (expense) – net		(53)		(75)		(13)
Income (loss) from continuing operations before income taxes		(367)		(920)		3,330
Provision (benefit) for income taxes		57		(349)		1,220
Income (loss) from continuing operations		(424)		(571)		2,110
Income (loss) from discontinued operations		0		0		4
Net income (loss) attributable to The Williams Companies, Inc.		$ (424)		$ (571)		$ 2,114
Basic earnings (loss) per common share:
Income (loss) from continuing operations		$ (0.57)		$ (0.76)		$ 2.93
Income (loss) from discontinued operations		0		0		0.01
Net income (loss)		$ (0.57)		$ (0.76)		$ 2.94
Weighted-average shares (thousands)		750,673		749,271		719,325
Diluted earnings (loss) per common share:
Income (loss) from continuing operations		$ (0.57)		$ (0.76)		$ 2.91
Income (loss) from discontinued operations		0		0		0.01
Net income (loss)		$ (0.57)		$ (0.76)		$ 2.92
Weighted-average shares (thousands)		750,673		749,271		723,641
Other comprehensive income (loss):
Equity in other comprehensive income (loss) of consolidated subsidiaries		$ 171		$ (204)		$ (96)
Other comprehensive income (loss) attributable to The Williams Companies, Inc.		1		33		(80)
Other comprehensive income (loss)		172		(171)		(176)
Other comprehensive income (loss) attributable to noncontrolling interests		69		(70)		(19)
Comprehensive Income (loss) attributable to The Williams Companies, Inc.		(321)		(672)		1,957
Assets, Current [Abstract]
Cash and cash equivalents		12		49		282	14	12
Other current assets and deferred charges							16	62
Total current assets							30	74
Investments in and advances to consolidated subsidiaries							22,359	30,927
Property, plant, and equipment – net							77	99
Other noncurrent assets							8	12
Total assets							22,474	31,112
Liabilities, Current [Abstract]
Accounts payable							27	27
Other current liabilities							169	163
Total current liabilities							196	190
Long-term debt							4,939	4,811
Notes payable - affiliates							8,171	15,506
Pension, other postretirement and other noncurrent liabilities							287	336
Deferred income taxes							4,238	4,121
Equity: [Abstract]
Common stock							785	784
Other stockholders' equity							3,858	5,364
Total stockholders’ equity							4,643	6,148
Total liabilities and stockholders' equity							22,474	$ 31,112
Condensed Statement Of Cash Flows Parent Company Only [Abstract]
Net Cash Provided (Used) by Operating Activities		(827)		(1,181)		(481)
FINANCING ACTIVITIES:
Proceeds from long-term debt		2,280		2,097		2,935
Payments of long-term debt		(2,155)		(1,817)		(671)
Changes in notes payable to affiliates		9		2,211		2,465
Tax benefit of stock-based awards		0		0		25
Proceeds from issuance of common stock		9		27		3,416
Dividends paid		(1,261)		(1,836)		(1,412)
Other – net		(6)		(30)		(36)
Net cash provided (used) by financing activities		(1,124)		652		6,722
INVESTING ACTIVITIES:
Capital expenditures		(13)		(29)		(54)
Purchase of Access Midstream Partners		0		0		(5,995)
Changes in investments in and advances to consolidated subsidiaries		1,966		521		(450)
Other – net		0		0		25
Net cash provided (used) by investing activities		1,953		492		(6,474)
Increase (decrease) in cash and cash equivalents		2		(37)		(233)
Cash and cash equivalents at beginning of year		12		49		282
Cash and cash equivalents at end of year		14		12		49
Guarantees [Abstract]
Guarantor Obligations, Maximum Exposure, Undiscounted							$ 305
Cash Dividends Received [Abstract]
Proceeds from Dividends Received		$ 1,700		$ 1,800		$ 1,900
[1]	For the years ended December 31, 2016 and December 31, 2015, 0.6 million and 1.7 million weighted-average nonvested restricted stock units, and 0.5 million and 1.5 million weighted-average stock options have been excluded from the computation of diluted earnings (loss) per common share as their inclusion would be antidilutive due to our loss from continuing operations attributable to The Williams Companies, Inc.

Schedule II Valuation and Qua97

Schedule II Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for doubtful accounts and for notes receivable [Member]
Valuation And Qualifying Accounts
Beginning Balance	[1]	$ 3	$ 0	$ 0
Additions Charged (Credited) To Cost and Expenses		6	3	0
Additions Other		0	0	0
Deductions		3	0	0
Ending Balance	[1]	6	3	0
Deferred Tax Asset Valuation Allowance [Member]
Valuation And Qualifying Accounts
Beginning Balance	[1]	190	206	181
Additions Charged (Credited) To Cost and Expenses		144	(16)	25
Additions Other		0	0	0
Deductions		0	0	0
Ending Balance	[1]	$ 334	$ 190	$ 206
[1]	Deducted from related assets.