Enable Midstream Partners (ENBL) 10-Q 5 Aug 20 2020 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2020	Jul. 17, 2020
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	1-36413
Entity Registrant Name	ENABLE MIDSTREAM PARTNERS, LP
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	72-1252419
Entity Address, Address Line One	499 West Sheridan Avenue,
Entity Address, Address Line Two	Suite 1500
Entity Address, City or Town	Oklahoma City,
Entity Address, State or Province	OK
Entity Address, Postal Zip Code	73102
City Area Code	405
Local Phone Number	525-7788
Title of 12(b) Security	Common Units Representing Limited Partner Interests
Trading Symbol	ENBL
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Entity Central Index Key	0001591763
Entity Common Stock, Shares Outstanding		435,462,758
Current Fiscal Year End Date	--12-31
Document Period End Date	Jun. 30, 2020

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues (including revenues from affiliates (Note 13)):
Total Revenues	$ 515	$ 735	$ 1,163	$ 1,530
Cost and Expenses (including expenses from affiliates (Note 13)):
Cost of natural gas and natural gas liquids (excluding depreciation and amortization shown separately)	177	317	403	695
Operation and maintenance	115	99	217	202
General and administrative	21	25	45	51
Depreciation and amortization	105	110	209	215
Impairments (Note 7)	0	0	28	0
Taxes other than income tax	17	17	35	35
Total Cost and Expenses	435	568	937	1,198
Operating Income	80	167	226	332
Other Income (Expense):
Interest expense	(46)	(48)	(93)	(94)
Equity in earnings of equity method affiliate	5	4	11	7
Other, net	5	1	5	1
Total Other Expense	(36)	(43)	(77)	(86)
Income Before Income Tax
Income Before Income Tax	44	124	149	246
Income tax benefit	0	0	0	(1)
Net Income
Net Income	44	124	149	247
Less: Net (loss) income attributable to noncontrolling interest
Less: Net (loss) income attributable to noncontrolling interest	0	0	(7)	1
Net Income Attributable to Limited Partners
Net Income Attributable to Limited Partners	44	124	156	246
Less: Series A Preferred Unit distributions (Note 6)
Less: Series A Preferred Unit distributions (Note 6)	9	9	18	18
Net Income Attributable to Common Units (Note 5)
Net Income Attributable to Common Units (Note 5)	35	115	138	228
Common Unit [Member]
Net Income Attributable to Common Units (Note 5)
Net Income Attributable to Common Units (Note 5)	$ 35	$ 115	$ 138	$ 228
Basic and Diluted earnings per unit and weighted average number of units outstanding
Basic earnings per unit (Note 5)	$ 0.08	$ 0.26	$ 0.32	$ 0.52
Diluted earnings per unit (Note 5)	$ 0.08	$ 0.26	$ 0.30	$ 0.52
Product
Revenues (including revenues from affiliates (Note 13)):
Total Revenues	$ 196	$ 393	$ 484	$ 836
Natural Gas, Gathering, Transportation, Marketing and Processing
Revenues (including revenues from affiliates (Note 13)):
Total Revenues	$ 319	$ 342	$ 679	$ 694

Condensed Consolidated Statem_2

Condensed Consolidated Statement of Comprehensive Income Statement (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 44	$ 124	$ 149	$ 247
Other comprehensive loss:
Unrealized losses on derivative instruments	0	(3)	(6)	(3)
Other comprehensive loss	0	(3)	(6)	(3)
Comprehensive income	44	121	143	244
Less: Comprehensive (loss) income attributable to noncontrolling interest	0	0	(7)	1
Comprehensive income attributable to Limited Partners	$ 44	$ 121	$ 150	$ 243

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Current Assets:
Cash and cash equivalents	$ 11	$ 4
Restricted cash	0
Accounts receivable, net of allowance for doubtful accounts (Note 1)	223	244
Accounts receivable—affiliated companies	15	25
Inventory	43	46
Gas imbalances	38	35
Other current assets	44	35
Total current assets	374	389
Property, Plant and Equipment:
Property, plant and equipment	13,172	13,161
Less: Accumulated depreciation and amortization	2,430	2,291
Property, plant and equipment, net	10,742	10,870
Other Assets:
Intangible assets, net	570	601
Goodwill	0	12
Investment in equity method affiliate	301	309
Other, net of allowance for doubtful accounts (Note 1)	74	85
Total other assets	945	1,007
Total Assets	12,061	12,266
Current Liabilities:
Accounts payable	88	161
Accounts payable—affiliated companies	2	1
Current portion of long-term debt	0	251
Short-term debt	30	155
Taxes accrued	38	32
Gas imbalances	19	19
Other	113	161
Total current liabilities	290	780
Other Liabilities:
Accumulated deferred income taxes, net	5	4
Regulatory liabilities	25	24
Other	75	80
Total other liabilities	105	108
Long-Term Debt	4,349	3,969
Commitments and Contingencies (Note 14)
Partners’ Equity:
Series A Preferred Units (14,520,000 issued and outstanding at June 30, 2020 and December 31, 2019)	362	362
Common Units (435,454,209 issued and outstanding at June 30, 2020 and 435,201,365 issued and outstanding at December 31, 2019)	6,937	7,013
Accumulated other comprehensive loss	(9)	(3)
Noncontrolling interest	27	37
Total Partners’ Equity	7,317	7,409
Total Liabilities and Partners’ Equity	$ 12,061	$ 12,266

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - shares	Jun. 30, 2020	Dec. 31, 2019
Common Unit [Member]
Common units issued	435,454,209	435,201,365
Common units outstanding	435,454,209	435,201,365
Series A Preferred Units [Member]
Preferred Units, Issued	14,520,000	14,520,000
Preferred Units, Outstanding	14,520,000	14,520,000

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash Flows from Operating Activities:
Net income	$ 149	$ 247
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	209	215
Deferred income taxes	1	(1)
Impairments	28	0
Net loss on sale/retirement of assets	17	2
Gain on extinguishment of debt	(5)	0
Equity in earnings of equity method affiliate	(11)	(7)
Return on investment in equity method affiliate	11	7
Equity-based compensation	7	9
Amortization of debt costs and discount	1	0
Changes in other assets and liabilities:
Accounts receivable, net	20	58
Accounts receivable—affiliated companies	10	(1)
Inventory	3	4
Gas imbalance assets	(3)	3
Other current assets	(10)	(3)
Other assets	3	6
Accounts payable	(71)	(111)
Accounts payable—affiliated companies	1	(1)
Gas imbalance liabilities	0	(4)
Other current liabilities	(45)	15
Other liabilities	(4)	(11)
Net cash provided by operating activities	311	427
Cash Flows from Investing Activities:
Capital expenditures	(102)	(252)
Proceeds from sale of assets	19	0
Return of investment in equity method affiliate	8	9
Other, net	2	(9)
Net cash used in investing activities	(73)	(252)
Cash Flows from Financing Activities:
(Decrease) increase in short-term debt	(125)	32
Proceeds from long-term debt, net of issuance costs	0	850
Repayment of long-term debt	(267)	(500)
Proceeds from Revolving Credit Facility	869	0
Repayment of Revolving Credit Facility	(469)	(250)
Distributions to common unitholders	(216)	(276)
Distributions to preferred unitholders	(18)	(18)
Distributions to non-controlling interests	(3)	(2)
Cash paid for employee equity-based compensation	(2)	(23)
Net cash used in financing activities	(231)	(187)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	7	(12)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	4	22
Cash, Cash Equivalents and Restricted Cash at End of Period	$ 11	$ 10

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Partners' Equity (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Noncontrolling Interest [Member]	Series A Preferred Units [Member]Preferred Units	Common Unit [Member]Partners' Capital	AOCI Attributable to Parent	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, AdjustmentCommon Unit [Member]Partners' Capital
Balance, beginning of period at Dec. 31, 2018	$ 7,618	$ 38	$ 362	$ 7,218	$ 0
Balance, beginning of period, units at Dec. 31, 2018			15	433
Changes in Partners' Capital
Net Income	123	1	$ 9	$ 113
Partners' Capital Account, Distributions	(148)	(1)	(9)	(138)
Partners' Capital Account, Unit-based Compensation, Net of Taxes	(10)			$ (10)
Equity-based compensation, net of units for employee taxes, units				2
Balance, end of period at Mar. 31, 2019	7,583	38	$ 362	$ 7,183	0
Balance, end of period, units at Mar. 31, 2019			15	435
Changes in Partners' Capital
Net Income	124	0	$ 9	$ 115
Other comprehensive loss	(3)				(3)
Partners' Capital Account, Distributions	(148)	(1)	(9)	(138)
Partners' Capital Account, Unit-based Compensation, Net of Taxes	3			$ 3
Equity-based compensation, net of units for employee taxes, units				0
Balance, end of period at Jun. 30, 2019	7,559	37	$ 362	$ 7,163	(3)
Balance, end of period, units at Jun. 30, 2019			15	435
Balance, beginning of period at Dec. 31, 2019	7,409	37	$ 362	$ 7,013	(3)	$ (3)	$ (3)
Balance, beginning of period, units at Dec. 31, 2019			15	435
Changes in Partners' Capital
Net Income	105	(7)	$ 9	$ 103
Other comprehensive loss	(6)				(6)
Partners' Capital Account, Distributions	(156)	(3)	(9)	(144)
Partners' Capital Account, Unit-based Compensation, Net of Taxes	3			$ 3
Equity-based compensation, net of units for employee taxes, units				0
Balance, end of period at Mar. 31, 2020	7,352	27	$ 362	$ 6,972	(9)
Balance, end of period, units at Mar. 31, 2020			15	435
Changes in Partners' Capital
Net Income	44	0	$ 9	$ 35
Partners' Capital Account, Distributions	(81)	0	(9)	(72)
Partners' Capital Account, Unit-based Compensation, Net of Taxes	2			$ 2
Equity-based compensation, net of units for employee taxes, units				0
Balance, end of period at Jun. 30, 2020	$ 7,317	$ 27	$ 362	$ 6,937	$ (9)
Balance, end of period, units at Jun. 30, 2020			15	435

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Organization Enable Midstream Partners, LP is a Delaware limited partnership whose assets and operations are organized into two reportable segments: (i) gathering and processing and (ii) transportation and storage. The gathering and processing segment primarily provides natural gas and crude oil gathering and natural gas processing services to our producer customers. The transportation and storage segment provides interstate and intrastate natural gas pipeline transportation and storage services primarily to our producer, power plant, LDC and industrial end-user customers. The Partnership’s natural gas gathering and processing assets are primarily located in Oklahoma, Texas, Arkansas and Louisiana and serve natural gas production in the Anadarko, Arkoma and Ark-La-Tex Basins. Crude oil gathering assets are located in Oklahoma and serve crude oil production in the SCOOP and STACK plays of the Anadarko Basin and in North Dakota and serve crude oil production in the Bakken Shale formation of the Williston Basin. The Partnership’s natural gas transportation and storage assets consist primarily of an interstate pipeline system extending from western Oklahoma and the Texas Panhandle to Louisiana, an interstate pipeline system extending from Louisiana to Illinois, an intrastate pipeline system in Oklahoma, and our investment in SESH, a pipeline extending from Louisiana to Alabama. CenterPoint Energy and OGE Energy each have 50% of the management interests in Enable GP. Enable GP is the general partner of the Partnership and has no other operating activities. Enable GP is governed by a board made up of two representatives designated by each of CenterPoint Energy and OGE Energy, along with the Partnership’s Chief Executive Officer and three independent board members CenterPoint Energy and OGE Energy mutually agreed to appoint. CenterPoint Energy and OGE Energy also own a 40% and 60% interest, respectively, in the incentive distribution rights held by Enable GP. As of June 30, 2020, CenterPoint Energy held approximately 53.7% or 233,856,623 of the Partnership’s common units, and OGE Energy held approximately 25.5% or 110,982,805 of the Partnership’s common units. Additionally, CenterPoint Energy holds 14,520,000 Series A Preferred Units. The limited partner interests of the Partnership have limited voting rights on matters affecting the business. As such, limited partners do not have rights to elect the Partnership’s general partner on an annual or continuing basis and may not remove Enable GP, its current general partner, without at least a 75% vote by all unitholders, including all units held by the Partnership’s limited partners, and Enable GP and its affiliates, voting together as a single class. As of June 30, 2020, the Partnership owned a 50% interest in SESH. See Note 8 for further discussion of SESH. For the six months ended June 30, 2020, the Partnership held a 50% ownership in Atoka and consolidated Atoka in its Condensed Consolidated Financial Statements as EOIT acted as the managing member of Atoka and had control over the operations of Atoka. In addition, the Partnership held a 60% interest in ESCP, which is consolidated in its Condensed Consolidated Financial Statements as EOCS acted as the managing member of ESCP and had control over the operations of ESCP. Basis of Presentation The accompanying condensed consolidated financial statements and related notes of the Partnership have been prepared pursuant to the rules and regulations of the SEC and GAAP. Pursuant to such rules and regulations, certain disclosures normally included in financial statements prepared in accordance with GAAP have been omitted. The accompanying condensed consolidated financial statements and related notes should be read in conjunction with the consolidated financial statements and related notes included in our Annual Report. The condensed consolidated financial statements and the related notes reflect all normal recurring adjustments that are, in the opinion of management, necessary to present fairly the financial position and results of operations for the respective periods. Amounts reported in the Partnership’s Condensed Consolidated Statements of Income are not necessarily indicative of amounts expected for a full-year period due to the effects of, among other things, (a) seasonal fluctuations in demand for energy and energy services, (b) changes in energy commodity prices, (c) timing of maintenance and other expenditures, (d) acquisitions and dispositions of businesses, assets and other interests, and (e) the impact of the ongoing COVID-19 pandemic and the economic effects of the pandemic which have resulted in a substantial decrease in natural gas, NGLs and crude oil prices. For a description of the Partnership’s reportable segments, see Note 16. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Sales and Retirements of Assets On September 23, 2019, the Partnership entered into an agreement to sell its undivided 1/12th interest in the Bistineau Storage Facility in Louisiana for approximately $19 million. On January 27, 2020, FERC approved the sale. The Partnership closed the sale on April 1, 2020. We did not recognize a gain or loss on this transaction. In April 2020, we sustained damage to an approximately 100-mile gas gathering system in the Ark-La-Tex Basin of our gathering and processing segment. We have ceased operation of this system and are in the process of retiring it. We recognized a loss on retirement of approximately $20 million during the three months ended June 30, 2020, which is included in Operation and maintenance expense in the Condensed Consolidated Statements of Income. Depreciation Expense On March 26, 2020, FERC issued an order approving MRT’s 2018 Rate Case and 2019 Rate Case settlements. As a result of the settlements, the new depreciation rates for MRT have been applied in accordance with the order. The new depreciation rates did not result in a material change in depreciation expense or results of operations. Accounts Receivable and Allowance for Doubtful Accounts The Partnership adopted ASU No. 2016-13, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” on January 1, 2020. Upon adoption, the Partnership recognized a $3 million cumulative adjustment to Partners’ Equity and a corresponding adjustment to Allowance for doubtful accounts. Accounts receivable are recorded at the invoiced amount and do not typically bear interest. The determination of the allowance for doubtful accounts requires management to make estimates and judgments regarding our customers’ ability to pay. The allowance for doubtful accounts is determined based primarily upon the historical loss-rate method established for various pools of accounts receivables with similar levels of credit risk. The historical loss-rates are then adjusted, as necessary, based on current conditions and forecast information that could result in future uncollectable amounts. On an ongoing basis, we evaluate our customers’ financial strength and liquidity based on aging of accounts receivable, payment history, and review of other relevant information, including ratings agency credit ratings and alerts, publicly available reports and news releases, and bank and trade references. It is the policy of management to review the outstanding accounts receivable and other receivable balances within other assets at least quarterly, giving consideration to credit losses, the aging of receivables, specific customer circumstances that may impact their ability to pay the amounts due and current and forecast economic conditions over the assets contractual lives. The following table summarizes the required allowance for doubtful accounts. June 30, 2020 January 1, 2020 (In millions) Accounts receivable $ 2 $ 2 Other assets 3 3 Total Allowance for doubtful accounts $ 5 $ 5 Inventory Natural gas inventory is held, through the transportation and storage segment, to provide operational support for pipeline deliveries and to manage leased intrastate storage capacity. Natural gas liquids inventory is held, through the gathering and processing segment, due to timing differences between the production of certain natural gas liquids and ultimate sale to third parties. Natural gas and natural gas liquids inventory is valued using moving average cost and is subsequently recorded at the lower of cost or net realizable value. The Partnership recorded write-downs to net realizable value related to natural gas and natural gas liquids inventory of $1 million and $5 million during the three months ended June 30, 2020 and 2019, respectively, and $7 million and $6 million during the six months ended June 30, 2020 and 2019, respectively.

New Accounting Pronouncements

New Accounting Pronouncements	6 Months Ended
	Jun. 30, 2020
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncements	New Accounting Pronouncements Accounting Standards to be Adopted in Future Periods Reference Rate Reform In March 2020, the FASB issued ASU No. 2020-04, “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting.” This standard provides optional guidance, for a limited time, to ease the potential burden in accounting for or recognizing the effects of reference rate reform on financial reporting. The standard was effective upon issuance and generally can be applied through December 31, 2022. The Partnership is currently evaluating the impact this ASU will have on our Condensed Consolidated Financial Statements and related disclosures.

Revenue

Revenue	6 Months Ended
	Jun. 30, 2020
Revenue from Contract with Customer [Abstract]
Revenue	Revenues The following tables disaggregate total revenues by major source from contracts with customers and the gain (loss) on derivative activity for the three and six months ended June 30, 2020 and 2019. Three Months Ended June 30, 2020 Gathering and Transportation Eliminations Total (In millions) Revenues: Product sales: Natural gas $ 47 $ 57 $ (53) $ 51 Natural gas liquids 143 3 (3) 143 Condensate 7 — — 7 Total revenues from natural gas, natural gas liquids, and condensate 197 60 (56) 201 Loss on derivative activity (4) (1) — (5) Total Product sales $ 193 $ 59 $ (56) $ 196 Service revenues: Demand revenues $ 34 $ 113 $ — $ 147 Volume-dependent revenues 164 11 (3) 172 Total Service revenues $ 198 $ 124 $ (3) $ 319 Total Revenues $ 391 $ 183 $ (59) $ 515 Three Months Ended June 30, 2019 Gathering and Transportation Eliminations Total (In millions) Revenues: Product sales: Natural gas $ 94 $ 108 $ (95) $ 107 Natural gas liquids 237 5 (5) 237 Condensate 33 — — 33 Total revenues from natural gas, natural gas liquids, and condensate 364 113 (100) 377 Gain on derivative activity 15 1 — 16 Total Product sales $ 379 $ 114 $ (100) $ 393 Service revenues: Demand revenues $ 68 $ 123 $ — $ 191 Volume-dependent revenues 140 15 (4) 151 Total Service revenues $ 208 $ 138 $ (4) $ 342 Total Revenues $ 587 $ 252 $ (104) $ 735 Six Months Ended June 30, 2020 Gathering and Transportation Eliminations Total (In millions) Revenues: Product sales: Natural gas $ 103 $ 130 $ (113) $ 120 Natural gas liquids 315 5 (5) 315 Condensate 34 — — 34 Total revenues from natural gas, natural gas liquids, and condensate 452 135 (118) 469 Gain (loss) on derivative activity 16 (1) — 15 Total Product sales $ 468 $ 134 $ (118) $ 484 Service revenues: Demand revenues $ 73 $ 255 $ — $ 328 Volume-dependent revenues 327 28 (4) 351 Total Service revenues $ 400 $ 283 $ (4) $ 679 Total Revenues $ 868 $ 417 $ (122) $ 1,163 Six Months Ended June 30, 2019 Gathering and Transportation Eliminations Total (In millions) Revenues: Product sales: Natural gas $ 222 $ 270 $ (236) $ 256 Natural gas liquids 507 11 (11) 507 Condensate 67 — — 67 Total revenues from natural gas, natural gas liquids, and condensate 796 281 (247) 830 Gain on derivative activity 6 — — 6 Total Product sales $ 802 $ 281 $ (247) $ 836 Service revenues: Demand revenues $ 128 $ 254 $ — $ 382 Volume-dependent revenues 287 33 (8) 312 Total Service revenues $ 415 $ 287 $ (8) $ 694 Total Revenues $ 1,217 $ 568 $ (255) $ 1,530 MRT Rate Case Settlements In June 2018, MRT filed a general NGA rate case (the 2018 Rate Case), and in October 2019, MRT filed a second rate case (the 2019 Rate Case). MRT began collecting the rates proposed in the 2018 Rate Case, subject to refund, on January 1, 2019. On March 26, 2020, FERC issued an order approving settlements filed in the 2018 Rate Case and the 2019 Rate Case. Upon issuance of the order and approval of the settlement of the MRT rate cases, the Partnership recognized $17 million of revenues from amounts previously held in reserve related to transportation and storage services performed in 2019. In May 2020, $21 million previously held in reserve was refunded to customers, which is inclusive of interest. Accounts Receivable The following table summarizes the components of accounts receivable, net of allowance for doubtful accounts. June 30, 2020 December 31, 2019 (In millions) Accounts Receivable: Customers $ 205 $ 239 Contract assets (1) 29 18 Non-customers 4 12 Total Accounts Receivable (2) $ 238 $ 269 ____________________ (1) Contract assets reflected in Total Accounts Receivable include accrued minimum volume commitments. Contract assets are primarily attributable to revenues associated with estimated shortfall volumes on certain annual minimum volume commitment arrangements. Total Accounts Receivable does not include contract assets related to firm service transportation contracts with tiered rates of $8 million as of June 30, 2020 and $6 million as of December 31, 2019, which are reflected in Other Assets. (2) Total Accounts Receivable includes Accounts receivable, net of allowance for doubtful accounts and Accounts receivable—affiliated companies. Contract Liabilities Our contract liabilities primarily consist of prepayments received from customers for which the good or service has not yet been provided in connection with the prepayment. The table below summarizes the change in the contract liabilities. June 30, 2020 December 31, 2019 Amounts recognized in revenues (In millions) Deferred revenues (1) $ 48 $ 48 $ 20 The table below summarizes the timing of recognition of these contract liabilities as of June 30, 2020. 2020 2021 2022 2023 2024 and After (In millions) Deferred revenues (1) $ 21 $ 8 $ 6 $ 6 $ 7 ____________________ (1) Deferred revenues includes deferred revenue — affiliated companies. This amount is included in Other current liabilities and Other long-term liabilities. Remaining Performance Obligations Our remaining performance obligations consist primarily of firm arrangements and minimum volume commitment arrangements. Upon completion of the performance obligations associated with these arrangements, customers are invoiced and revenue is recognized as Service revenues in the Condensed Consolidated Statements of Income. The table below summarizes the timing of recognition of the remaining performance obligations as of June 30, 2020. 2020 2021 2022 2023 2024 and After (In millions) Transportation and Storage $ 233 $ 406 $ 345 $ 324 $ 1,167 Gathering and Processing 57 121 123 121 313 Total remaining performance obligations $ 290 $ 527 $ 468 $ 445 $ 1,480

Leases

Leases	6 Months Ended
	Jun. 30, 2020
Leases [Abstract]
Leases	Leases As of June 30, 2020, we have right-of-use assets of $28 million recorded as Other Assets, $5 million of corresponding obligations recorded as Other Current Liabilities and $26 million of corresponding obligations recorded as Other Liabilities on the Partnership’s Condensed Consolidated Balance Sheet. All lease obligations outstanding during the three and six months ended June 30, 2020 were classified as operating leases, therefore all cash flows are reflected in Cash Flows from Operating Activities. The following table presents the Partnership’s rental costs associated with field equipment and buildings. Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions) Rental Costs: Field equipment $ 4 $ 5 $ 9 $ 12 Office space 1 2 2 4 As of June 30, 2020, the weighted average remaining lease term is 6.9 years and the weighted average discount rate is 5.46%. The following tables present the Partnership’s lease cost. Three Months Ended June 30, 2020 Gathering and Transportation Total (In millions) Lease Cost: Operating lease cost $ 1 $ — $ 1 Short-term lease cost 4 — 4 Total Lease Cost $ 5 $ — $ 5 Three Months Ended June 30, 2019 Gathering and Transportation Total (In millions) Lease Cost: Operating lease cost $ 3 $ — $ 3 Short-term lease cost 4 — 4 Total Lease Cost $ 7 $ — $ 7 Six Months Ended June 30, 2020 Gathering and Transportation Total (In millions) Lease Cost: Operating lease cost $ 3 $ — $ 3 Short-term lease cost 7 — 7 Variable lease cost 1 — 1 Total Lease Cost $ 11 $ — $ 11 Six Months Ended June 30, 2019 Gathering and Transportation Total (In millions) Lease Cost: Operating lease cost $ 5 $ — $ 5 Short-term lease cost 10 1 11 Total Lease Cost $ 15 $ 1 $ 16 Under ASC 842, as of June 30, 2020 , the Partnership has operating lease obligations expiring at various dates. The $4 million difference between undiscounted cash flows for operating leases and our $31 million of lease obligations is due to the impact of the applicable discount rate. Undiscounted cash flows for operating lease liabilities are as follows: Year Ended December 31, 2020 2021 2022 2023 2024 2025 and After Total (In millions) Noncancellable operating leases $ 4 $ 6 $ 5 $ 5 $ 4 $ 11 $ 35

Earnings Per Limited Partner Un

Earnings Per Limited Partner Unit	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
Earnings Per Limited Partner Unit	Earnings Per Limited Partner Unit The following table illustrates the Partnership’s calculation of earnings per unit for common units. Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions, except per unit data) Net income $ 44 $ 124 $ 149 $ 247 Net (loss) income attributable to noncontrolling interest — — (7) 1 Series A Preferred Unit distributions 9 9 18 18 General partner interest in net income — — — — Net income available to common unitholders $ 35 $ 115 $ 138 $ 228 Net income allocable to common units $ 35 $ 115 $ 138 $ 228 Dilutive effect of Series A Preferred Unit distributions — — 18 — Diluted net income allocable to common units $ 35 $ 115 $ 156 $ 228 Basic earnings per unit Common units $ 0.08 $ 0.26 $ 0.32 $ 0.52 Basic weighted average number of common units outstanding (1) 437 437 437 436 Dilutive effect of Series A Preferred Units — — 79 — Diluted weighted average number of common units outstanding 437 437 516 436 Diluted earnings per unit Common units $ 0.08 $ 0.26 $ 0.30 $ 0.52 ____________________ (1) Basic weighted average number of outstanding common units includes approximately two million time-based phantom units for the three and six months ended June 30, 2020, and one million time-based phantom units for the three and six months ended June 30, 2019.

Partners' Equity

Partners' Equity	6 Months Ended
	Jun. 30, 2020
Equity [Abstract]
Partners' Equity	Partners’ Equity The Partnership Agreement requires that, within 60 days after the end of each quarter, the Partnership distribute all of its available cash (as defined in the Partnership Agreement) to unitholders of record on the applicable record date. The Partnership paid or has authorized payment of the following cash distributions to common unitholders, as applicable, during 2020 and 2019 (in millions, except for per unit amounts): Three Months Ended Record Date Payment Date Per Unit Distribution Total Cash Distribution June 30, 2020 (1) August 18, 2020 August 25, 2020 $ 0.16525 $ 72 March 31, 2020 May 19, 2020 May 27, 2020 0.16525 72 December 31, 2019 February 18, 2020 February 25, 2020 0.3305 144 September 30, 2019 November 19, 2019 November 26, 2019 0.3305 144 June 30, 2019 August 20, 2019 August 27, 2019 0.3305 144 March 31, 2019 May 21, 2019 May 29, 2019 0.318 138 _____________________ (1) The Board of Directors declared a $0.16525 per common unit cash distribution on August 4, 2020, to be paid on August 25, 2020 to common unitholders of record at the close of business on August 18, 2020. The Partnership paid or has authorized payment of the following cash distributions to holders of the Series A Preferred Units during 2020 and 2019 (in millions, except for per unit amounts): Three Months Ended Record Date Payment Date Per Unit Distribution Total Cash Distribution June 30, 2020 (1) August 4, 2020 August 14, 2020 $ 0.625 $ 9 March 31, 2020 May 5, 2020 May 15, 2020 0.625 9 December 31, 2019 February 7, 2020 February 14, 2020 0.625 9 September 30, 2019 November 5, 2019 November 14, 2019 0.625 9 June 30, 2019 August 2, 2019 August 14, 2019 0.625 9 March 31, 2019 April 29, 2019 May 15, 2019 0.625 9 _____________________ (1) The Board of Directors declared a $0.625 per Series A Preferred Unit cash distribution on August 4, 2020, to be paid on August 14, 2020, to Series A Preferred unitholders of record at the close of business on August 4, 2020. ATM Program On May 12, 2017, the Partnership entered into an ATM Equity Offering Sales Agreement, pursuant to which the Partnership may issue and sell common units having an aggregate offering price of up to $200 million, by sales methods and at prices determined by market conditions and other factors at the time of our offerings. The registration statement filed with the SEC for the ATM Program expired on May 12, 2020, and the Partnership did not file a replacement registration statement.

Impairment of Long-lived Assets

Impairment of Long-lived Assets and Goodwill	6 Months Ended
	Jun. 30, 2020
Impairment of Long-lived Assets and Goodwill [Abstract]
Impairment of Long-lived Assets and Goodwill [Text Block]	(7) Impairments of Long-lived Assets and Goodwill Impairment of Long-lived Assets The Partnership periodically evaluates long-lived assets, including property, plant and equipment when events or changes in circumstances indicate that the carrying value of these assets may not be recoverable. The determination of whether an impairment has occurred is based on an estimate of undiscounted cash flows attributable to the assets, as compared to the carrying value of the assets. Due to decreases in natural gas and NGL market prices during 2020 as a result of the ongoing COVID-19 pandemic and the economic effects of the pandemic, together with the dispute over crude oil production levels between Russia and members of OPEC led by Saudi Arabia, as of March 31, 2020, management reassessed the carrying value of the Atoka assets, in which the Partnership owns a 50% interest in the consolidated joint venture, which is a component of the gathering and processing segment. Based on forecasted future undiscounted cash flows, management determined that the carrying value of the Atoka assets were not fully recoverable. The Partnership utilized the income approach (generally accepted valuation approach) to estimate the fair value of these assets. The primary inputs are forecasted cash flows and the discount rate. The fair value measurement is based on inputs that are not observable in the market and thus represent Level 3 inputs. Applying a discounted cash flow model to the property, plant and equipment, the Partnership recognized a $16 million impairment, which is included in Impairments on the Condensed Consolidated Statements of Income during the six months ended June 30, 2020 . Impairment of Goodwill In the fourth quarter of 2017, as a result of the acquisition of ETGP, the Partnership recorded $12 million of goodwill associated with the Ark-La-Tex Basin reporting unit, included in the gathering and processing reportable segment. The Partnership tests its goodwill for impairment annually on October 1st, or more frequently if events or changes in circumstances indicate that the carrying value of goodwill may not be recoverable. Goodwill is assessed for impairment by comparing the fair value of the reporting unit with its book value, including goodwill. During 2020, the commodity price declines due to the existing oversupply of crude oil, NGLs and natural gas were exacerbated by t he ongoing COVID-19 pandemic and the economic effects of the pandemic, in addition to the dispute over crude oil production levels between Russia and members of OPEC led by Saudi Arabia in the first quarter . Despite the subsequent agreement in April 2020 by a coalition of nations including Russia and Saudi Arabia to reduce production of crude oil, the price of NGLs and crude oil have remained significantly lower than pre-pandemic levels. Amid such crude oil, NGL and natural gas price declines, producers have been cutting back spending and shifting their focus from emphasizing reserves growth, to increasing net cash flows and reducing outstanding debt, which consequently resulted in a decrease in rig count and in forecasted producer activity in the Ark-La-Tex Basin reporting unit during the first quarter of 2020. At the same time, unit prices and market multiples for midstream companies with gathering and processing operations have dropped to their lowest levels in the last three years. Due to the continuing decrease in forward commodity prices, the reduction in forecasted producer activities, the resulting decrease in our forecasted cash flows and the increase in the weighted average cost of capital, the Partnership determined that the fair value of the goodwill associated with our Ark-La-Tex Basin reporting unit would more likely than not be impaired. As a result, the Partnership performed a quantitative test for our goodwill and determined that the carrying value of the Ark-La-Tex Basin reporting unit exceeded its fair value and that goodwill associated with the Ark-La-Tex Basin was completely impaired in the amount of $12 million. The impairment is included in Impairments on the Condensed Consolidated Statements of Income for the six months ended June 30, 2020. The following table presents the change in carrying amount of goodwill in each of our reportable segments. Gathering and Processing Transportation and Storage Total (In millions) Balance as of December 31, 2019 $ 12 $ — $ 12 Goodwill impairment (12) — (12) Balance as of June 30, 2020 $ — $ — $ —

Investment in Equity Method Aff

Investment in Equity Method Affiliate	6 Months Ended
	Jun. 30, 2020
Equity Method Investments and Joint Ventures [Abstract]
Investment in Equity Method Affiliate	Investment in Equity Method Affiliate The Partnership uses the equity method of accounting for investments in entities in which it has an ownership interest between 20% and 50% and exercises significant influence. SESH is owned 50% by Enbridge, Inc. and 50% by the Partnership. Pursuant to the terms of the SESH LLC Agreement, if, at any time, CenterPoint Energy has a right to receive less than 50% of our distributions through its interest in the Partnership and its economic interest in Enable GP, or does not have the ability to exercise certain control rights, Enbridge, Inc. may, under certain circumstances, have the right to purchase the Partnership’s interest in SESH at fair market value, subject to certain exceptions. The Partnership shares operations of SESH with Enbridge, Inc. under service agreements. The Partnership is responsible for the field operations of SESH. SESH reimburses each party for actual costs incurred, which are billed based upon a combination of direct charges and allocations. The Partnership billed SESH $2 million and $7 million during the three months ended June 30, 2020 and 2019, respectively, and $8 million and $10 million during the six months ended June 30, 2020 and 2019, respectively, associated with these service agreements. The Partnership includes equity in earnings of equity method affiliate under the Other Income (Expense) caption in the Condensed Consolidated Statements of Income. The following table presents the amount of Equity in earnings of equity method affiliate recognized and Distributions from equity method affiliate received. Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions) Equity in Earnings of Equity Method Affiliate $ 5 $ 4 $ 11 $ 7 Distributions from Equity Method Affiliate (1) $ 9 $ 4 $ 19 $ 16 ___________________ (1) Distributions from equity method affiliate includes a $5 million and $4 million return on investment and a $4 million and $0 return of investment for the three months ended June 30, 2020 and 2019, respectively. Distributions from equity method affiliate includes an $11 million and $7 million return on investment and an $8 million and $9 million return of investment for the six months ended June 30, 2020 and 2019, respectively. The following table includes the summarized financial information of SESH. Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions) Income Statements: Revenues $ 28 $ 27 $ 55 $ 54 Operating income $ 13 $ 11 $ 29 $ 22 Net income $ 10 $ 7 $ 21 $ 14

Debt

Debt	6 Months Ended
	Jun. 30, 2020
Debt Disclosure [Abstract]
Debt	Debt The following table presents the Partnership’s outstanding debt. June 30, 2020 December 31, 2019 Outstanding Principal Discount (1) Total Debt Outstanding Principal Premium (Discount) (1) Total Debt (In millions) Commercial Paper $ 30 $ — $ 30 $ 155 $ — $ 155 Revolving Credit Facility 400 — 400 — — — 2019 Term Loan Agreement 800 — 800 800 — 800 2024 Notes 600 — 600 600 — 600 2027 Notes 700 (2) 698 700 (2) 698 2028 Notes 800 (5) 795 800 (5) 795 2029 Notes 547 (1) 546 550 (1) 549 2044 Notes 531 — 531 550 — 550 EOIT Senior Notes — — — 250 1 251 Total debt $ 4,408 $ (8) $ 4,400 $ 4,405 $ (7) $ 4,398 Less: Short-term debt (2) 30 155 Less: Current portion of long-term debt (3) — 251 Less: Unamortized debt expense (4) 21 23 Total long-term debt $ 4,349 $ 3,969 ____________________ (1) Unamortized premium (discount) on long-term debt is amortized over the life of the respective debt. (2) Short-term debt includes $30 million and $155 million of outstanding commercial paper as of June 30, 2020 and December 31, 2019, respectively. (3) As of December 31, 2019, Current portion of long-term debt included $251 million outstanding balance of the EOIT Senior Notes which were repaid in March 2020. (4) As of June 30, 2020 and December 31, 2019, there was an additional $4 million of unamortized debt expense related to the Revolving Credit Facility included in Other assets, not included above. Commercial Paper The Partnership has a commercial paper program, pursuant to which the Partnership is authorized to issue up to $1.4 billion of commercial paper. The commercial paper program is supported by our Revolving Credit Facility, and outstanding commercial paper effectively reduces our borrowing capacity thereunder. There were $30 million and $155 million outstanding under our commercial paper program at June 30, 2020 and December 31, 2019 , respectively. A s of June 30, 2020, the weighted average interest rate for the outstanding commercial paper was 1.00%. Revolving Credit Facility The Partnership’s Revolving Credit Facility is a $1.75 billion, five one The Revolving Credit Facility provides that outstanding borrowings bear interest at the LIBOR and/or an alternate base rate, at the Partnership’s election, plus an applicable margin. The applicable margin is based on the Partnership’s designated credit ratings from S&P, Moody’s and Fitch Ratings. As of June 30, 2020, the applicable margin for LIBOR-based borrowings under the Revolving Credit Facility was 1.50% based on the Partnership’s credit ratings. In addition, the Revolving Credit Facility requires the Partnership to pay a fee on unused commitments. The commitment fee is based on the Partnership’s credit ratings. As of June 30, 2020, the commitment fee under the restated Revolving Credit Facility was 0.20% per annum based on the Partnership’s credit ratings. The commitment fee is recorded as interest expense in the Partnership’s Condensed Consolidated Statements of Income. 2019 Term Loan Agreement On January 29, 2019, the Partnership entered into an unsecured term loan agreement with Bank of America, N.A., as administrative agent, and the several lenders thereto. As of June 30, 2020, there was $800 million outstanding under the 2019 Term Loan Agreement. The 2019 Term Loan Agreement has a scheduled maturity date of January 29, 2022, but contains an option, which may be exercised up to two times, to extend the maturity date for an additional one Senior Notes As of June 30, 2020, the Partnership’s debt included the 2024 Notes, 2027 Notes, 2028 Notes, 2029 Notes and 2044 Notes, which had $8 million of unamortized discount and $21 million of unamortized debt expense at June 30, 2020, resulting in effective interest rates of 4.01%, 4.56%, 5.19%, 4.31% and 5.09%, respectively, during the six months ended June 30, 2020. In March 2020, the Partnership’s EOIT Senior Notes matured and were paid using proceeds from the Revolving Credit Facility. During the three months ended June 30, 2020, the Partnership repurchased $22 million aggregate principal amount of the 2029 Notes and 2044 Notes in open market transactions for approximately $17 million plus accrued interest, which resulted in a $5 million gain on extinguishment of debt. The gain is included in Other, net in the Condensed Consolidated Statements of Income. As of June 30, 2020, the Partnership was in compliance with all of its debt agreements, including financial covenants.

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	6 Months Ended
	Jun. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities The primary risks managed using derivative instruments are commodity price and interest rate risks. Derivatives Not Designated as Hedging Instruments Derivative instruments not designated as hedging instruments for accounting purposes are utilized to manage the Partnership’s exposure to commodity price risk. For derivative instruments not designated as hedging instruments, the gain or loss on the derivative is recognized currently in earnings. Quantitative Disclosures Related to Derivative Instruments Not Designated as Hedging Instruments The following table presents the Partnership’s derivative instruments that were not designated as hedging instruments for accounting purposes. June 30, 2020 December 31, 2019 Gross Notional Volume Purchases Sales Purchases Sales Natural gas— TBtu (1) Financial fixed futures/swaps 6 26 10 19 Financial basis futures/swaps 5 39 11 30 Financial swaptions (2) — 9 — 2 Physical purchases/sales — 3 — 6 Crude oil (for condensate)— MBbl (3) Financial futures/swaps — 540 — 990 Financial swaptions (2) — 150 — 225 Natural gas liquids— MBbl (4) Financial futures/swaps 1,830 1,840 2,490 2,415 Financial options — 60 — — ____________________ (1) As of June 30, 2020, 88.1% of the natural gas contracts had durations of one year or less and 11.9% had durations of more than one year and less than two years. As of December 31, 2019, 86.6% of the natural gas contracts had durations of one year or less and 13.4% had durations of more than one year and less than two years. (2) The notional volume contains a combined derivative instrument consisting of a fixed price swap and a sold option, which gives the counterparties the right, but not the obligation, to increase the notional volume hedged under the fixed price swap until the option expiration date. The notional volume represents the volume prior to option exercise. (3) As of June 30, 2020, 91.3% of the crude oil (for condensate) contracts had durations of one year or less and 8.7% had durations of more than one year and less than two years. As of December 31, 2019, 72.8% of the crude oil (for condensate) contracts had durations of one year or less and 27.2% had durations of more than one year and less than two years. (4) As of June 30, 2020, 97.5% of the natural gas liquids contracts had durations of one year or less and 2.5% had durations of more than one year and less than two years. As of December 31, 2019, 72.2% of the natural gas liquids contracts had durations of one year or less and 27.8% had durations of more than one year and less than two years. Derivatives Designated as Hedging Instruments Derivative instruments designated as hedging instruments for accounting purposes are utilized in managing the Partnership’s interest rate risk exposures. Quantitative Disclosures Related to Derivative Instruments Designated as Hedging Instruments The following table presents the Partnership’s derivative instruments that were designated as hedging instruments for accounting purposes. June 30, 2020 December 31, 2019 Gross Notional Value (In millions) Interest rate swaps $ 300 $ 300 Balance Sheet Presentation Related to Derivative Instruments The following table presents the fair value of the derivative instruments that are included in the Partnership’s Condensed Consolidated Balance Sheets that were not designated as hedging instruments for accounting purposes. June 30, 2020 December 31, 2019 Fair Value Instrument Balance Sheet Location Assets Liabilities Assets Liabilities (In millions) Natural gas Financial futures/swaps Other Current $ 7 $ 7 $ 7 $ 5 Financial swaptions Other Current 1 2 — — Physical purchases/sales Other Current 2 — 5 — Financial futures/swaps Other — — — 1 Financial swaptions Other 1 1 — — Crude oil (for condensate) Financial futures/swaps Other Current 2 14 1 19 Financial swaptions Other Current 3 — — — Financial futures/swaps Other — 2 — 8 Natural gas liquids Financial futures/swaps Other Current 20 3 25 3 Financial futures/swaps Other 2 — 11 2 Total gross commodity derivatives (1) $ 38 $ 29 $ 49 $ 38 _____________________ (1) See Note 11 for a reconciliation of the Partnership’s commodity derivatives fair value to the Partnership’s Condensed Consolidated Balance Sheets as of June 30, 2020 and December 31, 2019. The following table presents the fair value of the derivative instruments that are included in the Partnership’s Condensed Consolidated Balance Sheets that were designated as hedging instruments for accounting purposes. June 30, 2020 December 31, 2019 Fair Value Instrument Balance Sheet Location Assets Liabilities Assets Liabilities (In millions) Interest rate swaps Other Current $ — $ 6 $ — $ 1 Interest rate swaps Other — 3 — 2 Total gross interest rate derivatives (1) $ — $ 9 $ — $ 3 _____________________ (1) All interest rate derivative instruments that were designated as cash flow hedges are considered Level 2 as of June 30, 2020 and December 31, 2019. Income Statement Presentation Related to Derivative Instruments The following table presents the effect of derivative instruments on the Partnership’s Condensed Consolidated Statements of Income. Amounts Recognized in Income Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions) Natural gas Financial futures/swaps gains (losses) $ (1) $ 9 $ 3 $ 8 Financial swaptions losses (1) — (2) — Physical purchases/sales gains — 1 1 — Crude oil (for condensate) Financial futures/swaps gains (losses) (7) (10) 12 (21) Financial swaptions gains (losses) (2) — 2 — Natural gas liquids Financial futures/swaps gains (losses) 6 16 (1) 19 Total $ (5) $ 16 $ 15 $ 6 For derivatives not designated as hedges in the tables above, amounts recognized in income for the periods ended June 30, 2020 and 2019, if any, are reported in Product sales. The following table presents the components of gain (loss) on derivative activity in the Partnership’s Condensed Consolidated Statements of Income. Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions) Change in fair value of commodity derivatives $ (12) $ 11 $ (2) $ (1) Realized gain on commodity derivatives 7 5 17 7 Gain (loss) on commodity derivative activity $ (5) $ 16 $ 15 $ 6 The following table presents the effect of derivative instruments that were designated as hedging instruments on the Partnership’s Condensed Consolidated Statements of Income. Amounts Recognized in Income Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions) Interest rate swaps losses $ (1) $ — $ (1) $ — Total $ (1) $ — $ (1) $ — Interest rate derivatives designated as hedges are recognized in income once settled. Settlement amounts recognized in income for the periods ended June 30, 2020 and 2019 are reported in Interest expense. Credit-Risk Related Contingent Features in Derivative Instruments In the event Moody’s or S&P were to lower the Partnership’s senior unsecured debt rating to a below investment grade rating, the Partnership could be required to provide additional credit assurances to third parties, which could include letters of credit or cash collateral to satisfy its obligation under its financial and physical contracts relating to derivative instruments that are in a net liability position. As of June 30, 2020, under these obligations, the Partnership has posted no cash collateral related to natural gas swaps and swaptions, crude oil swaps and swaptions and NGL swaps and $1 million of additional collateral would be required to be posted by the Partnership in the event of a credit ratings downgrade to a below investment grade rating. In certain situations where the Partnership’s credit rating is lowered by Moody’s or S&P, the Partnership could be subject to an

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Certain assets and liabilities are recorded at fair value in the Condensed Consolidated Balance Sheets and are categorized based upon the level of judgment associated with the inputs used to measure their value. The Partnership determines the appropriate level for each financial asset and liability on a quarterly basis and recognizes transfers between levels at the end of the reporting period. For the three and six months ended June 30, 2020, there were no transfers between levels. As of June 30, 2020, there were no contracts classified as Level 3. Estimated Fair Value of Financial Instruments The fair values of all accounts receivable, notes receivable, accounts payable, commercial paper and other such financial instruments on the Condensed Consolidated Balance Sheets are estimated to be approximately equivalent to their carrying amounts due to their short-term nature and have been excluded from the table below. The following table summarizes the fair value and carrying amount of the Partnership’s financial instruments. June 30, 2020 December 31, 2019 Carrying Amount Fair Value Carrying Amount Fair Value (In millions) Debt Revolving Credit Facility (Level 2) (1) $ 400 $ 400 $ — $ — 2019 Term Loan Agreement (Level 2) 800 800 800 800 2024 Notes (Level 2) 600 588 600 614 2027 Notes (Level 2) 698 648 698 698 2028 Notes (Level 2) 795 742 795 811 2029 Notes (Level 2) 546 476 549 526 2044 Notes (Level 2) 531 424 550 506 EOIT Senior Notes (Level 2) — — 251 252 ____________________ (1) Borrowing capacity is effectively reduced by our borrowings outstanding under the commercial paper program. $30 million and $155 million of commercial paper was outstanding as of June 30, 2020 and December 31, 2019, respectively. The fair value of the Partnership’s Revolving Credit Facility, 2019 Term Loan Agreement, 2024 Notes, 2027 Notes, 2028 Notes, 2029 Notes, 2044 Notes and EOIT Senior Notes is based on quoted market prices and estimates of current rates available for similar issues with similar maturities and is classified as Level 2 in the fair value hierarchy. Non-Financial Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis Certain assets and liabilities are measured at fair value on a nonrecurring basis; that is, the assets and liabilities are not measured at fair value on an ongoing basis but are subject to fair value adjustments in certain circumstances (e.g., when there is evidence of impairment). As of June 30, 2020, no material fair value adjustments or fair value measurements were required for these non-financial assets or liabilities, other than those discussed in Note 7. Based upon review of forecast undiscounted cash flows as of June 30, 2020, all of the asset groups were considered recoverable, other than those discussed in Note 7. Future price declines, throughput declines, contracted capacity declines, cost increases, regulatory or political environment changes and other changes in market conditions, including the oversupply of crude oil, NGLs and natural gas as well as the ongoing COVID-19 pandemic and the economic effects of the pandemic, could reduce forecast undiscounted cash flows. Contracts with Master Netting Arrangements As of June 30, 2020, the Partnership’s Level 2 interest rate derivatives are recorded as liabilities with no netting adjustments. The following tables summarize the Partnership’s other assets and liabilities that are measured at fair value on a recurring basis. June 30, 2020 Commodity Contracts Gas Imbalances (1) Assets Liabilities Assets (2) Liabilities (3) (In millions) Quoted market prices in active market for identical assets (Level 1) $ 6 $ 23 $ — $ — Significant other observable inputs (Level 2) 32 6 15 13 Total fair value 38 29 15 13 Netting adjustments (28) (28) — — Total $ 10 $ 1 $ 15 $ 13 December 31, 2019 Commodity Contracts Gas Imbalances (1) Assets Liabilities Assets (2) Liabilities (3) (In millions) Quoted market prices in active market for identical assets (Level 1) $ 5 $ 31 $ — $ — Significant other observable inputs (Level 2) 44 7 14 11 Total fair value 49 38 14 11 Netting adjustments (37) (37) — — Total $ 12 $ 1 $ 14 $ 11 ______________________ (1) The Partnership uses the market approach to fair value its gas imbalance assets and liabilities at individual, or where appropriate an average of, current market indices applicable to the Partnership’s operations, not to exceed net realizable value. There were no netting adjustments as of June 30, 2020 and December 31, 2019. (2) Gas imbalance assets exclude fuel reserves for under retained fuel due from shippers of $23 million and $21 million at June 30, 2020 and December 31, 2019, respectively, which fuel reserves are based on the value of natural gas at the time the imbalance was created, and which are not subject to revaluation at fair market value. (3) Gas imbalance liabilities exclude fuel reserves for over retained fuel due to shippers of $6 million and $8 million at June 30, 2020 and December 31, 2019, respectively, which fuel reserves are based on the value of natural gas at the time the imbalance was created, and which are not subject to revaluation at fair market value.

Supplemental Disclosure of Cash

Supplemental Disclosure of Cash Flow Information	6 Months Ended
	Jun. 30, 2020
Supplemental Cash Flow Information [Abstract]
Supplemental Disclosure of Cash Flow Information	Supplemental Disclosure of Cash Flow Information The following table provides information regarding supplemental cash flow information: Six Months Ended June 30, 2020 2019 (In millions) Supplemental Disclosure of Cash Flow Information: Cash Payments: Interest, net of capitalized interest $ 96 $ 95 Income taxes, net of refunds 1 1 Non-cash transactions: Accounts payable related to capital expenditures 8 31 Lease liabilities related to (derecognition) recognition of right-of-use assets (5) 42 Impact of adoption of financial instruments-credit losses accounting standard (Note 1) (3) — The following table reconciles cash and cash equivalents and restricted cash on the Condensed Consolidated Balance Sheets to cash, cash equivalents and restricted cash on the Condensed Consolidated Statements of Cash Flows: June 30, 2020 2019 (In millions) Cash and cash equivalents $ 11 $ 9 Restricted cash — 1 Cash, cash equivalents and restricted cash shown in the Condensed Consolidated Statements of Cash Flows $ 11 $ 10

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2020
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions MRT provides firm transportation and firm storage services to CenterPoint Energy’s LDCs in Arkansas and Louisiana. As part of the MRT rate case settlements, contracts for these services were extended and are in effect through July 31, 2028 and will remain in effect thereafter unless and until terminated by either party upon twelve months’ prior written notice. EGT provides natural gas transportation and storage services to CenterPoint Energy’s LDCs in Arkansas, Louisiana, Oklahoma and Northeast Texas under a combination of contracts that include the following types of services: firm transportation, firm transportation with seasonal demand, firm storage, no-notice transportation with storage and maximum rate firm transportation. The firm transportation, firm transportation with seasonal demand, firm storage and no-notice transportation with storage contracts were extended and have terms running through March 31, 2030. The maximum rate firm transportation contracts were also extended and have terms running through March 31, 2024. The Partnership’s revenues from affiliated companies accounted for 7% and 6% of total revenues during the six months ended June 30, 2020 and 2019, respectively. The following table presents the amounts of revenues from affiliated companies included in the Partnership’s Condensed Consolidated Statements of Income. Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions) Gas transportation and storage service revenues — CenterPoint Energy $ 22 $ 23 $ 59 $ 56 Natural gas product sales — CenterPoint Energy 1 3 1 4 Gas transportation and storage service revenues — OGE Energy 10 13 19 26 Natural gas product sales — OGE Energy — — 5 1 Total revenues — affiliated companies $ 33 $ 39 $ 84 $ 87 The following table presents the amounts of natural gas purchased from affiliated companies included in the Partnership’s Condensed Consolidated Statements of Income. Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions) Cost of natural gas purchases — CenterPoint Energy $ — $ — $ 1 $ — Cost of natural gas purchases — OGE Energy 6 7 14 13 Total cost of natural gas purchases — affiliated companies $ 6 $ 7 $ 15 $ 13 Corporate services and seconded employees The Partnership receives services and support functions from each of CenterPoint Energy and OGE Energy under services agreements for an initial term that ended on April 30, 2016. The services agreements automatically extend year-to-year at the end of the initial term, unless terminated by the Partnership with at least 90 days’ notice prior to the end of any extension. Additionally, the Partnership may terminate the services agreements at any time with 180 days’ notice, if approved by the Board of Enable GP. The Partnership reimburses CenterPoint Energy and OGE Energy for these services up to annual caps, which for 2020 are $0 million and $1 million, respectively. As of June 30, 2020 , the Partnership had certain employees who are participants under OGE Energy’s defined benefit and retiree medical plans, who will remain seconded to the Partnership, subject to certain termination rights of the Partnership and OGE Energy. The Partnership’s reimbursement of OGE Energy for seconded employee costs arising out of OGE Energy’s defined benefit and retiree medical plans is fixed at actual cost subject to an annual cap of $5 million until secondment is terminated. The following table presents the amounts charged to the Partnership by affiliates for seconded employees, included primarily in Operation and maintenance and General and administrative expenses in the Partnership’s Condensed Consolidated Statements of Income. Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions) Seconded Employee Costs — OGE Energy $ 5 $ 5 $ 8 $ 11

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies The Partnership is routinely involved in legal, environmental, tax and regulatory proceedings before various courts, regulatory commissions and governmental agencies regarding matters arising in the ordinary course of business. Some of these proceedings may from time to time involve substantial amounts. The Partnership regularly analyzes current information and, as necessary, provides accruals for probable liabilities on the eventual disposition of these matters. The Partnership does not currently expect the disposition of these matters to have a material adverse effect on its financial condition, results of operations or cash flows. On January 1, 2017, the Partnership entered into a 10-year gathering and processing agreement, which became effective on July 1, 2018, with an affiliate of Energy Transfer Partners, LP for deliveries to the Godley Plant in Johnson County, Texas. As of June 30, 2020, the Partnership estimates the remaining associated minimum volume commitment fee to be $181 million. Minimum volume commitment fees are expected to be $9 million for the remainder of 2020, $23 million per year from 2021 through 2027 and $11 million in 2028. On September 13, 2018, the Partnership executed a precedent agreement for the development of the Gulf Run Pipeline, an interstate natural gas transportation project. On January 30, 2019, a final investment decision was made by Golden Pass LNG, the cornerstone shipper for the liquefied natural gas facility to be served by the Gulf Run Pipeline project.

Equity-Based Compensation

Equity-Based Compensation	6 Months Ended
	Jun. 30, 2020
Share-based Payment Arrangement [Abstract]
Equity-Based Compensation	Equity-Based Compensation The following table summarizes the Partnership’s equity-based compensation expense related to performance units and phantom units for the Partnership’s employees and independent directors. Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions) Performance units $ 2 $ 2 $ 4 $ 5 Phantom units 1 3 3 4 Total compensation expense $ 3 $ 5 $ 7 $ 9 The following table presents the assumptions related to the performance share units granted in 2020. 2020 Number of units granted 933,738 Fair value of units granted $ 7.00 Expected distribution yield 12.27 % Expected price volatility 27.70 % Risk-free interest rate 0.85 % Expected life of units (in years) 3 The following table presents the number of phantom units granted and the grant date fair value related to the phantom units granted in 2020. 2020 Phantom Units granted 947,632 Fair value of phantom units granted $2.67 - $10.13 Units Outstanding A summary of the activity for the Partnership’s performance units and phantom units applicable to the Partnership’s employees at June 30, 2020 and changes during 2020 are shown in the following table. Performance Units Phantom Units Number Weighted Average Grant-Date Fair Value, Per Unit Number Weighted Average Grant-Date Fair Value, Per Unit (In millions, except unit data) Units outstanding at December 31, 2019 1,393,329 $ 19.04 1,392,560 $ 14.65 Granted (1) 933,738 7.00 947,632 6.55 Vested (2) (385,267) 19.23 (360,005) 16.02 Forfeited (139,024) 14.57 (172,016) 10.49 Units outstanding at June 30, 2020 1,802,776 $ 13.11 1,808,171 $ 10.53 Aggregate intrinsic value of units outstanding at June 30, 2020 $ 8 $ 8 _____________________ (1) Performance units represents the target number of performance units granted. The actual number of performance units earned, if any, is dependent upon performance and may range from 0% to 200% of the target. (2) Performance units vested as of June 30, 2020 include 376,292 units from the 2017 annual grant, which were approved by the Board of Directors in 2017 and, based on the level of achievement of a performance goal established by the Board of Directors over the performance period of January 1, 2017 through December 31, 2019, no performance units vested. Unrecognized Compensation Cost The following table summarizes the Partnership’s unrecognized compensation cost for its non-vested performance units and phantom units, and the weighted-average periods over which the compensation cost is expected to be recognized. June 30, 2020 Unrecognized Compensation Cost Weighted Average Period for Recognition Performance Units $ 13 1.93 Phantom Units 10 1.76 Total $ 23 As of June 30, 2020, there were 5,275,303 units available for issuance under the long-term incentive plan.

Reportable Segments

Reportable Segments	6 Months Ended
	Jun. 30, 2020
Segment Reporting [Abstract]
Reportable Segments	Reportable Segments The Partnership’s determination of reportable segments considers the strategic operating units under which it manages sales, allocates resources and assesses performance of various products and services to customers in differing regulatory environments. The accounting policies of the reportable segments are the same as those described in the summary of significant accounting policies excerpt in the Partnership’s audited 2019 consolidated financial statements included in the Annual Report. The Partnership uses operating income as the measure of profit or loss for its reportable segments. The Partnership’s assets and operations are organized into two reportable segments: (i) gathering and processing, which primarily provides natural gas and crude oil gathering and natural gas processing services to our producer customers, and (ii) transportation and storage, which provides interstate and intrastate natural gas pipeline transportation and storage service primarily to our producer, power plant, LDC and industrial end-user customers. Financial data for reportable segments are as follows: Three Months Ended June 30, 2020 Gathering and Transportation (1) and Storage Eliminations Total (In millions) Product sales $ 193 $ 59 $ (56) $ 196 Service revenues 198 124 (3) 319 Total Revenues 391 183 (59) 515 Cost of natural gas and natural gas liquids (excluding depreciation and amortization shown separately) 176 59 (58) 177 Operation and maintenance, General and administrative 92 45 (1) 136 Depreciation and amortization 74 31 — 105 Taxes other than income tax 11 6 — 17 Operating income $ 38 $ 42 $ — $ 80 Total Assets $ 9,552 $ 5,662 $ (3,153) $ 12,061 Capital expenditures $ 24 $ 24 $ — $ 48 Three Months Ended June 30, 2019 Gathering and Transportation (1) and Storage Eliminations Total (In millions) Product sales $ 379 $ 114 $ (100) $ 393 Service revenues 208 138 (4) 342 Total Revenues 587 252 (104) 735 Cost of natural gas and natural gas liquids (excluding depreciation and amortization shown separately) 297 123 (103) 317 Operation and maintenance, General and administrative 75 50 (1) 124 Depreciation and amortization 78 32 — 110 Taxes other than income tax 10 7 — 17 Operating income $ 127 $ 40 $ — $ 167 Total assets as of December 31, 2019 $ 9,739 $ 5,886 $ (3,359) $ 12,266 Capital expenditures $ 90 $ 19 $ — $ 109 Six Months Ended June 30, 2020 Gathering and Transportation (1) and Storage Eliminations Total (In millions) Product sales $ 468 $ 134 $ (118) $ 484 Service revenues 400 283 (4) 679 Total Revenues 868 417 (122) 1,163 Cost of natural gas and natural gas liquids (excluding depreciation and amortization shown separately) 387 137 (121) 403 Operation and maintenance, General and administrative 173 90 (1) 262 Impairments 28 — — 28 Depreciation and amortization 148 61 — 209 Taxes other than income tax 22 13 — 35 Operating income $ 110 $ 116 $ — $ 226 Total Assets $ 9,552 $ 5,662 $ (3,153) $ 12,061 Capital expenditures $ 58 $ 44 $ — $ 102 Six Months Ended June 30, 2019 Gathering and Transportation (1) and Storage Eliminations Total (In millions) Product sales $ 802 $ 281 $ (247) $ 836 Service revenues 415 287 (8) 694 Total Revenues 1,217 568 (255) 1,530 Cost of natural gas and natural gas liquids (excluding depreciation and amortization shown separately) 657 292 (254) 695 Operation and maintenance, General and administrative 159 95 (1) 253 Depreciation and amortization 152 63 — 215 Taxes other than income tax 21 14 — 35 Operating income $ 228 $ 104 $ — $ 332 Total assets as of December 31, 2019 $ 9,739 $ 5,886 $ (3,359) $ 12,266 Capital expenditures $ 197 $ 55 $ — $ 252 _____________________ (1) See Note 8 for discussion regarding ownership interests in SESH and related equity earnings included in the transportation and storage segment for the three and six months ended June 30, 2020 and 2019.	[1]
[1]	See Note 8 for discussion regarding ownership interests in SESH and related equity earnings included in the transportation and storage segment for the three and six months ended June 30, 2020 and 2019.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization Enable Midstream Partners, LP is a Delaware limited partnership whose assets and operations are organized into two reportable segments: (i) gathering and processing and (ii) transportation and storage. The gathering and processing segment primarily provides natural gas and crude oil gathering and natural gas processing services to our producer customers. The transportation and storage segment provides interstate and intrastate natural gas pipeline transportation and storage services primarily to our producer, power plant, LDC and industrial end-user customers. The Partnership’s natural gas gathering and processing assets are primarily located in Oklahoma, Texas, Arkansas and Louisiana and serve natural gas production in the Anadarko, Arkoma and Ark-La-Tex Basins. Crude oil gathering assets are located in Oklahoma and serve crude oil production in the SCOOP and STACK plays of the Anadarko Basin and in North Dakota and serve crude oil production in the Bakken Shale formation of the Williston Basin. The Partnership’s natural gas transportation and storage assets consist primarily of an interstate pipeline system extending from western Oklahoma and the Texas Panhandle to Louisiana, an interstate pipeline system extending from Louisiana to Illinois, an intrastate pipeline system in Oklahoma, and our investment in SESH, a pipeline extending from Louisiana to Alabama. CenterPoint Energy and OGE Energy each have 50% of the management interests in Enable GP. Enable GP is the general partner of the Partnership and has no other operating activities. Enable GP is governed by a board made up of two representatives designated by each of CenterPoint Energy and OGE Energy, along with the Partnership’s Chief Executive Officer and three independent board members CenterPoint Energy and OGE Energy mutually agreed to appoint. CenterPoint Energy and OGE Energy also own a 40% and 60% interest, respectively, in the incentive distribution rights held by Enable GP. As of June 30, 2020, CenterPoint Energy held approximately 53.7% or 233,856,623 of the Partnership’s common units, and OGE Energy held approximately 25.5% or 110,982,805 of the Partnership’s common units. Additionally, CenterPoint Energy holds 14,520,000 Series A Preferred Units. The limited partner interests of the Partnership have limited voting rights on matters affecting the business. As such, limited partners do not have rights to elect the Partnership’s general partner on an annual or continuing basis and may not remove Enable GP, its current general partner, without at least a 75% vote by all unitholders, including all units held by the Partnership’s limited partners, and Enable GP and its affiliates, voting together as a single class. As of June 30, 2020, the Partnership owned a 50% interest in SESH. See Note 8 for further discussion of SESH. For the six months ended June 30, 2020, the Partnership held a 50% ownership in Atoka and consolidated Atoka in its Condensed Consolidated Financial Statements as EOIT acted as the managing member of Atoka and had control over the operations of Atoka. In addition, the Partnership held a 60% interest in ESCP, which is consolidated in its Condensed Consolidated Financial Statements as EOCS acted as the managing member of ESCP and had control over the operations of ESCP.
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements and related notes of the Partnership have been prepared pursuant to the rules and regulations of the SEC and GAAP. Pursuant to such rules and regulations, certain disclosures normally included in financial statements prepared in accordance with GAAP have been omitted. The accompanying condensed consolidated financial statements and related notes should be read in conjunction with the consolidated financial statements and related notes included in our Annual Report. The condensed consolidated financial statements and the related notes reflect all normal recurring adjustments that are, in the opinion of management, necessary to present fairly the financial position and results of operations for the respective periods. Amounts reported in the Partnership’s Condensed Consolidated Statements of Income are not necessarily indicative of amounts expected for a full-year period due to the effects of, among other things, (a) seasonal fluctuations in demand for energy and energy services, (b) changes in energy commodity prices, (c) timing of maintenance and other expenditures, (d) acquisitions and dispositions of businesses, assets and other interests, and (e) the impact of the ongoing COVID-19 pandemic and the economic effects of the pandemic which have resulted in a substantial decrease in natural gas, NGLs and crude oil prices.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Depreciation Expense	Depreciation ExpenseOn March 26, 2020, FERC issued an order approving MRT’s 2018 Rate Case and 2019 Rate Case settlements. As a result of the settlements, the new depreciation rates for MRT have been applied in accordance with the order. The new depreciation rates did not result in a material change in depreciation expense or results of operations.
Accounts Receivable and Allowance for Doubtful Accounts	Accounts Receivable and Allowance for Doubtful Accounts The Partnership adopted ASU No. 2016-13, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” on January 1, 2020. Upon adoption, the Partnership recognized a $3 million cumulative adjustment to Partners’ Equity and a corresponding adjustment to Allowance for doubtful accounts.
Inventory	InventoryNatural gas inventory is held, through the transportation and storage segment, to provide operational support for pipeline deliveries and to manage leased intrastate storage capacity. Natural gas liquids inventory is held, through the gathering and processing segment, due to timing differences between the production of certain natural gas liquids and ultimate sale to third parties. Natural gas and natural gas liquids inventory is valued using moving average cost and is subsequently recorded at the lower of cost or net realizable value.
New Accounting Pronouncements	New Accounting Pronouncements Accounting Standards to be Adopted in Future Periods Reference Rate Reform In March 2020, the FASB issued ASU No. 2020-04, “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting.” This standard provides optional guidance, for a limited time, to ease the potential burden in accounting for or recognizing the effects of reference rate reform on financial reporting. The standard was effective upon issuance and generally can be applied through December 31, 2022. The Partnership is currently evaluating the impact this ASU will have on our Condensed Consolidated Financial Statements and related disclosures.
Derivatives Instruments and Hedging Activities	The primary risks managed using derivative instruments are commodity price and interest rate risks. Derivatives Not Designated as Hedging Instruments Derivative instruments not designated as hedging instruments for accounting purposes are utilized to manage the Partnership’s exposure to commodity price risk. For derivative instruments not designated as hedging instruments, the gain or loss on the derivative is recognized currently in earnings.
Fair Value Measurements	Certain assets and liabilities are recorded at fair value in the Condensed Consolidated Balance Sheets and are categorized based upon the level of judgment associated with the inputs used to measure their value. The Partnership determines the appropriate level for each financial asset and liability on a quarterly basis and recognizes transfers between levels at the end of the reporting period. For the three and six months ended June 30, 2020, there were no transfers between levels. As of June 30, 2020, there were no contracts classified as Level 3.
Reportable Segments	The Partnership’s determination of reportable segments considers the strategic operating units under which it manages sales, allocates resources and assesses performance of various products and services to customers in differing regulatory environments. The accounting policies of the reportable segments are the same as those described in the summary of significant accounting policies excerpt in the Partnership’s audited 2019 consolidated financial statements included in the Annual Report. The Partnership uses operating income as the measure of profit or loss for its reportable segments.The Partnership’s assets and operations are organized into two reportable segments: (i) gathering and processing, which primarily provides natural gas and crude oil gathering and natural gas processing services to our producer customers, and (ii) transportation and storage, which provides interstate and intrastate natural gas pipeline transportation and storage service primarily to our producer, power plant, LDC and industrial end-user customers.

Accounting Policies (Tables)

Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2020
Accounting Policies [Abstract]
Accounts Receivable, Allowance for Credit Loss	The following table summarizes the required allowance for doubtful accounts. June 30, 2020 January 1, 2020 (In millions) Accounts receivable $ 2 $ 2 Other assets 3 3 Total Allowance for doubtful accounts $ 5 $ 5

Revenue (Tables)

Revenue (Tables)	6 Months Ended
	Jun. 30, 2020
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following tables disaggregate total revenues by major source from contracts with customers and the gain (loss) on derivative activity for the three and six months ended June 30, 2020 and 2019. Three Months Ended June 30, 2020 Gathering and Transportation Eliminations Total (In millions) Revenues: Product sales: Natural gas $ 47 $ 57 $ (53) $ 51 Natural gas liquids 143 3 (3) 143 Condensate 7 — — 7 Total revenues from natural gas, natural gas liquids, and condensate 197 60 (56) 201 Loss on derivative activity (4) (1) — (5) Total Product sales $ 193 $ 59 $ (56) $ 196 Service revenues: Demand revenues $ 34 $ 113 $ — $ 147 Volume-dependent revenues 164 11 (3) 172 Total Service revenues $ 198 $ 124 $ (3) $ 319 Total Revenues $ 391 $ 183 $ (59) $ 515 Three Months Ended June 30, 2019 Gathering and Transportation Eliminations Total (In millions) Revenues: Product sales: Natural gas $ 94 $ 108 $ (95) $ 107 Natural gas liquids 237 5 (5) 237 Condensate 33 — — 33 Total revenues from natural gas, natural gas liquids, and condensate 364 113 (100) 377 Gain on derivative activity 15 1 — 16 Total Product sales $ 379 $ 114 $ (100) $ 393 Service revenues: Demand revenues $ 68 $ 123 $ — $ 191 Volume-dependent revenues 140 15 (4) 151 Total Service revenues $ 208 $ 138 $ (4) $ 342 Total Revenues $ 587 $ 252 $ (104) $ 735 Six Months Ended June 30, 2020 Gathering and Transportation Eliminations Total (In millions) Revenues: Product sales: Natural gas $ 103 $ 130 $ (113) $ 120 Natural gas liquids 315 5 (5) 315 Condensate 34 — — 34 Total revenues from natural gas, natural gas liquids, and condensate 452 135 (118) 469 Gain (loss) on derivative activity 16 (1) — 15 Total Product sales $ 468 $ 134 $ (118) $ 484 Service revenues: Demand revenues $ 73 $ 255 $ — $ 328 Volume-dependent revenues 327 28 (4) 351 Total Service revenues $ 400 $ 283 $ (4) $ 679 Total Revenues $ 868 $ 417 $ (122) $ 1,163 Six Months Ended June 30, 2019 Gathering and Transportation Eliminations Total (In millions) Revenues: Product sales: Natural gas $ 222 $ 270 $ (236) $ 256 Natural gas liquids 507 11 (11) 507 Condensate 67 — — 67 Total revenues from natural gas, natural gas liquids, and condensate 796 281 (247) 830 Gain on derivative activity 6 — — 6 Total Product sales $ 802 $ 281 $ (247) $ 836 Service revenues: Demand revenues $ 128 $ 254 $ — $ 382 Volume-dependent revenues 287 33 (8) 312 Total Service revenues $ 415 $ 287 $ (8) $ 694 Total Revenues $ 1,217 $ 568 $ (255) $ 1,530
Schedule of Accounts Receivable	The following table summarizes the components of accounts receivable, net of allowance for doubtful accounts. June 30, 2020 December 31, 2019 (In millions) Accounts Receivable: Customers $ 205 $ 239 Contract assets (1) 29 18 Non-customers 4 12 Total Accounts Receivable (2) $ 238 $ 269 ____________________ (1) Contract assets reflected in Total Accounts Receivable include accrued minimum volume commitments. Contract assets are primarily attributable to revenues associated with estimated shortfall volumes on certain annual minimum volume commitment arrangements. Total Accounts Receivable does not include contract assets related to firm service transportation contracts with tiered rates of $8 million as of June 30, 2020 and $6 million as of December 31, 2019, which are reflected in Other Assets. (2) Total Accounts Receivable includes Accounts receivable, net of allowance for doubtful accounts and Accounts receivable—affiliated companies.	[1],[2]
Summary of Timing Recognition of Contract Liabilities	The table below summarizes the change in the contract liabilities. June 30, 2020 December 31, 2019 Amounts recognized in revenues (In millions) Deferred revenues (1) $ 48 $ 48 $ 20 The table below summarizes the timing of recognition of these contract liabilities as of June 30, 2020. 2020 2021 2022 2023 2024 and After (In millions) Deferred revenues (1) $ 21 $ 8 $ 6 $ 6 $ 7 ____________________ (1) Deferred revenues includes deferred revenue — affiliated companies. This amount is included in Other current liabilities and Other long-term liabilities.	[3]
Summary of Timing Recognition of Remaining Performance Obligations	The table below summarizes the timing of recognition of the remaining performance obligations as of June 30, 2020. 2020 2021 2022 2023 2024 and After (In millions) Transportation and Storage $ 233 $ 406 $ 345 $ 324 $ 1,167 Gathering and Processing 57 121 123 121 313 Total remaining performance obligations $ 290 $ 527 $ 468 $ 445 $ 1,480
[1]	Contract assets reflected in Total Accounts Receivable include accrued minimum volume commitments. Contract assets are primarily attributable to revenues associated with estimated shortfall volumes on certain annual minimum volume commitment arrangements. Total Accounts Receivable does not include contract assets related to firm service transportation contracts with tiered rates of $8 million as of June 30, 2020 and $6 million as of December 31, 2019, which are reflected in Other Assets.
[2]	Total Accounts Receivable includes Accounts receivable, net of allowance for doubtful accounts and Accounts receivable—affiliated companies.
[3]	Deferred revenues includes deferred revenue — affiliated companies. This amount is included in Other current liabilities and Other long-term liabilities.

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2020
Leases [Abstract]
Summary of Lease Expense	The following table presents the Partnership’s rental costs associated with field equipment and buildings. Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions) Rental Costs: Field equipment $ 4 $ 5 $ 9 $ 12 Office space 1 2 2 4 The following tables present the Partnership’s lease cost. Three Months Ended June 30, 2020 Gathering and Transportation Total (In millions) Lease Cost: Operating lease cost $ 1 $ — $ 1 Short-term lease cost 4 — 4 Total Lease Cost $ 5 $ — $ 5 Three Months Ended June 30, 2019 Gathering and Transportation Total (In millions) Lease Cost: Operating lease cost $ 3 $ — $ 3 Short-term lease cost 4 — 4 Total Lease Cost $ 7 $ — $ 7 Six Months Ended June 30, 2020 Gathering and Transportation Total (In millions) Lease Cost: Operating lease cost $ 3 $ — $ 3 Short-term lease cost 7 — 7 Variable lease cost 1 — 1 Total Lease Cost $ 11 $ — $ 11 Six Months Ended June 30, 2019 Gathering and Transportation Total (In millions) Lease Cost: Operating lease cost $ 5 $ — $ 5 Short-term lease cost 10 1 11 Total Lease Cost $ 15 $ 1 $ 16
Schedule of Operating Lease Obligations Expiration	Undiscounted cash flows for operating lease liabilities are as follows: Year Ended December 31, 2020 2021 2022 2023 2024 2025 and After Total (In millions) Noncancellable operating leases $ 4 $ 6 $ 5 $ 5 $ 4 $ 11 $ 35

Earnings Per Limited Partner _2

Earnings Per Limited Partner Unit (Tables)	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
Schedule Of Earnings Per Unit For Common Units	The following table illustrates the Partnership’s calculation of earnings per unit for common units. Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions, except per unit data) Net income $ 44 $ 124 $ 149 $ 247 Net (loss) income attributable to noncontrolling interest — — (7) 1 Series A Preferred Unit distributions 9 9 18 18 General partner interest in net income — — — — Net income available to common unitholders $ 35 $ 115 $ 138 $ 228 Net income allocable to common units $ 35 $ 115 $ 138 $ 228 Dilutive effect of Series A Preferred Unit distributions — — 18 — Diluted net income allocable to common units $ 35 $ 115 $ 156 $ 228 Basic earnings per unit Common units $ 0.08 $ 0.26 $ 0.32 $ 0.52 Basic weighted average number of common units outstanding (1) 437 437 437 436 Dilutive effect of Series A Preferred Units — — 79 — Diluted weighted average number of common units outstanding 437 437 516 436 Diluted earnings per unit Common units $ 0.08 $ 0.26 $ 0.30 $ 0.52 ____________________ (1) Basic weighted average number of outstanding common units includes approximately two million time-based phantom units for the three and six months ended June 30, 2020, and one million time-based phantom units for the three and six months ended June 30, 2019.	[1]
[1]	Basic weighted average number of outstanding common units includes approximately two million time-based phantom units for the three and six months ended June 30, 2020, and one million time-based phantom units for the three and six months ended June 30, 2019.

Partners' Equity (Tables)

Partners' Equity (Tables)	6 Months Ended
	Jun. 30, 2020
Equity [Abstract]
Schedule of Equity Transactions with Limited Partner	The Partnership paid or has authorized payment of the following cash distributions to common unitholders, as applicable, during 2020 and 2019 (in millions, except for per unit amounts): Three Months Ended Record Date Payment Date Per Unit Distribution Total Cash Distribution June 30, 2020 (1) August 18, 2020 August 25, 2020 $ 0.16525 $ 72 March 31, 2020 May 19, 2020 May 27, 2020 0.16525 72 December 31, 2019 February 18, 2020 February 25, 2020 0.3305 144 September 30, 2019 November 19, 2019 November 26, 2019 0.3305 144 June 30, 2019 August 20, 2019 August 27, 2019 0.3305 144 March 31, 2019 May 21, 2019 May 29, 2019 0.318 138 _____________________
Schedule of Cash Distributions to Series A Preferred Unitholders	The Partnership paid or has authorized payment of the following cash distributions to holders of the Series A Preferred Units during 2020 and 2019 (in millions, except for per unit amounts): Three Months Ended Record Date Payment Date Per Unit Distribution Total Cash Distribution June 30, 2020 (1) August 4, 2020 August 14, 2020 $ 0.625 $ 9 March 31, 2020 May 5, 2020 May 15, 2020 0.625 9 December 31, 2019 February 7, 2020 February 14, 2020 0.625 9 September 30, 2019 November 5, 2019 November 14, 2019 0.625 9 June 30, 2019 August 2, 2019 August 14, 2019 0.625 9 March 31, 2019 April 29, 2019 May 15, 2019 0.625 9 _____________________ (1) The Board of Directors declared a $0.625 per Series A Preferred Unit cash distribution on August 4, 2020, to be paid on August 14, 2020, to Series A Preferred unitholders of record at the close of business on August 4, 2020.	[1]
[1]	The Board of Directors declared a $0.625 per Series A Preferred Unit cash distribution on August 4, 2020, to be paid on August 14, 2020, to Series A Preferred unitholders of record at the close of business on August 4, 2020.

Impairment of Long-lived Asse_2

Impairment of Long-lived Assets and Goodwill (Tables)	6 Months Ended
	Jun. 30, 2020
Impairment of Long-lived Assets and Goodwill [Abstract]
Schedule of Goodwill [Table Text Block]	The following table presents the change in carrying amount of goodwill in each of our reportable segments. Gathering and Processing Transportation and Storage Total (In millions) Balance as of December 31, 2019 $ 12 $ — $ 12 Goodwill impairment (12) — (12) Balance as of June 30, 2020 $ — $ — $ —

Investment in Equity Method A_2

Investment in Equity Method Affiliate (Tables)	6 Months Ended
	Jun. 30, 2020
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Investments Detail	The following table presents the amount of Equity in earnings of equity method affiliate recognized and Distributions from equity method affiliate received. Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions) Equity in Earnings of Equity Method Affiliate $ 5 $ 4 $ 11 $ 7 Distributions from Equity Method Affiliate (1) $ 9 $ 4 $ 19 $ 16 ___________________ (1) Distributions from equity method affiliate includes a $5 million and $4 million return on investment and a $4 million and $0 return of investment for the three months ended June 30, 2020 and 2019, respectively. Distributions from equity method affiliate includes an $11 million and $7 million return on investment and an $8 million and $9 million return of investment for the six months ended June 30, 2020 and 2019, respectively. The following table includes the summarized financial information of SESH. Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions) Income Statements: Revenues $ 28 $ 27 $ 55 $ 54 Operating income $ 13 $ 11 $ 29 $ 22 Net income $ 10 $ 7 $ 21 $ 14	[1]
[1]	Distributions from equity method affiliate includes a $5 million and $4 million return on investment and a $4 million and $0 return of investment for the three months ended June 30, 2020 and 2019, respectively. Distributions from equity method affiliate includes an $11 million and $7 million return on investment and an $8 million and $9 million return of investment for the six months ended June 30, 2020 and 2019, respectively.

Debt (Tables)

Debt (Tables)	6 Months Ended
	Jun. 30, 2020
Debt Disclosure [Abstract]
Schedule of Debt	The following table presents the Partnership’s outstanding debt. June 30, 2020 December 31, 2019 Outstanding Principal Discount (1) Total Debt Outstanding Principal Premium (Discount) (1) Total Debt (In millions) Commercial Paper $ 30 $ — $ 30 $ 155 $ — $ 155 Revolving Credit Facility 400 — 400 — — — 2019 Term Loan Agreement 800 — 800 800 — 800 2024 Notes 600 — 600 600 — 600 2027 Notes 700 (2) 698 700 (2) 698 2028 Notes 800 (5) 795 800 (5) 795 2029 Notes 547 (1) 546 550 (1) 549 2044 Notes 531 — 531 550 — 550 EOIT Senior Notes — — — 250 1 251 Total debt $ 4,408 $ (8) $ 4,400 $ 4,405 $ (7) $ 4,398 Less: Short-term debt (2) 30 155 Less: Current portion of long-term debt (3) — 251 Less: Unamortized debt expense (4) 21 23 Total long-term debt $ 4,349 $ 3,969 ____________________ (1) Unamortized premium (discount) on long-term debt is amortized over the life of the respective debt. (2) Short-term debt includes $30 million and $155 million of outstanding commercial paper as of June 30, 2020 and December 31, 2019, respectively. (3) As of December 31, 2019, Current portion of long-term debt included $251 million outstanding balance of the EOIT Senior Notes which were repaid in March 2020.	[1],[2],[3],[4]
[1]	As of December 31, 2019, Current portion of long-term debt included $251 million outstanding balance of the EOIT Senior Notes which were repaid in March 2020.
[2]	As of June 30, 2020 and December 31, 2019, there was an additional $4 million of unamortized debt expense related to the Revolving Credit Facility included in Other assets, not included above.
[3]	Short-term debt includes $30 million and $155 million of outstanding commercial paper as of June 30, 2020 and December 31, 2019, respectively.
[4]	Unamortized premium (discount) on long-term debt is amortized over the life of the respective debt.

Derivative Instruments and He_2

Derivative Instruments and Hedging Activities (Tables)	6 Months Ended
	Jun. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments	The following table presents the Partnership’s derivative instruments that were not designated as hedging instruments for accounting purposes. June 30, 2020 December 31, 2019 Gross Notional Volume Purchases Sales Purchases Sales Natural gas— TBtu (1) Financial fixed futures/swaps 6 26 10 19 Financial basis futures/swaps 5 39 11 30 Financial swaptions (2) — 9 — 2 Physical purchases/sales — 3 — 6 Crude oil (for condensate)— MBbl (3) Financial futures/swaps — 540 — 990 Financial swaptions (2) — 150 — 225 Natural gas liquids— MBbl (4) Financial futures/swaps 1,830 1,840 2,490 2,415 Financial options — 60 — — ____________________ (1) As of June 30, 2020, 88.1% of the natural gas contracts had durations of one year or less and 11.9% had durations of more than one year and less than two years. As of December 31, 2019, 86.6% of the natural gas contracts had durations of one year or less and 13.4% had durations of more than one year and less than two years. (2) The notional volume contains a combined derivative instrument consisting of a fixed price swap and a sold option, which gives the counterparties the right, but not the obligation, to increase the notional volume hedged under the fixed price swap until the option expiration date. The notional volume represents the volume prior to option exercise. (3) As of June 30, 2020, 91.3% of the crude oil (for condensate) contracts had durations of one year or less and 8.7% had durations of more than one year and less than two years. As of December 31, 2019, 72.8% of the crude oil (for condensate) contracts had durations of one year or less and 27.2% had durations of more than one year and less than two years. (4) As of June 30, 2020, 97.5% of the natural gas liquids contracts had durations of one year or less and 2.5% had durations of more than one year and less than two years. As of December 31, 2019, 72.2% of the natural gas liquids contracts had durations of one year or less and 27.8% had durations of more than one year and less than two years. The following table presents the Partnership’s derivative instruments that were designated as hedging instruments for accounting purposes. June 30, 2020 December 31, 2019 Gross Notional Value (In millions) Interest rate swaps $ 300 $ 300	[1],[2],[3],[4]
Schedule of Derivative Assets at Fair Value	The following table presents the fair value of the derivative instruments that are included in the Partnership’s Condensed Consolidated Balance Sheets that were not designated as hedging instruments for accounting purposes. June 30, 2020 December 31, 2019 Fair Value Instrument Balance Sheet Location Assets Liabilities Assets Liabilities (In millions) Natural gas Financial futures/swaps Other Current $ 7 $ 7 $ 7 $ 5 Financial swaptions Other Current 1 2 — — Physical purchases/sales Other Current 2 — 5 — Financial futures/swaps Other — — — 1 Financial swaptions Other 1 1 — — Crude oil (for condensate) Financial futures/swaps Other Current 2 14 1 19 Financial swaptions Other Current 3 — — — Financial futures/swaps Other — 2 — 8 Natural gas liquids Financial futures/swaps Other Current 20 3 25 3 Financial futures/swaps Other 2 — 11 2 Total gross commodity derivatives (1) $ 38 $ 29 $ 49 $ 38 _____________________ (1) See Note 11 for a reconciliation of the Partnership’s commodity derivatives fair value to the Partnership’s Condensed Consolidated Balance Sheets as of June 30, 2020 and December 31, 2019. The following table presents the fair value of the derivative instruments that are included in the Partnership’s Condensed Consolidated Balance Sheets that were designated as hedging instruments for accounting purposes. June 30, 2020 December 31, 2019 Fair Value Instrument Balance Sheet Location Assets Liabilities Assets Liabilities (In millions) Interest rate swaps Other Current $ — $ 6 $ — $ 1 Interest rate swaps Other — 3 — 2 Total gross interest rate derivatives (1) $ — $ 9 $ — $ 3 _____________________ (1) All interest rate derivative instruments that were designated as cash flow hedges are considered Level 2 as of June 30, 2020 and December 31, 2019.
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	The following table presents the effect of derivative instruments on the Partnership’s Condensed Consolidated Statements of Income. Amounts Recognized in Income Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions) Natural gas Financial futures/swaps gains (losses) $ (1) $ 9 $ 3 $ 8 Financial swaptions losses (1) — (2) — Physical purchases/sales gains — 1 1 — Crude oil (for condensate) Financial futures/swaps gains (losses) (7) (10) 12 (21) Financial swaptions gains (losses) (2) — 2 — Natural gas liquids Financial futures/swaps gains (losses) 6 16 (1) 19 Total $ (5) $ 16 $ 15 $ 6 The following table presents the effect of derivative instruments that were designated as hedging instruments on the Partnership’s Condensed Consolidated Statements of Income. Amounts Recognized in Income Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions) Interest rate swaps losses $ (1) $ — $ (1) $ — Total $ (1) $ — $ (1) $ —
Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location	The following table presents the components of gain (loss) on derivative activity in the Partnership’s Condensed Consolidated Statements of Income. Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions) Change in fair value of commodity derivatives $ (12) $ 11 $ (2) $ (1) Realized gain on commodity derivatives 7 5 17 7 Gain (loss) on commodity derivative activity $ (5) $ 16 $ 15 $ 6
[1]	As of June 30, 2020, 88.1% of the natural gas contracts had durations of one year or less and 11.9% had durations of more than one year and less than two years. As of December 31, 2019, 86.6% of the natural gas contracts had durations of one year or less and 13.4% had durations of more than one year and less than two years.
[2]	As of June 30, 2020, 91.3% of the crude oil (for condensate) contracts had durations of one year or less and 8.7% had durations of more than one year and less than two years. As of December 31, 2019, 72.8% of the crude oil (for condensate) contracts had durations of one year or less and 27.2% had durations of more than one year and less than two years.
[3]	As of June 30, 2020, 97.5% of the natural gas liquids contracts had durations of one year or less and 2.5% had durations of more than one year and less than two years. As of December 31, 2019, 72.2% of the natural gas liquids contracts had durations of one year or less and 27.8% had durations of more than one year and less than two years.
[4]	The notional volume contains a combined derivative instrument consisting of a fixed price swap and a sold option, which gives the counterparties the right, but not the obligation, to increase the notional volume hedged under the fixed price swap until the option expiration date. The notional volume represents the volume prior to option exercise.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Schedule of Fair Value and Carrying Amount of Financial Instruments	The following table summarizes the fair value and carrying amount of the Partnership’s financial instruments. June 30, 2020 December 31, 2019 Carrying Amount Fair Value Carrying Amount Fair Value (In millions) Debt Revolving Credit Facility (Level 2) (1) $ 400 $ 400 $ — $ — 2019 Term Loan Agreement (Level 2) 800 800 800 800 2024 Notes (Level 2) 600 588 600 614 2027 Notes (Level 2) 698 648 698 698 2028 Notes (Level 2) 795 742 795 811 2029 Notes (Level 2) 546 476 549 526 2044 Notes (Level 2) 531 424 550 506 EOIT Senior Notes (Level 2) — — 251 252 ____________________ (1) Borrowing capacity is effectively reduced by our borrowings outstanding under the commercial paper program. $30 million and $155 million of commercial paper was outstanding as of June 30, 2020 and December 31, 2019, respectively.	[1]
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following tables summarize the Partnership’s other assets and liabilities that are measured at fair value on a recurring basis. June 30, 2020 Commodity Contracts Gas Imbalances (1) Assets Liabilities Assets (2) Liabilities (3) (In millions) Quoted market prices in active market for identical assets (Level 1) $ 6 $ 23 $ — $ — Significant other observable inputs (Level 2) 32 6 15 13 Total fair value 38 29 15 13 Netting adjustments (28) (28) — — Total $ 10 $ 1 $ 15 $ 13 December 31, 2019 Commodity Contracts Gas Imbalances (1) Assets Liabilities Assets (2) Liabilities (3) (In millions) Quoted market prices in active market for identical assets (Level 1) $ 5 $ 31 $ — $ — Significant other observable inputs (Level 2) 44 7 14 11 Total fair value 49 38 14 11 Netting adjustments (37) (37) — — Total $ 12 $ 1 $ 14 $ 11 ______________________ (1) The Partnership uses the market approach to fair value its gas imbalance assets and liabilities at individual, or where appropriate an average of, current market indices applicable to the Partnership’s operations, not to exceed net realizable value. There were no netting adjustments as of June 30, 2020 and December 31, 2019. (2) Gas imbalance assets exclude fuel reserves for under retained fuel due from shippers of $23 million and $21 million at June 30, 2020 and December 31, 2019, respectively, which fuel reserves are based on the value of natural gas at the time the imbalance was created, and which are not subject to revaluation at fair market value. (3) Gas imbalance liabilities exclude fuel reserves for over retained fuel due to shippers of $6 million and $8 million at June 30, 2020 and December 31, 2019, respectively, which fuel reserves are based on the value of natural gas at the time the imbalance was created, and which are not subject to revaluation at fair market value.	[2],[3],[4]
[1]	Borrowing capacity is effectively reduced by our borrowings outstanding under the commercial paper program. $30 million and $155 million of commercial paper was outstanding as of June 30, 2020 and December 31, 2019, respectively.
[2]	Gas imbalance assets exclude fuel reserves for under retained fuel due from shippers of $23 million and $21 million at June 30, 2020 and December 31, 2019, respectively, which fuel reserves are based on the value of natural gas at the time the imbalance was created, and which are not subject to revaluation at fair market value.
[3]	Gas imbalance liabilities exclude fuel reserves for over retained fuel due to shippers of $6 million and $8 million at June 30, 2020 and December 31, 2019, respectively, which fuel reserves are based on the value of natural gas at the time the imbalance was created, and which are not subject to revaluation at fair market value.
[4]	The Partnership uses the market approach to fair value its gas imbalance assets and liabilities at individual, or where appropriate an average of, current market indices applicable to the Partnership’s operations, not to exceed net realizable value. There were no netting adjustments as of June 30, 2020 and December 31, 2019.

Supplemental Disclosure of Ca_2

Supplemental Disclosure of Cash Flow Information (Tables)	6 Months Ended
	Jun. 30, 2020
Supplemental Cash Flow Information [Abstract]
Schedule of Cash Flow, Supplemental Disclosures	The following table provides information regarding supplemental cash flow information: Six Months Ended June 30, 2020 2019 (In millions) Supplemental Disclosure of Cash Flow Information: Cash Payments: Interest, net of capitalized interest $ 96 $ 95 Income taxes, net of refunds 1 1 Non-cash transactions: Accounts payable related to capital expenditures 8 31 Lease liabilities related to (derecognition) recognition of right-of-use assets (5) 42 Impact of adoption of financial instruments-credit losses accounting standard (Note 1) (3) —
Schedule of Restricted Cash and Cash Equivalents	The following table reconciles cash and cash equivalents and restricted cash on the Condensed Consolidated Balance Sheets to cash, cash equivalents and restricted cash on the Condensed Consolidated Statements of Cash Flows: June 30, 2020 2019 (In millions) Cash and cash equivalents $ 11 $ 9 Restricted cash — 1 Cash, cash equivalents and restricted cash shown in the Condensed Consolidated Statements of Cash Flows $ 11 $ 10
Schedule of Cash and Cash Equivalents	The following table reconciles cash and cash equivalents and restricted cash on the Condensed Consolidated Balance Sheets to cash, cash equivalents and restricted cash on the Condensed Consolidated Statements of Cash Flows: June 30, 2020 2019 (In millions) Cash and cash equivalents $ 11 $ 9 Restricted cash — 1 Cash, cash equivalents and restricted cash shown in the Condensed Consolidated Statements of Cash Flows $ 11 $ 10

Related Party Transactions (Tab

Related Party Transactions (Tables)	6 Months Ended
	Jun. 30, 2020
Related Party Transactions [Abstract]
Schedule of Revenues from Related Parties	The following table presents the amounts of revenues from affiliated companies included in the Partnership’s Condensed Consolidated Statements of Income. Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions) Gas transportation and storage service revenues — CenterPoint Energy $ 22 $ 23 $ 59 $ 56 Natural gas product sales — CenterPoint Energy 1 3 1 4 Gas transportation and storage service revenues — OGE Energy 10 13 19 26 Natural gas product sales — OGE Energy — — 5 1 Total revenues — affiliated companies $ 33 $ 39 $ 84 $ 87
Schedule of Natural Gas Purchased From Related Parties	The following table presents the amounts of natural gas purchased from affiliated companies included in the Partnership’s Condensed Consolidated Statements of Income. Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions) Cost of natural gas purchases — CenterPoint Energy $ — $ — $ 1 $ — Cost of natural gas purchases — OGE Energy 6 7 14 13 Total cost of natural gas purchases — affiliated companies $ 6 $ 7 $ 15 $ 13
Schedule of Amounts Charged to Partnership by Related Parties	The following table presents the amounts charged to the Partnership by affiliates for seconded employees, included primarily in Operation and maintenance and General and administrative expenses in the Partnership’s Condensed Consolidated Statements of Income. Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions) Seconded Employee Costs — OGE Energy $ 5 $ 5 $ 8 $ 11

Equity-Based Compensation (Tabl

Equity-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2020
Share-based Payment Arrangement [Abstract]
Disclosure of Share-based Compensation Arrangements by Share-based Payment Award	The following table summarizes the Partnership’s equity-based compensation expense related to performance units and phantom units for the Partnership’s employees and independent directors. Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (In millions) Performance units $ 2 $ 2 $ 4 $ 5 Phantom units 1 3 3 4 Total compensation expense $ 3 $ 5 $ 7 $ 9 The following table presents the assumptions related to the performance share units granted in 2020. 2020 Number of units granted 933,738 Fair value of units granted $ 7.00 Expected distribution yield 12.27 % Expected price volatility 27.70 % Risk-free interest rate 0.85 % Expected life of units (in years) 3 The following table presents the number of phantom units granted and the grant date fair value related to the phantom units granted in 2020. 2020 Phantom Units granted 947,632 Fair value of phantom units granted $2.67 - $10.13
Schedule of Share-based Compensation, Activity	A summary of the activity for the Partnership’s performance units and phantom units applicable to the Partnership’s employees at June 30, 2020 and changes during 2020 are shown in the following table. Performance Units Phantom Units Number Weighted Average Grant-Date Fair Value, Per Unit Number Weighted Average Grant-Date Fair Value, Per Unit (In millions, except unit data) Units outstanding at December 31, 2019 1,393,329 $ 19.04 1,392,560 $ 14.65 Granted (1) 933,738 7.00 947,632 6.55 Vested (2) (385,267) 19.23 (360,005) 16.02 Forfeited (139,024) 14.57 (172,016) 10.49 Units outstanding at June 30, 2020 1,802,776 $ 13.11 1,808,171 $ 10.53 Aggregate intrinsic value of units outstanding at June 30, 2020 $ 8 $ 8 _____________________ (1) Performance units represents the target number of performance units granted. The actual number of performance units earned, if any, is dependent upon performance and may range from 0% to 200% of the target. (2) Performance units vested as of June 30, 2020 include 376,292 units from the 2017 annual grant, which were approved by the Board of Directors in 2017 and, based on the level of achievement of a performance goal established by the Board of Directors over the performance period of January 1, 2017 through December 31, 2019, no performance units vested.	[1],[2]
Schedule of Unrecognized Compensation Cost, Nonvested Awards	summarizes the Partnership’s unrecognized compensation cost for its non-vested performance units and phantom units, and the weighted-average periods over which the compensation cost is expected to be recognized. June 30, 2020 Unrecognized Compensation Cost Weighted Average Period for Recognition Performance Units $ 13 1.93 Phantom Units 10 1.76 Total $ 23
[1]	Performance units represents the target number of performance units granted. The actual number of performance units earned, if any, is dependent upon performance and may range from 0% to 200% of the target.
[2]	Performance units vested as of June 30, 2020 include 376,292 units from the 2017 annual grant, which were approved by the Board of Directors in 2017 and, based on the level of achievement of a performance goal established by the Board of Directors over the performance period of January 1, 2017 through December 31, 2019, no performance units vested.

Reportable Segments (Tables)

Reportable Segments (Tables)	6 Months Ended
	Jun. 30, 2020
Segment Reporting [Abstract]
Schedule of Financial Data for Business Segments and Services	Financial data for reportable segments are as follows: Three Months Ended June 30, 2020 Gathering and Transportation (1) and Storage Eliminations Total (In millions) Product sales $ 193 $ 59 $ (56) $ 196 Service revenues 198 124 (3) 319 Total Revenues 391 183 (59) 515 Cost of natural gas and natural gas liquids (excluding depreciation and amortization shown separately) 176 59 (58) 177 Operation and maintenance, General and administrative 92 45 (1) 136 Depreciation and amortization 74 31 — 105 Taxes other than income tax 11 6 — 17 Operating income $ 38 $ 42 $ — $ 80 Total Assets $ 9,552 $ 5,662 $ (3,153) $ 12,061 Capital expenditures $ 24 $ 24 $ — $ 48 Three Months Ended June 30, 2019 Gathering and Transportation (1) and Storage Eliminations Total (In millions) Product sales $ 379 $ 114 $ (100) $ 393 Service revenues 208 138 (4) 342 Total Revenues 587 252 (104) 735 Cost of natural gas and natural gas liquids (excluding depreciation and amortization shown separately) 297 123 (103) 317 Operation and maintenance, General and administrative 75 50 (1) 124 Depreciation and amortization 78 32 — 110 Taxes other than income tax 10 7 — 17 Operating income $ 127 $ 40 $ — $ 167 Total assets as of December 31, 2019 $ 9,739 $ 5,886 $ (3,359) $ 12,266 Capital expenditures $ 90 $ 19 $ — $ 109 Six Months Ended June 30, 2020 Gathering and Transportation (1) and Storage Eliminations Total (In millions) Product sales $ 468 $ 134 $ (118) $ 484 Service revenues 400 283 (4) 679 Total Revenues 868 417 (122) 1,163 Cost of natural gas and natural gas liquids (excluding depreciation and amortization shown separately) 387 137 (121) 403 Operation and maintenance, General and administrative 173 90 (1) 262 Impairments 28 — — 28 Depreciation and amortization 148 61 — 209 Taxes other than income tax 22 13 — 35 Operating income $ 110 $ 116 $ — $ 226 Total Assets $ 9,552 $ 5,662 $ (3,153) $ 12,061 Capital expenditures $ 58 $ 44 $ — $ 102 Six Months Ended June 30, 2019 Gathering and Transportation (1) and Storage Eliminations Total (In millions) Product sales $ 802 $ 281 $ (247) $ 836 Service revenues 415 287 (8) 694 Total Revenues 1,217 568 (255) 1,530 Cost of natural gas and natural gas liquids (excluding depreciation and amortization shown separately) 657 292 (254) 695 Operation and maintenance, General and administrative 159 95 (1) 253 Depreciation and amortization 152 63 — 215 Taxes other than income tax 21 14 — 35 Operating income $ 228 $ 104 $ — $ 332 Total assets as of December 31, 2019 $ 9,739 $ 5,886 $ (3,359) $ 12,266 Capital expenditures $ 197 $ 55 $ — $ 252 _____________________ (1) See Note 8 for discussion regarding ownership interests in SESH and related equity earnings included in the transportation and storage segment for the three and six months ended June 30, 2020 and 2019.	[1]
[1]	See Note 8 for discussion regarding ownership interests in SESH and related equity earnings included in the transportation and storage segment for the three and six months ended June 30, 2020 and 2019.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Narrative (Details) $ in Millions	Apr. 08, 2020USD ($)	Apr. 01, 2020USD ($)	Jun. 30, 2020USD ($)board_membershares	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)board_membersegmentshares	Jun. 30, 2019USD ($)	Mar. 31, 2020USD ($)	Jan. 01, 2020USD ($)	Dec. 31, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Significant Accounting Policies [Line Items]
Number of reportable segments | segment					2
Number of representatives designated by each of CenterPoint Energy and OGE Energy | board_member			2		2
Number of independent board members | board_member			3		3
Percentage vote by all unitholders (at least 75%)					75.00%
Sale of interest		$ 19
Partners' Capital, Including Portion Attributable to Noncontrolling Interest			$ 7,317	$ 7,559	$ 7,317	$ 7,559	$ 7,352		$ 7,409	$ 7,583	$ 7,618
Accounts receivable			2		2			$ 2
Other assets			3		3			3
Total Allowance for doubtful accounts			5		5			$ 5
Inventory adjustments			$ 1	5	$ 7	6
Gathering and Processing
Significant Accounting Policies [Line Items]
Loss on retirement	$ 20
OGE Energy | Common Unit [Member]
Significant Accounting Policies [Line Items]
Units outstanding | shares			110,982,805		110,982,805
CenterPoint | Common Unit [Member]
Significant Accounting Policies [Line Items]
Units outstanding | shares			233,856,623		233,856,623
Partners' Capital | OGE Energy
Significant Accounting Policies [Line Items]
Percentage share of management rights			50.00%		50.00%
Percentage share of incentive distribution rights			60.00%		60.00%
Partners' Capital | CenterPoint
Significant Accounting Policies [Line Items]
Percentage share of management rights			50.00%		50.00%
Percentage share of incentive distribution rights			40.00%		40.00%
Partners' Capital | CenterPoint | Series A 10% Fixed to Floating Non Cumulative Redeemable Perpetual Preferred Units
Significant Accounting Policies [Line Items]
Series A preferred units held by CenterPoint Energy | shares			14,520,000		14,520,000
OGE Energy | Partners' Capital
Significant Accounting Policies [Line Items]
Limited partner ownership interest percentage					25.50%
Atoka
Significant Accounting Policies [Line Items]
Ownership interest (as a percentage)					50.00%
Atoka | Gathering and Processing
Significant Accounting Policies [Line Items]
Loss on retirement					$ 16
ESCP
Significant Accounting Policies [Line Items]
Ownership interest (as a percentage)					60.00%
CenterPoint | Partners' Capital
Significant Accounting Policies [Line Items]
Limited partner ownership interest percentage					53.70%
Partners' Capital | Common Unit [Member]
Significant Accounting Policies [Line Items]
Partners' Capital, Including Portion Attributable to Noncontrolling Interest			$ 6,937	$ 7,163	$ 6,937	$ 7,163	$ 6,972		7,013	$ 7,183	$ 7,218
Cumulative Effect, Period of Adoption, Adjustment
Significant Accounting Policies [Line Items]
Partners' Capital, Including Portion Attributable to Noncontrolling Interest									(3)
Cumulative Effect, Period of Adoption, Adjustment | Partners' Capital | Common Unit [Member]
Significant Accounting Policies [Line Items]
Partners' Capital, Including Portion Attributable to Noncontrolling Interest									$ (3)

Revenue - Disaggregation of Rev

Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	$ 201	$ 377	$ 469	$ 830
Gain (loss) on derivative activity	(5)	16	15	6
Total Revenues	515	735	1,163	1,530
Natural gas
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	51	107	120	256
Natural gas liquids
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	143	237	315	507
Condensate Natural Gas
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	7	33	34	67
Product
Disaggregation of Revenue [Line Items]
Total Revenues	196	393	484	836
Demand Service Revenue
Disaggregation of Revenue [Line Items]
Total Revenues	147	191	328	382
Volume Dependant Service Revenue
Disaggregation of Revenue [Line Items]
Total Revenues	172	151	351	312
Natural Gas, Gathering, Transportation, Marketing and Processing
Disaggregation of Revenue [Line Items]
Total Revenues	319	342	679	694
Operating Segments | Gathering and Processing
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	197	364	452	796
Gain (loss) on derivative activity	(4)	15	16	6
Total Revenues	391	587	868	1,217
Operating Segments | Gathering and Processing | Natural gas
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	47	94	103	222
Operating Segments | Gathering and Processing | Natural gas liquids
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	143	237	315	507
Operating Segments | Gathering and Processing | Condensate Natural Gas
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	7	33	34	67
Operating Segments | Gathering and Processing | Product
Disaggregation of Revenue [Line Items]
Total Revenues	193	379	468	802
Operating Segments | Gathering and Processing | Demand Service Revenue
Disaggregation of Revenue [Line Items]
Total Revenues	34	68	73	128
Operating Segments | Gathering and Processing | Volume Dependant Service Revenue
Disaggregation of Revenue [Line Items]
Total Revenues	164	140	327	287
Operating Segments | Gathering and Processing | Natural Gas, Gathering, Transportation, Marketing and Processing
Disaggregation of Revenue [Line Items]
Total Revenues	198	208	400	415
Operating Segments | Transportation and Storage
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	60	113	135	281
Gain (loss) on derivative activity	(1)	1	(1)	0
Total Revenues	183	252	417	568
Operating Segments | Transportation and Storage | Natural gas
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	57	108	130	270
Operating Segments | Transportation and Storage | Natural gas liquids
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	3	5	5	11
Operating Segments | Transportation and Storage | Condensate Natural Gas
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	0	0	0	0
Operating Segments | Transportation and Storage | Product
Disaggregation of Revenue [Line Items]
Total Revenues	59	114	134	281
Operating Segments | Transportation and Storage | Demand Service Revenue
Disaggregation of Revenue [Line Items]
Total Revenues	113	123	255	254
Operating Segments | Transportation and Storage | Volume Dependant Service Revenue
Disaggregation of Revenue [Line Items]
Total Revenues	11	15	28	33
Operating Segments | Transportation and Storage | Natural Gas, Gathering, Transportation, Marketing and Processing
Disaggregation of Revenue [Line Items]
Total Revenues	124	138	283	287
Eliminations
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	(56)	(100)	(118)	(247)
Gain (loss) on derivative activity	0	0	0	0
Total Revenues	(59)	(104)	(122)	(255)
Eliminations | Natural gas
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	(53)	(95)	(113)	(236)
Eliminations | Natural gas liquids
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	(3)	(5)	(5)	(11)
Eliminations | Condensate Natural Gas
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	0	0	0	0
Eliminations | Product
Disaggregation of Revenue [Line Items]
Total Revenues	(56)	(100)	(118)	(247)
Eliminations | Demand Service Revenue
Disaggregation of Revenue [Line Items]
Total Revenues	0	0	0	0
Eliminations | Volume Dependant Service Revenue
Disaggregation of Revenue [Line Items]
Total Revenues	(3)	(4)	(4)	(8)
Eliminations | Natural Gas, Gathering, Transportation, Marketing and Processing
Disaggregation of Revenue [Line Items]
Total Revenues	$ (3)	$ (4)	$ (4)	$ (8)

Revenue - Narrative (Details)

Revenue - Narrative (Details) $ in Millions	6 Months Ended
	Jun. 30, 2020USD ($)
Revenue from Contract with Customer [Abstract]
Revenue recognized related to rate case settlement	$ 17
Regulatory Liabilities, Refund to Customers	$ 21

Revenue - Accounts Receivable (

Revenue - Accounts Receivable (Details) - USD ($) $ in Millions		Jun. 30, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Customers		$ 205	$ 239
Contract assets	[1]	29	18
Non-customers		4	12
Total Accounts Receivable	[2]	238	269
Firm Service Transportation [Member]
Disaggregation of Revenue [Line Items]
Contract assets		$ 8	$ 6
[1]	Contract assets reflected in Total Accounts Receivable include accrued minimum volume commitments. Contract assets are primarily attributable to revenues associated with estimated shortfall volumes on certain annual minimum volume commitment arrangements. Total Accounts Receivable does not include contract assets related to firm service transportation contracts with tiered rates of $8 million as of June 30, 2020 and $6 million as of December 31, 2019, which are reflected in Other Assets.
[2]	Total Accounts Receivable includes Accounts receivable, net of allowance for doubtful accounts and Accounts receivable—affiliated companies.

Revenue - Summary of Changes in

Revenue - Summary of Changes in Contract Liabilities (Details) - USD ($) $ in Millions		6 Months Ended
		Jun. 30, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Deferred revenues (1)	[1]	$ 48	$ 48
Amounts recognized in revenues	[1]	$ 20
[1]	Deferred revenues includes deferred revenue — affiliated companies. This amount is included in Other current liabilities and Other long-term liabilities.

Revenue - Summary of Recognitio

Revenue - Summary of Recognition Contract Liabilities (Details) $ in Millions	6 Months Ended
	Jun. 30, 2020USD ($)	[1]
Revenue from Contract with Customer [Abstract]
2020	$ 21
2021	8
2022	6
2023	6
2024 and After	$ 7
[1]	Deferred revenues includes deferred revenue — affiliated companies. This amount is included in Other current liabilities and Other long-term liabilities.

Revenue - Summary of Recognit_2

Revenue - Summary of Recognition of Remaining Performance Obligations (Details) $ in Millions	Jun. 30, 2020USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Total remaining performance obligations	$ 290
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 | Transportation and Storage
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	6 months
Total remaining performance obligations	$ 233
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 | Gathering and Processing
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	6 months
Total remaining performance obligations	$ 57
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Total remaining performance obligations	$ 527
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | Transportation and Storage
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Total remaining performance obligations	$ 406
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | Gathering and Processing
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Total remaining performance obligations	$ 121
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Total remaining performance obligations	$ 468
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | Transportation and Storage
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Total remaining performance obligations	$ 345
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | Gathering and Processing
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Total remaining performance obligations	$ 123
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Total remaining performance obligations	$ 445
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | Transportation and Storage
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Total remaining performance obligations	$ 324
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | Gathering and Processing
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Total remaining performance obligations	$ 121
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	26 years 5 months
Total remaining performance obligations	$ 1,480
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | Transportation and Storage
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	23 years 5 months
Total remaining performance obligations	$ 1,167
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | Gathering and Processing
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	5 years 2 months
Total remaining performance obligations	$ 313

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Lessee, Lease, Description [Line Items]
Right-of-use assets	$ 31		$ 31
Difference between undiscounted cash flows for operating leases	4		4
Rental costs	$ 5	$ 7	$ 11	$ 16
Weighted average lease term (in years)	6 years 10 months 24 days		6 years 10 months 24 days
Weighted average discount rate (as a percentage)	5.46%		5.46%
Other Assets
Lessee, Lease, Description [Line Items]
Right-of-use assets	$ 28		$ 28
Other Current Liabilities
Lessee, Lease, Description [Line Items]
Operating Lease, Liability, Current	5		5
Other Liabilities
Lessee, Lease, Description [Line Items]
Operating Lease, Liability, Noncurrent	26		26
Field equipment
Lessee, Lease, Description [Line Items]
Rental costs	4	5	9	12
Buildings
Lessee, Lease, Description [Line Items]
Rental costs	$ 1	$ 2	$ 2	$ 4

Leases - Summary of Lease Expen

Leases - Summary of Lease Expense (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 1	$ 3	$ 3	$ 5
Short-term lease cost	4	4	7	11
Variable Lease, Cost			1
Total Lease Cost	5	7	11	16
Gathering and Processing
Lessee, Lease, Description [Line Items]
Operating lease cost	1	3	3	5
Short-term lease cost	4	4	7	10
Variable Lease, Cost			1
Total Lease Cost	5	7	11	15
Transportation and Storage
Lessee, Lease, Description [Line Items]
Operating lease cost	0	0	0	0
Short-term lease cost	0	0	0	1
Variable Lease, Cost			0
Total Lease Cost	$ 0	$ 0	$ 0	$ 1

Leases - Schedule of Operating

Leases - Schedule of Operating Lease Obligations Expiration (Details) $ in Millions	Jun. 30, 2020USD ($)
Leases [Abstract]
2020	$ 4
2021	6
2022	5
2023	5
2024	4
2025 and After	11
Total	$ 35

Earnings Per Limited Partner _3

Earnings Per Limited Partner Unit (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income		$ 44	$ 124	$ 149	$ 247
Net (loss) income attributable to noncontrolling interest		0	0	(7)	1
Series A Preferred Unit distributions		9	9	18	18
General partner interest in net income		0	0	0	0
Net Income Attributable to Common Units (Note 5)		$ 35	$ 115	$ 138	$ 228
Phantom units
Basic weighted average number of outstanding
Basic weighted average number of outstanding		2	1	2	1
Common Unit [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net Income Attributable to Common Units (Note 5)		$ 35	$ 115	$ 138	$ 228
Dilutive effect of Series A Preferred Unit distributions		0	0	18	0
Diluted net income		$ 35	$ 115	$ 156	$ 228
Basic earnings per unit
Basic earnings per unit		$ 0.08	$ 0.26	$ 0.32	$ 0.52
Basic weighted average number of outstanding
Basic weighted average number of outstanding	[1]	437	437	437	436
Dilutive effect of Series A Preferred Units (in units)		0	0	79	0
Diluted weighted average number of outstanding units		437	437	516	436
Diluted earnings per unit		$ 0.08	$ 0.26	$ 0.30	$ 0.52
[1]	Basic weighted average number of outstanding common units includes approximately two million time-based phantom units for the three and six months ended June 30, 2020, and one million time-based phantom units for the three and six months ended June 30, 2019.

Partners' Equity - Schedule of

Partners' Equity - Schedule of Cash Distributions (Details) - USD ($) $ / shares in Units, $ in Millions

Aug. 25, 2020

Aug. 18, 2020

Aug. 14, 2020

Aug. 04, 2020

May 27, 2020

May 19, 2020

May 15, 2020

May 05, 2020

Feb. 25, 2020

Feb. 18, 2020

Feb. 14, 2020

Feb. 07, 2020

Nov. 26, 2019

Nov. 19, 2019

Nov. 14, 2019

Nov. 05, 2019

Aug. 27, 2019

Aug. 20, 2019

Aug. 14, 2019

Aug. 02, 2019

May 29, 2019

May 21, 2019

May 15, 2019

Apr. 29, 2019

Distribution Made to Limited Partner [Line Items]

Record Date

May 19, 2020

Feb. 18, 2020

Nov. 19, 2019

Aug. 20, 2019

May 21, 2019

Payment Date

May 27, 2020

Feb. 25, 2020

Nov. 26, 2019

Aug. 27, 2019

May 29, 2019

Series A 10% Fixed to Floating Non Cumulative Redeemable Perpetual Preferred Units | Preferred Units

Distribution Made to Limited Partner [Line Items]

Record Date

May 5, 2020

Feb. 7, 2020

Nov. 5, 2019

Aug. 2, 2019

Apr. 29, 2019

Payment Date

May 15, 2020

Feb. 14, 2020

Nov. 14, 2019

Aug. 14, 2019

May 15, 2019

Cash Distribution

Distribution Made to Limited Partner [Line Items]

Cash distribution declared (in dollars per unit)

$ 0.16525

$ 0.3305

$ 0.3305

$ 0.3305

$ 0.318

Distribution made to unitholders

$ 72

$ 144

$ 144

$ 144

$ 138

Cash Distribution | Series A 10% Fixed to Floating Non Cumulative Redeemable Perpetual Preferred Units | Preferred Units

Distribution Made to Limited Partner [Line Items]

Cash distribution declared (in dollars per unit)

$ 0.625

$ 0.625

$ 0.625

$ 0.625

$ 0.625

Distribution made to unitholders

$ 9

$ 9

$ 9

$ 9

$ 9

Subsequent Event | Series A 10% Fixed to Floating Non Cumulative Redeemable Perpetual Preferred Units | Preferred Units

Distribution Made to Limited Partner [Line Items]

Record Date

[1]

Aug. 4, 2020

Payment Date

[1]

Aug. 14, 2020

Subsequent Event | Cash Distribution | Series A 10% Fixed to Floating Non Cumulative Redeemable Perpetual Preferred Units | Preferred Units

Distribution Made to Limited Partner [Line Items]

Cash distribution declared (in dollars per unit)

[1]

$ 0.625

Distribution made to unitholders

[1]

$ 9

Cash distribution (in dollars per unit)

$ 0.625

Forecast | Subsequent Event

Distribution Made to Limited Partner [Line Items]

Record Date

[2]

Aug. 18, 2020

Payment Date

[2]

Aug. 25, 2020

Forecast | Subsequent Event | Cash Distribution

Distribution Made to Limited Partner [Line Items]

Cash distribution declared (in dollars per unit)

[2]

$ 0.16525

Distribution made to unitholders

[2]

$ 72

Cash distribution (in dollars per unit)

$ 0.16525

[1]

The Board of Directors declared a $0.625 per Series A Preferred Unit cash distribution on August 4, 2020, to be paid on August 14, 2020, to Series A Preferred unitholders of record at the close of business on August 4, 2020.

[2]

The Board of Directors declared a $0.16525 per common unit cash distribution on August 4, 2020, to be paid on August 25, 2020 to common unitholders of record at the close of business on August 18, 2020.

Partners' Equity - Narrative (D

Partners' Equity - Narrative (Details) - USD ($)	May 12, 2017	Jun. 30, 2020
Distribution Made to Limited Partner [Line Items]
Limited partners' capital account, required quarterly distribution period		60 days
ATM Program
Distribution Made to Limited Partner [Line Items]
Aggregate offering price	$ 200,000,000

Impairment of Long-Lived Asse_3

Impairment of Long-Lived Assets (Details) - USD ($) $ in Millions	Apr. 08, 2020	Jun. 30, 2020
Gathering and Processing
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment of long-lived assets	$ 20
Atoka
Impaired Long-Lived Assets Held and Used [Line Items]
Ownership interest (as a percentage)		50.00%
Atoka | Gathering and Processing
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment of long-lived assets		$ 16

Impairment of Goodwill (Details

Impairment of Goodwill (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2017
Goodwill [Roll Forward]
Balance as of December 31, 2019	$ 12
Goodwill impairment	(12)
Balance as of June 30, 2020	0
Gathering and Processing
Goodwill [Roll Forward]
Balance as of December 31, 2019	12
Goodwill acquired		$ 12
Goodwill impairment	(12)
Balance as of June 30, 2020	0
Transportation and Storage
Goodwill [Roll Forward]
Balance as of December 31, 2019	0
Goodwill impairment	0
Balance as of June 30, 2020	$ 0

Investment in Equity Method A_3

Investment in Equity Method Affiliate - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Schedule of Equity Method Investments [Line Items]
Amount billed associated with service agreements	$ 515	$ 735	$ 1,163	$ 1,530
SESH
Schedule of Equity Method Investments [Line Items]
Percentage of distributions through limited partner interest			50.00%
SESH | Enbridge, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50.00%		50.00%
SESH | Enable Midstream Partners, LP [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50.00%		50.00%
SESH | Equity Method Investee | Shared Operations Service Agreements
Schedule of Equity Method Investments [Line Items]
Amount billed associated with service agreements	$ 2	$ 7	$ 8	$ 10

Investment in Equity Method A_4

Investment in Equity Method Affiliate - Schedule of Investments (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Equity Method Investment, Summarized Financial Information [Abstract]
Equity in earnings of equity method affiliate		$ 5	$ 4	$ 11	$ 7
Distributions from Equity Method Affiliates:
Return on investment in equity method affiliate				11	7
Return of investment in equity method affiliate				8	9
Operating income		80	167	226	332
Net income		44	124	149	247
SESH
Equity Method Investment, Summarized Financial Information [Abstract]
Equity in earnings of equity method affiliate		5	4	11	7
Distributions from Equity Method Affiliates:
Distributions from equity method affiliate	[1]	9	4	19	16
Return on investment in equity method affiliate		5	4	11	7
Return of investment in equity method affiliate		4	0	8	9
Revenues		28	27	55	54
Operating income		13	11	29	22
Net income		$ 10	$ 7	$ 21	$ 14
[1]	Distributions from equity method affiliate includes a $5 million and $4 million return on investment and a $4 million and $0 return of investment for the three months ended June 30, 2020 and 2019, respectively. Distributions from equity method affiliate includes an $11 million and $7 million return on investment and an $8 million and $9 million return of investment for the six months ended June 30, 2020 and 2019, respectively.

Debt - Schedule of Outstanding

Debt - Schedule of Outstanding Debt (Details) - USD ($)		Jun. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Short-term debt		$ 30,000,000	$ 155,000,000
Outstanding Principal		4,408,000,000	4,405,000,000
Premium (Discount)	[1]	(8,000,000)	(7,000,000)
Total Debt		4,400,000,000	4,398,000,000
Less: Unamortized debt expense	[2]	(21,000,000)	(23,000,000)
Total long-term debt		4,349,000,000	3,969,000,000
2019 Term Loan Agreement | 2019 Term Loan Agreement
Debt Instrument [Line Items]
Outstanding Principal		800,000,000	800,000,000
Premium (Discount)	[1]	0	0
Total Debt		800,000,000	800,000,000
Senior Notes | 2024 Notes
Debt Instrument [Line Items]
Outstanding Principal		600,000,000	600,000,000
Premium (Discount)	[1]	0	0
Total Debt		600,000,000	600,000,000
Senior Notes | 2027 Notes
Debt Instrument [Line Items]
Outstanding Principal		700,000,000	700,000,000
Premium (Discount)	[1]	(2,000,000)	(2,000,000)
Total Debt		698,000,000	698,000,000
Senior Notes | 2028 Notes
Debt Instrument [Line Items]
Outstanding Principal		800,000,000	800,000,000
Premium (Discount)	[1]	(5,000,000)	(5,000,000)
Total Debt		795,000,000	795,000,000
Senior Notes | 2029 Notes
Debt Instrument [Line Items]
Outstanding Principal		547,000,000	550,000,000
Premium (Discount)	[1]	(1,000,000)	(1,000,000)
Total Debt		546,000,000	549,000,000
Senior Notes | 2044 Notes
Debt Instrument [Line Items]
Outstanding Principal		531,000,000	550,000,000
Premium (Discount)	[1]	0	0
Total Debt		531,000,000	550,000,000
Senior Notes | EOIT Senior Notes | EOIT
Debt Instrument [Line Items]
Outstanding Principal		0	250,000,000
Premium (Discount)	[1]	0	1,000,000
Total Debt		0	251,000,000
Senior Notes | Senior notes due in 2020
Debt Instrument [Line Items]
Less: Current portion of long-term debt	[3]	0	251,000,000
Revolving Credit Facility
Debt Instrument [Line Items]
Outstanding Principal		400,000,000	0
Premium (Discount)	[1]	0	0
Total Debt		400,000,000	0
Unamortized debt expense related to Revolving Credit Facility		4,000,000	4,000,000
Commercial Paper
Debt Instrument [Line Items]
Short-term debt	[4]	30,000,000	155,000,000
Premium (Discount)	[1]	$ 0	$ 0
[1]	Unamortized premium (discount) on long-term debt is amortized over the life of the respective debt.
[2]	As of June 30, 2020 and December 31, 2019, there was an additional $4 million of unamortized debt expense related to the Revolving Credit Facility included in Other assets, not included above.
[3]	As of December 31, 2019, Current portion of long-term debt included $251 million outstanding balance of the EOIT Senior Notes which were repaid in March 2020.
[4]	Short-term debt includes $30 million and $155 million of outstanding commercial paper as of June 30, 2020 and December 31, 2019, respectively.

Debt - Narrative (Details)

Debt - Narrative (Details)		Jan. 29, 2019USD ($)	Apr. 06, 2018USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Debt Instrument [Line Items]
Commercial paper, authorized				$ 1,400,000,000
Commercial paper outstanding				30,000,000		$ 155,000,000
Debt Instrument, Repurchased Face Amount				22,000,000
Debt Instrument, Repurchase Amount				17,000,000
Gain on extinguishment of debt				$ 5,000,000	$ 0
2019 Term Loan Agreement
Debt Instrument [Line Items]
Weighted average interest rate percentage				2.12%
Number of times option maybe exercised to extend term of Term Loan Facility		2
Debt Instrument, Term of Extension Period		1 year
Debt Instrument, Principle Advance				$ 800,000,000
LIBOR | 2019 Term Loan Agreement
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage				1.25%
Senior Notes | Senior Notes including 2019 Notes, 2024 Notes, and 2044 Notes
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount				$ 8,000,000
Unamortized debt expense				$ 21,000,000
Senior Notes | 2024 Notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate During Period				4.01%
Senior Notes | 2027 Notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate During Period				4.56%
Senior Notes | 2028 Notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate During Period				5.19%
Senior Notes | 2029 Notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate During Period				4.31%
Senior Notes | 2044 Notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate During Period				5.09%
Commercial Paper
Debt Instrument [Line Items]
Commercial paper outstanding	[1]			$ 30,000,000		$ 155,000,000
Weighted average interest rate percentage				1.00%
Revolving Credit Facility
Debt Instrument [Line Items]
Weighted average interest rate percentage				1.92%
Maximum borrowing capacity			$ 1,750,000,000
Duration of term loan facility (in years)			5 years
Increase in maximum borrowing capacity			$ 875,000,000
Number of times option maybe exercised to extend term of Term Loan Facility			2
Debt Instrument, Term of Extension Period			1 year
Letters of credit principal advances				$ 400,000,000
Letters of credit outstanding amount				$ 3,000,000
Commitment fee percentage				0.20%
Revolving Credit Facility | LIBOR
Debt Instrument [Line Items]
Applicable margin percentage				1.50%
Minimum | Eurodollar | 2019 Term Loan Agreement
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		0.75%
Minimum | Base Rate | 2019 Term Loan Agreement
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		0.00%
Maximum | Eurodollar | 2019 Term Loan Agreement
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		1.50%
Maximum | Base Rate | 2019 Term Loan Agreement
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		0.50%
[1]	Short-term debt includes $30 million and $155 million of outstanding commercial paper as of June 30, 2020 and December 31, 2019, respectively.

Derivative Instruments and He_3

Derivative Instruments and Hedging Activities Quantitative Disclosures Related to Derivative Instruments (Details) - Not Designated as Hedging Instrument bbl in Thousands, MMBTU in Millions		6 Months Ended	12 Months Ended
		Jun. 30, 2020MMBTUbbl	Dec. 31, 2019MMBTUbbl
Natural Gas, Financial fixed futures/swaps | Purchases
Derivative [Line Items]
Derivative, gross notional volume (TBtu) | MMBTU	[1]	6	10
Natural Gas, Financial fixed futures/swaps | Sales
Derivative [Line Items]
Derivative, gross notional volume (TBtu) | MMBTU	[1]	26	19
Natural gas, Financial basis futures/swaps | Purchases
Derivative [Line Items]
Derivative, gross notional volume (TBtu) | MMBTU	[1]	5	11
Natural gas, Financial basis futures/swaps | Sales
Derivative [Line Items]
Derivative, gross notional volume (TBtu) | MMBTU	[1]	39	30
Natural gas, Financial swaptions | Purchases
Derivative [Line Items]
Derivative, gross notional volume (TBtu) | MMBTU	[1],[2]	0	0
Natural gas, Financial swaptions | Sales
Derivative [Line Items]
Derivative, gross notional volume (TBtu) | MMBTU	[1],[2]	9	2
Physical purchases/sales | Purchases
Derivative [Line Items]
Derivative, gross notional volume (TBtu) | MMBTU	[1]	0	0
Physical purchases/sales | Sales
Derivative [Line Items]
Derivative, gross notional volume (TBtu) | MMBTU	[1]	3	6
Crude oil, Financial Futures/swaps | Purchases
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Volume | bbl	[3]	0	0
Crude oil, Financial Futures/swaps | Sales
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Volume | bbl	[3]	540	990
Crude oil, Financial options | Purchases
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Volume | bbl	[2],[3]	0	0
Crude oil, Financial options | Sales
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Volume | bbl	[2],[3]	150	225
Natural gas liquids, Financial Futures/swaps | Purchases
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Volume | bbl	[4]	1,830	2,490
Natural gas liquids, Financial Futures/swaps | Sales
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Volume | bbl	[4]	1,840	2,415
Natural gas liquids, Options [Member] | Purchases
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Volume | bbl	[4]	0	0
Natural gas liquids, Options [Member] | Sales
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Volume | bbl	[4]	60	0
Natural gas
Derivative [Line Items]
Percent of contract with durations of one year or less		88.10%	86.60%
Percent of contracts with durations of more than one year and less than two years		11.90%	13.40%
Crude oil (for condensate)
Derivative [Line Items]
Percent of contract with durations of one year or less		91.30%	72.80%
Percent of contracts with durations of more than one year and less than two years		8.70%	27.20%
Natural gas liquids
Derivative [Line Items]
Percent of contract with durations of one year or less		97.50%	72.20%
Percent of contracts with durations of more than one year and less than two years		2.50%	27.80%
[1]	As of June 30, 2020, 88.1% of the natural gas contracts had durations of one year or less and 11.9% had durations of more than one year and less than two years. As of December 31, 2019, 86.6% of the natural gas contracts had durations of one year or less and 13.4% had durations of more than one year and less than two years.
[2]	The notional volume contains a combined derivative instrument consisting of a fixed price swap and a sold option, which gives the counterparties the right, but not the obligation, to increase the notional volume hedged under the fixed price swap until the option expiration date. The notional volume represents the volume prior to option exercise.
[3]	As of June 30, 2020, 91.3% of the crude oil (for condensate) contracts had durations of one year or less and 8.7% had durations of more than one year and less than two years. As of December 31, 2019, 72.8% of the crude oil (for condensate) contracts had durations of one year or less and 27.2% had durations of more than one year and less than two years.
[4]	As of June 30, 2020, 97.5% of the natural gas liquids contracts had durations of one year or less and 2.5% had durations of more than one year and less than two years. As of December 31, 2019, 72.2% of the natural gas liquids contracts had durations of one year or less and 27.8% had durations of more than one year and less than two years.

Derivative Instruments and He_4

Derivative Instruments and Hedging Activities - Derivative Instruments Designated as Hedging Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Designated as Hedging Instrument | Interest Rate Swap
Derivative [Line Items]
Gross Notional Value	$ 300	$ 300

Derivative Instruments and He_5

Derivative Instruments and Hedging Activities - Balance Sheet Location (Details) - USD ($) $ in Millions		Jun. 30, 2020	Dec. 31, 2019
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	[1]	$ 38	$ 49
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	29	38
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	[2]	0	0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[2]	9	3
Interest rate swaps | Designated as Hedging Instrument | Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		0	0
Interest rate swaps | Designated as Hedging Instrument | Other Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		6	1
Interest rate swaps | Designated as Hedging Instrument | Other Noncurrent Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		0	0
Interest rate swaps | Designated as Hedging Instrument | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		3	2
Natural gas | Financial futures/swaps | Not Designated as Hedging Instrument | Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		7	7
Natural gas | Financial futures/swaps | Not Designated as Hedging Instrument | Other Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		7	5
Natural gas | Financial futures/swaps | Not Designated as Hedging Instrument | Other Noncurrent Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		0	0
Natural gas | Financial futures/swaps | Not Designated as Hedging Instrument | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0	1
Natural gas | Financial swaptions | Not Designated as Hedging Instrument | Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		1	0
Natural gas | Financial swaptions | Not Designated as Hedging Instrument | Other Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		2	0
Natural gas | Financial swaptions | Not Designated as Hedging Instrument | Other Noncurrent Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		1	0
Natural gas | Financial swaptions | Not Designated as Hedging Instrument | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		1	0
Natural gas | Physical purchases/sales | Not Designated as Hedging Instrument | Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		2	5
Natural gas | Physical purchases/sales | Not Designated as Hedging Instrument | Other Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0	0
Crude oil (for condensate) | Financial futures/swaps | Not Designated as Hedging Instrument | Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		2	1
Crude oil (for condensate) | Financial futures/swaps | Not Designated as Hedging Instrument | Other Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		14	19
Crude oil (for condensate) | Financial futures/swaps | Not Designated as Hedging Instrument | Other Noncurrent Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		0	0
Crude oil (for condensate) | Financial futures/swaps | Not Designated as Hedging Instrument | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		2	8
Crude oil (for condensate) | Financial swaptions | Not Designated as Hedging Instrument | Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		3	0
Crude oil (for condensate) | Financial swaptions | Not Designated as Hedging Instrument | Other Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0	0
Natural gas liquids | Financial futures/swaps | Not Designated as Hedging Instrument | Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		20	25
Natural gas liquids | Financial futures/swaps | Not Designated as Hedging Instrument | Other Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		3	3
Natural gas liquids | Financial futures/swaps | Not Designated as Hedging Instrument | Other Noncurrent Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		2	11
Natural gas liquids | Financial futures/swaps | Not Designated as Hedging Instrument | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		$ 0	$ 2
[1]	See Note 11 for a reconciliation of the Partnership’s commodity derivatives fair value to the Partnership’s Condensed Consolidated Balance Sheets as of June 30, 2020 and December 31, 2019.
[2]	All interest rate derivative instruments that were designated as cash flow hedges are considered Level 2 as of June 30, 2020 and December 31, 2019.

Derivative Instruments and He_6

Derivative Instruments and Hedging Activities - Amounts Recognized in Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on derivative, net	$ (5)	$ 16	$ 15	$ 6
Change in fair value of commodity derivatives	(12)	11	(2)	(1)
Realized gain on commodity derivatives	7	5	17	7
Gain (loss) on commodity derivative activity	(5)	16	15	6
Cash collateral posted	0		0
Cash collateral required if ratings are lowered	1		1
Gain (Loss) on Hedging Activity	(1)	0	(1)	0
Interest Rate Swap
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Hedging Activity	(1)	0	(1)	0
Natural gas | Financial futures/swaps
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on commodity derivative activity	(1)	9	3	8
Natural gas | Financial swaptions
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on commodity derivative activity	(1)	0	(2)	0
Natural gas | Physical purchases/sales
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on commodity derivative activity	0	1	1	0
Condensate | Financial futures/swaps
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on commodity derivative activity	(7)	(10)	12	(21)
Condensate | Financial swaptions
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on commodity derivative activity	(2)	0	2	0
Natural gas liquids | Financial futures/swaps
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on commodity derivative activity	$ 6	$ 16	$ (1)	$ 19

Fair Value Measurements - Carry

Fair Value Measurements - Carrying and Fair Value Amounts (Details) - USD ($)		Jun. 30, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term debt		$ 30,000,000	$ 155,000,000
Carrying Amount | Significant other observable inputs (Level 2) | 2019 Term Loan Agreement | 2019 Term Loan Agreement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
2019 Term Loan Agreement (Level 2)		800,000,000	800,000,000
Carrying Amount | Significant other observable inputs (Level 2) | Senior Notes | 2024 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		600,000,000	600,000,000
Carrying Amount | Significant other observable inputs (Level 2) | Senior Notes | 2027 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		698,000,000	698,000,000
Carrying Amount | Significant other observable inputs (Level 2) | Senior Notes | 2028 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		795,000,000	795,000,000
Carrying Amount | Significant other observable inputs (Level 2) | Senior Notes | 2029 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		546,000,000	549,000,000
Carrying Amount | Significant other observable inputs (Level 2) | Senior Notes | 2044 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		531,000,000	550,000,000
Carrying Amount | Significant other observable inputs (Level 2) | Senior Notes | EOIT Senior Notes | EOIT
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		0	251,000,000
Carrying Amount | Significant other observable inputs (Level 2) | Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Revolving Credit Facility (Level 2)	[1]	400,000,000	0
Fair Value | Significant other observable inputs (Level 2) | 2019 Term Loan Agreement | 2019 Term Loan Agreement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
2019 Term Loan Agreement (Level 2)		800,000,000	800,000,000
Fair Value | Significant other observable inputs (Level 2) | Senior Notes | 2024 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		588,000,000	614,000,000
Fair Value | Significant other observable inputs (Level 2) | Senior Notes | 2027 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		648,000,000	698,000,000
Fair Value | Significant other observable inputs (Level 2) | Senior Notes | 2028 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		742,000,000	811,000,000
Fair Value | Significant other observable inputs (Level 2) | Senior Notes | 2029 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		476,000,000	526,000,000
Fair Value | Significant other observable inputs (Level 2) | Senior Notes | 2044 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		424,000,000	506,000,000
Fair Value | Significant other observable inputs (Level 2) | Senior Notes | EOIT Senior Notes | EOIT
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		0	252,000,000
Fair Value | Significant other observable inputs (Level 2) | Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Revolving Credit Facility (Level 2)	[1]	400,000,000	0
Commercial Paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term debt	[2]	$ 30,000,000	$ 155,000,000
[1]	Borrowing capacity is effectively reduced by our borrowings outstanding under the commercial paper program. $30 million and $155 million of commercial paper was outstanding as of June 30, 2020 and December 31, 2019, respectively.
[2]	Short-term debt includes $30 million and $155 million of outstanding commercial paper as of June 30, 2020 and December 31, 2019, respectively.

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Hierarchy (Details) - USD ($) $ in Millions		Jun. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Retained fuel due from shippers		$ 23	$ 21
Over retained fuel due from shippers		6	8
Commodity Contracts | Recurring Measurement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, total fair value		38	49
Liabilities, total fair value		29	38
Asset netting adjustments		(28)	(37)
Liability netting adjustments		(28)	(37)
Assets		10	12
Liabilities		1	1
Commodity Contracts | Recurring Measurement | Quoted market prices in active market for identical assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		6	5
Liabilities		23	31
Commodity Contracts | Recurring Measurement | Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		32	44
Liabilities		6	7
Gas Imbalances | Recurring Measurement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, total fair value	[1],[2]	15	14
Liabilities, total fair value	[2],[3]	13	11
Asset netting adjustments	[1],[2]	0	0
Liability netting adjustments	[2],[3]	0	0
Assets	[1],[2]	15	14
Liabilities	[2],[3]	13	11
Gas Imbalances | Recurring Measurement | Quoted market prices in active market for identical assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	[1],[2]	0	0
Liabilities	[2],[3]	0	0
Gas Imbalances | Recurring Measurement | Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	[1],[2]	15	14
Liabilities	[2],[3]	$ 13	$ 11
[1]	Gas imbalance assets exclude fuel reserves for under retained fuel due from shippers of $23 million and $21 million at June 30, 2020 and December 31, 2019, respectively, which fuel reserves are based on the value of natural gas at the time the imbalance was created, and which are not subject to revaluation at fair market value.
[2]	The Partnership uses the market approach to fair value its gas imbalance assets and liabilities at individual, or where appropriate an average of, current market indices applicable to the Partnership’s operations, not to exceed net realizable value. There were no netting adjustments as of June 30, 2020 and December 31, 2019.
[3]	Gas imbalance liabilities exclude fuel reserves for over retained fuel due to shippers of $6 million and $8 million at June 30, 2020 and December 31, 2019, respectively, which fuel reserves are based on the value of natural gas at the time the imbalance was created, and which are not subject to revaluation at fair market value.

Supplemental Disclosure of Ca_3

Supplemental Disclosure of Cash Flow Information - Supplemental Disclosure of Cash Flow Information (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Interest, net of capitalized interest	$ 96	$ 95
Income Taxes Paid, Net	1	1
Accounts payable related to capital expenditures	8	31
Lease liabilities related to (derecognition) recognition of right-of-use assets	(5)
Lease liabilities related to (derecognition) recognition of right-of-use assets		42
Partners' Capital, Including Portion Attributable to Noncontrolling Interest	7,317	7,559	$ 7,352	$ 7,409	$ 7,583	$ 7,618
Common Unit [Member] | Partners' Capital
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Partners' Capital, Including Portion Attributable to Noncontrolling Interest	$ 6,937	$ 7,163	$ 6,972	7,013	$ 7,183	$ 7,218
Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Partners' Capital, Including Portion Attributable to Noncontrolling Interest				(3)
Cumulative Effect, Period of Adoption, Adjustment | Common Unit [Member] | Partners' Capital
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Partners' Capital, Including Portion Attributable to Noncontrolling Interest				$ (3)

Supplemental Disclosure of Ca_4

Supplemental Disclosure of Cash Flow Information - Reconciliation of Cash and Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Supplemental Cash Flow Information [Abstract]
Cash and cash equivalents	$ 11	$ 4	$ 9
Restricted cash	0		1
Cash, cash equivalents and restricted cash shown in the Condensed Consolidated Statements of Cash Flows	$ 11	$ 4	$ 10	$ 22

Related Party Transactions - Na

Related Party Transactions - Narrative (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Related Party Transaction [Line Items]
Partnership's revenues from affiliated companies as a percent of total revenues	7.00%	6.00%
Subsidiary of Common Parent | CenterPoint | Three Services Included in Transportation and Storage Agreements
Related Party Transaction [Line Items]
Period of written notice	180 days
CenterPoint and OGE Energy | Minimum
Related Party Transaction [Line Items]
Period notice of termination for reimbursements for all employee costs	90 days
OGE Energy | Defined Benefit and Retiree Medical Plans
Related Party Transaction [Line Items]
Expense reimbursement, 2018 and thereafter	$ 5
OGE Energy | Certain Services and Support Functions
Related Party Transaction [Line Items]
Expense reimbursement annual caps	1
CenterPoint | Certain Services and Support Functions
Related Party Transaction [Line Items]
Expense reimbursement annual caps	$ 0

Related Party Transactions - Re

Related Party Transactions - Related Party Activity (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Related Party Transaction [Line Items]
Revenues from affiliated companies	$ 33	$ 39	$ 84	$ 87
Cost of natural gas purchases from affiliate	6	7	15	13
CenterPoint
Related Party Transaction [Line Items]
Cost of natural gas purchases from affiliate	0	0	1	0
CenterPoint | Gas Transportation and Storage
Related Party Transaction [Line Items]
Revenues from affiliated companies	22	23	59	56
CenterPoint | Gas Sales
Related Party Transaction [Line Items]
Revenues from affiliated companies	1	3	1	4
OGE Energy
Related Party Transaction [Line Items]
Cost of natural gas purchases from affiliate	6	7	14	13
OGE Energy | Gas Transportation and Storage
Related Party Transaction [Line Items]
Revenues from affiliated companies	10	13	19	26
OGE Energy | Gas Sales
Related Party Transaction [Line Items]
Revenues from affiliated companies	0	0	5	1
OGE Energy | Seconded Employee Costs
Related Party Transaction [Line Items]
Seconded employee costs	$ 5	$ 5	$ 8	$ 11

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Millions	Sep. 13, 2018	Jan. 01, 2017	Jun. 30, 2020
Gathering and processing agreement term (in years)		10 years
Minimum volume commitment fee			$ 181
Minimum volume commitment fees remaining in 2020			9
Minimum volume commitment fees per year from 2021 through 2027			23
Minimum volume commitment fees in 2028			11
Estimated Cost to Complete Pipeline Project			$ 500
Firm transportation service agreement term (in years)	20 years

Equity-Based Compensation (Deta

Equity-Based Compensation (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation expense	$ 3	$ 5	$ 7	$ 9
Performance units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation expense	2	2	4	5
Phantom units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation expense	$ 1	$ 3	$ 3	$ 4

Equity-Based Compensation - Sch

Equity-Based Compensation - Schedule of Assumptions Related to Performance Share Units (Details) - Performance units	6 Months Ended
	Jun. 30, 2020$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of units granted | shares	933,738	[1]
Fair value of units granted | $ / shares	$ 7	[1]
Expected distribution yield	12.27%
Expected price volatility	27.70%
Risk-free interest rate	0.85%
Expected life of units (in years)	3 years
[1]	Performance units represents the target number of performance units granted. The actual number of performance units earned, if any, is dependent upon performance and may range from 0% to 200% of the target.

Equity-Based Compensation - Pha

Equity-Based Compensation - Phantom Units (Details)	6 Months Ended
	Jun. 30, 2020$ / sharesshares
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of phantom units granted (in dollars per share)	$ 2.67
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of phantom units granted (in dollars per share)	$ 10.13
Phantom units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Phantom Units granted | shares	947,632	[1]
Fair value of phantom units granted (in dollars per share)	$ 6.55	[1]
[1]	Performance units represents the target number of performance units granted. The actual number of performance units earned, if any, is dependent upon performance and may range from 0% to 200% of the target.

Equity-Based Compensation - Equ

Equity-Based Compensation - Equity Units Activity (Details) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2020USD ($)$ / sharesshares
Minimum
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Granted (in dollars per unit)	$ 2.67
Maximum
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Granted (in dollars per unit)	$ 10.13
Performance units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Units Outstanding (in units) | shares	1,393,329
Granted (in units) | shares	933,738	[1]
Vested (in units) | shares	(385,267)	[2]
Forfeited (in units) | shares	(139,024)
Units Outstanding (in units) | shares	1,802,776
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Units Outstanding (in dollars per unit)	$ 19.04
Granted (in dollars per unit)	7	[1]
Vested (in dollars per unit)	19.23	[2]
Forfeited (in dollars per unit)	14.57
Units Outstanding (in dollars per unit)	$ 13.11
Aggregate Intrinsic Value of Units Outstanding | $	$ 8
Performance units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Payout percentage	0.00%
Performance units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Payout percentage	200.00%
Performance units | Annual Grant in 2017 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted (in units) | shares	376,292
Phantom units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Units Outstanding (in units) | shares	1,392,560
Granted (in units) | shares	947,632	[1]
Vested (in units) | shares	(360,005)	[2]
Forfeited (in units) | shares	(172,016)
Units Outstanding (in units) | shares	1,808,171
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Units Outstanding (in dollars per unit)	$ 14.65
Granted (in dollars per unit)	6.55	[1]
Vested (in dollars per unit)	16.02	[2]
Forfeited (in dollars per unit)	10.49
Units Outstanding (in dollars per unit)	$ 10.53
Aggregate Intrinsic Value of Units Outstanding | $	$ 8
[1]	Performance units represents the target number of performance units granted. The actual number of performance units earned, if any, is dependent upon performance and may range from 0% to 200% of the target.
[2]	Performance units vested as of June 30, 2020 include 376,292 units from the 2017 annual grant, which were approved by the Board of Directors in 2017 and, based on the level of achievement of a performance goal established by the Board of Directors over the performance period of January 1, 2017 through December 31, 2019, no performance units vested.

Equity-Based Compensation - Unr

Equity-Based Compensation - Unrecognized Compensation Cost (Details) $ in Millions	6 Months Ended
	Jun. 30, 2020USD ($)shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost (In millions)	$ 23
Performance units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost (In millions)	$ 13
Weighted Average Period for Recognition (In years)	1 year 11 months 4 days
Phantom units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost (In millions)	$ 10
Weighted Average Period for Recognition (In years)	1 year 9 months 3 days
Long Term Incentive Plan | Common Unit [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance | shares	5,275,303

Reportable Segments - Schedule

Reportable Segments - Schedule of Financial Data for Business Segments and Services (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)segment	Jun. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			2
Total Revenues	$ 515	$ 735	$ 1,163	$ 1,530
Cost of natural gas and natural gas liquids (excluding depreciation and amortization shown separately)	177	317	403	695
Operation and maintenance, General and administrative	136	124	262	253
Depreciation and amortization	105	110	209	215
Impairments	0	0	28	0
Taxes other than income tax	17	17	35	35
Operating Income	80	167	226	332
Total assets	12,061		12,061		$ 12,266
Capital expenditures	48	109	102	252
Operating Segments | Gathering and Processing
Segment Reporting Information [Line Items]
Total Revenues	391	587	868	1,217
Cost of natural gas and natural gas liquids (excluding depreciation and amortization shown separately)	176	297	387	657
Operation and maintenance, General and administrative	92	75	173	159
Depreciation and amortization	74	78	148	152
Impairments			28
Taxes other than income tax	11	10	22	21
Operating Income	38	127	110	228
Total assets	9,552		9,552		9,739
Capital expenditures	24	90	58	197
Operating Segments | Transportation and Storage
Segment Reporting Information [Line Items]
Total Revenues	183	252	417	568
Cost of natural gas and natural gas liquids (excluding depreciation and amortization shown separately)	59	123	137	292
Operation and maintenance, General and administrative	45	50	90	95
Depreciation and amortization	31	32	61	63
Impairments			0
Taxes other than income tax	6	7	13	14
Operating Income	42	40	116	104
Total assets	5,662		5,662		5,886
Capital expenditures	24	19	44	55
Eliminations
Segment Reporting Information [Line Items]
Total Revenues	(59)	(104)	(122)	(255)
Cost of natural gas and natural gas liquids (excluding depreciation and amortization shown separately)	(58)	(103)	(121)	(254)
Operation and maintenance, General and administrative	(1)	(1)	(1)	(1)
Depreciation and amortization	0	0	0	0
Impairments			0
Taxes other than income tax	0	0	0	0
Operating Income	0	0	0	0
Total assets	(3,153)		(3,153)		$ (3,359)
Capital expenditures	0	0	0	0
Product
Segment Reporting Information [Line Items]
Total Revenues	196	393	484	836
Product | Operating Segments | Gathering and Processing
Segment Reporting Information [Line Items]
Total Revenues	193	379	468	802
Product | Operating Segments | Transportation and Storage
Segment Reporting Information [Line Items]
Total Revenues	59	114	134	281
Product | Eliminations
Segment Reporting Information [Line Items]
Total Revenues	(56)	(100)	(118)	(247)
Natural Gas, Gathering, Transportation, Marketing and Processing
Segment Reporting Information [Line Items]
Total Revenues	319	342	679	694
Natural Gas, Gathering, Transportation, Marketing and Processing | Operating Segments | Gathering and Processing
Segment Reporting Information [Line Items]
Total Revenues	198	208	400	415
Natural Gas, Gathering, Transportation, Marketing and Processing | Operating Segments | Transportation and Storage
Segment Reporting Information [Line Items]
Total Revenues	124	138	283	287
Natural Gas, Gathering, Transportation, Marketing and Processing | Eliminations
Segment Reporting Information [Line Items]
Total Revenues	$ (3)	$ (4)	$ (4)	$ (8)