DCP Midstream (DCP-PC) 10-Q 5 Nov 20 2020 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2020	Oct. 30, 2020
Cover [Abstract]
Entity Registrant Name	DCP MIDSTREAM, LP
Document Period End Date	Sep. 30, 2020
Amendment Flag	false
Document Fiscal Year Focus	2020
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Document Fiscal Period Focus	Q3
Entity Central Index Key	0001338065
Current Fiscal Year End Date	--12-31
Document Type	10-Q
City Area Code	(303)
Local Phone Number	595-3331
Entity Address, Postal Zip Code	80202
Entity Address, Address Line One	370 17th Street
Entity Address, Address Line Two	Suite 2500
Entity Address, City or Town	Denver
Entity Address, State or Province	CO
Entity Current Reporting Status	Yes
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	03-0567133
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-32678
Entity Shell Company	false
Entity Interactive Data Current	Yes
Entity Common Stock, Shares Outstanding		208,351,528
Series B Preferred Limited Partners [Member]
Title of 12(b) Security	7.875% Series B Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units
Trading Symbol	DCP PRB
Security Exchange Name	NYSE
Series C Preferred Limited Partners [Member]
Title of 12(b) Security	7.95% Series C Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units
Trading Symbol	DCP PRC
Security Exchange Name	NYSE
Limited Partners
Title of 12(b) Security	Common units representing limited partnership interests
Trading Symbol	DCP
Security Exchange Name	NYSE

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 14	$ 1
Accounts receivable:
Trade, net of allowance for doubtful accounts of $4 and $3 million, respectively	528	726
Affiliates	150	138
Other	16	14
Inventories	28	46
Unrealized gains on derivative instruments	91	32
Collateral cash deposits	21	111
Other	18	12
Total current assets	866	1,080
Property, plant and equipment, net	8,046	8,811
Goodwill	0	159
Intangible assets, net	46	61
Investments in unconsolidated affiliates	3,668	3,724
Unrealized gains on derivative instruments	40	2
Operating lease assets	83	107
Other long-term assets	165	183
Total assets	12,914	14,127
Accounts payable:
Trade	394	638
Affiliates	119	100
Other	23	35
Current debt	504	603
Unrealized losses on derivative instruments	83	58
Accrued interest	73	80
Accrued taxes	68	65
Accrued wages and benefits	47	58
Capital spending accrual	4	28
Other	98	128
Total current liabilities	1,413	1,793
Long-term debt	5,244	5,321
Unrealized losses on derivative instruments	29	20
Deferred income taxes	30	30
Operating lease liabilities	76	88
Other long-term liabilities	240	242
Total liabilities	7,032	7,494
Equity:
Limited partners (208,329,928 common units authorized, issued and outstanding, respectively)	5,100	5,861
Accumulated other comprehensive loss	(7)	(7)
Total partners’ equity	5,854	6,605
Noncontrolling interests	28	28
Total equity	5,882	6,633
Total liabilities and equity	12,914	14,127
Allowance for Doubtful Accounts Receivable, Current	$ 4	3
Common unitholders, units outstanding (in shares)	208,329,928
Common unitholders, units issued (in shares)	208,351,528
Series A Preferred Limited Partners [Member]
Equity:
Preferred Units, Preferred Partners' Capital Accounts	$ 499	489
Total equity	$ 499	$ 489
Preferred Units, Issued	500,000	500,000
Preferred Units, Outstanding	500,000	500,000
Series B Preferred Limited Partners [Member]
Equity:
Preferred Units, Preferred Partners' Capital Accounts	$ 156	$ 156
Total equity	$ 156	$ 156
Preferred Units, Issued	6,450,000	6,450,000
Preferred Units, Outstanding	6,450,000	6,450,000
Series C Preferred Limited Partners [Member]
Equity:
Preferred Units, Preferred Partners' Capital Accounts	$ 106	$ 106
Total equity	$ 106	$ 106
Preferred Units, Issued	4,400,000	4,400,000
Preferred Units, Outstanding	4,400,000	4,400,000

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Operating revenues:
Trading and marketing gains (losses), net	$ 11	$ (1)	$ 156	$ 1
Total operating revenues	1,586	1,699	4,517	5,696
Operating costs and expenses:
Operating and maintenance expense	146	187	447	547
Depreciation and amortization expense	92	100	284	304
General and administrative expense	66	66	173	201
Other expense, net	(4)	0	(12)	(6)
Asset Impairment	0	247	746	247
Loss on sale of assets, net	0	0	0	14
Restructuring costs	0	2	9	11
Total operating costs and expenses	1,526	1,910	5,009	5,798
Operating (loss) income	60	(211)	(492)	(102)
Earnings from unconsolidated affiliates	130	114	331	344
Interest expense, net	(77)	(79)	(226)	(221)
(Loss) income before income taxes	113	(176)	(387)	21
Income tax expense	1	1	2	2
Net income	112	(177)	(389)	19
Net income attributable to noncontrolling interests	(1)	(1)	(3)	(3)
Net income attributable to partners	111	(178)	(392)	16
Series A preferred limited partners' interest in net income	(9)	(9)	(28)	(28)
Series B preferred limited partners' interest in net income	(3)	(3)	(9)	(9)
Series C preferred limited partners' interest in net income	(3)	(3)	(7)	(7)
General partner’s interest in net income	0	(35)	0	(118)
Net income allocable to limited partners	$ 96	$ (228)	$ (436)	$ (146)
Net income per limited partner unit — basic and diluted	$ 0.46	$ (1.59)	$ (2.09)	$ (1.02)
Weighted Average Limited Partnership Units Outstanding, Basic	208,300	143,300	208,300	143,300
Net Income (Loss), Net of Tax, Per Outstanding Limited Partnership Unit, Diluted	$ 0.46	$ (1.59)	$ (2.09)	$ (1.02)
Weighted Average Limited Partnership Units Outstanding, Diluted	208,700	143,300	208,300	143,300
Natural Gas, NGLs and Condensate [Member] | Third Party
Operating revenues:
Sales of natural gas, NGLs and condensate	$ 1,204	$ 1,353	$ 3,378	$ 4,489
Operating costs and expenses:
Purchases and related costs	944	1,041	2,539	3,658
Transportation, Processing and Other [Member]
Operating revenues:
Sales of natural gas, NGLs and condensate	109	101	330	326
Affiliated Entity | Natural Gas, NGLs and Condensate [Member]
Operating revenues:
Sales of natural gas, NGLs and condensate	262	246	653	880
Operating costs and expenses:
Purchases and related costs	32	47	89	177
Affiliated Entity | Transportation Fees
Operating costs and expenses:
Purchases and related costs	$ 242	$ 220	$ 710	$ 633

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ 112	$ (177)	$ (389)	$ 19
Other comprehensive income:
Other comprehensive income	0	0	0	0
Other comprehensive income	0	0	0	0
Total comprehensive income	112	(177)	(389)	19
Total comprehensive income attributable to noncontrolling interests	(1)	(1)	(3)	(3)
Total comprehensive income attributable to partners	$ 111	$ (178)	$ (392)	$ 16

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
OPERATING ACTIVITIES:
Net (loss) income	$ 112	$ (177)	$ (389)	$ 19
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	92	100	284	304
Earnings from unconsolidated affiliates	(130)	(114)	(331)	(344)
Distributions from unconsolidated affiliates			489	398
Net unrealized (gains) losses on derivative instruments	11	26	(66)	41
Loss on sale of assets, net	0	0	0	14
Asset Impairment	0	247	746	247
Other, net			(27)	(9)
Change in operating assets and liabilities, which (used) provided cash, net of effects of acquisitions:
Accounts receivable			(185)	(201)
Inventories			(13)	(10)
Accounts payable			(230)	(181)
Decrease in Other Operating Assets and Liabilities, Net			63	(81)
Net cash provided by operating activities			791	637
INVESTING ACTIVITIES:
Capital expenditures	(23)	(106)	(125)	(414)
Investments in unconsolidated affiliates	(12)	(56)	(102)	(326)
Payments to Acquire Equity Method Investments			107	326
Proceeds from Equity Method Investment, Distribution, Return of Capital			5	0
Proceeds from sale of assets			2	155
Net cash used in investing activities			(225)	(585)
FINANCING ACTIVITIES:
Proceeds from debt			3,958	4,705
Payments of debt			4,137	4,246
Distributions to preferred limited partners			34	34
Distributions to limited partners and general partner			(325)	(463)
Payments to Noncontrolling Interests			(3)	(4)
Payments of Debt Issuance Costs			(8)	(9)
Proceeds from (Payments for) Other Financing Activities			(1)	0
Net cash provided by (used in) financing activities			(550)	(51)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect			16	1
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Beginning Balance			1	1
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Ending Balance	17	2	17	2
Cash and cash equivalents, end of period	14	2	14	2
Restricted Cash, Current	$ 3	$ 0	$ 3	$ 0

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity - USD ($) $ in Millions	Total	Series A Preferred Limited Partners [Member]	Series B Preferred Limited Partners [Member]	Series C Preferred Limited Partners [Member]	Limited Partners	General Partner	Accumulated Other Comprehensive (Loss) Income	Noncontrolling Interests
Beginning balance at Dec. 31, 2018	$ 7,297	$ 489	$ 156	$ 106	$ 6,418	$ 107	$ (8)	$ 29
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)	76	9	3	2	20	41	0	1
Total Cash Distribution to Unitholders	(159)	0	(3)	(2)	(111)	(43)	0	0
Distributions to noncontrolling interests	(1)	0	0	0	0	0	0	1
Ending balance at Mar. 31, 2019	7,213	498	156	106	6,327	105	(8)	29
Beginning balance at Dec. 31, 2018	7,297	489	156	106	6,418	107	(8)	29
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)	19
Other comprehensive income	0
Ending balance at Sep. 30, 2019	6,815	499	156	106	5,937	97	(8)	28
Beginning balance at Mar. 31, 2019	7,213	498	156	106	6,327	105	(8)	29
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)	120	10	3	2	62	42	0	1
Total Cash Distribution to Unitholders	(178)	(18)	(3)	(2)	(112)	(43)	0	0
Distributions to noncontrolling interests	(2)	0	0	0	0	0	0	(2)
Ending balance at Jun. 30, 2019	7,153	490	156	106	6,277	104	(8)	28
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)	(177)	9	3	3	(228)	35	0	1
Other comprehensive income	0
Total Cash Distribution to Unitholders	(160)	0	(3)	(3)	(112)	(42)	0	0
Distributions to noncontrolling interests	(1)	0	0	0	0	0	0	(1)
Ending balance at Sep. 30, 2019	6,815	499	156	106	5,937	$ 97	(8)	28
Beginning balance at Dec. 31, 2019	6,633	489	156	106	5,861		(7)	28
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)	(549)	9	3	2	(564)		0	1
Total Cash Distribution to Unitholders	(167)	0	(3)	(2)	(162)		0	0
Distributions to noncontrolling interests	(1)	0	0	0	0		0	(1)
Ending balance at Mar. 31, 2020	5,916	498	156	106	5,135		(7)	28
Beginning balance at Dec. 31, 2019	6,633	489	156	106	5,861		(7)	28
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)	(389)
Other comprehensive income	0
Ending balance at Sep. 30, 2020	5,882	499	156	106	5,100		(7)	28
Beginning balance at Mar. 31, 2020	5,916	498	156	106	5,135		(7)	28
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)	48	10	3	2	32		0	1
Total Cash Distribution to Unitholders	(104)	(18)	(3)	(2)	(81)		0	0
Distributions to noncontrolling interests	(1)	0	0	0	0		0	(1)
Ending balance at Jun. 30, 2020	5,859	490	156	106	5,086		(7)	28
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)	112	9	3	3	96		0	1
Other comprehensive income	0
Total Cash Distribution to Unitholders	(88)	0	(3)	(3)	(82)		0	0
Distributions to noncontrolling interests	(1)	0	0	0	0		0	(1)
Ending balance at Sep. 30, 2020	$ 5,882	$ 499	$ 156	$ 106	$ 5,100		$ (7)	$ 28

Accounting Policies

Accounting Policies	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]	2. Update to Significant Accounting PoliciesCash, Cash Equivalents, and Restricted Cash - We consider investments in highly liquid financial instruments purchased with an original stated maturity of 90 days or less and temporary investments of cash in short-term money market securities to be cash equivalents. Restricted cash primarily consists of amounts held in our non-qualified deferred compensation plan. Restricted cash is excluded from cash and cash equivalents and is included in other current or long-term assets.

Recent Accounting Pronouncement

Recent Accounting Pronouncements (Notes)	9 Months Ended
	Sep. 30, 2020
Recent Accounting Pronouncements, Policy [Abstract]
Recent Accounting Pronouncements and Changes in Accounting Principles [Text Block]	. Recent Accounting Pronouncements FASB ASU, 2020-04 “ Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting ” or ASU 2020-04 - In March 2020, the FASB issued ASU 2020-04, which provides optional expedients and exceptions for applying GAAP to contract modifications, hedging relationships, and other transactions that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. This ASU is effective for interim and annual reporting periods that include or are subsequent to March 12, 2020. We adopted this ASU on March 12, 2020 and it did not have a material impact on our condensed consolidated financial statements. FASB ASU, 2018-15 “ Intangibles - Goodwill and Other - Internal-use Software (Subtopic 350-40): Customers Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract ” or ASU 2018-15 - In August 2018, the FASB issued ASU 2018-15, which aligns the accounting for costs incurred to implement a cloud computing arrangement that is a service contract with the guidance on capitalizing costs associated with developing or obtaining internal-use software. This ASU is effective for interim and annual reporting periods beginning after December 15, 2019, with the option to early adopt for financial statements that have not been issued. We adopted this ASU on January 1, 2020 and it did not have a material impact on our condensed consolidated financial statements. FASB ASU, 2016-13 “ Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments ” or ASU 2016-13 - In June 2016, the FASB issued ASU 2016-13, which amends current measurement techniques used to estimate credit losses for financial assets. This ASU is effective for interim and annual reporting periods beginning after December 15, 2019, with the option to early adopt for financial statements that have not been issued. We adopted this ASU on January 1, 2020 and it did not have a material impact on our condensed consolidated financial statements.

Contract Liabilities (Notes)

Contract Liabilities (Notes)	9 Months Ended
	Sep. 30, 2020
Contract Assets and Liabilities [Abstract]
Contract Assets and Liabilities [Text Block]	. Contract Liabilities Our contract liabilities consist of deferred revenue received from reimbursable projects. The noncurrent portion of deferred revenue is included in other long-term liabilities on our condensed consolidated balance sheets. The following table summarizes changes in contract liabilities included in our condensed consolidated balance sheets: September 30, 2020 (millions) Balance, beginning of period $ 33 Additions 3 Revenue recognized (a) (1) Balance, end of period $ 35 (a) Deferred revenue recognized is included in transportation, processing and other on the condensed consolidated statement of operations. The contract liabilities disclosed in the table above will be recognized as revenue as the obligations are satisfied over their average remaining contract life, which is 35 years as of September 30, 2020.

Agreements and Transactions wit

Agreements and Transactions with Affiliates	9 Months Ended
	Sep. 30, 2020
Related Party Transactions [Abstract]
Agreements and Transactions with Affiliates	. Agreements and Transactions with Affiliates DCP Midstream, LLC Services Agreement and Other General and Administrative Charges Under the Services and Employee Secondment Agreement (the “Services Agreement ” ), we are required to reimburse DCP Midstream, LLC for costs, expenses, and expenditures incurred or payments made on our behalf for general and administrative functions including, but not limited to, legal, accounting, compliance, treasury, insurance administration and claims processing, risk management, health, safety and environmental, information technology, human resources, benefit plan maintenance and administration, credit, payroll, internal audit, taxes and engineering, as well as salaries and benefits of seconded employees, insurance coverage and claims, capital expenditures, maintenance and repair costs and taxes. There is no limit on the reimbursements we make to DCP Midstream, LLC under the Services Agreement for costs, expenses and expenditures incurred or payments made on our behalf. The following table summarizes employee related costs that were charged by DCP Midstream, LLC to the Partnership that are included in the condensed consolidated statements of operations: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (millions) Employee related costs charged by DCP Midstream, LLC Operating and maintenance expense $ 39 $ 49 $ 121 $ 148 General and administrative expense $ 43 $ 45 $ 113 $ 136 Restructuring costs $ — $ 2 $ 9 $ 11 Phillips 66 and its Affiliates We sell a portion of our residue gas and NGLs to and purchase NGLs from Phillips 66 and its respective affiliates. We anticipate continuing to sell commodities to and purchase commodities from Phillips 66 and its affiliates in the ordinary course of business. Unconsolidated Affiliates We sell a portion of our residue gas and NGLs to, purchase natural gas and other NGL products from, provide gathering and transportation services to, and receive transportation services from unconsolidated affiliates. We anticipate continuing to purchase and sell commodities and receive and provide services to unconsolidated affiliates in the ordinary course of business. Summary of Transactions with Affiliates The following table summarizes our transactions with affiliates: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (millions) Phillips 66 (including its affiliates): Sales of natural gas, NGLs and condensate to affiliates $ 247 $ 237 $ 616 $ 853 Purchases and related costs from affiliates $ 15 $ 33 $ 52 $ 114 Transportation and related costs from affiliates $ 26 $ 19 $ 70 $ 47 Operating and maintenance and general administrative expenses $ 4 $ 3 $ 10 $ 10 Enbridge (including its affiliates): Sales of natural gas, NGLs and condensate to affiliates $ 1 $ — $ 2 $ — Purchases and related costs from affiliates $ 2 $ 6 $ 2 $ 19 Transportation and related costs from affiliates $ 1 $ — $ 1 $ 1 Operating and maintenance and general administrative expenses $ — $ — $ 1 $ — Unconsolidated affiliates: Sales of natural gas, NGLs and condensate to affiliates $ 14 $ 9 $ 35 $ 27 Transportation, processing, and other to affiliates $ 3 $ 1 $ 9 $ 2 Purchases and related costs from affiliates $ 15 $ 8 $ 35 $ 44 Transportation and related costs from affiliates $ 215 $ 201 $ 639 $ 585 We had balances with affiliates as follows: September 30, 2020 December 31, 2019 (millions) Phillips 66 (including its affiliates): Accounts receivable $ 132 $ 117 Accounts payable $ 43 $ 20 Other assets $ 1 $ — Enbridge (including its affiliates): Accounts payable $ 2 $ 2 Unconsolidated affiliates: Accounts receivable $ 18 $ 21 Accounts payable $ 74 $ 78

Inventories (Notes)

Inventories (Notes)	9 Months Ended
	Sep. 30, 2020
Inventory Disclosure [Abstract]
Inventories	Inventories Inventories were as follows: September 30, 2020 December 31, 2019 (millions) Natural gas $ 18 $ 19 NGLs 10 27 Total inventories $ 28 $ 46 We recognize lower of cost or net realizable value adjustments when the carrying value of our inventories exceeds their estimated market value. These non-cash charges are a component of purchases and related costs in the condensed consolidated statements of operations. We recognized $6 million of lower of cost or net realizable value adjustments for the nine months ended September 30, 2020 and $8 million of lower of cost or net realizable value adjustments during the nine months ended September 30, 2019.

Property, Plant and Equipment (

Property, Plant and Equipment (Notes)	9 Months Ended
	Sep. 30, 2020
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and Equipment A summary of property, plant and equipment by classification is as follows: Depreciable September 30, 2020 December 31, 2019 (millions) Gathering and transmission systems 20 — 50 Years $ 7,659 $ 8,406 Processing, storage and terminal facilities 35 — 60 Years 4,948 5,305 Other 3 — 30 Years 583 585 Finance lease assets 3 — 6 Years 25 25 Construction work in progress 172 183 Property, plant and equipment 13,387 14,504 Accumulated depreciation (5,341) (5,693) Property, plant and equipment, net $ 8,046 $ 8,811 Capitalized interest on construction projects was $1 million and $3 million for the three and nine months ended September 30, 2020, respectively, and $2 million and $12 million for the three and nine months ended September 30, 2019, respectively.

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Notes)	9 Months Ended
	Sep. 30, 2020
Goodwill Disclosure [Abstract]
Goodwill Disclosure [Text Block]	Goodwill During the first quarter of 2020, certain areas of our business, as well as those of other midstream companies in our peer group, suffered a significant decline in market value. This indicated both a reduction of estimated enterprise value and an increase to our estimated discount rate. We performed an analysis to determine the estimated fair value of the North reporting unit as of March 31, 2020 and concluded that its carrying value exceeded its fair value by more than the recorded amount of goodwill within the reporting unit, resulting in an impairment charge of $159 million. The significant decline in commodity prices and demand have decreased forecasted cash flows such that, while in excess of asset book value on an undiscounted basis, they were not sufficient to recover the value of allocated goodwill in the North reporting unit. The carrying amount of goodwill in each of our reportable segments was as follows: As of September 30, 2020 As of September 30, 2019 Gathering and Processing Logistics and Marketing Total Gathering and Processing Logistics and Marketing Total (millions) Balance, beginning of period $ 159 $ — $ 159 $ 159 $ 72 $ 231 Impairment (159) — (159) — (35) (35) Dispositions — — — — (37) (37) Balance, end of period $ — $ — $ — $ 159 $ — $ 159 Intangible assets consist of customer contracts, including commodity purchase, transportation and processing contracts and related relationships. The gross carrying amount and accumulated amortization of these intangible assets are included in the accompanying consolidated balance sheets as intangible assets, net, and are as follows: September 30, December 31, 2020 2019 (millions) Gross carrying amount $ 145 $ 145 Accumulated amortization (88) (84) Accumulated impairment (11) — Intangible assets, net $ 46 $ 61

Investments in Unconsolidated A

Investments in Unconsolidated Affiliates	9 Months Ended
	Sep. 30, 2020
Equity Method Investments and Joint Ventures [Abstract]
Investments in Unconsolidated Affiliates	Investments in Unconsolidated Affiliates The following table summarizes our investments in unconsolidated affiliates: Carrying Value as of Percentage September 30, December 31, 2019 (millions) DCP Sand Hills Pipeline, LLC 66.67% $ 1,742 $ 1,764 DCP Southern Hills Pipeline, LLC 66.67% 732 738 Front Range Pipeline LLC 33.33% 201 206 Gulf Coast Express LLC 25.00% 438 449 Texas Express Pipeline LLC 10.00% 97 101 Mont Belvieu Enterprise Fractionator 12.50% 27 27 Mont Belvieu 1 Fractionator 20.00% 7 9 Discovery Producer Services LLC 40.00% 248 322 Cheyenne Connector 50.00% 153 83 Panola Pipeline Company, LLC 15.00% 21 22 Other Various 2 3 Total investments in unconsolidated affiliates $ 3,668 $ 3,724 Earnings from investments in unconsolidated affiliates were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (millions) DCP Sand Hills Pipeline, LLC $ 73 $ 72 $ 221 $ 212 DCP Southern Hills Pipeline, LLC 19 17 59 62 Front Range Pipeline LLC 9 7 29 23 Gulf Coast Express LLC 17 8 49 8 Texas Express Pipeline LLC 4 3 13 12 Mont Belvieu Enterprise Fractionator 4 3 10 10 Mont Belvieu 1 Fractionator 3 3 9 11 Discovery Producer Services LLC (a) (3) 1 (63) 4 Cheyenne Connector 3 — 3 — Other 1 — 1 2 Total earnings from unconsolidated affiliates $ 130 $ 114 $ 331 $ 344 (a) See Note 11 for further discussion. The following tables summarize the combined financial information of our investments in unconsolidated affiliates: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (millions) Statements of operations: Operating revenue $ 523 $ 438 $ 1,560 $ 1,291 Operating expenses $ 196 $ 167 $ 572 $ 520 Net income $ 326 $ 271 $ 985 $ 771 September 30, December 31, (millions) Balance sheets: Current assets $ 347 $ 463 Long-term assets 7,564 7,546 Current liabilities (165) (231) Long-term liabilities (258) (252) Net assets $ 7,488 $ 7,526

Fair Value Measurement (Notes)

Fair Value Measurement (Notes)	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Derivatives and Fair Value	11. Fair Value Measurement Valuation Hierarchy Our fair value measurements are grouped into a three-level valuation hierarchy and are categorized in their entirety in the same level of the fair value hierarchy as the lowest level input that is significant to the entire measurement. The valuation hierarchy is based upon the transparency of inputs to the valuation of an asset or liability as of the measurement date. The three levels are defined as follows. • Level 1 — inputs are unadjusted quoted prices for identical assets or liabilities in active markets. • Level 2 — inputs include quoted prices for similar assets and liabilities in active markets, and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument. • Level 3 — inputs are unobservable and considered significant to the fair value measurement. A financial instrument’s categorization within the hierarchy is based upon the level of judgment involved in the most significant input in the determination of the instrument’s fair value. Following is a description of the valuation methodologies used as well as the general classification of such instruments pursuant to the hierarchy. Commodity Derivative Assets and Liabilities We enter into a variety of derivative financial instruments, which may include exchange traded instruments (such as New York Mercantile Exchange, or NYMEX, crude oil or natural gas futures) or over-the-counter, or OTC, instruments (such as natural gas contracts, crude oil or NGL swaps). The exchange traded instruments are generally executed with a highly rated broker dealer serving as the clearinghouse for individual transactions. Our activities expose us to varying degrees of commodity price risk. To mitigate a portion of this risk and to manage commodity price risk related primarily to owned natural gas storage and pipeline assets, we engage in natural gas asset based trading and marketing, and we may enter into natural gas and crude oil derivatives to lock in a specific margin when market conditions are favorable. A portion of this may be accomplished through the use of exchange traded derivative contracts. Such instruments are generally classified as Level 1 since the value is equal to the quoted market price of the exchange traded instrument as of our balance sheet date, and no adjustments are required. Depending upon market conditions and our strategy we may enter into exchange traded derivative positions with a significant time horizon to maturity. Although such instruments are exchange traded, market prices may only be readily observable for a portion of the duration of the instrument. In order to calculate the fair value of these instruments, readily observable market information is utilized to the extent it is available; however, in the event that readily observable market data is not available, we may interpolate or extrapolate based upon observable data. In instances where we utilize an interpolated or extrapolated value, and it is considered significant to the valuation of the contract as a whole, we would classify the instrument within Level 3. We also engage in the business of trading energy related products and services, which exposes us to market variables and commodity price risk. We may enter into physical contracts or financial instruments with the objective of realizing a positive margin from the purchase and sale of these commodity-based instruments. We may enter into derivative instruments for NGLs or other energy related products, primarily using the OTC derivative instrument markets, which are not as active and liquid as exchange traded instruments. Market quotes for such contracts may only be available for short dated positions (up to six months), and an active market itself may not exist beyond such time horizon. Contracts entered into with a relatively short time horizon for which prices are readily observable in the OTC market are generally classified within Level 2. Contracts with a longer time horizon, for which we internally generate a forward curve to value such instruments, are generally classified within Level 3. The internally generated curve may utilize a variety of assumptions including, but not limited to, data obtained from third-party pricing services, historical and future expected relationship of NGL prices to crude oil prices, the knowledge of expected supply sources coming online, expected weather trends within certain regions of the United States, and the future expected demand for NGLs. Each instrument is assigned to a level within the hierarchy at the end of each financial quarter depending upon the extent to which the valuation inputs are observable. Generally, an instrument will move toward a level within the hierarchy that requires a lower degree of judgment as the time to maturity approaches, and as the markets in which the asset trades will likely become more liquid and prices more readily available in the market, thus reducing the need to rely upon our internally developed assumptions. However, the level of a given instrument may change, in either direction, depending upon market conditions and the availability of market observable data. Nonfinancial Assets and Liabilities We utilize fair value to perform impairment tests as required on our property, plant and equipment, goodwill, equity investments in unconsolidated affiliates, and intangible assets. The inputs used to determine such fair value are primarily based upon internally developed cash flow models and would generally be classified within Level 3 in the event that we were required to measure and record such assets at fair value within our condensed consolidated financial statements. Additionally, we use fair value to determine the inception value of our asset retirement obligations. The inputs used to determine such fair value are primarily based upon costs incurred historically for similar work, as well as estimates from independent third parties for costs that would be incurred to restore leased property to the contractually stipulated condition, and would generally be classified within Level 3. During the three months ended March 31, 2020, we determined that triggering events had occurred with respect to specific asset groups as a result of the impact of commodity prices on the respective recently prepared budget forecasts, coupled with a negative outlook for long-term production volume forecasts for these asset groups. We used the income approach to calculate the fair value of the asset group and compared it to the carrying value. The primary inputs to our calculation were forecasted future commodity pricing and the discount rate. The impairment amount recorded represented the difference between the fair and carrying values. As a result, we recognized a $587 million impairment loss associated with certain asset groups in the Permian and South regions of our Gathering and Processing segment and an impairment of $61 million of our equity investment in Discovery Producer Services LLC (“Discovery”). We may identify additional triggering events requiring future evaluations of the recoverability of the carrying value of our long-lived assets and investments that could result in future impairments. Such impairments could have a significant effect on our results of operations, which would be recognized in the period in which the carrying value is determined to be not fully recoverable. The following table presents certain assets and asset groups measured at fair value on a non-recurring basis, by condensed consolidated balance sheet caption as of the date of measurement, March 31, 2020. March 31, 2020 Fair Value Asset Impairments (millions) Long-lived assets $ 96 $ 587 Goodwill — 159 Direct investment in unconsolidated affiliate 256 61 Total $ 352 $ 807 The following table summarizes the significant unobservable inputs used in the valuation of certain assets and asset groups measured at fair value on a non-recurring basis as of date of measurement, March 31, 2020. March 31, 2020 Asset Groups Valuation Techniques Unobservable Inputs Range (low-high) (a) Average (b) Long-lived assets, investment in unconsolidated affiliate, goodwill Discounted cash flow Oil prices $34.52 - $67.61 $ 55.98 Per barrel Natural gas prices $2.28 - $4.12 $ 3.35 Per MMBtu NGL prices $0.30 - $0.62 $ 0.52 Per gallon Discount rate 14% 14% Terminal value multiple 8x 8x Goodwill Market comparable companies EBITDA multiple 5.2x - 16.5x 8x (a) Commodity prices represent an average per year. (b) Represents the arithmetic average of the inputs and is not weighted by the relative fair value or volumetric amount. The following table presents the financial instruments carried at fair value on a recurring basis as of September 30, 2020 and December 31, 2019, by condensed consolidated balance sheet caption and by valuation hierarchy, as described above: September 30, 2020 December 31, 2019 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total (millions) Current assets: Commodity derivatives $ 59 $ 32 $ — $ 91 $ 13 $ 15 $ 4 $ 32 Long-term assets: Commodity derivatives $ 16 $ 20 $ 4 $ 40 $ 1 $ 1 $ — $ 2 Long-term investments $ 14 $ 1 $ — $ 15 $ — $ — $ — $ — Current liabilities: Commodity derivatives $ (37) $ (45) $ (1) $ (83) $ (15) $ (42) $ (1) $ (58) Long-term liabilities: Commodity derivatives $ (13) $ (15) $ (1) $ (29) $ (2) $ (15) $ (3) $ (20) Changes in Levels 1 and 2 Fair Value Measurements The determination to classify a financial instrument within Level 1 or Level 2 is based upon the availability of quoted prices for identical or similar assets and liabilities in active markets. Depending upon the information readily observable in the market, and/or the use of identical or similar quoted prices, which are significant to the overall valuation, the classification of any individual financial instrument may differ from one measurement date to the next. Changes in Level 3 Fair Value Measurements The tables below illustrate a rollforward of the amounts included in our condensed consolidated balance sheets for derivative financial instruments that we have classified within Level 3. Since financial instruments classified as Level 3 typically include a combination of observable components (that is, components that are actively quoted and can be validated to external sources) and unobservable components, the gains and losses in the table below may include changes in fair value due in part to observable market factors, or changes to our assumptions on the unobservable components. Depending upon the information readily observable in the market, and/or the use of unobservable inputs, which are significant to the overall valuation, the classification of any individual financial instrument may differ from one measurement date to the next. The significant unobservable inputs used in determining fair value include adjustments by other market-based or independently sourced market data such as historical commodity volatilities, crude oil future yield curves, and/or counterparty specific considerations. In the event that there is a movement to/from the classification of an instrument as Level 3, we would reflect such items in the table below within the “Transfers into/out of Level 3” captions. We manage our overall risk at the portfolio level and in the execution of our strategy, we may use a combination of financial instruments, which may be classified within any level. Since Level 1 and Level 2 risk management instruments are not included in the rollforward below, the gains or losses in the table do not reflect the effect of our total risk management activities. Commodity Derivative Instruments Current Long-Term Current Long-Term (millions) Three months ended September 30, 2020 (a): Beginning balance $ 1 $ — $ (3) $ (4) Net unrealized (losses) gains included in earnings (1) 4 (1) 3 Transfers out of Level 3 — — 2 — Settlements — — 1 — Ending balance $ — $ 4 $ (1) $ (1) Net unrealized gains on derivatives still held included in earnings $ — $ 4 $ 1 $ 3 Three months ended September 30, 2019 (a): Beginning balance $ 8 $ 2 $ (1) $ — Net unrealized gains (losses) included in earnings 7 (1) 1 (5) Transfers out of Level 3 (8) — — — Settlements (2) — (1) — Ending balance $ 5 $ 1 $ (1) $ (5) Net unrealized gains (losses) on derivatives still held included in earnings $ 3 $ (1) $ — $ (5) Commodity Derivative Instruments Current Long-Term Current Long-Term (millions) Nine months ended September 30, 2020 (a): Beginning balance $ 4 $ — $ (1) $ (3) Net unrealized (losses) gains included in earnings (1) 8 8 2 Transfers out of Level 3 — (4) — — Settlements (3) — (8) — Ending balance $ — $ 4 $ (1) $ (1) Net unrealized (losses) gains on derivatives still held included in earnings $ (2) $ 4 $ (1) $ 1 Nine months ended September 30, 2019 (a): Beginning balance $ 14 $ 2 $ — $ (2) Net unrealized gains (losses) included in earnings 7 (1) — (6) Transfers out of Level 3 (7) — — 3 Settlements (9) — (1) — Ending balance $ 5 $ 1 $ (1) $ (5) Net unrealized gains (losses) on derivatives still held included in earnings $ 5 $ 1 $ (1) $ (5) (a) There were no purchases, issuances or sales of derivatives or transfers into Level 3 for the three and nine months ended September 30, 2020 and 2019. Quantitative Inform ation and Fair Value Sensitivities Related to Level 3 Unobservable Inputs We utilize the market approach to measure the fair value of our commodity contracts. The significant unobservable inputs used in this approach to fair value are longer dated price quotes. Our sensitivity to these longer dated forward curve prices are presented in the table below. Significant changes in any of those inputs in isolation would result in significantly different fair value measurements, depending on our short or long position in contracts. September 30, 2020 Product Group Fair Value Valuation Techniques Unobservable Input Forward Weighted Average (a) (millions) Assets Natural gas $ 4 Market approach Longer dated forward curve prices $1.90-$2.68 $1.86 Per MMBtu Liabilities NGLs $ (2) Market approach Longer dated forward curve prices $0.14-$0.89 $0.43 Per gallon (a) Unobservable inputs were weighted by the instrument's notional amounts. Estimated Fair Value of Financial Instruments Valuation of a contract’s fair value is validated by an internal group independent of the marketing group. While common industry practices are used to develop valuation techniques, changes in pricing methodologies or the underlying assumptions could result in significantly different fair values and income recognition. When available, quoted market prices or prices obtained through external sources are used to determine a contract’s fair value. For contracts with a delivery location or duration for which quoted market prices are not available, fair value is determined based on pricing models developed primarily from historical and expected relationships with quoted market prices. The fair value of accounts receivable and accounts payable are not materially different from their carrying amounts because of the short-term nature of these instruments or the stated rates approximating market rates. Derivative instruments are carried at fair value. We determine the fair value of our fixed-rate senior notes and junior subordinated notes based on quotes obtained from bond dealers. The carrying value of borrowings under the Credit Agreement and the Securitization Facility approximate fair value as their interest rates are based on prevailing market interest rates. We classify the fair values of our outstanding debt balances within Level 2 of the valuation hierarchy. As of September 30, 2020 and December 31, 2019, the carrying value and fair value of our total debt, including current maturities, were as follows: September 30, 2020 December 31, 2019 Carrying Value (a) Fair Value Carrying Value (a) Fair Value (millions) Total debt $ 5,761 $ 5,632 $ 5,936 $ 6,130

Leases (Notes)

Leases (Notes)	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Leases of Lessee Disclosure [Text Block]	12. Leases We have operating leases for transportation agreements, office space, and field equipment. We have finance leases for field equipment and vehicles. Our leases have remaining lease terms ranging from less than one year to 21 years, some of which may include options to extend leases up to 20 years, and some of which may include options to terminate the leases in less than one year. Extension options on certain compressors and field equipment were included in the lease terms used to calculate our operating lease assets and liabilities as it is reasonably certain that we exercise those options. Operating and finance leases are included on our condensed consolidated balance sheet as follows: Location in Condensed Consolidated Balance Sheet As of September 30, 2020 December 31, 2019 (millions) Assets Operating lease assets Operating lease assets $ 83 $ 107 Finance lease assets Property, plant and equipment 25 25 Total right of use assets 108 132 Liabilities Current liabilities Operating lease liabilities Other current liabilities $ 24 $ 24 Finance lease liabilities Current debt 4 3 Noncurrent liabilities Operating lease liabilities Operating lease liabilities $ 76 $ 88 Finance lease liabilities Long-term debt 23 22 Total lease liabilities $ 127 $ 137 Variable lease costs primarily consist of common area maintenance on our office spaces and variable transportation costs. The components of lease expense are as follows: Location in Condensed Consolidated Statement of Operations Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (millions) Operating lease cost Operating and maintenance expense $ 7 $ 6 $ 21 $ 17 Finance lease cost Amortization of right of use assets Depreciation and amortization expense 1 — 2 — Interest on lease liabilities Interest expense 1 — 1 — Variable lease cost Operating and maintenance expense 2 2 5 5 Short term lease cost Operating and maintenance expense 1 2 3 4 Total lease cost $ 12 $ 10 $ 32 $ 26 Maturities of operating and finance lease liabilities under non-cancelable leases as of September 30, 2020 are as follows: Future Minimum Lease Payments as of September 30, 2020 Operating Leases Finance Leases (millions) 2020 - remainder $ 7 $ 1 2021 26 5 2022 22 5 2023 18 5 2024 11 6 Thereafter 30 11 Total lease payments $ 114 $ 33 Less imputed interest (14) (6) Total lease liabilities $ 100 $ 27 Supplemental cash flow information related to leases is as follows: Nine Months Ended September 30, 2020 2019 (millions) Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 20 $ 18 Operating cash flows from finance leases 3 — Financing cash flows from finance leases 1 — Right-of-use assets obtained in exchange for operating lease obligations: $ 6 $ 33 Right-of-use assets obtained in exchange for finance lease obligations: $ 5 $ 5 Other information related to operating leases as follows: Weighted average remaining lease term 6 years 5 years Weighted average discount rate 4.00 % 4.00 % Other information related to finance leases as follows: Weighted average remaining lease term 5 years 5 years Weighted average discount rate 3.00 % 4.00 %

Debt (Notes)

Debt (Notes)	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Debt	13. Debt September 30, 2020 December 31, 2019 (millions) Senior notes: Issued March 2010, interest at 5.350% payable semi-annually, due March 2020 (a) $ — $ 600 Issued September 2011, interest at 4.750% payable semi-annually, due September 2021 500 500 Issued March 2012, interest at 4.950% payable semi-annually, due April 2022 350 350 Issued March 2013, interest at 3.875% payable semi-annually, due March 2023 500 500 Issued July 2018 and January 2019, interest at 5.375% payable semi-annually, due July 2025 825 825 Issued June 2020, interest at 5.625% payable semi-annually, due July 2027 500 — Issued May 2019, interest at 5.125% payable semi-annually, due May 2029 600 600 Issued August 2000, interest at 8.125% payable semi-annually, due August 2030 (a) 300 300 Issued October 2006, interest at 6.450% payable semi-annually, due November 2036 300 300 Issued September 2007, interest at 6.750% payable semi-annually, due September 2037 450 450 Issued March 2014, interest at 5.600% payable semi-annually, due April 2044 400 400 Junior subordinated notes: Issued May 2013, interest at 5.850% payable semi-annually, due May 2043 550 550 Credit agreement: Revolving credit facility, weighted-average variable interest rate of 1.510%, as of September 30, 2020, due December 2024 125 200 Accounts receivable securitization facility: Accounts receivable securitization facility, weighted-average variable interest rate of 1.050% as of September 30, 2020, due August 2022 350 350 Fair value adjustments related to interest rate swap fair value hedges (a) 18 19 Unamortized issuance costs (40) (37) Unamortized discount, net (7) (8) Finance lease liabilities 27 25 Total debt 5,748 5,924 Current finance lease liabilities 4 3 Current debt 500 600 Total long-term debt $ 5,244 $ 5,321 (a) The swaps associated with this debt were previously terminated. The remaining long-term fair value related to the swaps is being amortized as a reduction to interest expense through 2030, the original maturity dates of the debt. Senior Notes Issuance On June 24, 2020, we issued $500 million aggregate principal amount of 5.625% Senior Notes due July 2027, unless redeemed prior to maturity. We received proceeds of $494 million, net of underwriters' fees and related expenses, which we used for general partnership purposes, including the repayment of indebtedness under our Credit Agreement and the funding of capital expenditures. Interest on the notes is payable semi-annually in arrears on January 15 and July 15 of each year, commencing January 15, 2021. Senior Notes and Junior Subordinated Notes Our senior notes and junior subordinated notes, collectively referred to as our debt securities, mature and become payable on their respective due dates, and are not subject to any sinking fund or mandatory redemption provisions. The senior notes are senior unsecured obligations that are guaranteed by the Partnership and rank equally in a right of payment with our other senior unsecured indebtedness, including indebtedness under our Credit Agreement, and the junior subordinated notes are unsecured and rank subordinate in right of payment to all of our existing and future senior indebtedness. The debt securities include an optional redemption whereby we may elect to redeem the notes, in whole or in part from time-to-time for a premium. Additionally, we may defer the payment of all or part of the interest on the junior subordinated notes for one or more periods up to 5 consecutive years. The underwriters’ fees and related expenses are recorded in our condensed consolidated balance sheets within the carrying amount of long-term debt and will be amortized over the term of the notes. Credit Agreement We are a party to a $1.4 billion unsecured revolving Credit Agreement, which matures on December 9, 2024. The Credit Agreement also grants us the option to increase the revolving loan commitment by an aggregate principal amount of up to $500 million, subject to requisite lender approval. The Credit Agreement may be extended for up to two additional one-year periods subject to requisite lender approval. Loans under the Credit Agreement may be used for working capital and other general partnership purposes including acquisitions. The Credit Agreement allows for unrestricted cash and cash equivalents to be netted against consolidated indebtedness for purposes of calculating the Partnership’s Consolidated Leverage Ratio (as defined in the Credit Agreement). Additionally, under the Credit Agreement, the Consolidated Leverage Ratio of the Partnership as of the end of any fiscal quarter shall not exceed 5.00 to 1.0; provided that, if there is a Qualified Acquisition (as defined in the Credit Agreement), the maximum Consolidated Leverage Ratio shall not exceed 5.50 to 1.0 at the end of the three consecutive fiscal quarters, including the fiscal quarter in which the Qualified Acquisition occurs. Our cost of borrowing under the Credit Agreement is determined by a ratings-based pricing grid. Indebtedness under the Credit Agreement bears interest at either: (1) LIBOR, plus an applicable margin of 1.35% based on our current credit rating; or (2) (a) the base rate which shall be the higher of the prime rate, the Federal Funds rate plus 0.50% or the LIBOR Market Index rate plus 1.00%, plus (b) an applicable margin of 0.35% based on our current credit rating. The Credit Agreement incurs an annual facility fee of 0.275% based on our current credit rating. This fee is paid on drawn and undrawn portions of the $1.4 billion revolving credit facility. As of September 30, 2020, we had unused borrowing capacity of $1,265 million, net of $125 million of outstanding borrowings and $10 million of letters of credit, under the Credit Agreement. Our borrowing capacity may be limited by financial covenants set forth in the Credit Agreement. The financial covenants set forth in the Credit Agreement limit the Partnership's ability to incur incremental debt by the unused borrowing capacity of $1,265 million as of September 30, 2020. Except in the case of a default, amounts borrowed under our Credit Agreement will not become due prior to the December 9, 2024 maturity date. Accounts Receivable Securitization Facility The Securitization Facility provides up to $350 million of borrowing capacity through August 2022 at LIBOR market index rates plus a margin. Under this Securitization Facility, certain of the Partnership’s wholly owned subsidiaries sell or contribute receivables to another of the Partnership’s consolidated subsidiaries, DCP Receivables LLC (“DCP Receivables”), a bankruptcy-remote special purpose entity created for the sole purpose of the Securitization Facility. DCP Receivables’ sole activity consists of purchasing receivables from the Partnership’s wholly owned subsidiaries that participate in the Securitization Facility and providing these receivables as collateral for DCP Receivables’ borrowings under the Securitization Facility. DCP Receivables is a separate legal entity and the accounts receivable of DCP Receivables, up to the amount of the outstanding debt under the Securitization Facility, are not available to satisfy the claims of creditors of the Partnership, its subsidiaries selling receivables under the Securitization Facility, or their affiliates. Any excess receivables are eligible to satisfy the claims of creditors of the Partnership, its subsidiaries selling receivables under the Securitization Facility, or their affiliates. The amount available for borrowing may be limited by the availability of eligible receivables and other customary factors and conditions, as well as the covenants set forth in the Securitization Facility. As of September 30, 2020, DCP Receivables had $614 million of our accounts receivable securing borrowings of $350 million under the Securitization Facility. The maturities of our debt as of September 30, 2020 are as follows: Debt (millions) 2021 $ 500 2022 700 2023 500 2024 125 Thereafter 3,925 Total debt $ 5,750

Risk Management and Hedging Act

Risk Management and Hedging Activities (Notes)	9 Months Ended
	Sep. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Risk Management and Hedging Activities	Risk Management and Hedging Activities Our operations expose us to a variety of risks including but not limited to changes in the prices of commodities that we buy or sell, changes in interest rates, and the creditworthiness of each of our counterparties. We manage certain of these exposures with either physical or financial transactions. We have established a comprehensive risk management policy and a risk management committee (the “Risk Management Committee”), to monitor and manage market risks associated with commodity prices and counterparty credit. The Risk Management Committee is composed of senior executives who receive regular briefings on positions and exposures, credit exposures and overall risk management in the context of market activities. The Risk Management Committee is responsible for the overall management of credit risk and commodity price risk, including monitoring exposure limits. Collateral As of September 30, 2020, we had cash deposits of $21 million, included in collateral cash deposits in our condensed consolidated balance sheets. Additionally, as of September 30, 2020, we held letters of credit of $51 million from counterparties to secure their future performance under financial or physical contracts. Collateral amounts held or posted may be fixed or may vary, depending on the value of the underlying contracts, and could cover normal purchases and sales, services, trading and hedging contracts. In many cases, we and our counterparties have publicly disclosed credit ratings, which may impact the amounts of collateral requirements. Physical forward contracts and financial derivatives are generally cash settled at the expiration of the contract term. These transactions are generally subject to specific credit provisions within the contracts that would allow the seller, at its discretion, to suspend deliveries, cancel agreements or continue deliveries to the buyer after the buyer provides security for payment satisfactory to the seller. Offsetting Certain of our derivative instruments are subject to a master netting or similar arrangement, whereby we may elect to settle multiple positions with an individual counterparty through a single net payment. Each of our individual derivative instruments are presented on a gross basis on the condensed consolidated balance sheets, regardless of our ability to net settle our positions. Instruments that are governed by agreements that include net settle provisions allow final settlement, when presented with a termination event, of outstanding amounts by extinguishing the mutual debts owed between the parties in exchange for a net amount due. We have trade receivables and payables associated with derivative instruments, subject to master netting or similar agreements, which are not included in the table below. The following summarizes the gross and net amounts of our derivative instruments: September 30, 2020 December 31, 2019 Gross Amounts Amounts Not Net Gross Amounts Amounts Not Net (millions) Assets: Commodity derivatives $ 131 $ — $ 131 $ 34 $ — $ 34 Liabilities: Commodity derivatives $ (112) $ — $ (112) $ (78) $ — $ (78) Summarized Derivative Information The fair value of our derivative instruments that are marked-to-market each period, as well as the location of each within our condensed consolidated balance sheets, by major category, is summarized below. We have no derivative instruments that are designated as hedging instruments for accounting purposes as of September 30, 2020 and December 31, 2019. Balance Sheet Line Item September 30, December 31, Balance Sheet Line Item September 30, December 31, (millions) (millions) Derivative Assets Not Designated as Hedging Instruments: Derivative Liabilities Not Designated as Hedging Instruments: Commodity derivatives: Commodity derivatives: Unrealized gains on derivative instruments — current $ 91 $ 32 Unrealized losses on derivative instruments — current $ (83) $ (58) Unrealized gains on derivative instruments — long-term 40 2 Unrealized losses on derivative instruments — long-term (29) (20) Total $ 131 $ 34 Total $ (112) $ (78) The following summarizes the balance and activity within AOCI relative to our interest rate, commodity and foreign currency cash flow hedges as of and for the three months ended September 30, 2020: Interest Commodity Foreign Total (millions) Net deferred (losses) gains in AOCI (beginning balance) $ (2) $ (6) $ 1 $ (7) Net deferred (losses) gains in AOCI (ending balance) $ (2) $ (6) $ 1 $ (7) Deferred losses in AOCI expected to be reclassified into earnings over the next 12 months $ (1) $ — $ — $ (1) The following summarizes the balance and activity within AOCI relative to our interest rate, commodity and foreign currency cash flow hedges as of and for the nine months ended September 30, 2020: Interest Commodity Foreign Total (millions) Net deferred (losses) gains in AOCI (beginning balance) $ (2) $ (6) $ 1 $ (7) Net deferred (losses) gains in AOCI (ending balance) $ (2) $ (6) $ 1 $ (7) Deferred losses in AOCI expected to be reclassified into earnings over the next 12 months $ (1) $ — $ — $ (1) (a) Relates to Discovery, an unconsolidated affiliate. The following summarizes the balance and activity within AOCI relative to our interest rate, commodity and foreign currency cash flow hedges as of and for the three months ended September 30, 2019: Interest Commodity Foreign Total (millions) Net deferred (losses) gains in AOCI (beginning balance) $ (3) $ (6) $ 1 $ (8) Net deferred (losses) gains in AOCI (ending balance) $ (3) $ (6) $ 1 $ (8) The following summarizes the balance and activity within AOCI relative to our interest rate, commodity and foreign currency cash flow hedges as of and for the nine months ended September 30, 2019: Interest Commodity Foreign Total (millions) Net deferred (losses) gains in AOCI (beginning balance) $ (3) $ (6) $ 1 $ (8) Net deferred (losses) gains in AOCI (ending balance) $ (3) $ (6) $ 1 $ (8) (a) Relates to Discovery, an unconsolidated affiliate. For the nine months ended September 30, 2020 and 2019, no derivative losses attributable to the ineffective portion or to amounts excluded from effectiveness testing were recognized in trading and marketing gains or losses, net or interest expense in our condensed consolidated statements of operations. For the nine months ended September 30, 2020 and 2019, no derivative losses were reclassified from AOCI to trading and marketing gains or losses, net or interest expense as a result of the discontinuance of cash flow hedges related to certain forecasted transactions that are not probable of occurring. Changes in the value of derivative instruments, for which the hedge method of accounting has not been elected from one period to the next, are recorded in the condensed consolidated statements of operations. The following summarizes these amounts and the location within the condensed consolidated statements of operations that such amounts are reflected: Commodity Derivatives: Statements of Operations Line Item Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (millions) Realized gains $ 22 $ 25 $ 90 $ 42 Unrealized (losses) gains (11) (26) 66 (41) Trading and marketing gains (losses), net $ 11 $ (1) $ 156 $ 1 We do not have any derivative financial instruments that qualify as a hedge of a net investment. The following tables represent, by commodity type, our net long or short positions that are expected to partially or entirely settle in each respective year. To the extent that we have long dated derivative positions that span multiple calendar years, the contract will appear in more than one line item in the tables below. September 30, 2020 Crude Oil Natural Gas Natural Gas Natural Gas Year of Expiration Net Short Net Short Position Net Short Net Long (Short) 2020 (253,000) (14,287,500) (932,160) 5,600,000 2021 (791,000) (65,332,500) (8,471,590) (735,000) 2022 (43,000) (21,900,000) (1,486,842) 12,775,000 2023 — — (1,440,000) 7,300,000 2024 — — (1,440,000) 7,630,000 2025 — — (960,000) 1,365,000 September 30, 2019 Crude Oil Natural Gas Natural Gas Natural Gas Year of Expiration Net Short Net Short Position Net Short Net Long 2019 (549,000) (21,679,350) (13,139,076) 2,135,000 2020 (1,391,000) (5,145,900) (17,677,943) 18,507,500 2021 (154,000) — (5,381,993) 3,650,000 2022 — — (1,140) 8,212,500 2023 — — — 7,300,000

Partnership Equity and Distribu

Partnership Equity and Distributions (Notes)	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Partnership Equity and Distributions	Partnership Equity and Distributions Common Units — During the nine months ended September 30, 2020 and 2019, we issued no common units pursuant to our at-the-market program. Distributions — The following table presents our cash distributions paid in 2020 and 2019: Payment Date Per Unit Total Cash (millions) Distributions to common unitholders August 14, 2020 $ 0.39 $ 82 May 15, 2020 $ 0.39 $ 81 February 14, 2020 $ 0.78 $ 162 November 14, 2019 $ 0.78 $ 155 August 14, 2019 $ 0.78 $ 154 May 15, 2019 $ 0.78 $ 155 February 14, 2019 $ 0.78 $ 154 Distributions to Series A Preferred unitholders June 15, 2020 $ 36.875 $ 18 December 16, 2019 $ 36.875 $ 19 June 17, 2019 $ 36.875 $ 18 Distributions to Series B Preferred unitholders September 15, 2020 $ 0.4922 $ 3 June 15, 2020 $ 0.4922 $ 3 March 16, 2020 $ 0.4922 $ 3 December 16, 2019 $ 0.4922 $ 4 September 16, 2019 $ 0.4922 $ 3 June 17, 2019 $ 0.4922 $ 3 March 15, 2019 $ 0.4922 $ 3 Distributions to Series C Preferred unitholders July 15, 2020 $ 0.4969 $ 3 April 15, 2020 $ 0.4969 $ 2 January 15, 2020 $ 0.4969 $ 2 October 15, 2019 $ 0.4969 $ 2 July 15, 2019 $ 0.4969 $ 3 April 15, 2019 $ 0.4969 $ 2 January 15, 2019 $ 0.5576 $ 2

Net Income or Loss per Limited

Net Income or Loss per Limited Partner Unit (Notes)	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Net Income or Loss per Limited Partner Unit	16. Net Income or Loss per Limited Partner Unit Prior to the equity restructuring transaction, we used the two-class method when calculating the net income unit applicable to limited partners, because we had more than one participating security consisting of limited partner common units, general partner units and IDRs. Subsequent to the equity restructuring transaction that occurred on November 6, 2019, our general partner and its IDRs no longer participate in earnings or distributions. There were 319,350 restricted phantom units outstanding as of September 30, 2020 that were excluded from the calculation of diluted net loss per unit for the nine months ended September 30, 2020 because including them would have been anti-dilutive. We have the ability to elect to settle restricted phantom units at our discretion in either cash or common units. For units granted during 2020, we have the ability and intent to settle vested units through the issuance of common units. Basic and diluted net income per limited partner unit was calculated as follows for the three and nine months ended September 30, 2020 and 2019. Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (millions, except per unit amounts) Net income (loss) attributable to limited partners $ 96 $ (228) $ (436) $ (146) Weighted average limited partner units outstanding, basic 208,342,746 143,322,121 208,334,185 143,318,943 Dilutive effects of nonvested restricted phantom units 319,350 — — — Weighted average limited partner units outstanding, diluted 208,662,096 143,322,121 208,334,185 143,318,943 Net income (loss) per limited partner unit, basic $ 0.46 $ (1.59) $ (2.09) $ (1.02) Net income (loss) per limited partner unit, diluted $ 0.46 $ (1.59) $ (2.09) $ (1.02)

Commitments and Contingent Liab

Commitments and Contingent Liabilities (Notes)	9 Months Ended
	Sep. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingent Liabilities	Commitments and Contingent Liabilities Litigation — We are not a party to any significant legal proceedings, but are a party to various administrative and regulatory proceedings and commercial disputes that have arisen in the ordinary course of our business. Management currently believes that the ultimate resolution of the foregoing matters, taken as a whole, and after consideration of amounts accrued, insurance coverage or other indemnification arrangements, will not have a material adverse effect on our results of operations, financial position, or cash flow. Insurance — Our insurance coverage is carried with third-party insurers and with an affiliate of Phillips 66. Our insurance coverage includes: (i) general liability insurance covering third-party exposures; (ii) statutory workers’ compensation insurance; (iii) automobile liability insurance for all owned, non-owned and hired vehicles; (iv) excess liability insurance above the established primary limits for general liability and automobile liability insurance; (v) property insurance, which covers the replacement value of real and personal property and includes business interruption; and (vi) insurance covering our directors and officers for acts related to our business activities. All coverage is subject to certain limits and deductibles, the terms and conditions of which are common for companies with similar types of operations. Environment, Health and Safety — The operation of pipelines, plants and other facilities for gathering, transporting, processing, treating, fractionating, or storing natural gas, NGLs and other products is subject to stringent and complex laws and regulations pertaining to the environment, health and safety. As an owner or operator of these facilities, we must comply with laws and regulations at the federal, state and, in some cases, local levels that relate to worker health and safety, public health and safety, pipeline safety, air and water quality, solid and hazardous waste management and disposal, and other environmental matters. The cost of planning, designing, constructing and operating pipelines, plants, and other facilities incorporates compliance with environmental laws and regulations, health and safety standards applicable to workers and the public, and safety standards applicable to our various facilities. In addition, there is increasing focus from (i) regulatory bodies and communities, and through litigation, on hydraulic fracturing and the real or perceived environmental or public health impacts of this technique, which indirectly presents some risk to our available supply of natural gas and the resulting supply of NGLs; (ii) regulatory bodies regarding pipeline system safety which could impose additional regulatory burdens and increase the cost of our operations; (iii) state and federal regulatory officials regarding the emission of greenhouse gases and other air emissions, which could impose regulatory burdens and increase the cost of our operations; and (iv) regulatory bodies and communities that could prevent or delay the development of fossil fuel energy infrastructure such as pipelines, plants, and other facilities used in our business. Failure to comply with these various health, safety and environmental laws and regulations may trigger a variety of administrative, civil and potentially criminal enforcement measures, including citizen suits, which can include the assessment of monetary penalties, the imposition of remedial requirements, and the issuance of injunctions or restrictions on operation. Management believes that, based on currently known information, compliance with these existing laws and regulations will not have a material adverse effect on our results of operations, financial position or cash flows. The following pending proceedings involve governmental authorities under federal, state, and local laws regulating the discharge of materials into the environment. It is not possible for us to predict the final outcome of these pending proceedings; however, we do not expect the outcome of one or more of these proceedings to have a material adverse effect to our results of operations, financial position, or cash flows: • In 2018, the New Mexico Environment Department (“NMED”) issued two separate Notices of Violation (“NOV”) relating to upset and malfunction event emissions at two of our gas processing plants. Following information exchanges and discussions with NMED regarding the events and the propriety of the alleged violations, in February 2019 we entered into preliminary settlement agreements to resolve the alleged violations under each NOV for administrative penalties approximating $150,000 and $142,000, respectively, which, to date, have not been consummated. Subsequently, in August 2020, NMED issued an Administrative Compliance Order (the “August ACO”) alleging that emissions at four of our natural gas processing plants, inclusive of the two gas processing plants subject to the aforementioned NOVs, exceeded respective air permit limits or requirements during various instances of what we reported were facility upsets, malfunctions, startups or shutdowns from May of 2017 through August 2018. The factual allegations and asserted penalties underlying the foregoing NOVs were incorporated into the August ACO, which asserts an administrative civil penalty of approximately $3.3 million for those emissions events and others at the four gas processing plants during the stated period of time. We intend to challenge the allegations and asserted penalties in the August ACO based on legal limitations, including that emissions in exceedance of permit limits or requirements due to facility upset, malfunction, startup, and shutdown events are not subject to civil penalties under New Mexico law. We formally responded to the August ACO and will engage in information exchanges and discussions with NMED about the propriety of the allegations and asserted penalties, and the matter may go to hearing. • In 2018, the Colorado Department of Public Health and Environment (“CDPHE”) issued a Compliance Advisory in relation to an improperly permitted facility flare and related air emissions from flare operations at one of our gas processing plants that we self-disclosed to CDPHE in December 2017. Following information exchanges and discussions with CDPHE, a resolution was proposed pursuant to which the plant's air permit would be revised to include the flare and emissions limits for such flare in addition to us paying an administrative penalty as well as an economic benefit payment generally covering the period when the flare was required to be included in the facility air permit, in a combined amount expected to be between approximately $375,000 and $460,000. We are still evaluating and holding discussions with CDPHE as to the foregoing amounts and proposed settlement terms. • In June 2020, NMED issued an Administrative Compliance Order (the “June ACO”) alleging that emissions at several of our field compression sites exceeded respective air permit limits or requirements during various instances of what we reported were facility upsets, malfunctions, startups or shutdowns between 2018 to the first half of 2019. The June ACO asserts an administrative civil penalty of approximately $5.3 million. We intend to challenge the allegations and asserted penalties based on legal limitations, including that emissions in exceedance of permit limits or requirements due to facility upset, malfunction, startup, and shutdown events are not subject to civil penalties under New Mexico law. We formally responded to the June ACO and will engage in information exchanges and discussions with NMED about the propriety of the allegations and asserted penalties, and the matter may go to hearing.

Restructuring (Notes)

Restructuring (Notes)	9 Months Ended
	Sep. 30, 2020
Restructuring and Related Activities [Abstract]
Restructuring and Related Activities Disclosure [Text Block]	Restructuring CostsIn April 2020, we announced a reduction in force of 15%, which resulted in $9 million of nonrecurring expense for the nine months ended September 30, 2020. We do not expect to incur any significant additional expense in relation to the reduction in force.

Business Segments (Notes)

Business Segments (Notes)	9 Months Ended
	Sep. 30, 2020
Segment Reporting [Abstract]
Business Segments	Business SegmentsOur operations are organized into two reportable segments: (i) Logistics and Marketing and (ii) Gathering and Processing. These segments are monitored separately by management for performance against our internal forecast and are consistent with internal financial reporting. These segments have been identified based on the differing products and services, regulatory environment and the expertise required for these operations. Our Gathering and Processing reportable segment includes operating segments that have been aggregated based on the nature of the products and services provided. Adjusted gross margin is a performance measure utilized by management to monitor the operations of each segment. The accounting policies of the reportable segments are the same as those described in the summary of significant accounting policies included in Note 2 of the Notes to Consolidated Financial Statements in “Financial Statements and Supplementary Data” included as Item 8 in our Annual Report on Form 10-K for the year ended December 31, 2019. Our Logistics and Marketing segment includes transporting, trading, marketing, storing natural gas and NGLs, and fractionating NGLs. Our Gathering and Processing segment consists of gathering, compressing, treating, processing natural gas, producing and fractionating NGLs, and recovering condensate. The remainder of our business operations is presented as “Other,” and consists of unallocated corporate costs. Elimination of inter-segment transactions are reflected in the Eliminations column. The following tables set forth our segment information: Three Months Ended September 30, 2020: Logistics and Marketing Gathering and Processing Other Eliminations Total (millions) Total operating revenue $ 1,438 $ 857 $ — $ (709) $ 1,586 Adjusted gross margin (a) $ 88 $ 280 $ — $ — $ 368 Operating and maintenance expense (8) (135) (3) — (146) General and administrative expense (1) (8) (57) — (66) Depreciation and amortization expense (3) (82) (7) — (92) Other expense, net (2) (2) — — (4) Earnings (loss) from unconsolidated affiliates 132 (2) — — 130 Interest expense — — (77) — (77) Income tax expense — — (1) — (1) Net income (loss) $ 206 $ 51 $ (145) $ — $ 112 Net income attributable to noncontrolling interests — (1) — — (1) Net income (loss) attributable to partners $ 206 $ 50 $ (145) $ — $ 111 Non-cash derivative mark-to-market $ 28 $ (39) $ — $ — $ (11) Capital expenditures $ 1 $ 13 $ 9 $ — $ 23 Investments in unconsolidated affiliates, net $ 12 $ — $ — $ — $ 12 Nine Months Ended September 30, 2020: Logistics and Marketing Gathering and Processing Other Eliminations Total (millions) Total operating revenue $ 3,946 $ 2,388 $ — $ (1,817) $ 4,517 Adjusted gross margin (a) $ 268 $ 911 $ — $ — $ 1,179 Operating and maintenance expense (24) (411) (12) — (447) General and administrative expense (4) (15) (154) — (173) Depreciation and amortization expense (9) (253) (22) — (284) Asset impairments — (746) — — (746) Other expense, net (6) (4) (2) — (12) Restructuring costs — — (9) — (9) Earnings (loss) from unconsolidated affiliates 394 (63) — — 331 Interest expense — — (226) — (226) Income tax expense — — (2) — (2) Net income (loss) $ 619 $ (581) $ (427) $ — $ (389) Net income attributable to noncontrolling interests — (3) — — (3) Net income (loss) attributable to partners $ 619 $ (584) $ (427) $ — $ (392) Non-cash derivative mark-to-market $ 75 $ (9) $ — $ — $ 66 Non-cash lower of cost or net realizable value adjustments $ 6 $ — $ — $ — $ 6 Capital expenditures $ 2 $ 112 $ 11 $ — $ 125 Investments in unconsolidated affiliates, net $ 102 $ — $ — $ — $ 102 Three Months Ended September 30, 2019: Logistics and Marketing Gathering and Processing Other Eliminations Total (millions) Total operating revenue $ 1,509 $ 916 $ — $ (726) $ 1,699 Adjusted gross margin (a) $ 61 $ 330 $ — $ — $ 391 Operating and maintenance expense (9) (172) (6) — (187) General and administrative expense (2) (5) (59) — (66) Depreciation and amortization expense (4) (88) (8) — (100) Asset impairments (35) (212) — — (247) Restructuring costs — — (2) — (2) Earnings from unconsolidated affiliates 113 1 — — 114 Interest expense — — (79) — (79) Income tax expense — — (1) — (1) Net income (loss) $ 124 $ (146) $ (155) $ — $ (177) Net income attributable to noncontrolling interests — (1) — — (1) Net income (loss) attributable to partners $ 124 $ (147) $ (155) $ — $ (178) Non-cash derivative mark-to-market $ (21) $ (5) $ — $ — $ (26) Capital expenditures $ 3 $ 99 $ 4 $ — $ 106 Investments in unconsolidated affiliates, net $ 56 $ — $ — $ — $ 56 Nine Months Ended September 30, 2019: Logistics and Marketing Gathering and Processing Other Eliminations Total (millions) Total operating revenue $ 5,167 $ 3,228 $ — $ (2,699) $ 5,696 Adjusted gross margin (a) $ 207 $ 1,021 $ — $ — $ 1,228 Operating and maintenance expense (29) (502) (16) — (547) General and administrative expense (6) (17) (178) — (201) Depreciation and amortization expense (10) (272) (22) — (304) Asset impairments (35) (212) — — (247) Other expense, net (1) (5) — — (6) Loss on sale of assets, net (10) (4) — — (14) Restructuring costs — — (11) — (11) Earnings from unconsolidated affiliates 340 4 — — 344 Interest expense — — (221) — (221) Income tax expense — — (2) — (2) Net income (loss) $ 456 $ 13 $ (450) $ — $ 19 Net income attributable to noncontrolling interests — (3) — — (3) Net income (loss) attributable to partners $ 456 $ 10 $ (450) $ — $ 16 Non-cash derivative mark-to-market $ (15) $ (26) $ — $ — $ (41) Non-cash lower of cost or net realizable value adjustments $ 8 $ — $ — $ — $ 8 Capital expenditures $ 28 $ 375 $ 11 $ — $ 414 Investments in unconsolidated affiliates, net $ 326 $ — $ — $ — $ 326 September 30, December 31, 2020 2019 (millions) Segment long-term assets: Gathering and Processing $ 7,851 $ 8,904 Logistics and Marketing 3,968 3,848 Other (b) 229 295 Total long-term assets 12,048 13,047 Current assets 866 1,080 Total assets $ 12,914 $ 14,127 (a) Adjusted gross margin consists of total operating revenues, including commodity derivative activity, less purchases and related costs. Adjusted gross margin is viewed as a non-GAAP financial measure under the rules of the SEC, but is included as a supplemental disclosure because it is a primary performance measure used by management as it represents the results of product sales versus product purchases. As an indicator of our operating performance, adjusted gross margin should not be considered an alternative to, or more meaningful than, net income, net cash provided by operating activities or gross margin as determined in accordance with GAAP. Our adjusted gross margin may not be comparable to a similarly titled measure of another company because other entities may not calculate adjusted gross margin in the same manner.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information (Notes)	9 Months Ended
	Sep. 30, 2020
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Supplemental Cash Flow Information Nine Months Ended September 30, 2020 2019 (millions) Cash paid for interest: Cash paid for interest, net of amounts capitalized $ 222 $ 204 Cash paid for income taxes, net of income tax refunds $ 2 $ 3 Non-cash investing and financing activities: Property, plant and equipment acquired with accounts payable and accrued liabilities $ 5 $ 21 Other non-cash activities: Operating lease assets arising from the implementation of Topic 842 $ — $ 84 Right-of-use assets obtained in exchange for operating and finance lease liabilities $ 11 $ 38

Subsequent Events (Notes)

Subsequent Events (Notes)	9 Months Ended
	Sep. 30, 2020
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On October 16, 2020, we announced that the board of directors of the General Partner declared a quarterly distribution on our common units of $0.39 per common unit. The distribution will be paid on November 13, 2020 to unitholders of record on October 30, 2020. On the same date, we announced that the board of directors of the General Partner declared a semi-annual distribution on our Series A Preferred Units of $36.875 per unit. The distribution will be paid on December 15, 2020 to unitholders of record on December 1, 2020. On the same date, the board of directors of the General Partner declared a quarterly distribution on our Series B and Series C Preferred Units of $0.4922 and $0.4969 per unit, respectively. The Series B distributions will be paid on December 15, 2020 to unitholders of record on December 1, 2020. The Series C distribution will be paid on January 15, 2021 to unitholders of record on January 4, 2021.

Description of Business and Bas

Description of Business and Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Significant Accounting Policies [Text Block]	The condensed consolidated financial statements have been prepared in accordance with GAAP. Conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and notes. Although these estimates are based on management's best available knowledge of current and expected future events, actual results could differ from these estimates, which may be significantly impacted by various factors, including those outside of our control, such as the impact of a sustained deterioration in commodity prices and volumes, which would negatively impact our results of operations, financial condition and cash flows.
Business Description and Basis of Presentation [Text Block]	The condensed consolidated financial statements have been prepared in accordance with GAAP. Conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and notes. Although these estimates are based on management's best available knowledge of current and expected future events, actual results could differ from these estimates, which may be significantly impacted by various factors, including those outside of our control, such as the impact of a sustained deterioration in commodity prices and volumes, which would negatively impact our results of operations, financial condition and cash flows. All intercompany balances and transactions have been eliminated in consolidation. These unaudited condensed consolidated financial statements in this Quarterly Report on Form 10-Q have been prepared pursuant to the rules and regulations of the SEC. Accordingly, these condensed consolidated financial statements reflect all adjustments, consisting of normal recurring adjustments, that are, in the opinion of management, necessary to present fairly the financial position and results of operations for the respective interim periods. Certain information and note disclosures normally included in our annual financial statements prepared in accordance with GAAP have been condensed or omitted from these interim financial statements pursuant to such rules and regulations, although we believe that the disclosures made are adequate to make the information presented not misleading. Results of operations for the three and nine months ended September 30, 2020 are not necessarily indicative of the results that may be expected for the year ending December 31, 2020. These unaudited condensed consolidated financial statements and other information included in this Quarterly Report on Form 10-Q should be read in conjunction with the 2019 audited consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2019.

Accounting Policies (Policies)

Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies [Text Block]	The condensed consolidated financial statements have been prepared in accordance with GAAP. Conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and notes. Although these estimates are based on management's best available knowledge of current and expected future events, actual results could differ from these estimates, which may be significantly impacted by various factors, including those outside of our control, such as the impact of a sustained deterioration in commodity prices and volumes, which would negatively impact our results of operations, financial condition and cash flows.
Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy	Cash, Cash Equivalents, and Restricted Cash - We consider investments in highly liquid financial instruments purchased with an original stated maturity of 90 days or less and temporary investments of cash in short-term money market securities to be cash equivalents. Restricted cash primarily consists of amounts held in our non-qualified deferred compensation plan. Restricted cash is excluded from cash and cash equivalents and is included in other current or long-term assets.

Revenue Recognition (Tables)

Revenue Recognition (Tables)	9 Months Ended
	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Disaggregation of Revenue [Table Text Block]	We disaggregate our revenue from contracts with customers by type of contract for each of our reportable segments, as we believe it best depicts the nature, timing and uncertainty of our revenue and cash flows. The following tables set forth our revenue by those categories: Three Months Ended September 30, 2020 Logistics and Marketing Gathering and Processing Eliminations Total (millions) Sales of natural gas $ 437 $ 330 $ (308) $ 459 Sales of NGLs and condensate (a) 951 456 (400) 1,007 Transportation, processing and other 13 97 (1) 109 Trading and marketing gains (losses), net (b) 37 (26) — 11 Total operating revenues $ 1,438 $ 857 $ (709) $ 1,586 Nine Months Ended September 30, 2020 Logistics and Marketing Gathering and Processing Eliminations Total (millions) Sales of natural gas $ 1,203 $ 927 $ (842) $ 1,288 Sales of NGLs and condensate (a) 2,592 1,125 (974) 2,743 Transportation, processing and other 37 294 (1) 330 Trading and marketing gains, net (b) 114 42 — 156 Total operating revenues $ 3,946 $ 2,388 $ (1,817) $ 4,517 (a) Includes $303 million and $2,006 million for the three and nine months ended September 30, 2020, respectively, of revenues from physical sales contracts and buy-sell exchange transactions in our Logistics and Marketing segment, which are not within the scope of FASB ASU 2014-09 “ Revenue from Contracts with Customers ” (Topic 606). (b) Not within the scope of Topic 606. Three Months Ended September 30, 2019 Logistics and Marketing Gathering and Processing Eliminations Total (millions) Sales of natural gas $ 461 $ 374 $ (317) $ 518 Sales of NGLs and condensate (a) 1,052 437 (408) 1,081 Transportation, processing and other 11 91 (1) 101 Trading and marketing (losses) gains, net (b) (15) 14 — (1) Total operating revenues $ 1,509 $ 916 $ (726) $ 1,699 Nine Months Ended September 30, 2019 Logistics and Marketing Gathering and Processing Eliminations Total (millions) Sales of natural gas $ 1,543 $ 1,294 $ (1,135) $ 1,702 Sales of NGLs and condensate (a) 3,610 1,620 (1,563) 3,667 Transportation, processing and other 35 292 (1) 326 Trading and marketing (losses) gains, net (b) (21) 22 — 1 Total operating revenues $ 5,167 $ 3,228 $ (2,699) $ 5,696 (a) Includes $704 million and $2,384 million for the three and nine months ended September 30, 2019, respectively, of revenues from physical sales contracts and buy-sell exchange transactions in our Logistics and Marketing segment, which are not within the scope of Topic 606. (b) Not within the scope of Topic 606.

Contract Liabilities (Tables)

Contract Liabilities (Tables)	9 Months Ended
	Sep. 30, 2020
Contract Assets and Liabilities [Abstract]
Contract with Customer, Asset and Liability [Table Text Block]	September 30, 2020 (millions) Balance, beginning of period $ 33 Additions 3 Revenue recognized (a) (1) Balance, end of period $ 35 (a) Deferred revenue recognized is included in transportation, processing and other on the condensed consolidated statement of operations.

Agreements and Transactions w_2

Agreements and Transactions with Affiliates (Tables)	9 Months Ended
	Sep. 30, 2020
Related Party Transaction [Line Items]
Schedule of Fees Incurred and Other Fees Paid	The following table summarizes employee related costs that were charged by DCP Midstream, LLC to the Partnership that are included in the condensed consolidated statements of operations: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (millions) Employee related costs charged by DCP Midstream, LLC Operating and maintenance expense $ 39 $ 49 $ 121 $ 148 General and administrative expense $ 43 $ 45 $ 113 $ 136 Restructuring costs $ — $ 2 $ 9 $ 11
Summary of Transactions with Affiliates	The following table summarizes our transactions with affiliates: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (millions) Phillips 66 (including its affiliates): Sales of natural gas, NGLs and condensate to affiliates $ 247 $ 237 $ 616 $ 853 Purchases and related costs from affiliates $ 15 $ 33 $ 52 $ 114 Transportation and related costs from affiliates $ 26 $ 19 $ 70 $ 47 Operating and maintenance and general administrative expenses $ 4 $ 3 $ 10 $ 10 Enbridge (including its affiliates): Sales of natural gas, NGLs and condensate to affiliates $ 1 $ — $ 2 $ — Purchases and related costs from affiliates $ 2 $ 6 $ 2 $ 19 Transportation and related costs from affiliates $ 1 $ — $ 1 $ 1 Operating and maintenance and general administrative expenses $ — $ — $ 1 $ — Unconsolidated affiliates: Sales of natural gas, NGLs and condensate to affiliates $ 14 $ 9 $ 35 $ 27 Transportation, processing, and other to affiliates $ 3 $ 1 $ 9 $ 2 Purchases and related costs from affiliates $ 15 $ 8 $ 35 $ 44 Transportation and related costs from affiliates $ 215 $ 201 $ 639 $ 585 We had balances with affiliates as follows: September 30, 2020 December 31, 2019 (millions) Phillips 66 (including its affiliates): Accounts receivable $ 132 $ 117 Accounts payable $ 43 $ 20 Other assets $ 1 $ — Enbridge (including its affiliates): Accounts payable $ 2 $ 2 Unconsolidated affiliates: Accounts receivable $ 18 $ 21 Accounts payable $ 74 $ 78

Inventories (Tables)

Inventories (Tables)	9 Months Ended
	Sep. 30, 2020
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories were as follows: September 30, 2020 December 31, 2019 (millions) Natural gas $ 18 $ 19 NGLs 10 27 Total inventories $ 28 $ 46

Property, Plant and Equipment_2

Property, Plant and Equipment (Tables)	9 Months Ended
	Sep. 30, 2020
Property, Plant and Equipment [Abstract]
Classification of Property, Plant and Equipment	A summary of property, plant and equipment by classification is as follows: Depreciable September 30, 2020 December 31, 2019 (millions) Gathering and transmission systems 20 — 50 Years $ 7,659 $ 8,406 Processing, storage and terminal facilities 35 — 60 Years 4,948 5,305 Other 3 — 30 Years 583 585 Finance lease assets 3 — 6 Years 25 25 Construction work in progress 172 183 Property, plant and equipment 13,387 14,504 Accumulated depreciation (5,341) (5,693) Property, plant and equipment, net $ 8,046 $ 8,811

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2020
Goodwill Disclosure [Abstract]
Schedule of Goodwill [Table Text Block]	As of September 30, 2020 As of September 30, 2019 Gathering and Processing Logistics and Marketing Total Gathering and Processing Logistics and Marketing Total (millions) Balance, beginning of period $ 159 $ — $ 159 $ 159 $ 72 $ 231 Impairment (159) — (159) — (35) (35) Dispositions — — — — (37) (37) Balance, end of period $ — $ — $ — $ 159 $ — $ 159
Schedule of Finite-Lived Intangible Assets	September 30, December 31, 2020 2019 (millions) Gross carrying amount $ 145 $ 145 Accumulated amortization (88) (84) Accumulated impairment (11) — Intangible assets, net $ 46 $ 61

Investments in Unconsolidated_2

Investments in Unconsolidated Affiliates (Tables)	9 Months Ended
	Sep. 30, 2020
Equity Method Investments and Joint Ventures [Abstract]
Investments in Unconsolidated Affiliates	The following table summarizes our investments in unconsolidated affiliates: Carrying Value as of Percentage September 30, December 31, 2019 (millions) DCP Sand Hills Pipeline, LLC 66.67% $ 1,742 $ 1,764 DCP Southern Hills Pipeline, LLC 66.67% 732 738 Front Range Pipeline LLC 33.33% 201 206 Gulf Coast Express LLC 25.00% 438 449 Texas Express Pipeline LLC 10.00% 97 101 Mont Belvieu Enterprise Fractionator 12.50% 27 27 Mont Belvieu 1 Fractionator 20.00% 7 9 Discovery Producer Services LLC 40.00% 248 322 Cheyenne Connector 50.00% 153 83 Panola Pipeline Company, LLC 15.00% 21 22 Other Various 2 3 Total investments in unconsolidated affiliates $ 3,668 $ 3,724
Schedule Of Earnings From Investment In Unconsolidated Affiliates [Table Text Block]	: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (millions) DCP Sand Hills Pipeline, LLC $ 73 $ 72 $ 221 $ 212 DCP Southern Hills Pipeline, LLC 19 17 59 62 Front Range Pipeline LLC 9 7 29 23 Gulf Coast Express LLC 17 8 49 8 Texas Express Pipeline LLC 4 3 13 12 Mont Belvieu Enterprise Fractionator 4 3 10 10 Mont Belvieu 1 Fractionator 3 3 9 11 Discovery Producer Services LLC (a) (3) 1 (63) 4 Cheyenne Connector 3 — 3 — Other 1 — 1 2 Total earnings from unconsolidated affiliates $ 130 $ 114 $ 331 $ 344
Equity Method Investment Summarized Financial Information, Statement of Operations [Table Text Block]	The following tables summarize the combined financial information of our investments in unconsolidated affiliates: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (millions) Statements of operations: Operating revenue $ 523 $ 438 $ 1,560 $ 1,291 Operating expenses $ 196 $ 167 $ 572 $ 520 Net income $ 326 $ 271 $ 985 $ 771
Equity Method Investment Summarized Financial Information Balance Sheet Table [Table Text Block]	September 30, December 31, (millions) Balance sheets: Current assets $ 347 $ 463 Long-term assets 7,564 7,546 Current liabilities (165) (231) Long-term liabilities (258) (252) Net assets $ 7,488 $ 7,526

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Details of Impairment of Long-Lived Assets Held and Used by Asset	March 31, 2020 Fair Value Asset Impairments (millions) Long-lived assets $ 96 $ 587 Goodwill — 159 Direct investment in unconsolidated affiliate 256 61 Total $ 352 $ 807
Fair Value Measurements, Nonrecurring	March 31, 2020 Asset Groups Valuation Techniques Unobservable Inputs Range (low-high) (a) Average (b) Long-lived assets, investment in unconsolidated affiliate, goodwill Discounted cash flow Oil prices $34.52 - $67.61 $ 55.98 Per barrel Natural gas prices $2.28 - $4.12 $ 3.35 Per MMBtu NGL prices $0.30 - $0.62 $ 0.52 Per gallon Discount rate 14% 14% Terminal value multiple 8x 8x Goodwill Market comparable companies EBITDA multiple 5.2x - 16.5x 8x (a) Commodity prices represent an average per year. (b) Represents the arithmetic average of the inputs and is not weighted by the relative fair value or volumetric amount.
Financial Instruments Carried at Fair Value	September 30, 2020 December 31, 2019 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total (millions) Current assets: Commodity derivatives $ 59 $ 32 $ — $ 91 $ 13 $ 15 $ 4 $ 32 Long-term assets: Commodity derivatives $ 16 $ 20 $ 4 $ 40 $ 1 $ 1 $ — $ 2 Long-term investments $ 14 $ 1 $ — $ 15 $ — $ — $ — $ — Current liabilities: Commodity derivatives $ (37) $ (45) $ (1) $ (83) $ (15) $ (42) $ (1) $ (58) Long-term liabilities: Commodity derivatives $ (13) $ (15) $ (1) $ (29) $ (2) $ (15) $ (3) $ (20)
Fair Value Assets and Liabilities Measured On Recurring Basis Unobservable Input Reconciliation	Commodity Derivative Instruments Current Long-Term Current Long-Term (millions) Three months ended September 30, 2020 (a): Beginning balance $ 1 $ — $ (3) $ (4) Net unrealized (losses) gains included in earnings (1) 4 (1) 3 Transfers out of Level 3 — — 2 — Settlements — — 1 — Ending balance $ — $ 4 $ (1) $ (1) Net unrealized gains on derivatives still held included in earnings $ — $ 4 $ 1 $ 3 Three months ended September 30, 2019 (a): Beginning balance $ 8 $ 2 $ (1) $ — Net unrealized gains (losses) included in earnings 7 (1) 1 (5) Transfers out of Level 3 (8) — — — Settlements (2) — (1) — Ending balance $ 5 $ 1 $ (1) $ (5) Net unrealized gains (losses) on derivatives still held included in earnings $ 3 $ (1) $ — $ (5) Commodity Derivative Instruments Current Long-Term Current Long-Term (millions) Nine months ended September 30, 2020 (a): Beginning balance $ 4 $ — $ (1) $ (3) Net unrealized (losses) gains included in earnings (1) 8 8 2 Transfers out of Level 3 — (4) — — Settlements (3) — (8) — Ending balance $ — $ 4 $ (1) $ (1) Net unrealized (losses) gains on derivatives still held included in earnings $ (2) $ 4 $ (1) $ 1 Nine months ended September 30, 2019 (a): Beginning balance $ 14 $ 2 $ — $ (2) Net unrealized gains (losses) included in earnings 7 (1) — (6) Transfers out of Level 3 (7) — — 3 Settlements (9) — (1) — Ending balance $ 5 $ 1 $ (1) $ (5) Net unrealized gains (losses) on derivatives still held included in earnings $ 5 $ 1 $ (1) $ (5)
Schedule of Valuation Processes	September 30, 2020 Product Group Fair Value Valuation Techniques Unobservable Input Forward Weighted Average (a) (millions) Assets Natural gas $ 4 Market approach Longer dated forward curve prices $1.90-$2.68 $1.86 Per MMBtu Liabilities NGLs $ (2) Market approach Longer dated forward curve prices $0.14-$0.89 $0.43 Per gallon
Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block]	September 30, 2020 and December 31, 2019, the carrying value and fair value of our total debt, including current maturities, were as follows: September 30, 2020 December 31, 2019 Carrying Value (a) Fair Value Carrying Value (a) Fair Value (millions) Total debt $ 5,761 $ 5,632 $ 5,936 $ 6,130

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Schedule of Leasing Assets and Liabilities [Table Text Block]	Location in Condensed Consolidated Balance Sheet As of September 30, 2020 December 31, 2019 (millions) Assets Operating lease assets Operating lease assets $ 83 $ 107 Finance lease assets Property, plant and equipment 25 25 Total right of use assets 108 132 Liabilities Current liabilities Operating lease liabilities Other current liabilities $ 24 $ 24 Finance lease liabilities Current debt 4 3 Noncurrent liabilities Operating lease liabilities Operating lease liabilities $ 76 $ 88 Finance lease liabilities Long-term debt 23 22 Total lease liabilities $ 127 $ 137
Lease, Cost [Table Text Block]	Location in Condensed Consolidated Statement of Operations Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (millions) Operating lease cost Operating and maintenance expense $ 7 $ 6 $ 21 $ 17 Finance lease cost Amortization of right of use assets Depreciation and amortization expense 1 — 2 — Interest on lease liabilities Interest expense 1 — 1 — Variable lease cost Operating and maintenance expense 2 2 5 5 Short term lease cost Operating and maintenance expense 1 2 3 4 Total lease cost $ 12 $ 10 $ 32 $ 26
Lessee, Operating Lease, Liability, Maturity [Table Text Block]	Future Minimum Lease Payments as of September 30, 2020 Operating Leases Finance Leases (millions) 2020 - remainder $ 7 $ 1 2021 26 5 2022 22 5 2023 18 5 2024 11 6 Thereafter 30 11 Total lease payments $ 114 $ 33 Less imputed interest (14) (6) Total lease liabilities $ 100 $ 27
Leases - Other Information	Nine Months Ended September 30, 2020 2019 (millions) Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 20 $ 18 Operating cash flows from finance leases 3 — Financing cash flows from finance leases 1 — Right-of-use assets obtained in exchange for operating lease obligations: $ 6 $ 33 Right-of-use assets obtained in exchange for finance lease obligations: $ 5 $ 5 Other information related to operating leases as follows: Weighted average remaining lease term 6 years 5 years Weighted average discount rate 4.00 % 4.00 % Other information related to finance leases as follows: Weighted average remaining lease term 5 years 5 years Weighted average discount rate 3.00 % 4.00 %

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Schedule of Debt	September 30, 2020 December 31, 2019 (millions) Senior notes: Issued March 2010, interest at 5.350% payable semi-annually, due March 2020 (a) $ — $ 600 Issued September 2011, interest at 4.750% payable semi-annually, due September 2021 500 500 Issued March 2012, interest at 4.950% payable semi-annually, due April 2022 350 350 Issued March 2013, interest at 3.875% payable semi-annually, due March 2023 500 500 Issued July 2018 and January 2019, interest at 5.375% payable semi-annually, due July 2025 825 825 Issued June 2020, interest at 5.625% payable semi-annually, due July 2027 500 — Issued May 2019, interest at 5.125% payable semi-annually, due May 2029 600 600 Issued August 2000, interest at 8.125% payable semi-annually, due August 2030 (a) 300 300 Issued October 2006, interest at 6.450% payable semi-annually, due November 2036 300 300 Issued September 2007, interest at 6.750% payable semi-annually, due September 2037 450 450 Issued March 2014, interest at 5.600% payable semi-annually, due April 2044 400 400 Junior subordinated notes: Issued May 2013, interest at 5.850% payable semi-annually, due May 2043 550 550 Credit agreement: Revolving credit facility, weighted-average variable interest rate of 1.510%, as of September 30, 2020, due December 2024 125 200 Accounts receivable securitization facility: Accounts receivable securitization facility, weighted-average variable interest rate of 1.050% as of September 30, 2020, due August 2022 350 350 Fair value adjustments related to interest rate swap fair value hedges (a) 18 19 Unamortized issuance costs (40) (37) Unamortized discount, net (7) (8) Finance lease liabilities 27 25 Total debt 5,748 5,924 Current finance lease liabilities 4 3 Current debt 500 600 Total long-term debt $ 5,244 $ 5,321
Future Maturities of Long-Term Debt	The maturities of our debt as of September 30, 2020 are as follows: Debt (millions) 2021 $ 500 2022 700 2023 500 2024 125 Thereafter 3,925 Total debt $ 5,750

Risk Management and Hedging A_2

Risk Management and Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of Gross and Net Amounts of Derivative Instruments	September 30, 2020 December 31, 2019 Gross Amounts Amounts Not Net Gross Amounts Amounts Not Net (millions) Assets: Commodity derivatives $ 131 $ — $ 131 $ 34 $ — $ 34 Liabilities: Commodity derivatives $ (112) $ — $ (112) $ (78) $ — $ (78)
Schedule of Designated and Non-Designated Derivative Instruments in Statement of Financial Position, Fair Value	The fair value of our derivative instruments that are marked-to-market each period, as well as the location of each within our condensed consolidated balance sheets, by major category, is summarized below. We have no derivative instruments that are designated as hedging instruments for accounting purposes as of September 30, 2020 and December 31, 2019. Balance Sheet Line Item September 30, December 31, Balance Sheet Line Item September 30, December 31, (millions) (millions) Derivative Assets Not Designated as Hedging Instruments: Derivative Liabilities Not Designated as Hedging Instruments: Commodity derivatives: Commodity derivatives: Unrealized gains on derivative instruments — current $ 91 $ 32 Unrealized losses on derivative instruments — current $ (83) $ (58) Unrealized gains on derivative instruments — long-term 40 2 Unrealized losses on derivative instruments — long-term (29) (20) Total $ 131 $ 34 Total $ (112) $ (78)
Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block]	The following summarizes the balance and activity within AOCI relative to our interest rate, commodity and foreign currency cash flow hedges as of and for the three months ended September 30, 2020: Interest Commodity Foreign Total (millions) Net deferred (losses) gains in AOCI (beginning balance) $ (2) $ (6) $ 1 $ (7) Net deferred (losses) gains in AOCI (ending balance) $ (2) $ (6) $ 1 $ (7) Deferred losses in AOCI expected to be reclassified into earnings over the next 12 months $ (1) $ — $ — $ (1) The following summarizes the balance and activity within AOCI relative to our interest rate, commodity and foreign currency cash flow hedges as of and for the nine months ended September 30, 2020: Interest Commodity Foreign Total (millions) Net deferred (losses) gains in AOCI (beginning balance) $ (2) $ (6) $ 1 $ (7) Net deferred (losses) gains in AOCI (ending balance) $ (2) $ (6) $ 1 $ (7) Deferred losses in AOCI expected to be reclassified into earnings over the next 12 months $ (1) $ — $ — $ (1) (a) Relates to Discovery, an unconsolidated affiliate. The following summarizes the balance and activity within AOCI relative to our interest rate, commodity and foreign currency cash flow hedges as of and for the three months ended September 30, 2019: Interest Commodity Foreign Total (millions) Net deferred (losses) gains in AOCI (beginning balance) $ (3) $ (6) $ 1 $ (8) Net deferred (losses) gains in AOCI (ending balance) $ (3) $ (6) $ 1 $ (8) The following summarizes the balance and activity within AOCI relative to our interest rate, commodity and foreign currency cash flow hedges as of and for the nine months ended September 30, 2019: Interest Commodity Foreign Total (millions) Net deferred (losses) gains in AOCI (beginning balance) $ (3) $ (6) $ 1 $ (8) Net deferred (losses) gains in AOCI (ending balance) $ (3) $ (6) $ 1 $ (8) (a) Relates to Discovery, an unconsolidated affiliate.
Schedule of Changes in Derivative Instruments Not Designated as Hedging Instruments	Commodity Derivatives: Statements of Operations Line Item Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (millions) Realized gains $ 22 $ 25 $ 90 $ 42 Unrealized (losses) gains (11) (26) 66 (41) Trading and marketing gains (losses), net $ 11 $ (1) $ 156 $ 1
Schedule of Net Long or Short Positions Expected to be Realized	September 30, 2020 Crude Oil Natural Gas Natural Gas Natural Gas Year of Expiration Net Short Net Short Position Net Short Net Long (Short) 2020 (253,000) (14,287,500) (932,160) 5,600,000 2021 (791,000) (65,332,500) (8,471,590) (735,000) 2022 (43,000) (21,900,000) (1,486,842) 12,775,000 2023 — — (1,440,000) 7,300,000 2024 — — (1,440,000) 7,630,000 2025 — — (960,000) 1,365,000 September 30, 2019 Crude Oil Natural Gas Natural Gas Natural Gas Year of Expiration Net Short Net Short Position Net Short Net Long 2019 (549,000) (21,679,350) (13,139,076) 2,135,000 2020 (1,391,000) (5,145,900) (17,677,943) 18,507,500 2021 (154,000) — (5,381,993) 3,650,000 2022 — — (1,140) 8,212,500 2023 — — — 7,300,000

Partnership Equity and Distri_2

Partnership Equity and Distributions (Tables)	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Cash Distribution	Payment Date Per Unit Total Cash (millions) Distributions to common unitholders August 14, 2020 $ 0.39 $ 82 May 15, 2020 $ 0.39 $ 81 February 14, 2020 $ 0.78 $ 162 November 14, 2019 $ 0.78 $ 155 August 14, 2019 $ 0.78 $ 154 May 15, 2019 $ 0.78 $ 155 February 14, 2019 $ 0.78 $ 154 Distributions to Series A Preferred unitholders June 15, 2020 $ 36.875 $ 18 December 16, 2019 $ 36.875 $ 19 June 17, 2019 $ 36.875 $ 18 Distributions to Series B Preferred unitholders September 15, 2020 $ 0.4922 $ 3 June 15, 2020 $ 0.4922 $ 3 March 16, 2020 $ 0.4922 $ 3 December 16, 2019 $ 0.4922 $ 4 September 16, 2019 $ 0.4922 $ 3 June 17, 2019 $ 0.4922 $ 3 March 15, 2019 $ 0.4922 $ 3 Distributions to Series C Preferred unitholders July 15, 2020 $ 0.4969 $ 3 April 15, 2020 $ 0.4969 $ 2 January 15, 2020 $ 0.4969 $ 2 October 15, 2019 $ 0.4969 $ 2 July 15, 2019 $ 0.4969 $ 3 April 15, 2019 $ 0.4969 $ 2 January 15, 2019 $ 0.5576 $ 2

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	. Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (millions, except per unit amounts) Net income (loss) attributable to limited partners $ 96 $ (228) $ (436) $ (146) Weighted average limited partner units outstanding, basic 208,342,746 143,322,121 208,334,185 143,318,943 Dilutive effects of nonvested restricted phantom units 319,350 — — — Weighted average limited partner units outstanding, diluted 208,662,096 143,322,121 208,334,185 143,318,943 Net income (loss) per limited partner unit, basic $ 0.46 $ (1.59) $ (2.09) $ (1.02) Net income (loss) per limited partner unit, diluted $ 0.46 $ (1.59) $ (2.09) $ (1.02)

Business Segments (Tables)

Business Segments (Tables)	9 Months Ended
	Sep. 30, 2020
Segment Reporting [Abstract]
Segment Information	Three Months Ended September 30, 2020: Logistics and Marketing Gathering and Processing Other Eliminations Total (millions) Total operating revenue $ 1,438 $ 857 $ — $ (709) $ 1,586 Adjusted gross margin (a) $ 88 $ 280 $ — $ — $ 368 Operating and maintenance expense (8) (135) (3) — (146) General and administrative expense (1) (8) (57) — (66) Depreciation and amortization expense (3) (82) (7) — (92) Other expense, net (2) (2) — — (4) Earnings (loss) from unconsolidated affiliates 132 (2) — — 130 Interest expense — — (77) — (77) Income tax expense — — (1) — (1) Net income (loss) $ 206 $ 51 $ (145) $ — $ 112 Net income attributable to noncontrolling interests — (1) — — (1) Net income (loss) attributable to partners $ 206 $ 50 $ (145) $ — $ 111 Non-cash derivative mark-to-market $ 28 $ (39) $ — $ — $ (11) Capital expenditures $ 1 $ 13 $ 9 $ — $ 23 Investments in unconsolidated affiliates, net $ 12 $ — $ — $ — $ 12 Nine Months Ended September 30, 2020: Logistics and Marketing Gathering and Processing Other Eliminations Total (millions) Total operating revenue $ 3,946 $ 2,388 $ — $ (1,817) $ 4,517 Adjusted gross margin (a) $ 268 $ 911 $ — $ — $ 1,179 Operating and maintenance expense (24) (411) (12) — (447) General and administrative expense (4) (15) (154) — (173) Depreciation and amortization expense (9) (253) (22) — (284) Asset impairments — (746) — — (746) Other expense, net (6) (4) (2) — (12) Restructuring costs — — (9) — (9) Earnings (loss) from unconsolidated affiliates 394 (63) — — 331 Interest expense — — (226) — (226) Income tax expense — — (2) — (2) Net income (loss) $ 619 $ (581) $ (427) $ — $ (389) Net income attributable to noncontrolling interests — (3) — — (3) Net income (loss) attributable to partners $ 619 $ (584) $ (427) $ — $ (392) Non-cash derivative mark-to-market $ 75 $ (9) $ — $ — $ 66 Non-cash lower of cost or net realizable value adjustments $ 6 $ — $ — $ — $ 6 Capital expenditures $ 2 $ 112 $ 11 $ — $ 125 Investments in unconsolidated affiliates, net $ 102 $ — $ — $ — $ 102 Three Months Ended September 30, 2019: Logistics and Marketing Gathering and Processing Other Eliminations Total (millions) Total operating revenue $ 1,509 $ 916 $ — $ (726) $ 1,699 Adjusted gross margin (a) $ 61 $ 330 $ — $ — $ 391 Operating and maintenance expense (9) (172) (6) — (187) General and administrative expense (2) (5) (59) — (66) Depreciation and amortization expense (4) (88) (8) — (100) Asset impairments (35) (212) — — (247) Restructuring costs — — (2) — (2) Earnings from unconsolidated affiliates 113 1 — — 114 Interest expense — — (79) — (79) Income tax expense — — (1) — (1) Net income (loss) $ 124 $ (146) $ (155) $ — $ (177) Net income attributable to noncontrolling interests — (1) — — (1) Net income (loss) attributable to partners $ 124 $ (147) $ (155) $ — $ (178) Non-cash derivative mark-to-market $ (21) $ (5) $ — $ — $ (26) Capital expenditures $ 3 $ 99 $ 4 $ — $ 106 Investments in unconsolidated affiliates, net $ 56 $ — $ — $ — $ 56 Nine Months Ended September 30, 2019: Logistics and Marketing Gathering and Processing Other Eliminations Total (millions) Total operating revenue $ 5,167 $ 3,228 $ — $ (2,699) $ 5,696 Adjusted gross margin (a) $ 207 $ 1,021 $ — $ — $ 1,228 Operating and maintenance expense (29) (502) (16) — (547) General and administrative expense (6) (17) (178) — (201) Depreciation and amortization expense (10) (272) (22) — (304) Asset impairments (35) (212) — — (247) Other expense, net (1) (5) — — (6) Loss on sale of assets, net (10) (4) — — (14) Restructuring costs — — (11) — (11) Earnings from unconsolidated affiliates 340 4 — — 344 Interest expense — — (221) — (221) Income tax expense — — (2) — (2) Net income (loss) $ 456 $ 13 $ (450) $ — $ 19 Net income attributable to noncontrolling interests — (3) — — (3) Net income (loss) attributable to partners $ 456 $ 10 $ (450) $ — $ 16 Non-cash derivative mark-to-market $ (15) $ (26) $ — $ — $ (41) Non-cash lower of cost or net realizable value adjustments $ 8 $ — $ — $ — $ 8 Capital expenditures $ 28 $ 375 $ 11 $ — $ 414 Investments in unconsolidated affiliates, net $ 326 $ — $ — $ — $ 326 September 30, December 31, 2020 2019 (millions) Segment long-term assets: Gathering and Processing $ 7,851 $ 8,904 Logistics and Marketing 3,968 3,848 Other (b) 229 295 Total long-term assets 12,048 13,047 Current assets 866 1,080 Total assets $ 12,914 $ 14,127 (a) Adjusted gross margin consists of total operating revenues, including commodity derivative activity, less purchases and related costs. Adjusted gross margin is viewed as a non-GAAP financial measure under the rules of the SEC, but is included as a supplemental disclosure because it is a primary performance measure used by management as it represents the results of product sales versus product purchases. As an indicator of our operating performance, adjusted gross margin should not be considered an alternative to, or more meaningful than, net income, net cash provided by operating activities or gross margin as determined in accordance with GAAP. Our adjusted gross margin may not be comparable to a similarly titled measure of another company because other entities may not calculate adjusted gross margin in the same manner.

Statement of Cash Flows, Supple

Statement of Cash Flows, Supplemental Disclosures (Tables)	9 Months Ended
	Sep. 30, 2020
Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract]
Summary of Supplemental Cash Flow Information	Nine Months Ended September 30, 2020 2019 (millions) Cash paid for interest: Cash paid for interest, net of amounts capitalized $ 222 $ 204 Cash paid for income taxes, net of income tax refunds $ 2 $ 3 Non-cash investing and financing activities: Property, plant and equipment acquired with accounts payable and accrued liabilities $ 5 $ 21 Other non-cash activities: Operating lease assets arising from the implementation of Topic 842 $ — $ 84 Right-of-use assets obtained in exchange for operating and finance lease liabilities $ 11 $ 38

Description of Business and B_2

Description of Business and Basis of Presentation - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2020
Investments in Greater Than 20%
Business Acquisition [Line Items]
Equity method ownership investment (as percent)	20.00%
Investments in Less Than 20%
Business Acquisition [Line Items]
Equity method ownership investment (as percent)	20.00%
DCP Midstream, LLC | DCP Midstream GP, LLC
Business Acquisition [Line Items]
Ownership interest percentage by parent	100.00%
DCP Midstream, LLC | DCP Midstream LP
Business Acquisition [Line Items]
Ownership interest percentage by parent	57.00%
Phillips 66 | DCP Midstream, LLC
Business Acquisition [Line Items]
Ownership interest percentage by parent	50.00%
Enbridge | DCP Midstream, LLC
Business Acquisition [Line Items]
Ownership interest percentage by parent	50.00%

Revenue Recognition (Details)

Revenue Recognition (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Trading and marketing gains (losses), net	$ 11	$ (1)	$ 156	$ 1
Total operating revenues	1,586	1,699	4,517	5,696
Revenue, Remaining Performance Obligation, Amount	356		$ 356
Revenue, Performance Obligation, Description of Timing			four years
Revenue from contract with customer not within the scope of Topic 606	303	704	$ 2,006	2,384
Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Sales of natural gas, NGLs and condensate	459	518	1,288	1,702
NGLs and Condensate [Member]
Disaggregation of Revenue [Line Items]
Sales of natural gas, NGLs and condensate	1,007	1,081	2,743	3,667
Transportation, Processing and Other [Member]
Disaggregation of Revenue [Line Items]
Sales of natural gas, NGLs and condensate	109	101	330	326
Gathering and Processing
Disaggregation of Revenue [Line Items]
Sales of natural gas, NGLs and condensate	97	91
Trading and marketing gains (losses), net	(26)	14	42	22
Total operating revenues	857	916	2,388	3,228
Gathering and Processing | Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Sales of natural gas, NGLs and condensate	330	374	927	1,294
Gathering and Processing | NGLs and Condensate [Member]
Disaggregation of Revenue [Line Items]
Sales of natural gas, NGLs and condensate	456	437	1,125	1,620
Gathering and Processing | Transportation, Processing and Other [Member]
Disaggregation of Revenue [Line Items]
Sales of natural gas, NGLs and condensate			294	292
Logistics and Marketing
Disaggregation of Revenue [Line Items]
Sales of natural gas, NGLs and condensate	13	11
Trading and marketing gains (losses), net	37	(15)	114	(21)
Total operating revenues	1,438	1,509	3,946	5,167
Logistics and Marketing | Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Sales of natural gas, NGLs and condensate	437	461	1,203	1,543
Logistics and Marketing | NGLs and Condensate [Member]
Disaggregation of Revenue [Line Items]
Sales of natural gas, NGLs and condensate	951	1,052	2,592	3,610
Logistics and Marketing | Transportation, Processing and Other [Member]
Disaggregation of Revenue [Line Items]
Sales of natural gas, NGLs and condensate			37	35
Eliminations
Disaggregation of Revenue [Line Items]
Sales of natural gas, NGLs and condensate	(1)	(1)
Trading and marketing gains (losses), net	0	0	0	0
Total operating revenues	(709)	(726)	(1,817)	(2,699)
Eliminations | Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Sales of natural gas, NGLs and condensate	(308)	(317)	(842)	(1,135)
Eliminations | NGLs and Condensate [Member]
Disaggregation of Revenue [Line Items]
Sales of natural gas, NGLs and condensate	$ (400)	$ (408)	(974)	(1,563)
Eliminations | Transportation, Processing and Other [Member]
Disaggregation of Revenue [Line Items]
Sales of natural gas, NGLs and condensate			$ (1)	$ (1)

Contract Liabilities (Details)

Contract Liabilities (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Contract Assets and Liabilities [Abstract]
Contract with Customer, Liability	$ 35	$ 33
Contract with Customer, Liability, Additions	3
Contract with Customer, Liability, Revenue Recognized	$ (1)
Contract with Customer, Timing of Satisfaction of Performance Obligation and Payment	35 years

Agreements and Transactions w_3

Agreements and Transactions with Affiliates - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Operating Expense
Related Party Transaction [Line Items]
Employee related costs	$ 39	$ 49	$ 121	$ 148
General and Administrative Expense
Related Party Transaction [Line Items]
Employee related costs	43	45	113	136
Restructuring costs
Related Party Transaction [Line Items]
Employee related costs	$ 0	$ 2	$ 9	$ 11

Agreements and Transactions w_4

Agreements and Transactions with Affiliates - Transactions with Affiliates (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Related Party Transaction [Line Items]
Operating and maintenance expense	$ 146	$ 187	$ 447	$ 547
Affiliated Entity | Phillips 66
Related Party Transaction [Line Items]
Operating and maintenance expense	4	3	10	10
Natural Gas, NGLs and Condensate [Member] | Affiliated Entity | Unconsolidated Affiliates
Related Party Transaction [Line Items]
Sales of natural gas, NGLs and condensate	14	9	35	27
Purchases and related costs	15	8	35	44
Natural Gas, NGLs and Condensate [Member] | Affiliated Entity | Phillips 66
Related Party Transaction [Line Items]
Sales of natural gas, NGLs and condensate	247	237	616	853
Purchases and related costs	15	33	52	114
Natural Gas, NGLs and Condensate [Member] | Affiliated Entity | Enbridge
Related Party Transaction [Line Items]
Sales of natural gas, NGLs and condensate	1	0	2	0
Purchases and related costs	2	6	2	19
Operating and maintenance expense	0	0	1	0
Transportation, Processing and Other [Member]
Related Party Transaction [Line Items]
Sales of natural gas, NGLs and condensate	109	101	330	326
Transportation, Processing and Other [Member] | Affiliated Entity | Unconsolidated Affiliates
Related Party Transaction [Line Items]
Sales of natural gas, NGLs and condensate	3	1	9	2
Purchases and related costs	215	201	639	585
Transportation, Processing and Other [Member] | Affiliated Entity | Phillips 66
Related Party Transaction [Line Items]
Purchases and related costs	26	19	70	47
Transportation, Processing and Other [Member] | Affiliated Entity | Enbridge
Related Party Transaction [Line Items]
Purchases and related costs	$ 1	$ 0	$ 1	$ 1

Agreements and Transactions w_5

Agreements and Transactions with Affiliates - Balances with Affiliates (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Related Party Transaction [Line Items]
Accounts receivable	$ 150	$ 138
Accounts payable	119	100
Cash and cash equivalents	14	1	$ 2
Unconsolidated Affiliates
Related Party Transaction [Line Items]
Accounts receivable	18	21
Accounts payable	74	78
Phillips 66
Related Party Transaction [Line Items]
Accounts receivable	132	117
Accounts payable	43	20
Related Party Transaction, Due from (to) Related Party, Noncurrent	1	0
Enbridge
Related Party Transaction [Line Items]
Accounts payable	$ 2	$ 2

Inventories - Schedule of Inven

Inventories - Schedule of Inventories (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Components Of Inventory [Line Items]
Total inventories	$ 28	$ 46
Natural Gas [Member]
Components Of Inventory [Line Items]
Total inventories	18	19
Natural Gas Liquids
Components Of Inventory [Line Items]
Total inventories	$ 10	$ 27

Inventories - Additional Inform

Inventories - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Inventory Disclosure [Abstract]
Lower of cost or net realizable value adjustment	$ (6)	$ (8)

Property, Plant and Equipment -

Property, Plant and Equipment - Classification of Property, Plant and Equipment (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 13,387	$ 14,504
Accumulated depreciation	(5,341)	(5,693)
Property, plant and equipment, net	8,046	8,811
Gathering and transmission systems
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 7,659	8,406
Gathering and transmission systems | Minimum
Property, Plant and Equipment [Line Items]
Depreciable life of property, plant and equipment	20 years
Gathering and transmission systems | Maximum
Property, Plant and Equipment [Line Items]
Depreciable life of property, plant and equipment	50 years
Processing, storage and terminal facilities
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 4,948	5,305
Processing, storage and terminal facilities | Minimum
Property, Plant and Equipment [Line Items]
Depreciable life of property, plant and equipment	35 years
Processing, storage and terminal facilities | Maximum
Property, Plant and Equipment [Line Items]
Depreciable life of property, plant and equipment	60 years
Other
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 583	585
Other | Minimum
Property, Plant and Equipment [Line Items]
Depreciable life of property, plant and equipment	3 years
Other | Maximum
Property, Plant and Equipment [Line Items]
Depreciable life of property, plant and equipment	30 years
Finance lease assets [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 25	25
Finance lease assets [Member] | Minimum
Property, Plant and Equipment [Line Items]
Depreciable life of property, plant and equipment	3 years
Finance lease assets [Member] | Maximum
Property, Plant and Equipment [Line Items]
Depreciable life of property, plant and equipment	6 years
Construction work in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 172	$ 183

Property, Plant and Equipment_3

Property, Plant and Equipment - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Property, Plant and Equipment [Abstract]
Interest capitalized on construction projects	$ 1	$ 2	$ 3	$ 12
Depreciation expense	$ 90	$ 98	$ 279	$ 298

Goodwill (Details)

Goodwill (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Line Items]
Goodwill	$ 0	$ 159	$ 159	$ 231
Goodwill, Written off Related to Sale of Business Unit	0	37
Goodwill, Impairment Loss, Net of Tax	159	35
Gathering and Processing
Goodwill [Line Items]
Goodwill	0	159	159	159
Goodwill, Written off Related to Sale of Business Unit	0	0
Goodwill, Impairment Loss, Net of Tax	159	0
Logistics and Marketing
Goodwill [Line Items]
Goodwill	0	0	$ 0	$ 72
Goodwill, Written off Related to Sale of Business Unit	0	37
Goodwill, Impairment Loss, Net of Tax	$ 0	$ 35

Intangible Assets (Details)

Intangible Assets (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 145	$ 145
Finite-Lived Intangible Assets, Accumulated Amortization	88	84
Impairment of Intangible Assets, Finite-lived	11	0
Intangible assets, net	$ 46	$ 61

Investments In Unconsolidated_3

Investments In Unconsolidated Affiliates - Investments In Unconsolidated Affiliates (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated affiliates	$ 3,668	$ 3,724
DCP Sand Hills Pipeline, LLC
Schedule of Equity Method Investments [Line Items]
Equity method ownership investment (as percent)	66.67%
Investments in unconsolidated affiliates	$ 1,742	1,764
DCP Southern Hills Pipeline, LLC
Schedule of Equity Method Investments [Line Items]
Equity method ownership investment (as percent)	66.67%
Investments in unconsolidated affiliates	$ 732	738
Front Range Pipeline LLC
Schedule of Equity Method Investments [Line Items]
Equity method ownership investment (as percent)	33.33%
Investments in unconsolidated affiliates	$ 201	206
Gulf Coast Express [Member]
Schedule of Equity Method Investments [Line Items]
Equity method ownership investment (as percent)	25.00%
Investments in unconsolidated affiliates	$ 438	449
Texas Express Pipeline LLC
Schedule of Equity Method Investments [Line Items]
Equity method ownership investment (as percent)	10.00%
Investments in unconsolidated affiliates	$ 97	101
Cheyenne Connector
Schedule of Equity Method Investments [Line Items]
Equity method ownership investment (as percent)	50.00%
Investments in unconsolidated affiliates	$ 153	83
Mont Belvieu Enterprise Fractionator
Schedule of Equity Method Investments [Line Items]
Equity method ownership investment (as percent)	12.50%
Investments in unconsolidated affiliates	$ 27	27
Mont Belvieu 1 Fractionator
Schedule of Equity Method Investments [Line Items]
Equity method ownership investment (as percent)	20.00%
Investments in unconsolidated affiliates	$ 7	9
Discovery Producer Services LLC
Schedule of Equity Method Investments [Line Items]
Equity method ownership investment (as percent)	40.00%
Investments in unconsolidated affiliates	$ 248	322
Panola Pipeline Company, LLC
Schedule of Equity Method Investments [Line Items]
Equity method ownership investment (as percent)	15.00%
Investments in unconsolidated affiliates	$ 21	22
Other
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated affiliates	$ 2	$ 3

Investments in Unconsolidated_4

Investments in Unconsolidated Affiliates - Earnings from Investments in Unconsolidated Affiliates (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Schedule of Equity Method Investments [Line Items]
Earnings from unconsolidated affiliates	$ 130	$ 114	$ 331	$ 344
DCP Sand Hills Pipeline, LLC
Schedule of Equity Method Investments [Line Items]
Earnings from unconsolidated affiliates	73	72	221	212
DCP Southern Hills Pipeline, LLC
Schedule of Equity Method Investments [Line Items]
Earnings from unconsolidated affiliates	19	17	59	62
Front Range Pipeline LLC
Schedule of Equity Method Investments [Line Items]
Earnings from unconsolidated affiliates	9	7	29	23
Gulf Coast Express [Member]
Schedule of Equity Method Investments [Line Items]
Earnings from unconsolidated affiliates	17	8	49	8
Texas Express Pipeline LLC
Schedule of Equity Method Investments [Line Items]
Earnings from unconsolidated affiliates	4	3	13	12
Cheyenne Connector
Schedule of Equity Method Investments [Line Items]
Earnings from unconsolidated affiliates	3	0	3	0
Mont Belvieu Enterprise Fractionator
Schedule of Equity Method Investments [Line Items]
Earnings from unconsolidated affiliates	4	3	10	10
Mont Belvieu 1 Fractionator
Schedule of Equity Method Investments [Line Items]
Earnings from unconsolidated affiliates	3	3	9	11
Discovery Producer Services LLC
Schedule of Equity Method Investments [Line Items]
Earnings from unconsolidated affiliates	(3)	1	(63)	4
Other
Schedule of Equity Method Investments [Line Items]
Earnings from unconsolidated affiliates	$ 1	$ 0	$ 1	$ 2

Investments in Unconsolidated_5

Investments in Unconsolidated Affiliates - Equity Method Investment Summarized Financial Information, Statement of Operations (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Equity Method Investments and Joint Ventures [Abstract]
Operating revenue	$ 523	$ 438	$ 1,560	$ 1,291
Operating expenses	196	167	572	520
Net income	$ 326	$ 271	$ 985	$ 771

Investments in Unconsolidated_6

Investments in Unconsolidated Affiliates - Equity Method Investment Summarized Financial Information, Balance Sheet (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Current assets	$ 347	$ 463
Long-term assets	7,564	7,546
Current liabilities	(165)	(231)
Long-term liabilities	(258)	(252)
Net assets	$ 7,488	$ 7,526

Fair Value Measurement - Impair

Fair Value Measurement - Impairment (Details) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)
Impaired Long-Lived Assets Held and Used [Line Items]
Property, plant, and equipment impairment		$ 587
Goodwill, Impairment Loss		159
Asset Impairment	$ 0		$ 247	$ 746	$ 247
Equity Method Investment, Other than Temporary Impairment		61
Total Impairment Charges, including Equity Method Investments		807
Level 3
Impaired Long-Lived Assets Held and Used [Line Items]
Property, Plant, and Equipment		96
Goodwill		0
Assets		352
Equity Method Investments, Fair Value Disclosure		$ 256
Level 3 | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Measurement Input		14
Level 3 | Valuation Technique, Discounted Cash Flow | Measurement Input, Terminal Value Multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Measurement Input		8
Level 3 | Arithmetic Average | Market Approach Valuation Technique | Measurement Input, EBITDA Multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Goodwill, Measurement Input		8
Level 3 | Arithmetic Average | Oil | Valuation Technique, Discounted Cash Flow | Measurement Input, Commodity Future Price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Measurement Input		55.98
Level 3 | Arithmetic Average | Natural Gas [Member] | Valuation Technique, Discounted Cash Flow | Measurement Input, Commodity Future Price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Measurement Input		3.35
Level 3 | Arithmetic Average | Natural Gas Liquids | Valuation Technique, Discounted Cash Flow | Measurement Input, Commodity Future Price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Measurement Input		0.52
Level 3 | Minimum | Market Approach Valuation Technique | Measurement Input, EBITDA Multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Goodwill, Measurement Input		5.2
Level 3 | Minimum | Oil | Valuation Technique, Discounted Cash Flow | Measurement Input, Commodity Future Price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Measurement Input		34.52
Level 3 | Minimum | Natural Gas [Member] | Valuation Technique, Discounted Cash Flow | Measurement Input, Commodity Future Price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Measurement Input		2.28
Level 3 | Minimum | Natural Gas Liquids | Valuation Technique, Discounted Cash Flow | Measurement Input, Commodity Future Price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Measurement Input		0.30
Level 3 | Maximum | Market Approach Valuation Technique | Measurement Input, EBITDA Multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Goodwill, Measurement Input		16.5
Level 3 | Maximum | Oil | Valuation Technique, Discounted Cash Flow | Measurement Input, Commodity Future Price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Measurement Input		67.61
Level 3 | Maximum | Natural Gas [Member] | Valuation Technique, Discounted Cash Flow | Measurement Input, Commodity Future Price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Measurement Input		4.12
Level 3 | Maximum | Natural Gas Liquids | Valuation Technique, Discounted Cash Flow | Measurement Input, Commodity Future Price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Measurement Input		0.62

Fair Value Measurement - Financ

Fair Value Measurement - Financial Instruments Carried at Fair Value (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Current Assets
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	$ 0	$ 5	$ 0	$ 5	$ 1	$ 4	$ 8	$ 14
Net realized and unrealized gains (losses) included in earnings	(1)	7	(1)	7
Transfers out of Level 3	0	(8)	0	(7)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	0	2	(3)	(9)
Net unrealized gains (losses) on derivatives still held included in earnings	0	3	(2)	5
Current Assets | Commodity derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivatives - assets	91		91			32
Long- Term Assets
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	4	1	4	1	0	0	2	2
Net realized and unrealized gains (losses) included in earnings	4	(1)	8	(1)
Transfers out of Level 3	0	0	(4)	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	0	0	0	0
Net unrealized gains (losses) on derivatives still held included in earnings	4	(1)	4	1
Long- Term Assets | Commodity derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivatives - assets	40		40			2
Long- Term Assets | Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Restricted Investments, at Fair Value	15		15			0
Current Liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value	(1)	(1)	(1)	(1)	(3)	1	(1)	0
Net realized and unrealized (losses) gains included in earnings	(1)	1	8	0
Transfers out of Level 3	(2)
Transfers out of Level 3		0	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	(1)	1
Settlements			(8)	(1)
Net unrealized gains (losses) on derivatives still held included in earnings	1	0	(1)	(1)
Current Liabilities | Commodity derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivatives - liabilities	83		83			58
Long- Term Liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value	(1)	(5)	(1)	(5)	$ (4)	3	$ 0	$ 2
Net realized and unrealized (losses) gains included in earnings	3	(5)	2	(6)
Transfers out of Level 3	0
Transfers out of Level 3		0	0	3
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	0	0
Settlements			0	0
Net unrealized gains (losses) on derivatives still held included in earnings	3	$ (5)	1	$ (5)
Long- Term Liabilities | Commodity derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivatives - liabilities	29		29			20
Level 1 | Current Assets | Commodity derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivatives - assets	59		59			13
Level 1 | Long- Term Assets | Commodity derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivatives - assets	16		16			1
Level 1 | Long- Term Assets | Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Restricted Investments, at Fair Value	14		14			0
Level 1 | Current Liabilities | Commodity derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivatives - liabilities	37		37			15
Level 1 | Long- Term Liabilities | Commodity derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivatives - liabilities	13		13			2
Level 2 | Current Assets | Commodity derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivatives - assets	32		32			15
Level 2 | Long- Term Assets | Commodity derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivatives - assets	20		20			1
Level 2 | Long- Term Assets | Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Restricted Investments, at Fair Value	1		1			0
Level 2 | Current Liabilities | Commodity derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivatives - liabilities	45		45			42
Level 2 | Long- Term Liabilities | Commodity derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivatives - liabilities	15		15			15
Level 3 | Current Assets | Commodity derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivatives - assets	0		0			4
Level 3 | Long- Term Assets | Commodity derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivatives - assets	4		4			0
Level 3 | Long- Term Assets | Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Restricted Investments, at Fair Value	0		0			0
Level 3 | Current Liabilities | Commodity derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivatives - liabilities	1		1			1
Level 3 | Long- Term Liabilities | Commodity derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivatives - liabilities	$ 1		$ 1			$ (3)

Fair Value Measurement - Conden

Fair Value Measurement - Condensed Consolidated Balance Sheets for Derivative Financial Instruments (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Current Assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Ending balance	$ 1	$ 8	$ 4	$ 14
Net realized and unrealized gains (losses) included in earnings	(1)	7	(1)	7
Transfers out of Level 3	0	(8)	0	(7)
Settlements	0	2	(3)	(9)
Ending balance	0	5	0	5
Net unrealized gains (losses) on derivatives still held included in earnings	0	3	(2)	5
Long- Term Assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Ending balance	0	2	0	2
Net realized and unrealized gains (losses) included in earnings	4	(1)	8	(1)
Transfers out of Level 3	0	0	(4)	0
Settlements	0	0	0	0
Ending balance	4	1	4	1
Net unrealized gains (losses) on derivatives still held included in earnings	4	(1)	4	1
Current Liabilities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Transfers out of Level 3	(2)
Settlements	(1)	1
Net unrealized gains (losses) on derivatives still held included in earnings	1	0	(1)	(1)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	3	1	(1)	0
Net realized and unrealized (losses) gains included in earnings	(1)	1	8	0
Transfers out of Level 3		0	0	0
Settlements			(8)	(1)
Ending balance	1	1	1	1
Long- Term Liabilities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Transfers out of Level 3	0
Settlements	0	0
Net unrealized gains (losses) on derivatives still held included in earnings	3	(5)	1	(5)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	4	0	(3)	(2)
Net realized and unrealized (losses) gains included in earnings	3	(5)	2	(6)
Transfers out of Level 3		0	0	3
Settlements			0	0
Ending balance	$ 1	$ 5	$ 1	$ 5

Schedule of Valuation Processes

Schedule of Valuation Processes (Detail) - Level 3 $ in Millions	Sep. 30, 2020USD ($)$ / gal	Mar. 31, 2020USD ($)
Fair Value Inputs Assets And Liabilities Quantitative Information [Line Items]
Assets | $		$ 352
Market Approach Valuation Technique | Derivative Liabilities | Natural Gas Liquids
Fair Value Inputs Assets And Liabilities Quantitative Information [Line Items]
Liabilities, fair value | $	$ (2)
Market Approach Valuation Technique | Derivative Liabilities | Natural Gas Liquids | Minimum
Fair Value Inputs Assets And Liabilities Quantitative Information [Line Items]
Forward curve prices	0.14
Market Approach Valuation Technique | Derivative Liabilities | Natural Gas Liquids | Maximum
Fair Value Inputs Assets And Liabilities Quantitative Information [Line Items]
Forward curve prices	0.89
Market Approach Valuation Technique | Derivative Liabilities | Natural Gas Liquids | Weighted Average [Member]
Fair Value Inputs Assets And Liabilities Quantitative Information [Line Items]
Forward curve prices	0.43
Market Approach Valuation Technique | Derivative Assets | Natural Gas [Member]
Fair Value Inputs Assets And Liabilities Quantitative Information [Line Items]
Assets | $	$ 4
Market Approach Valuation Technique | Derivative Assets | Natural Gas [Member] | Minimum
Fair Value Inputs Assets And Liabilities Quantitative Information [Line Items]
Forward curve prices	1.90
Market Approach Valuation Technique | Derivative Assets | Natural Gas [Member] | Maximum
Fair Value Inputs Assets And Liabilities Quantitative Information [Line Items]
Forward curve prices	2.68
Market Approach Valuation Technique | Derivative Assets | Natural Gas [Member] | Weighted Average [Member]
Fair Value Inputs Assets And Liabilities Quantitative Information [Line Items]
Forward curve prices	1.86

Carrying Value and Fair Value o

Carrying Value and Fair Value of Debt (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Total Debt, Carrying Value	$ 5,761	$ 5,936
Total Debt, Fair Value	$ 5,632	$ 6,130

Leases, Additional Information

Leases, Additional Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Lessee, Lease, Description [Line Items]
Operating Lease Extension Term	20 years
Operating Lease, Payments	$ 20	$ 18
Finance Lease, Interest Payment on Liability	3	0
Finance Lease, Principal Payments	1	0
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 6	$ 33
Finance Lease, Weighted Average Remaining Lease Term	5 years	5 years
Finance Lease, Weighted Average Discount Rate, Percent	3.00%	4.00%
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	$ 5	$ 5
Operating Lease, Weighted Average Remaining Lease Term	6 years	5 years
Operating Lease, Weighted Average Discount Rate, Percent	4.00%	4.00%
Minimum
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Renewal Term	1 year
Lessee, Finance Lease, Renewal Term	1 year
Maximum
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Renewal Term	21 years
Lessee, Finance Lease, Renewal Term	21 years

Schedule of Leased Assets and L

Schedule of Leased Assets and Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease assets	$ 83	$ 107
Finance lease assets	25	25
Total right of use assets	108	132
Operating Lease, Liability, Current	24	24
Finance Lease, Liability, Current	4	3
Operating lease liabilities	76	88
Finance Lease, Liability, Noncurrent	23	22
Total lease liabilities	$ 127	$ 137

Leases, Lease Cost (Details)

Leases, Lease Cost (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income and Expenses, Lessee [Abstract]
Operating Lease, Cost	$ 7	$ 6	$ 21	$ 17
Finance Lease, Right-of-Use Asset, Amortization	1	0	2	0
Finance Lease, Interest Expense	1	0	1	0
Variable Lease, Cost	2	2	5	5
Short-term Lease, Cost	1	2	3	4
Lease, Cost	$ 12	$ 10	$ 32	$ 26

Leases, Schedule of Minimum Ope

Leases, Schedule of Minimum Operating and Finance Lease Payments (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Leases [Abstract]
Lessee, Operating Lease, Liability, Payments, Year One	$ 7
Lessee, Operating Lease, Liability, Payments, Due Year Two	26
Lessee, Operating Lease, Liability, Payments, Due Year Three	22
Lessee, Operating Lease, Liability, Payments, Due Year Four	18
Lessee, Operating Lease, Liability, Payments, Due Year Five	11
Lessee, Operating Lease, Liability, Payments, Due after Year Five	30
Lessee, Operating Lease, Liability, Payments, Due	114
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	14
Operating Lease, Liability	100
Finance Lease, Liability, Payments, Year One	1
Finance Lease, Liability, Payments, Due Year Two	5
Finance Lease, Liability, Payments, Due Year Three	5
Finance Lease, Liability, Payments, Due Year Four	5
Finance Lease, Liability, Payments, Due Year Five	6
Finance Lease, Liability, Payments, Due after Year Five	11
Finance Lease, Liability, Payments, Due	33
Finance Lease, Liability, Undiscounted Excess Amount	6
Finance Lease, Liability	$ 27	$ 25

Leases, Supplemental Cash Flow

Leases, Supplemental Cash Flow and Other Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Lessee Disclosure [Abstract]
Operating Lease, Payments	$ 20	$ 18
Finance Lease, Interest Payment on Liability	3	0
Finance Lease, Principal Payments	1	0
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	6	33
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	$ 5	$ 5
Operating Lease, Weighted Average Remaining Lease Term	6 years	5 years
Finance Lease, Weighted Average Remaining Lease Term	5 years	5 years
Operating Lease, Weighted Average Discount Rate, Percent	4.00%	4.00%
Finance Lease, Weighted Average Discount Rate, Percent	3.00%	4.00%

Debt - Schedule of Debt (Detail

Debt - Schedule of Debt (Detail) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Facility [Line Items]
Fair value adjustments related to interest rate swap fair value hedges	$ 18	$ 19
Unamortized issuance costs	(40)	(37)
Unamortized discount	(7)	(8)
Finance Lease, Liability	27	25
Total debt	5,748	5,924
Finance Lease, Liability, Current	4	3
Current debt	500	600
Long-term debt	5,244	5,321
Debt Instrument, Interest Rate, Stated Percentage [Abstract]
Proceeds from Debt, Net of Issuance Costs	494
Credit Agreement
Facility [Line Items]
Credit Facility	$ 125	200
Weighted-average variable interest rate	1.51%
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,400
Accounts Receivable Securitization Facility
Facility [Line Items]
Accounts Receivable Securitization Agreement	$ 350	350
Weighted-average variable interest rate	1.05%
Line of Credit Facility, Maximum Borrowing Capacity	$ 350
Accounts Recievable included in the Securitization Transaction	614
Senior Notes | Issued March 2010, interest at 5.350% payable semiannually, due March 2020
Facility [Line Items]
Senior Notes	$ 0	600
Debt interest rate percentage	5.35%
Debt Instrument, Interest Rate, Stated Percentage [Abstract]
Debt Instrument, Face Amount	$ 0	600
Senior Notes | Issued September 2011, interest at 4.750% payable semiannually, due September 2021
Facility [Line Items]
Senior Notes	$ 500	500
Debt interest rate percentage	4.75%
Debt Instrument, Interest Rate, Stated Percentage [Abstract]
Debt Instrument, Face Amount	$ 500	500
Senior Notes | Issued March 2012, interest at 4.950% payable semi-annually, due April 2022
Facility [Line Items]
Senior Notes	$ 350	350
Debt interest rate percentage	4.95%
Debt Instrument, Interest Rate, Stated Percentage [Abstract]
Debt Instrument, Face Amount	$ 350	350
Senior Notes | Issued March 2013, interest at 3.875% payable semi-annually, due March 2023
Facility [Line Items]
Senior Notes	$ 500	500
Debt interest rate percentage	3.875%
Debt Instrument, Interest Rate, Stated Percentage [Abstract]
Debt Instrument, Face Amount	$ 500	500
Senior Notes | Issued July 2018 and January 2019, interest at 5.375% payable semi-annually, due July 2025
Facility [Line Items]
Senior Notes	$ 825	825
Debt interest rate percentage	5.375%
Debt Instrument, Interest Rate, Stated Percentage [Abstract]
Debt Instrument, Face Amount	$ 825	825
Senior Notes | Issued June 2020, interest at 5.625% payable semi-annually, due July 2027
Facility [Line Items]
Senior Notes	$ 500	0
Debt interest rate percentage	5.625%
Debt Instrument, Interest Rate, Stated Percentage [Abstract]
Debt Instrument, Face Amount	$ 500	0
Senior Notes | Issued May 2019, interest at 5.125% payable semiannually, due May 2029
Facility [Line Items]
Senior Notes	$ 600	600
Debt interest rate percentage	5.125%
Debt Instrument, Interest Rate, Stated Percentage [Abstract]
Debt Instrument, Face Amount	$ 600	600
Senior Notes | Issued August 2000, interest at 8.125% payable semi-annually, due August 2030
Facility [Line Items]
Senior Notes	$ 300	300
Debt interest rate percentage	8.125%
Debt Instrument, Interest Rate, Stated Percentage [Abstract]
Debt Instrument, Face Amount	$ 300	300
Senior Notes | Issued October 2006, interest at 6.450% payable semi-annually, due November 2036
Facility [Line Items]
Senior Notes	$ 300	300
Debt interest rate percentage	6.45%
Debt Instrument, Interest Rate, Stated Percentage [Abstract]
Debt Instrument, Face Amount	$ 300	300
Senior Notes | Issued September 2007, interest at 6.750% payable semi-annually, due September 2037
Facility [Line Items]
Senior Notes	$ 450	450
Debt interest rate percentage	6.75%
Debt Instrument, Interest Rate, Stated Percentage [Abstract]
Debt Instrument, Face Amount	$ 450	450
Senior Notes | Issued March 2014, interest at 5.600% payable semi-annually, due April 2044
Facility [Line Items]
Senior Notes	$ 400	400
Debt interest rate percentage	5.60%
Debt Instrument, Interest Rate, Stated Percentage [Abstract]
Debt Instrument, Face Amount	$ 400	400
Junior subordinated notes | Issued May 2013, interest at 5.850% payable semi-annually, due May 2043
Facility [Line Items]
Senior Notes	$ 550	550
Debt interest rate percentage	5.85%
Debt Instrument, Interest Rate, Stated Percentage [Abstract]
Debt Instrument, Face Amount	$ 550	$ 550

Debt - Additional Information (

Debt - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Proceeds from Debt, Net of Issuance Costs	$ 494
Line of Credit Facility, Borrowing Capacity, Description	500	$ 500
Accounts Receivable Securitization Facility
Debt Instrument [Line Items]
Accounts Recievable included in the Securitization Transaction	614	614
Line of Credit Facility, Maximum Borrowing Capacity	350	350
Credit Agreement
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	1,400	$ 1,400
Basis spread determined by credit rating		0.35%
Commitment fee percentage		0.275%
Letter of credit amount outstanding	(10)	$ (10)
Debt covenants, maximum borrowing amount	$ 1,265	$ 1,265
Credit Agreement | LIBOR
Debt Instrument [Line Items]
Variable rate basis spread		1.35%
Credit Agreement | LIBOR Market Index
Debt Instrument [Line Items]
Variable rate basis spread		1.00%
Credit Agreement | Maximum
Debt Instrument [Line Items]
Maximum leverage ratio in event of acquisition	5.50	5.50
Credit Agreement | Quarters After June 30, 2018 | Maximum
Debt Instrument [Line Items]
Maximum leverage ratio	5	5
Credit Agreement | Quarters After June 30, 2018 | Minimum
Debt Instrument [Line Items]
Maximum leverage ratio	1	1
Issued July 2018 and January 2019, interest at 5.375% payable semi-annually, due July 2025 | Senior Notes
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 825	$ 825	$ 825
Debt Instrument, Interest Rate, Stated Percentage	5.375%	5.375%
Issued May 2019, interest at 5.125% payable semiannually, due May 2029 | Senior Notes
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 600	$ 600	$ 600
Debt Instrument, Interest Rate, Stated Percentage	5.125%	5.125%

Debt - Future Maturities of Lon

Debt - Future Maturities of Long-Term Debt (Detail) $ in Millions	Sep. 30, 2020USD ($)
Maturities of Long-term Debt [Abstract]
2021	$ 500
2022	700
2023	500
2024	125
Thereafter	3,925
Long Term Debt Maturities Repayments Of Principal Total	$ 5,750

Risk Management and Hedging A_3

Risk Management and Hedging Activities - Additional Information (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Derivative [Line Items]
Collateral, cash deposits	$ 21
Letters of credit received	51
Unrealized gains on derivative instruments	91	$ 32
Unrealized gains on derivative instruments	40	2
Derivative Instruments and Hedges, Liabilities	(83)	(58)
Derivative Instruments and Hedges, Liabilities, Noncurrent	$ (29)	$ (20)

Risk Management and Hedging A_4

Risk Management and Hedging Activities - Summary of Gross and Net Amounts of Derivative Instruments (Detail) - Commodity derivatives - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Offsetting Assets [Line Items]
Gross Amounts of Assets Presented in the Balance Sheet	$ 131	$ 34
Derivative Asset, Not Offset in Balance Sheet	0	0
Net Amount	131	34
Offsetting Liabilities [Line Items]
Gross Amounts of Liabilities Presented in the Balance Sheet	112	78
Derivative Liability, Not Offset in Balance Sheet	0	0
Net Amount	$ 112	$ 78

Risk Management and Hedging A_5

Risk Management and Hedging Activities - Schedule of Designated and Non-Designated Derivative Instruments in Statement of Financial Position, Fair Value (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Derivative Asset [Abstract]
Derivative Instruments and Hedges, Current Assets	$ 91	$ 32
Derivative Instruments and Hedges, Assets, Noncurrent	40	2
Derivative Liability [Abstract]
Derivative Instruments and Hedges, Current Liabilities	83	58
Derivative Instruments and Hedges, Liabilities, Noncurrent	29	20
Commodity derivatives | Derivative Asset Not Designated As Hedging Instruments [Member]
Derivative Asset [Abstract]
Derivative Instruments and Hedges, Current Assets	91	32
Derivative Instruments and Hedges, Assets, Noncurrent	40	2
Derivative Instruments Not Designated as Hedging Instruments, Total Assets, at Fair Value	131	34
Commodity derivatives | Derivative Liabilities Not Designated As Hedging Instruments [Member]
Derivative Liability [Abstract]
Derivative Instruments and Hedges, Current Liabilities	83	58
Derivative Instruments and Hedges, Liabilities, Noncurrent	29	20
Derivative Instruments Not Designated as Hedging Instruments, Total Liabilities, at Fair Value	$ 112	$ 78

Risk Management and Hedging A_6

Risk Management and Hedging Activities - Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Derivative [Line Items]
Accumulated Other Comprehensive (Loss) Income	$ (7)		$ (7)			$ (7)
Trading and marketing gains (losses), net	11	$ (1)	156	$ 1
Commodity derivatives | Derivative Assets Not Designated As Hedging Instruments
Derivative [Line Items]
Realized gains	22	25	90	42
Unrealized gains (losses)	(11)	(26)	66	(41)
Trading and marketing gains (losses), net	11	(1)	156	1
Accumulated Net Gain (Loss) from Cash Flow Hedges
Derivative [Line Items]
Accumulated Other Comprehensive (Loss) Income	(7)	(8)	(7)	(8)	$ (7)	(7)	$ (8)	$ (8)
Accumulated Net Gain (Loss) from Cash Flow Hedges | Interest Rate Derivatives
Derivative [Line Items]
Accumulated Other Comprehensive (Loss) Income	(2)	(3)	(2)	(3)	(2)	(2)	(3)	(3)
Accumulated Net Gain (Loss) from Cash Flow Hedges | Commodity derivatives
Derivative [Line Items]
Accumulated Other Comprehensive (Loss) Income	(6)	(6)	(6)	(6)	(6)	(6)	(6)	(6)
Accumulated Net Gain (Loss) from Cash Flow Hedges | Foreign Currency Derivatives
Derivative [Line Items]
Accumulated Other Comprehensive (Loss) Income	1	$ 1	1	$ 1	$ 1	$ 1	$ 1	$ 1
Cash Flow Hedging [Member]
Derivative [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	(1)		(1)
Cash Flow Hedging [Member] | Interest Rate Derivatives
Derivative [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	(1)		(1)
Cash Flow Hedging [Member] | Commodity derivatives
Derivative [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	0		0
Cash Flow Hedging [Member] | Foreign Currency Derivatives
Derivative [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	$ 0		$ 0

Risk Management and Hedging A_7

Risk Management and Hedging Activities - Schedule of Changes in Derivative Instruments not Designated as Hedging Instruments (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Derivative [Line Items]
Trading and marketing (losses) gains, net	$ 11	$ (1)	$ 156	$ 1
Derivative Assets Not Designated As Hedging Instruments | Commodity derivatives
Derivative [Line Items]
Realized gains	22	25	90	42
Unrealized gains (losses)	(11)	(26)	66	(41)
Trading and marketing (losses) gains, net	$ 11	$ (1)	$ 156	$ 1

Risk Management and Hedging A_8

Risk Management and Hedging Activities - Schedule of Net Long or Short Positions Expected to be Realized (Detail)	9 Months Ended
	Sep. 30, 2020MMBTUbbl	Sep. 30, 2019MMBTUbbl
Crude Oil
Net (Short) Position, Volume [Abstract]
Net (Short) Position (Bbls), Year One | bbl	(253,000)	(549,000)
Net (Short) Position (Bbls), Year Two | bbl	(791,000)	(1,391,000)
Net (Short) Position (Bbls), Year Three | bbl	(43,000)	(154,000)
Net (Short) Position (Bbls), Year Four | bbl	0	0
Net Long (Short) Position (Bbls), Year Five | bbl	0	0
Net (Short) Positions (Bbls), Year Six | bbl	0
Natural Gas [Member]
Net Long (Short) Position, MMBtu [Abstract]
Net (Short) Long Position (MMBtu), Year One | MMBTU	(14,287,500)	(21,679,350)
Net (Short) Long Position (MMBtu), Year Two | MMBTU	(65,332,500)	(5,145,900)
Net Long Position (MMBtu), Year Three | MMBTU	(21,900,000)	0
Net Long Position (MMBtu), Year Four | MMBTU	0	0
Net Long Position (MMBtu), Year Five | MMBTU	0	0
Net Long (Short) Positions (MMBtu), year Six | MMBTU	0
Natural Gas Liquids
Net (Short) Position, Volume [Abstract]
Net (Short) Position (Bbls), Year One | bbl	(932,160)	(13,139,076)
Net (Short) Position (Bbls), Year Two | bbl	(8,471,590)	(17,677,943)
Net (Short) Position (Bbls), Year Three | bbl	(1,486,842)	(5,381,993)
Net (Short) Position (Bbls), Year Four | bbl	(1,440,000)	(1,140)
Net Long (Short) Position (Bbls), Year Five | bbl	(1,440,000)	0
Net (Short) Positions (Bbls), Year Six | bbl	(960,000)
Natural Gas Basis Swaps
Net Long (Short) Position, MMBtu [Abstract]
Net (Short) Long Position (MMBtu), Year One | MMBTU	5,600,000	2,135,000
Net (Short) Long Position (MMBtu), Year Two | MMBTU	(735,000)	18,507,500
Net Long Position (MMBtu), Year Three | MMBTU	12,775,000	3,650,000
Net Long Position (MMBtu), Year Four | MMBTU	7,300,000	8,212,500
Net Long Position (MMBtu), Year Five | MMBTU	7,630,000	7,300,000
Net Long (Short) Positions (MMBtu), year Six | MMBTU	1,365,000

Partnership Equity and Distri_3

Partnership Equity and Distributions - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2020shares
Partnership Equity And Distribution [Line Items]
Common unitholders, units issued (in shares)	208,351,528
DCP Midstream LP | DCP Midstream, LLC
Partnership Equity And Distribution [Line Items]
Ownership interest percentage by parent	57.00%

Partnership Equity and Distri_4

Partnership Equity and Distributions - Cash Distribution (Detail) - USD ($) $ / shares in Units, $ in Millions	Sep. 15, 2020	Aug. 14, 2020	Jul. 15, 2020	Jun. 15, 2020	May 15, 2020	Apr. 15, 2020	Mar. 16, 2020	Feb. 14, 2020	Jan. 15, 2020	Dec. 16, 2019	Nov. 14, 2019	Oct. 15, 2019	Sep. 16, 2019	Aug. 14, 2019	Jul. 15, 2019	Jun. 17, 2019	May 15, 2019	Apr. 15, 2019	Mar. 15, 2019	Feb. 14, 2019	Jan. 15, 2019	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019
Distribution Made to Limited Partner [Line Items]
Total Cash Distribution																						$ 88	$ 104	$ 167	$ 160	$ 178	$ 159
Series A Preferred Limited Partners [Member]
Distribution Made to Limited Partner [Line Items]
Preferred Limited Partnership Distribution; Distribution Amount Paid				$ 36.875						$ 36.875						$ 36.875
Total Cash Distribution				$ 18						$ 19						$ 18						0	18	0	0	18	0
Series B Preferred Limited Partners [Member]
Distribution Made to Limited Partner [Line Items]
Preferred Limited Partnership Distribution; Distribution Amount Paid	$ 0.4922			$ 0.4922			$ 0.4922			$ 0.4922			$ 0.4922			$ 0.4922			$ 0.4922
Total Cash Distribution	$ 3			$ 3			$ 3			$ 4			$ 3			$ 3			$ 3			3	3	3	3	3	3
Series C Preferred Limited Partners [Member]
Distribution Made to Limited Partner [Line Items]
Preferred Limited Partnership Distribution; Distribution Amount Paid			$ 0.4969			$ 0.4969			$ 0.4969			$ 0.4969			$ 0.4969			$ 0.4969			$ 0.5576
Total Cash Distribution			$ 3			$ 2			$ 2			$ 2			$ 3			$ 2			$ 2	3	2	2	3	2	2
Limited Partners
Distribution Made to Limited Partner [Line Items]
Per Unit Distribution (in dollars per share)		$ 0.39			$ 0.39			$ 0.78			$ 0.78			$ 0.78			$ 0.78			$ 0.78
Total Cash Distribution		$ 82			$ 81			$ 162			$ 155			$ 154			$ 155			$ 154		$ 82	$ 81	$ 162	$ 112	$ 112	$ 111

Net Income or Loss per Limite_2

Net Income or Loss per Limited Partner Unit Additional Detail (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Weighted Average Number Diluted Shares Outstanding Adjustment	208,662,096	143,322,121	208,334,185	143,318,943
Net Income (Loss), Per Outstanding Limited Partnership Unit, Basic, Net of Tax	$ 0.46	$ (1.59)	$ (2.09)	$ (1.02)
Net Income (Loss), Net of Tax, Per Outstanding Limited Partnership Unit, Diluted	$ 0.46	$ (1.59)	$ (2.09)	$ (1.02)
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	319,350	0	0	0
Weighted Average Number of Shares Outstanding, Basic	208,342,746	143,322,121	208,334,185	143,318,943
Net Income (Loss) Allocated to Limited Partners	$ 96	$ (228)	$ (436)	$ (146)
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount			319,350

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income tax expense	$ 1	$ 1	$ 2	$ 2
Deferred income taxes	$ 30		$ 30		$ 30

Commitments and Contingent Li_2

Commitments and Contingent Liabilities (Details)	Sep. 30, 2020USD ($)
New Mexico Environment Department Notice of Violation 1 [Member]
Other Commitments [Line Items]
Estimated Litigation Liability	$ 150,000
New Mexico Environment Department Notice of Violation 2 [Member]
Other Commitments [Line Items]
Estimated Litigation Liability	142,000
New Mexico Environment Department Notice of Violation 3 [Domain]
Other Commitments [Line Items]
Estimated Litigation Liability	5,300,000
New Mexico Environment Department Notice of Violation 4 [Domain]
Other Commitments [Line Items]
Estimated Litigation Liability	3,300,000
Low end of estimate
Other Commitments [Line Items]
Estimated Litigation Liability	375,000
High end of estimate
Other Commitments [Line Items]
Estimated Litigation Liability	$ 460,000

Restructuring (Details)

Restructuring (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 0	$ 2	$ 9	$ 11
Restructuring and Related Cost, Number of Positions Eliminated, Inception to Date Percent	15.00%		15.00%
Restructuring and Related Cost, Expected Cost	$ 9		$ 9

Business Segments - Segment Inf

Business Segments - Segment Information (Detail) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Total operating revenues	$ 1,586			$ 1,699			$ 4,517	$ 5,696
Gross margin	368			391			1,179	1,228
Operating and maintenance expense	(146)			(187)			(447)	(547)
Depreciation and amortization expense	(92)			(100)			(284)	(304)
General and administrative expense	(66)			(66)			(173)	(201)
Asset Impairments	0			(247)			(746)	(247)
Other expense, net	(4)			0			(12)	(6)
Loss on sale of assets, net	0			0			0	(14)
Restructuring Costs	0			(2)			(9)	(11)
Earnings from unconsolidated affiliates	130			114			331	344
Interest expense, net	(77)			(79)			(226)	(221)
Income tax expense	1			1			2	2
Net income	112	$ 48	$ (549)	(177)	$ 120	$ 76	(389)	19
Net income attributable to noncontrolling interests	(1)			(1)			(3)	(3)
Net income attributable to partners	111			(178)			(392)	16
Non-cash derivative mark-to-market	(11)			(26)			66	(41)
Non-cash lower of cost or net realizable value adjustment							6	8
Capital expenditures	23			106			125	414
Investments in unconsolidated affiliates, net	12			56			102	326
Logistics and Marketing
Segment Reporting Information [Line Items]
Total operating revenues	1,438			1,509			3,946	5,167
Gathering and Processing
Segment Reporting Information [Line Items]
Total operating revenues	857			916			2,388	3,228
Operating Segments | Logistics and Marketing
Segment Reporting Information [Line Items]
Total operating revenues	1,438			1,509			3,946	3,228
Gross margin	88			61			268	1,021
Operating and maintenance expense	(8)			(9)			(24)	(502)
Depreciation and amortization expense	(3)			(4)			(9)	(272)
General and administrative expense	(1)			(2)			(4)	(17)
Asset Impairments				35			0	(35)
Other expense, net	(2)						(6)	(5)
Loss on sale of assets, net								(10)
Restructuring Costs				0			0	0
Earnings from unconsolidated affiliates	132			(113)			394	4
Interest expense, net	0			0			0	0
Income tax expense	0			0			0	0
Net income	206			124			619	456
Net income attributable to noncontrolling interests	0			0			0	(3)
Net income attributable to partners	206			124			619	456
Non-cash derivative mark-to-market	28			(21)			75	(26)
Capital expenditures	1			3			2	375
Investments in unconsolidated affiliates, net	12			56			102	0
Operating Segments | Gathering and Processing
Segment Reporting Information [Line Items]
Total operating revenues	857			916			2,388	5,167
Gross margin	280			330			911	207
Operating and maintenance expense	(135)			(172)			(411)	(29)
Depreciation and amortization expense	(82)			(88)			(253)	(10)
General and administrative expense	(8)			(5)			(15)	(6)
Asset Impairments				212			(746)	(212)
Other expense, net	(2)						(4)	(1)
Loss on sale of assets, net								(4)
Restructuring Costs				0			0	0
Earnings from unconsolidated affiliates	(2)			(1)			(63)	340
Interest expense, net	0			0			0	0
Income tax expense	0			0			0	0
Net income	51			(146)			(581)	13
Net income attributable to noncontrolling interests	(1)			(1)			(3)	0
Net income attributable to partners	50			(147)			(584)	10
Non-cash derivative mark-to-market	(39)			(5)			(9)	(15)
Non-cash lower of cost or net realizable value adjustment							0	0
Capital expenditures	13			99			112	28
Investments in unconsolidated affiliates, net	0			0			0	326
Other
Segment Reporting Information [Line Items]
Total operating revenues	0			0			0	0
Gross margin	0			0			0	0
Operating and maintenance expense	(3)			(6)			(12)	(16)
Depreciation and amortization expense	(7)			(8)			(22)	(22)
General and administrative expense	(57)			(59)			(154)	(178)
Asset Impairments				0			0	0
Other expense, net	0						(2)	0
Loss on sale of assets, net								0
Restructuring Costs				(2)			(9)	(11)
Earnings from unconsolidated affiliates	0			0			0	0
Interest expense, net	(77)			(79)			(226)	(221)
Income tax expense	1			1			2	2
Net income	(145)			(155)			(427)	(450)
Net income attributable to noncontrolling interests	0			0			0	0
Net income attributable to partners	(145)			(155)			(427)	(450)
Non-cash derivative mark-to-market	0			0			0	0
Non-cash lower of cost or net realizable value adjustment							0	0
Capital expenditures	9			4			11	11
Investments in unconsolidated affiliates, net	0			0			0	0
Eliminations
Segment Reporting Information [Line Items]
Total operating revenues	(709)			(726)			(1,817)	(2,699)
Gross margin	0			0			0	0
Operating and maintenance expense	0			0				0
Depreciation and amortization expense	0			0			0	0
General and administrative expense	0			0			0	0
Asset Impairments				0				0
Other expense, net	0							0
Restructuring Costs				0			0	0
Earnings from unconsolidated affiliates	0			0			0	0
Interest expense, net	0			0			0	0
Income tax expense	0			0			0	0
Net income	0			0			0	0
Net income attributable to noncontrolling interests				0			0	0
Net income attributable to partners	0			0			0	0
Non-cash derivative mark-to-market	0			0				0
Non-cash lower of cost or net realizable value adjustment							0	0
Capital expenditures	0			0			0	0
Investments in unconsolidated affiliates, net	$ 0			$ 0			$ 0	$ 0

Business Segments - Segment Ass

Business Segments - Segment Assets (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Segment Reporting, Asset Reconciling Item [Line Items]
Segment long-term assets	$ 12,048	$ 13,047
Current assets	866	1,080
Total assets	12,914	14,127
Operating Segments | Logistics and Marketing
Segment Reporting, Asset Reconciling Item [Line Items]
Segment long-term assets	3,968	3,848
Operating Segments | Gathering and Processing
Segment Reporting, Asset Reconciling Item [Line Items]
Segment long-term assets	7,851	8,904
Other
Segment Reporting, Asset Reconciling Item [Line Items]
Segment long-term assets	$ 229	$ 295

Statement of Cash Flows, Supp_2

Statement of Cash Flows, Supplemental Disclosures (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Item Effected [Line Items]
Cash paid for interest, net of amounts capitalized	$ 222	$ 204
Income Taxes Paid, Net	2	3
Property, plant and equipment acquired with accounts payable and accrued liabilities	5	21
Right-of-Use Assets Obtained in Exchange for Operating and Finance Lease Liabilities	11	38
Accounting Standards Update 2016-02 [Member]
Item Effected [Line Items]
Cumulative Effect of Implementation of Topic 842	$ 0	$ 84

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions

Jan. 15, 2021

Jan. 04, 2021

Dec. 15, 2020

Dec. 01, 2020

Nov. 13, 2020

Oct. 30, 2020

Oct. 16, 2020

Sep. 15, 2020

Jul. 15, 2020

Jun. 15, 2020

Apr. 15, 2020

Mar. 16, 2020

Jan. 15, 2020

Dec. 16, 2019

Oct. 15, 2019

Sep. 16, 2019

Jul. 15, 2019

Jun. 17, 2019

Apr. 15, 2019

Mar. 15, 2019

Jan. 15, 2019

Sep. 30, 2020

Subsequent Event [Line Items]

Restructuring and Related Cost, Number of Positions Eliminated, Inception to Date Percent

15.00%

Restructuring and Related Cost, Expected Cost

$ 9

Series A Preferred Limited Partners [Member]

Subsequent Event [Line Items]

Preferred Limited Partnership Unit; Distribution Amount Declared

$ 36.875

$ 36.875

$ 36.875

Series B Preferred Limited Partners [Member]

Subsequent Event [Line Items]

Preferred Limited Partnership Unit; Distribution Amount Declared

$ 0.4922

$ 0.4922

$ 0.4922

$ 0.4922

$ 0.4922

$ 0.4922

$ 0.4922

Series C Preferred Limited Partners [Member]

Subsequent Event [Line Items]

Preferred Limited Partnership Unit; Distribution Amount Declared

$ 0.4969

$ 0.4969

$ 0.4969

$ 0.4969

$ 0.4969

$ 0.4969

$ 0.5576

Subsequent Event [Member]

Subsequent Event [Line Items]

Distribution Made to Limited Partner, Distributions Declared, Per Unit

$ 0.39

Distribution Made to Common Unitholders, Declaration Date

Oct. 16, 2020

Distribution Made to Limited Partner, Date of Record

Oct. 30, 2020

Distribution Made to Limited Partner, Distribution Date

Nov. 13, 2020

Subsequent Event [Member] | Series A Preferred Limited Partners [Member]

Subsequent Event [Line Items]

Preferred Limited Partner Distribution: Record Date

Dec. 1, 2020

Preferred Limited Partnership Distribution; Distribution Date

Dec. 15, 2020

Preferred Limited Partnership Unit; Distribution Amount Declared

$ 36.875

Subsequent Event [Member] | Series B Preferred Limited Partners [Member]

Subsequent Event [Line Items]

Distribution Made to Common Unitholders, Declaration Date

Oct. 16, 2020

Preferred Limited Partner Distribution: Record Date

Dec. 1, 2020

Preferred Limited Partnership Distribution; Distribution Date

Dec. 15, 2020

Preferred Limited Partnership Unit; Distribution Amount Declared

$ 0.4922

Subsequent Event [Member] | Series C Preferred Limited Partners [Member]

Subsequent Event [Line Items]

Distribution Made to Common Unitholders, Declaration Date

Oct. 16, 2020

Preferred Limited Partner Distribution: Record Date

Jan. 4, 2021

Preferred Limited Partnership Distribution; Distribution Date

Jan. 15, 2021

Preferred Limited Partnership Unit; Distribution Amount Declared

$ 0.4969