Shell Midstream Partners (SHLX) 10-K23 Feb 212020 FY Annual reportFinancial data

Company Profile

Cover Page

Cover Page - USD ($) $ in Millions	12 Months Ended
Cover Page - USD ($) $ in Millions	Dec. 31, 2020	Feb. 22, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Document Transition Report	false
Entity File Number	001-36710
Entity Registrant Name	Shell Midstream Partners, L.P.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-5223743
Entity Address, Address Line One	150 N. Dairy Ashford
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77079
City Area Code	832
Local Phone Number	337-2034
Title of 12(b) Security	Common Units, Representing Limited Partner Interests
Trading Symbol	SHLX
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 1,518
Entity Common Stock, Shares Outstanding		393,289,537
Documents Incorporated by Reference	Documents incorporated by reference: None
Entity Central Index Key	0001610466
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 320	$ 290
Accounts receivable – third parties, net	20	12
Accounts receivable – related parties	21	29
Allowance oil	9	12
Prepaid expenses	24	16
Total current assets	394	359
Equity method investments	1,013	926
Property, plant and equipment, net	699	726
Operating lease right-of-use assets	4	4
Other investments	2	2
Contract assets – related parties	233	0
Other assets	2	2
Total assets	2,347	2,019
Current liabilities
Accounts payable – third parties	5	5
Accounts payable – related parties	16	10
Deferred revenue – third parties	4	0
Deferred revenue – related parties	19	0
Accrued liabilities – third parties	10	12
Accrued liabilities – related parties	28	19
Total current liabilities	82	46
Noncurrent liabilities
Debt payable – related party	2,692	2,692
Operating lease liabilities	4	4
Finance lease liabilities	24	24
Deferred revenue and other unearned income	3	2
Total noncurrent liabilities	2,723	2,722
Total liabilities	2,805	2,768
Commitments and Contingencies (Note 15)
(DEFICIT) EQUITY
Preferred unitholders (50,782,904 and 0 units issued and outstanding as of December 31, 2020 and December 31, 2019)	(1,059)	0
Financing receivables – related parties	(298)	0
Accumulated other comprehensive loss	(9)	(8)
Total partners’ deficit	(481)	(775)
Noncontrolling interests	23	26
Total deficit	(458)	(749)
Total liabilities and deficit	2,347	2,019
Shell Pipeline Company L P
(DEFICIT) EQUITY
General partner – SPLC (0 and 4,761,012 units issued and outstanding as of December 31, 2020 and December 31, 2019)	0	(4,014)
Common Units
(DEFICIT) EQUITY
Common unitholders	3,382	3,450
Common Units \| Shell Pipeline Company L P
(DEFICIT) EQUITY
Common unitholders	$ (2,497)	$ (203)

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - shares	Dec. 31, 2020	Dec. 31, 2019
Common unitholders' capital account, units outstanding (in shares)	393,289,537
Shell Pipeline Company L P
Preferred units, issued (in shares)	50,782,904	0
Preferred units, outstanding (in shares)	50,782,904	0
General partners' capital account, units issued (in units)	0	4,761,012
General partners' capital account, units outstanding (in units)	0	4,761,012
Common unitholders
Common unitholders' capital account, units issued (in shares)	123,832,233	123,832,233
Common unitholders' capital account, units outstanding (in shares)	123,832,233	123,832,233
Common unitholders \| Shell Pipeline Company L P
Common unitholders' capital account, units issued (in shares)	269,457,304	109,457,304
Common unitholders' capital account, units outstanding (in shares)	269,457,304	109,457,304

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue
Revenue from contract with customer	$ 424	$ 447	$ 469
Revenues, Total	481	503	525
Costs and expenses
Operations and maintenance – third parties	48	65	108
Operations and maintenance – related parties	114	59	54
Cost of product sold	24	36	32
Loss (gain) from revision of asset retirement obligation	0	2	(3)
General and administrative – third parties	7	11	8
General and administrative – related parties	49	49	52
Depreciation, amortization and accretion	50	49	46
Property and other taxes	20	17	16
Total costs and expenses	312	288	313
Operating income	169	215	212
Income from equity method investments	417	373	235
Dividend income from other investments	0	14	67
Other income	40	36	31
Investment, dividend and other income	457	423	333
Interest income	23	4	2
Interest expense	93	96	64
Income before income taxes	556	546	483
Income tax expense	0	0	1
Net income	556	546	482
Less: Net income attributable to noncontrolling interests	13	18	18
Net income attributable to the Partnership	543	528	464
Preferred unitholder’s interest in net income	36	0	0
General partner’s interest in net income attributable to the Partnership	55	147	134
Limited Partners’ interest in net income attributable to the Partnership’s common unitholders	$ 452	$ 381	$ 330
Net income per Limited Partner Unit - Basic and Diluted:
Distributions per Limited Partner unit (in dollars per share)	$ 1.8400	$ 1.7500	$ 1.4950
Common
Costs and expenses
Net income attributable to the Partnership		$ 381	$ 330
Net income per Limited Partner Unit - Basic and Diluted:
Common - Basic (in dollars per share)	1.28	$ 1.66	$ 1.50
Common - Diluted (in dollars per share)	$ 1.25	$ 1.66	$ 1.50
Weighted average Limited Partner Units outstanding - Basic and Diluted:
Common units - basic (in shares)	38.2	229.2	220.3
Common units – public
Costs and expenses
Net income	$ 160	$ 204	$ 182
Weighted average Limited Partner Units outstanding - Basic and Diluted:
Common units - basic (in shares)	123.8	123.8	121.3
Common units - diluted (in shares)	123.8	123.8	121.3
Common units – public \| Shell Pipeline Company L P
Costs and expenses
Net income	$ 292	$ 177	$ 147
Common units - SPLC \| Shell Pipeline Company L P
Weighted average Limited Partner Units outstanding - Basic and Diluted:
Common units - basic (in shares)	229.7	105.4	99
Common units - diluted (in shares)	267.9	105.4	99
Third Parties \| Transportation, Terminaling And Storage Services
Revenue
Revenue from contract with customer	$ 123	$ 143	$ 209
Third Parties \| Product Revenue
Revenue
Revenue from contract with customer	0	5	2
Related Parties
Revenue
Lease revenue – related parties	57	56	56
Related Parties \| Transportation, Terminaling And Storage Services
Revenue
Revenue from contract with customer	282	264	229
Related Parties \| Product Revenue
Revenue
Revenue from contract with customer	$ 19	$ 35	$ 29

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 556	$ 546	$ 482
Other comprehensive loss, net of tax:
Remeasurements of pension and other postretirement benefits related to equity method investments, net of tax	(1)	(2)	0
Comprehensive income	555	544	482
Noncontrolling interests	13	18	18
Comprehensive income attributable to the Partnership	$ 542	$ 526	$ 464

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities
Net income	$ 556	$ 546	$ 482
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation, amortization and accretion	50	49	46
Amortization of contract assets - related parties	11	0	0
Loss (gain) from revision of asset retirement obligation	0	2	(3)
Non-cash interest expense	1	1	1
Allowance oil reduction to net realizable value	8	1	5
Undistributed equity earnings	(4)	(6)	(6)
Changes in operating assets and liabilities
Accounts receivable	0	7	(7)
Allowance oil	(6)	0	(6)
Prepaid expenses and other assets	(7)	0	(4)
Accounts payable	7	2	(7)
Deferred revenue and other unearned income	24	(11)	(4)
Accrued liabilities	10	6	10
Net cash provided by operating activities	650	597	507
Cash flows from investing activities
Capital expenditures	(27)	(38)	(49)
Acquisitions from Parent	0	(90)	(482)
Contributions to investment	0	(25)	(28)
Return of investment	91	66	48
Net cash provided by (used in) investing activities	64	(87)	(511)
Cash flows from financing activities
Payment of equity issuance costs	(2)	0	0
Net proceeds from equity offerings	0	0	973
Borrowings under credit facilities	0	600	1,820
Repayments of credit facilities	0	0	(1,573)
Contributions from general partner	0	0	20
Capital distributions to general partner	0	(510)	(738)
Distributions to noncontrolling interests	(16)	(17)	(16)
Distributions to unitholders and general partner	(670)	(519)	(423)
Other contributions from Parent	2	19	12
Credit facility issuance costs	0	0	(1)
Receipt of principal payments on financing receivables	3	0	0
Repayment of principal on finance leases	(1)	(1)	0
Net cash (used in) provided by financing activities	(684)	(428)	74
Net increase in cash and cash equivalents	30	82	70
Cash and cash equivalents at beginning of the period	290	208	138
Cash and cash equivalents at end of the period	320	290	208
Non-cash investing and financing transactions:
Change in asset retirement obligation	0	0	2
Change in accrued capital expenditures	(5)	(3)	2
Other non-cash contributions from Parent	$ 0	$ 0	$ 2

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN (DEFICIT) EQUITY - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Preferred PartnerShell Pipeline Company L P	Common units – public	Common units – publicCumulative Effect, Period of Adoption, Adjustment	Common units – publicShell Pipeline Company L P	Common units – publicShell Pipeline Company L PCumulative Effect, Period of Adoption, Adjustment	General Partner SPLCShell Pipeline Company L P	General Partner SPLCShell Pipeline Company L PCumulative Effect, Period of Adoption, Adjustment	Financing Receivables	Accumulated Other Comprehensive Loss	Noncontrolling Interests
Beginning balance at Dec. 31, 2017	$ (566)	$ (2)	$ 0	$ 2,774	$ (1)	$ (507)	$ 1	$ (2,856)	$ (2)	$ 0	$ 0	$ 23
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	482			182		147		135				18
Net proceeds from equity offerings	973			673		300
Contributions from general partner	20							20
Other contributions from Parent	13							13
Distributions to noncontrolling interests	(16)											(16)
Distributions to unitholders and general partner	(423)			(169)		(139)		(115)
Acquisitions	(738)							(738)
Ending balance at Dec. 31, 2018	(257)	$ (9)	0	3,459	$ (4)	(198)	$ (5)	(3,543)		0	0	25
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	546			204		177		147				18
Other contributions from Parent	19							25			(6)
Distributions to noncontrolling interests	(17)											(17)
Other comprehensive income (loss)	(2)										(2)
Distributions to unitholders and general partner	(519)			(209)		(177)		(133)
Acquisitions	(510)							(510)
Ending balance at Dec. 31, 2019	(749)		0	3,450		(203)		(4,014)		0	(8)	26
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	556		36	160		292		55				13
Other contributions from Parent	2					2		0
Distributions to noncontrolling interests	(16)											(16)
Other comprehensive income (loss)	(1)										(1)
Distributions to unitholders and general partner	(670)		(24)	(228)		(308)		(110)
Principal repayments on financing receivables	3									3
Acquisitions	417		(1,071)			(2,280)		4,069		(301)
Ending balance at Dec. 31, 2020	$ (458)		$ (1,059)	$ 3,382		$ (2,497)		$ 0		$ (298)	$ (9)	$ 23

Description of the Business and

Description of the Business and Basis of Presentation	12 Months Ended
Description of the Business and Basis of Presentation	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of the Business and Basis of Presentation	Description of the Business and Basis of Presentation Shell Midstream Partners, L.P. (“we,” “us,” “our,” “SHLX” or “the Partnership”) is a Delaware limited partnership formed by Royal Dutch Shell plc on March 19, 2014 to own and operate pipeline and other midstream assets, including certain assets received from Shell Pipeline Company LP (“SPLC”) and its affiliates. We conduct our operations either through our wholly owned subsidiary Shell Midstream Operating LLC (“Operating Company”) or through direct ownership. Our general partner is Shell Midstream Partners GP LLC (“general partner”). References to “RDS”, “Shell” or “Parent” refer collectively to Royal Dutch Shell plc and its controlled affiliates, other than us, our subsidiaries and our general partner. Until April 1, 2020, our general partner owned an approximate 2% general partner economic interest in the Partnership, including the incentive distribution rights (“IDRs”). On April 1, 2020, we closed the transactions contemplated by the Partnership Interests Restructuring Agreement with our general partner dated February 27, 2020 (the “Partnership Interests Restructuring Agreement”), pursuant to which the IDRs were eliminated and the 2% general partner economic interest was converted into a non-economic general partner interest in the Partnership. As of December 31, 2020, our general partner holds a non-economic general partner interest in the Partnership, and affiliates of SPLC own a 68.5% limited partner interest (269,457,304 common units) and 50,782,904 Series A perpetual convertible preferred units (the “Series A Preferred Units”) in the Partnership. These common units and preferred units, on an as-converted basis, represent a 72% interest in the Partnership. See Note 3 — Acquisitions and Other Transactions and Note 11 — (Deficit) Equity for additional details. Description of the Business We own, operate, develop and acquire pipelines and other midstream and logistics assets. As of December 31, 2020, our assets include interests in entities that own (a) crude oil and refined products pipelines and terminals that serve as key infrastructure to transport onshore and offshore crude oil production to Gulf Coast and Midwest refining markets and deliver refined products from those markets to major demand centers and (b) storage tanks and financing receivables that are secured by pipelines, storage tanks, docks, truck and rail racks and other infrastructure used to stage and transport intermediate and finished products. The Partnership’s assets also include interests in entities that own natural gas and refinery gas pipelines that transport offshore natural gas to market hubs and deliver refinery gas from refineries and plants to chemical sites along the Gulf Coast. We generate revenue from the transportation, terminaling and storage of crude oil, refined products and intermediate and finished products through our pipelines, storage tanks, docks, truck and rail racks, generate income from our equity and other investments and generate interest income from financing receivables on certain logistic assets. Our operations consist of one reportable segment. The following table reflects our ownership interests as of December 31, 2020: SHLX Ownership Pecten Midstream LLC (“Pecten”) 100.0 % Sand Dollar Pipeline LLC (“Sand Dollar”) 100.0 % Triton West LLC (“Triton”) 100.0 % Zydeco Pipeline Company LLC (“Zydeco”) (1) 92.5 % Mattox Pipeline Company LLC (“Mattox”) 79.0 % Amberjack Pipeline Company LLC (“Amberjack”) – Series A/Series B 75.0% / 50.0% Mars Oil Pipeline Company LLC (“Mars”) 71.5 % Odyssey Pipeline L.L.C. (“Odyssey”) 71.0 % Bengal Pipeline Company LLC (“Bengal”) 50.0 % Crestwood Permian Basin LLC (“Permian Basin”) 50.0 % LOCAP LLC (“LOCAP”) 41.48 % Explorer Pipeline Company (“Explorer”) 38.59 % Poseidon Oil Pipeline Company, L.L.C. (“Poseidon”) 36.0 % Colonial Enterprises, Inc. (“Colonial”) 16.125 % Proteus Oil Pipeline Company, LLC (“Proteus”) 10.0 % Endymion Oil Pipeline Company, LLC (“Endymion”) 10.0 % Cleopatra Gas Gathering Company, LLC (“Cleopatra”) 1.0 % (1) SPLC owns the remaining 7.5% ownership interest in Zydeco. Basis of Presentation Our consolidated financial statements include all subsidiaries required to be consolidated under generally accepted accounting principles in the United States (“GAAP”). Our reporting currency is U.S. dollars, and all references to dollars are U.S. dollars. The accompanying consolidated financial statements and related notes have been prepared under the rules and regulations of the Securities and Exchange Commission (the “SEC”). These rules and regulations conform to the accounting principles contained in the Financial Accounting Standards Board’s (“FASB”) Accounting Standards Codification, the single source of GAAP. Our consolidated subsidiaries include Pecten, Sand Dollar, Triton, Zydeco, Odyssey and the Operating Company. Asset acquisitions of additional interests in previously consolidated subsidiaries and interests in equity method and other investments are included in the financial statements prospectively from the effective date of each acquisition. In cases where these types of acquisitions are considered acquisitions of businesses under common control, the financial statements are retrospectively adjusted. Expense Allocations. Our consolidated statements of income also include expense allocations for certain functions performed by SPLC and Shell on our behalf. Such costs are included in either general and administrative expenses or operations and maintenance expenses in the accompanying consolidated statements of income, depending on the nature of the employee’s role in our operations. The expense allocations have been determined on a basis that we, SPLC and Shell consider to be a reasonable reflection of the utilization of the services provided or the benefit received during the periods presented. See Note 4 — Related Party Transactions for details of operating agreements impacting expense allocations, as well as details of related party transactions.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Principles of Consolidation Our consolidated financial statements include all subsidiaries where we have control. The assets and liabilities in the accompanying consolidated financial statements have been reflected on a historical basis. All significant intercompany accounts and transactions are eliminated upon consolidation. See Note 1 — Description of the Business and Basis of Presentation for additional details. Regulation Certain businesses are subject to regulation by various authorities including, but not limited to, FERC. Regulatory bodies exercise statutory authority over matters such as construction, rates and ratemaking and agreements with customers. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported of assets, liabilities, revenues and expenses in the accompanying consolidated financial statements and notes. Actual results could differ from those estimates. Common Control Transactions Assets and businesses acquired from our Parent and its subsidiaries are accounted for as common control transactions whereby the net assets acquired are combined with ours at our Parent’s historical carrying value. If any recognized consideration transferred in such a transaction exceeds the carrying value of the net assets acquired, the excess is treated as a capital distribution to our general partner, similar to a dividend. If the carrying value of the net assets acquired exceeds any recognized consideration transferred including, if applicable, the fair value of any limited partner units issued, then our Parent would record an impairment, and our net assets acquired would be recorded at fair value. Cash consideration up to the carrying value of net assets acquired is presented as an investing activity in our consolidated statement of cash flows. Cash consideration in excess of the carrying value of net assets acquired is presented as a financing activity in our consolidated statement of cash flows. Assets and businesses sold to our Parent are also common control transactions accounted for using historical carrying value with any resulting gain treated as a contribution from Parent. Revenue Recognition Our revenues are primarily generated from the transportation, terminaling and storage of crude oil, refined gas and refined petroleum products through our pipelines, terminals, storage tanks, docks, truck and rail racks. We recognize revenue when we transfer promised goods or services to customers in an amount that reflects the consideration to which we expect to be entitled in exchange for those goods or services. We recognize revenue through the application of a five-step model, which includes: identification of the contract; identification of the performance obligations; determination of the transaction price; allocation of the transaction price to the performance obligations; and recognition of revenue as the entity satisfies the performance obligations. See Note 12 — Revenue Recognition for information and disclosures related to revenue from contracts with customers. Leases, Sale Leaseback When entering into sale-leaseback transactions as a buyer-lessor, the requirements in Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers, and all related accounting standards updates to such Topic (collectively, “the revenue standard”) are applied in determining whether the transfer of an asset shall be accounted for as a sale of the asset by assessing whether it satisfies a performance obligation under the contract by transferring control of an asset. If the seller-lessee transfers control of an asset to us, we account for the transfer of the asset as a purchase and recognize the transferred asset. The subsequent leaseback of the asset is accounted for in accordance with ASC Topic 842, Leases (the “lease standard”), in the same manner as any other lease. If the seller-lessee does not transfer the control of an asset to us, the failed sale-leaseback transaction is accounted for as a financing arrangement. Transactions in which control of an asset is not transferred are accounted for as financing receivables in accordance with ASC Topic 310, Receivables. Since the seller-lessee did not transfer the control of assets to us in the April 2020 Transaction (defined in Note 3 — Acquisitions and Other Transactions below), we did not recognize the transferred assets, and instead they were accounted for as financing receivables. Receivables issued in exchange for the Partnership’s capital stock are presented as a component of the partners’ (deficit) equity. Since the Partnership issued common units and preferred units as consideration in exchange for the financing receivables in the April 2020 Transaction, we recorded the financing receivables as contra-equity. Refer to Note 3 — Acquisitions and Other Transactions and Note 11 – (Deficit) Equity for additional details. We recognize interest income on the financing receivables on the basis of the imputed interest rate determined in accordance with ASC Topic 835, Interest. Cash and Cash Equivalents Our cash and cash equivalents includes cash and short-term highly liquid overnight deposits. Accounts Receivable and Allowance for Doubtful Accounts Accounts receivable represent valid claims against customers for products sold or services rendered, net of allowances for doubtful accounts. We assess the creditworthiness of our counterparties on an ongoing basis and require security, including prepayments and other forms of collateral, when appropriate. We establish provisions for losses on third-party accounts receivable due from shippers and operators based on current expected credit losses. As of December 31, 2020 and 2019, we did not have a material amount of allowance for doubtful accounts. Equity Method Investments We account for investments where we have the ability to exercise significant influence, but not control, under the equity method of accounting. Income from equity method investments represents our proportionate share of net income generated by the equity method investees. Differences in the basis of the investments and the underlying net asset value of the investees, if any, are amortized into net income over the remaining useful lives of the underlying assets. Equity method investments are assessed for impairment whenever changes in the facts and circumstances indicate a loss in value has occurred, if the loss is deemed to be other-than-temporary. When the loss is deemed to be other-than-temporary, the carrying value of the equity method investment is written down to fair value. Property, Plant and Equipment Our property, plant and equipment is recorded at its historical cost of construction or, upon acquisition, at either the fair value of the assets acquired or the historical carrying value to the entity that placed the asset in service. Expenditures for major renewals and betterments are capitalized while those minor replacement, maintenance and repairs that do not improve or extend asset life are expensed when incurred. For constructed assets, we capitalize all construction-related direct labor and material costs, as well as indirect construction costs. We capitalize interest on certain projects. For 2020, 2019 and 2018, the total amount of interest capitalized was immaterial. We use the straight-line method to depreciate property, plant and equipment based on the estimated useful life of the asset. We report gains or losses on dispositions of fixed assets as Loss (gain) from revision of asset retirement obligations (“AROs”) and disposition of fixed assets in the accompanying consolidated statements of income. Impairment of Long-lived Assets We evaluate long-lived assets of identifiable business activities for impairment when events or changes in circumstances indicate, in our management’s judgment, that the carrying value of such assets may not be recoverable. These events include a significant decrease in the market value of the asset, changes in the manner in which we intend to use a long-lived asset, decisions to sell an asset and adverse changes in the legal or business environment such as adverse actions by regulators. If an event occurs, which is a determination that involves judgment, we perform an impairment assessment by comparing estimated undiscounted future cash flows associated with the asset to the asset’s net book value. If the net book value exceeds our estimate of undiscounted future cash flows, an impairment is calculated as the amount the net book value exceeds the estimated fair value associated with the asset. We determined that there were no asset impairments in 2020, 2019 or 2018. Income Taxes We are not a taxable entity for U.S. federal income tax purposes or for the majority of states that impose an income tax. Taxes on our net income are generally borne by our partners through the allocation of taxable income. Our income tax expense results from partnership activity in the state of Texas, as conducted by Zydeco, Sand Dollar and Triton. Income tax expense for 2020, 2019 and 2018 was immaterial. Other Investments We account for equity investments in entities where we do not have control or significant influence at fair value with changes in fair value recognized in net income when the fair value is readily determinable. For investments without readily determinable fair values, we carry such investments at cost less impairments, if any. These investments are remeasured either upon the occurrence of an observable price change or upon identification of impairment. These investments are reported as Other investments in our consolidated balance sheets and dividends received are reported in Dividend income from other investments in our consolidated income statements. Our equity investments which are accounted for at cost as they do not have readily determinable fair values, consist of: December 31, 2020 December 31, 2019 Ownership Amount Ownership Amount Cleopatra 1.0 % $ 2 1.0 % $ 2 During the years ended December 31, 2020 and 2019, we did not identify the occurrence of an observable price change or an identification of impairment for these equity investments. Asset Retirement Obligations AROs represent contractual or regulatory obligations associated with the retirement of long-lived assets that result from the acquisition, construction, development and/or normal use of the asset. Our AROs were zero as of both December 31, 2020 and 2019. Our assets include pipelines and terminals that have contractual or regulatory obligations that will need to be settled at retirement. The settlement date of these obligations will depend mostly on the various supply sources that connect to our systems and the ongoing demand for usage in the markets we serve. We expect these supply sources and market demands to continue for the foreseeable future. As the settlement dates of obligations are indeterminate, there is not sufficient information to make a reasonable estimate of the ARO of our remaining assets as of December 31, 2020 and 2019. We re-evaluate our AROs in each reporting period, and future developments could impact the amounts we record. Pensions and Other Postretirement Benefits We do not have our own employees. Employees that work on our pipelines or terminals are employees of SPLC, and we share employees with other SPLC-controlled and non-controlled entities. For presentation of these accompanying consolidated financial statements, our portion of payroll costs and employee benefit plan costs have been allocated as a charge to us by SPLC and Shell Oil Company. Shell Oil Company sponsors various employee pension and postretirement health and life insurance plans. For purposes of these accompanying consolidated financial statements, we are considered to be participating in the benefit plans of Shell Oil Company. We participate in the following defined benefits plans: Shell Oil Pension Plan, Shell Oil Retiree Health Care Plan and Pennzoil-Quaker State Retiree Medical & Life Insurance. As a participant in these benefit plans, we recognize as expense in each period an allocation from Shell Oil Company, and we do not recognize any employee benefit plan assets or liabilities. See Note 4 — Related Party Transactions for total pension and benefit expenses under these plans. Legal We are subject to litigation and regulatory proceedings as the result of our business operations and transactions. We use both internal and external counsel in evaluating our potential exposure to adverse outcomes from orders, judgments or settlements. In general, we expense legal costs as incurred. When we identify specific litigation that is expected to continue for a significant period of time, is probable to occur and may require substantial expenditures, we identify a range of possible costs expected to be required to litigate the matter to a conclusion or reach an acceptable settlement, and we accrue for the most probable outcome. To the extent that actual outcomes differ from our estimates, or additional facts and circumstances cause us to revise our estimates, our earnings will be affected. Environmental Matters We are subject to federal, state, and local environmental laws and regulations. Environmental expenditures are expensed or capitalized depending on their economic benefit. We expense costs such as permits, compliance with existing environmental regulations, remedial investigations, soil sampling, testing and monitoring costs to meet applicable environmental laws and regulations where prudently incurred or determined to be reasonably possible in the ordinary course of business. We are permitted to recover such expenditures through tariff rates charged to customers. We also expense costs that relate to an existing condition caused by past environmental incidents, which do not contribute to current or future revenue generation. We record environmental liabilities when environmental assessments and/or remedial efforts are probable and we can reasonably estimate the costs. Generally, our recording of these accruals coincides with our completion of a feasibility study or our commitment to a formal plan of action. We recognize receivables for anticipated associated insurance recoveries when such recoveries are deemed to be probable. For 2020, 2019 and 2018, the environmental cleanup costs incurred were immaterial. At both December 31, 2020 and 2019, the accruals for environmental clean-up costs pursuant to a Consent Decree issued in 1998 by the State of Washington Department of Ecology with respect to our products terminal located in Seattle, Washington were immaterial. The costs relate to ongoing groundwater compliance monitoring and other remedial activities. Refer to Note 4 — Related Party Transactions under the Omnibus Agreement (defined below) for additional details. We routinely conduct reviews of potential environmental issues and claims that could impact our assets or operations. These reviews assist us in identifying environmental issues and estimating the costs and timing of remediation efforts. In making environmental liability estimations, we consider the material effect of environmental compliance, pending legal actions against us and potential third-party liability claims. Often, as the remediation evaluation and effort progresses, additional information is obtained, requiring revisions to estimated costs. These revisions are reflected in our income statement in the period in which they are probable and reasonably estimable. Other Contingencies We recognize liabilities for other contingencies when we have an exposure that indicates it is both probable that a liability has been incurred and the amount of loss can be reasonably estimated. Where the most likely outcome of a contingency can be reasonably estimated, we accrue a liability for that amount. Where the most likely outcome cannot be estimated, a range of potential losses is established and if no one amount in that range is more likely than any other, the lower end of the range is accrued. Fair Value Estimates We measure assets and liabilities requiring fair value presentation or disclosure using an exit price ( i.e. , the price that would be received to sell an asset or paid to transfer a liability) and disclose such amounts according to the quality of valuation inputs under the following hierarchy: Level 1: Quoted prices in an active market for identical assets or liabilities. Level 2: Inputs other than quoted prices that are directly or indirectly observable. Level 3: Unobservable inputs that are significant to the fair value of assets or liabilities. We classify the fair value of an asset or liability based on the lowest level of input significant to its measurement. A fair value initially reported as Level 3 will be subsequently reported as Level 2 if the unobservable inputs become inconsequential to its measurement or corroborating market data becomes available. Asset and liability fair values initially reported as Level 2 will be subsequently reported as Level 3 if corroborating market data becomes unavailable. The carrying amounts of our accounts receivable, accounts payable and accrued liabilities approximate their fair values due to their short-term nature. Net income per limited partner unit Prior to the April 2020 Transaction, we used the two-class method when calculating the net income per unit applicable to limited partners as there were different participating securities included in the calculation – including common units, general partner units and IDRs. After the April 2020 Transaction, the IDRs were eliminated, the 2% general partner economic interest was converted into a non-economic general partner interest in the Partnership and the newly issued Series A Preferred Units did not qualify as participating securities. Since the transaction occurred during 2020, the two-class method was still applied to the year-to-date calculation but was not applied to calculations for any quarterly periods beginning with the second quarter of 2020. See Note 11 — (Deficit) Equity for additional information. Reclassifications Certain reclassifications have been made to prior period amounts in our consolidated statements of income and consolidated balance sheets to conform to the current period presentation. The net effect of these reclassifications was not material to our consolidated financial statements. Recent Accounting Pronouncements Standards Adopted as of January 1, 2020 In June 2016, the FASB issued Accounting Standards Update (“ASU”) 2016-13 to Topic 326, Financial Instruments — Credit Losses: Measurement of Credit Losses on Financial Instruments, which replaces the current incurred loss impairment method with a method that reflects expected credit losses on financial instruments. The measurement of current expected credit losses under the new guidance is applicable to financial assets measured at amortized cost, including third-party trade receivables. We adopted the new standard effective January 1, 2020, using the modified retrospective method for all financial assets measured. No cumulative-effect adjustment to retained earnings was required upon adoption. The adoption of ASU 2016-13 did not have a material impact on our consolidated financial statements. Standards Not Adopted as of December 31, 2020 In August 2020, the FASB issued ASU 2020-06, Debt — Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging — Contracts in Entity’s Own Equity. The update will simplify the accounting for convertible instruments by reducing the number of accounting models for convertible debt instruments and convertible preferred stock. Limiting the accounting models may result in fewer embedded conversion features being separately recognized from the host contract as compared with current GAAP. This update also amends the guidance for the derivatives scope exception for contracts in an entity’s own equity to reduce form-over-substance-based accounting conclusions. The update is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2021 for SEC filers, excluding smaller reporting companies. Early adoption is permitted, but not earlier than January 1, 2021, including interim periods within that year. Management is currently evaluating the appropriate date of adoption and the effect of the adoption of this update on our consolidated financial statements. The effect will largely depend on the composition and terms of our financial instruments at the time of adoption.

Acquisitions and Divestiture

Acquisitions and Divestiture	12 Months Ended
Acquisitions and Divestiture	Dec. 31, 2020
Business Combinations [Abstract]
Acquisitions and Other Transactions	Acquisitions and Other Transactions April 2020 Transaction On April 1, 2020, we closed the following transactions (together referred to as the “April 2020 Transaction”): • Pursuant to a Purchase and Sale Agreement dated as of February 27, 2020 (the “Purchase and Sale Agreement”) between the Partnership and Triton, SPLC, Shell GOM Pipeline Company LLC (“SGOM”), Shell Chemical LP (“Shell Chemical”) and Equilon Enterprises LLC d/b/a Shell Oil Products US (“SOPUS”), we acquired 79% of the issued and outstanding membership interests in Mattox from SGOM (the “Mattox Transaction”), and SOPUS and Shell Chemical transferred to Triton, as a designee of the Partnership, certain logistics assets at the Shell Norco Manufacturing Complex located in Norco, Louisiana (such assets, the “Norco Assets,” and such transaction, the “Norco Transaction”); and • Simultaneously with the closing of the transactions contemplated by the Purchase and Sale Agreement, we also closed the transactions contemplated by the Partnership Interests Restructuring Agreement, pursuant to which we eliminated all of the IDRs and converted the 2% economic general partner interest in the Partnership into a non-economic general partner interest (the “GP/IDR Restructuring”). Our general partner or its assignee has also agreed to waive a portion of the distributions that would otherwise be payable on the common units issued to SPLC as part of the April 2020 Transaction, in an amount of $20 million per quarter for each of four consecutive fiscal quarters, beginning with the distribution made with respect to the second quarter of 2020. As consideration for the April 2020 Transaction, the Partnership issued 50,782,904 Series A Preferred Units to SPLC at a price of $23.63 per unit, plus 160,000,000 newly issued common units. Certain third-party fair value appraisals were performed to determine the fair value of the total consideration as well as the fair values of each of the Mattox Transaction, the Norco Transaction and the GP/IDR Restructuring, as of April 1, 2020. Because the components of the April 2020 Transaction were entered in contemplation of each other and were transactions among entities under common control, the fair values of the April 2020 Transaction were used solely for the purpose of allocating a portion of the consideration on a relative fair value basis to the Norco Transaction. In connection with the April 2020 Transaction, the Partnership recorded the following balances as of April 1, 2020: Equity method investment (1) $ 174 Financing receivables – related parties (2) 302 Contract assets - related parties (3) 244 April 2020 Transaction $ 720 (1) Equity method investment was recorded at SGOM’s historical carrying value of the 79% interest in Mattox. See more discussion in the section entitled “Mattox Transaction” below. (2) Financing receivables under the failed sale leaseback were recorded at the fair value of the property, plant and equipment of the Norco Assets transferred by SOPUS and Shell Chemical and recognized as a component of the Partners’ deficit. See more discussion in the section entitled “Norco Transaction” below. (3) Contract assets were recorded based on the difference between the consideration allocated to the Norco Transaction and the financing receivables. See more discussion in the section entitled “Norco Transaction” below. Mattox Transaction We acquired 79% of the issued and outstanding membership interests in Mattox from SGOM. The acquisition was accounted for as a transaction among entities under common control on a prospective basis as an asset acquisition. As a result of the Mattox Transaction, we have significant influence, but not control, over Mattox and account for this investment as an equity method investment. As such, we recorded the acquired equity interests in Mattox at SGOM’s historical carrying value of $174 million, which is included in Equity method investments in our consolidated balance sheet as of December 31, 2020. See Note 5 —Equity Method Investments for additional details. Norco Transaction SOPUS and Shell Chemical transferred certain logistics assets at the Shell Norco Manufacturing Complex located in Norco, Louisiana, which are comprised of crude, chemicals, intermediate and finished product pipelines, storage tanks, docks, truck and rail racks and supporting infrastructure, to Triton, as a designee of the Partnership. The Partnership simultaneously leased the Norco Assets back to SOPUS and Shell Chemical pursuant to the terminaling services agreements entered into among Triton, SOPUS and Shell Chemical related to the Norco Assets. The Partnership receives an annual net payment of $140 million, which is the total annual payment pursuant to the terminaling services agreements of $151 million, less $11 million, which primarily represents the allocated utility costs from SOPUS related to the Norco Assets. Both payments are subject to annual Consumer Price Index adjustments. The transfer of the Norco Assets combined with the terminaling services agreements were accounted for as a failed sale leaseback under the lease standard , as control of the assets did not transfer to the Partnership. As a result, the transaction was treated as a financing arrangement. As the Norco Transaction was entered into simultaneously and in contemplation of the Mattox Transaction and the GP/IDR Restructuring components, we allocated $546 million of the fair value of the consideration of the April 2020 Transaction to the Norco Transaction based on its relative stand-alone fair value to the other components of the April 2020 Transaction. From this amount, we recorded financing receivables of $302 million, based on the fair value of the Norco Assets’ property, plant and equipment transferred from SOPUS and Shell Chemical, using a combination of market and cost valuation approaches. The financing receivables were recorded as the fair value of property, plant and equipment because the annual payments received by the Partnership are directly related to the lease of the property, plant and equipment of the Norco Assets. Since the financing receivables from SOPUS and Shell Chemical arose from transactions involving the issuance of the Partnership’s common and preferred units, the financing receivables are presented as a component of (deficit) equity and not as assets on the balance sheet. As of April 1, 2020, we also recorded contract assets in the amount of $244 million, which represent the difference between the allocated fair value of the Norco Transaction of $546 million and the recognized financing receivables of $302 million. The contract assets represent the excess of the fair value embedded within the terminaling services agreements transferred by the Partnership to SOPUS and Shell Chemical as part of entering into the terminaling services agreements. See Note 12 — Revenue Recognition for additional details. The amount of contract assets recognized was dependent on the allocated fair value of the consideration to the Norco Transaction, which was determined using the fair values of the consideration transferred and the fair values of each of the three components of the April 2020 Transaction. The newly issued common units were valued using a market approach based on the market opening price of the Partnership’s common units as of April 1, 2020, less a discount for the waiver described above and a marketability discount. The Series A Preferred Units were valued using an income approach based on a trinomial lattice model. Further, the fair values of the three components of the April 2020 Transaction were determined using an income approach of discounted cash flows at an average discount rate for each of the Mattox Transaction, the Norco Transaction and the GP/IDR Restructuring components of 14%, 11% and 20%, respectively. GP/IDR Restructuring On April 1, 2020, we also closed the transactions contemplated by the Partnership Interests Restructuring Agreement, which included the elimination of all the IDRs and the cancellation of all of the general partner units, both of which were held by our general partner, and amended and restated our partnership agreement to reflect these and other changes (as so amended, the “Second Amended and Restated Partnership Agreement”). The 2% general partner economic interest was converted into a non-economic general partner interest. Because the components of the April 2020 Transaction were among entities under common control, our general partner’s negative equity balance of $4 billion at April 1, 2020 was transferred to SPLC’s equity accounts, allocated between its holdings of common units and preferred units, based on the relative fair value of the consideration related to the issuance of common units and preferred units in the April 2020 Transaction. Upon the closing of the April 2020 Transaction, the Partnership had 393,289,537 common units outstanding, of which SPLC’s wholly owned subsidiary, Shell Midstream LP Holdings LLC (“LP Holdings”), owned 269,457,304 common units in the Partnership, representing an aggregate 68.5% limited partner interest. The Partnership also had 50,782,904 of Series A Preferred Units outstanding, which are entitled to receive a quarterly distribution of $0.2363 per unit and all of which are owned by LP Holdings. See Note 11 — (Deficit) Equity for additional details. 2019 Acquisition On June 6, 2019, we acquired SPLC’s remaining 25.97% ownership interest in Explorer and 10.125% ownership interest in Colonial for consideration valued at $800 million (the “June 2019 Acquisition”). The June 2019 Acquisition increased our ownership interest in Explorer to 38.59% and in Colonial to 16.125%. The June 2019 Acquisition closed pursuant to a Contribution Agreement dated May 10, 2019 (the “May 2019 Contribution Agreement”) between us and SPLC, and is accounted for as a transaction between entities under common control on a prospective basis as an asset acquisition. As such, we recorded the acquired equity interests at SPLC’s historical carrying value of $90 million, which is included in Equity method investments in our consolidated balance sheet. In addition, as a transfer between entities under common control, we recorded Accumulated other comprehensive loss of $6 million related to historical remeasurements of pension and other postretirement benefits provided by Explorer and Colonial to their employees. We recognized $510 million of cash consideration in excess of the historical carrying value of equity interests acquired as a capital distribution to our general partner in accordance with our policy for common control transactions. We funded the June 2019 Acquisition with $600 million in cash consideration from borrowings under our Ten Year Fixed Facility (as defined in Note 8 — Related Party Debt ) with Shell Treasury Center (West) Inc. (“STCW”) and non-cash equity consideration valued at $200 million. Pursuant to the May 2019 Contribution Agreement, t he number of common units representing the equity consideration was determined by dividing the contribution amount (25% of total consideration of $800 million) by the price per unit of $20.68, which represents the volume weighted average sales prices of the common units calculated for the five trading day period ended on April 30, 2019, less the general partner units issued to our general partner in order to maintain its 2% general partner interest in us. The equity issued consisted of 9,477,756 common units issued to LP Holdings, an indirect subsidiary of Shell, and 193,424 general partner units issued to our general partner in order to maintain its 2% general partner interest in us. These common and general partner units issued were assigned no book value because the cash consideration exceeded the historical carrying value of equity interests acquired. Accordingly, the units issued had no impact on partner capital accounts, other than changing ownership percentages. As a result of the June 2019 Acquisition, we now have significant influence over both Explorer and Colonial and account for these investments as equity method investments (see Note 5 — Equity Method Investments for further details). 2018 Acquisition On May 11, 2018, we acquired SPLC’s ownership interests in Amberjack, which is comprised of 75% of the issued and outstanding Series A membership interests of Amberjack and 50% of the issued and outstanding Series B membership interests of Amberjack, for $1,220 million (the “May 2018 Acquisition”). The May 2018 Acquisition closed pursuant to a Purchase and Sale Agreement dated May 9, 2018 between us and SPLC, and is accounted for as a transaction between entities under common control on a prospective basis as an asset acquisition. We acquired historical carrying value of net assets under common control of $482 million, which is included in Equity method investments in our consolidated balance sheet. We recognized $738 million of consideration in excess of the historical carrying value of net assets acquired as a capital distribution to our general partner in accordance with our policy for common control transactions. We funded the May 2018 Acquisition with $494 million in borrowings under our Five Note 8 — Related Party Debt ) and $726 million in borrowings under our Five Note 8 — Related Party Debt

Related Party Transactions

Related Party Transactions	12 Months Ended
Related Party Transactions	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Related party transactions include transactions with SPLC and Shell, including those entities in which Shell has an ownership interest but does not have control. Acquisition Agreements Refer to Note 3 — Acquisitions and Other Transactions for a description of other applicable agreements. Partnership Interests Restructuring Agreement On February 27, 2020, we and our general partner entered into the Partnership Interests Restructuring Agreement, pursuant to which the IDRs were eliminated and the 2% general partner economic interest was converted into a non-economic general partner interest in the Partnership. Purchase and Sale Agreement On February 27, 2020, we entered into the Purchase and Sale Agreement by and among Triton, SPLC, SGOM, Shell Chemical and SOPUS, pursuant to which we acquired 79% of the issued and outstanding membership interests in Mattox from SGOM and SOPUS and Shell Chemical transferred to Triton, as a designee of the Partnership, the Norco Assets. Omnibus Agreement On November 3, 2014, we entered into an Omnibus Agreement with SPLC and our general partner concerning our payment of an annual general and administrative services fee to SPLC as well as our reimbursement of certain costs incurred by SPLC on our behalf. On February 19, 2019, we, our general partner, SPLC, the Operating Company and Shell Oil Company terminated the Omnibus Agreement effective as of February 1, 2019, and we, our general partner, SPLC and the Operating Company entered into a new Omnibus Agreement effective February 1, 2019 (the “2019 Omnibus Agreement”). On February 18, 2020, pursuant to the 2019 Omnibus Agreement, the Board of Directors of our general partner (the “Board”) approved a 3% inflationary increase to the annual general and administrative fee for 2020. The 2019 Omnibus Agreement addresses, among other things, the following matters: • our payment of an annual general and administrative fee of approximately $11 million for the provision of certain services by SPLC; • our obligation to reimburse SPLC for certain direct or allocated costs and expenses incurred by SPLC on our behalf; and • our obligation to reimburse SPLC for all expenses incurred by SPLC as a result of us becoming and continuing as a publicly-traded entity; we will reimburse our general partner for these expenses to the extent the fees relating to such services are not included in the general and administrative fee. Under the 2019 Omnibus Agreement, SPLC agreed to indemnify us against tax liabilities relating to assets acquired at our initial public offering (such offering, the “IPO,” and such assets “initial assets”) that are identified prior to the date that is 60 days after the expiration of the statute of limitations applicable to such liabilities. This obligation has no threshold or cap. We in turn agreed to indemnify SPLC against events and conditions associated with the ownership or operation of our initial assets (other than any liabilities against which SPLC is specifically required to indemnify us as described above). During 2020 and 2019, neither we nor SPLC made any claims for indemnification under the 2019 Omnibus Agreement. Trade Marks License Agreement We, our general partner and SPLC entered into a Trade Marks License Agreement with Shell Trademark Management Inc. effective as of February 1, 2019. The Trade Marks License Agreement grants us the use of certain Shell trademarks and trade names and expires on January 1, 2024 unless earlier terminated by either party upon 360 days’ notice. Tax Sharing Agreement We have entered into a tax sharing agreement with Shell. Pursuant to this agreement, we have agreed to reimburse Shell for state and local income and franchise taxes attributable to any activity of our operating subsidiaries and reported on Shell’s state or local income or franchise tax returns filed on a combined or unitary basis. Reimbursements under this agreement equal the amount of tax our applicable operating subsidiaries would be required to pay with respect to such activity, if such subsidiaries were to file a combined or unitary tax return separate from Shell. Shell will compute and invoice us for the tax reimbursement amount within 15 days of Shell filing its combined or unitary tax return on which such activity is included. We may be required to make prepayments toward the tax reimbursement amount to the extent that Shell is required to make estimated tax payments during the relevant tax year. The tax sharing agreement currently in place is effective for all taxable periods ending on or after December 31, 2017. The current agreement replaced a similar tax sharing agreement between Zydeco and Shell, which was effective for all tax periods ending before December 31, 2017. Reimbursements settled in the years ended December 31, 2020, 2019 and 2018 were not material to our consolidated statements of income. Other Agreements We have entered into several customary agreements with SPLC and Shell. These agreements include pipeline operating agreements, reimbursement agreements and services agreements. Operating Agreements On December 1, 2019, we entered into an Operating and Administrative Management Agreement with SPLC (the “2019 Operating Agreement”). Pursuant to the 2019 Operating Agreement, SPLC provides certain operations, maintenance and administrative services for the assets wholly owned by Pecten, Sand Dollar and Triton (collectively, the “Owners”). The Owners are required to reimburse SPLC for certain costs in connection with the services that SPLC provides pursuant to the 2019 Operating Agreement. SPLC and the Owners each provide standard indemnifications as operator and asset owners, respectively. Upon entering into the 2019 Operating Agreement, certain operating agreements previously entered into between SPLC and each of the Owners were terminated. In December 2017, we were assigned an operating agreement for Odyssey, whereby SPLC performs physical operations and maintenance services and provides general and administrative services for Odyssey. Odyssey is required to reimburse SPLC for costs and expenses incurred in connection with such services. Also pursuant to the agreement, SPLC and Odyssey agree to standard indemnifications as operator and asset owner, respectively. Beginning July 1, 2014, Zydeco entered into an operating and management agreement with SPLC under which SPLC provides general management and administrative services to us. Therefore, we do not receive allocated corporate expenses from SPLC or Shell under this agreement. We receive direct and allocated field and regional expenses including payroll expenses not covered under this agreement. Partnership Agreement Concurrently with the execution of the Partnership Interests Restructuring Agreement, on April 1, 2020, we executed the Second Amended and Restated Partnership Agreement, which amended and restated the Partnership’s First Amended and Restated Agreement of Limited Partnership dated November 3, 2014, (“First Amended and Restated Partnership Agreement”) as the same was previously amended, in its entirety. Under the Second Amended and Restated Partnership Agreement, the IDRs were eliminated, the economic general partnership interest was converted into a non-economic general partner interest, and our general partner or its assignee agreed to waive a portion of the distributions that would otherwise be payable on the common units issued to SPLC as part of the April 2020 Transaction, in an amount of $20 million per quarter for four consecutive fiscal quarters, beginning with the distribution made with respect to the second quarter of 2020. The transaction closed simultaneously with the closing of the transactions described in Note 3 — Acquisitions and Other Transactions—April 2020 Transaction. Prior to the execution of the Second Amended and Restated Partnership Agreement, on December 21, 2018, we executed Amendment No. 2 (the “Second Amendment”) to the First Amended and Restated Partnership Agreement. Under the Second Amendment, our general partner agreed to waive $50 million of distributions in 2019 by agreeing to reduce distributions to holders of the IDRs by: (1) $17 million for the three months ended March 31, 2019, (2) $17 million for the three months ended June 30, 2019 and (3) $16 million for the three months ended September 30, 2019. Noncontrolling Interests For Zydeco, noncontrolling interest consists of SPLC’s 7.5% retained ownership interest as of December 31, 2020, 2019 and 2018. For Odyssey, noncontrolling interest consists of GEL Offshore Pipeline LLC’s (“GEL”) 29.0% retained ownership interest as of December 31, 2020, 2019 and 2018. Other Related Party Balances Other related party balances consist of the following: December 31, 2020 2019 Accounts receivable $ 21 $ 29 Prepaid expenses 22 15 Other assets 2 2 Contract assets (1) 233 — Accounts payable (2) 16 10 Deferred revenue 19 — Accrued liabilities (3) 28 19 Debt payable (4) 2,692 2,692 Financing receivables (1) 298 — (1) Contract assets and Financing receivables were recognized in connection with the April 2020 Transaction. Refer to the section entitled “Sale Leaseback” below for additional details. Financing receivables were presented as a component of (deficit) equity. (2) Accounts payable reflects amounts owed to SPLC for reimbursement of third-party expenses incurred by SPLC for our benefit. (3) As of December 31, 2020, Accrued liabilities reflects $16 million accrued interest and $12 million other accrued liabilities, which are primarily related to the accrued operation and maintenance expenses on the Norco Assets. As of December 31, 2019, Accrued liabilities reflects $18 million accrued interest and $1 million other accrued liabilities. (4) Debt payable reflects borrowings outstanding net of unamortized debt issuance costs of $2 million as of both December 31, 2020 and December 31, 2019. Related Party Credit Facilities We have entered into five credit facilities with STCW: the Ten Seven Five Five Five Note 8 — Related Party Debt for definitions and additional information regarding these credit facilities. Related Party Revenues and Expenses We provide crude oil transportation, terminaling and storage services to related parties under long-term contracts. We entered into these contracts in the normal course of our business. Our revenue from related parties for 2020, 2019 and 2018 is disclosed in Note 12 — Revenue Recognition . The following table shows related party expenses, including certain personnel costs, incurred by Shell and SPLC on our behalf that are reflected in the accompanying consolidated statements of income for the indicated periods. Included in these amounts, and disclosed below, is our share of operating and general corporate expenses, as well as the fees paid to SPLC under certain agreements. 2020 2019 2018 Allocated operating expenses $ 45 $ 18 $ 15 Major maintenance costs (1) 6 — — Insurance expense (2) 20 18 15 Other (3) 43 23 24 Operations and maintenance – related parties $ 114 $ 59 $ 54 Allocated general corporate expenses $ 29 $ 28 $ 33 Management Agreement fee 9 9 9 Omnibus Agreement fee 11 11 9 Other — 1 1 General and administrative – related parties $ 49 $ 49 $ 52 (1) Major maintenance costs are expensed as incurred in connection with the maintenance services of the Norco Assets. Refer to section entitled “Sale Leaseback” below for additional details. (2) The majority of our insurance coverage is provided by a wholly owned subsidiary of Shell. The remaining coverage is provided by third-party insurers. (3) Other expenses primarily relate to salaries and wages, other payroll expenses and special maintenance. For a discussion of services performed by Shell on our behalf, see Note 1 — Description of the Business and Basis of Presentation – Basis of Presentation – Expense Allocations. Pension and Retirement Savings Plans Employees who directly or indirectly support our operations participate in the pension, postretirement health and life insurance and defined contribution benefit plans sponsored by Shell, which include other Shell subsidiaries. Our share of pension and postretirement health and life insurance costs for 2020, 2019 and 2018 was $5 million, $6 million and $6 million, respectively. Our share of defined contribution benefit plan costs for 2020, 2019 and 2018 was $2 million, $2 million and $3 million, respectively. Pension and defined contribution benefit plan expenses are included in either General and administrative – related parties or Operations and maintenance – related parties in the accompanying consolidated statements of income, depending on the nature of the employee’s role in our operations. Severance We have recorded voluntary and involuntary severance costs of $7 million and $3 million in 2020 and 2018, respectively. These costs for 2019 were not material. Severance expenses are included in either General and administrative – related parties or Operations and maintenance – related parties, depending on the nature of the employee’s role in our operations. Equity and Other Investments We have equity and other investments in various entities. In some cases we may be required to make capital contributions or other payments to these entities. See Note 5 — Equity Method Investments for additional details. Reimbursements from Our General Partner Historically, reimbursements received were primarily related to the directional drill project on the Zydeco pipeline system (the “directional drill project”). As the directional drill project was completed at the end of 2019, the amounts incurred by the project in 2020, and associated claims for reimbursement from our Parent, were not material. In 2019 and 2018, the amounts were $19 million and $12 million, respectively. These reimbursements are included in Other contributions from Parent in the accompanying consolidated statements of cash flows and consolidated statements of (deficit) equity. For each of these periods, this amount reflects our proportionate share of the directional drill project costs and expenses. Further, in the fourth quarter of 2019, we received approximately $9 million from SPLC with respect to a Mars storage revenue reimbursement provision contained in the Purchase and Sale Agreement entered into in 2016 that was recognized as an additional capital contribution. See Note 5 — Equity Method Investments for additional details. Sale Leaseback Pursuant to the terminaling services agreement entered into among Triton, SOPUS and Shell Chemical related to the Norco Assets acquired in the April 2020 Transaction (see Note 3 — Acquisitions and Other Transactions ), the Partnership receives an annual net payment of $140 million, which is the total annual payment pursuant to the terminaling service agreements of $151 million, less $11 million, which primarily represents the allocated utility costs from SOPUS related to the Norco Assets. Both annual payments are subject to annual Consumer Price Index adjustments. The transfer of the Norco Assets, combined with the terminaling services agreements, were accounted for as a failed sale leaseback under the lease standard. As a result, the transaction was treated as a financing arrangement in which the underlying assets were not recognized in property, plant and equipment of the Partnership as control of the Norco Assets did not transfer to the Partnership, and instead were recorded as financing receivables from SOPUS and Shell Chemical on April 1, 2020 in the amount of $302 million. We recognize interest income on the financing receivables recorded in the April 2020 Transaction on the basis of an imputed interest rate of 11.1% related to SOPUS and 7.4% related to Shell Chemical. The following table shows the interest income, reduction in the financing receivables, as well as the cash payments received for interest income and cash principal payments received on financing receivables for the year ended December 31, 2020: For the Year Ended December 31, 2020 Interest income $ 23 Reduction in the financing receivables 3 Cash payments received for interest income 20 Cash principal payments received on financing receivables 3 The transfer of the Norco Assets and the terminaling services agreements as a result of the April 2020 Transaction have operation and maintenance service components and major maintenance service components (together “service components”). Consistent with our operating lease arrangements, we allocate a portion of the arrangement’s transaction price to any service components within the scope of the revenue standard and defer the revenue, if necessary, until the point at which the performance obligation is met. We present the revenue earned from the service components under the revenue standard within Transportation, terminaling and storage services – related parties in the consolidated statements of income. Contract assets were also recorded in the amount of $244 million as of April 1, 2020. See Note 12 — Revenue Recognition

Equity Method Investments

Equity Method Investments	12 Months Ended
Equity Method Investments	Dec. 31, 2020
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	For each of the following investments, we have the ability to exercise significant influence over these investments based on certain governance provisions and our participation in the significant activities and decisions that impact the management and economic performance of the investments. Equity method investments comprise the following as of the dates indicated: December 31, 2020 2019 Ownership Amount Ownership Amount Mattox (1) 79% $ 163 — $ — Amberjack – Series A / Series B 75.0% / 50.0% 382 75.0% / 50.0% 426 Mars 71.5% 152 71.5% 161 Bengal 50.0% 88 50.0% 88 Permian Basin 50.0% 83 50.0% 91 LOCAP 41.48% 12 41.48% 9 Explorer (2) 38.59% 73 38.59% 88 Poseidon 36.0% — 36.0% — Colonial (2) 16.125% 29 16.125% 30 Proteus 10.0% 14 10.0% 15 Endymion 10.0% 17 10.0% 18 $ 1,013 $ 926 (1) Mattox was acquired as part of the April 2020 Transaction. This interest has been accounted for on a prospective basis. See below for additional information. (2) As part of the June 2019 Acquisition, these interests have been accounted for prospectively. See below for additional information. We acquired a 79% interest in Mattox from SGOM in the April 2020 Transaction. This investment qualifies for equity method accounting, as we exercise significant influence but do not control this investment. Upon acquisition, we recorded SGOM’s historical carrying value of the equity interests transferred as a transaction between entities under common control, totaling $174 million. We recognize equity earnings for Mattox prospectively from the date of acquisition, and record the distributions from Mattox as a reduction to the equity method investment balance. We acquired an additional 25.97% interest in Explorer and an additional 10.125% interest in Colonial in the June 2019 Acquisition. As a result, these investments now qualify for equity method accounting as we have the ability to exercise significant influence over these investments as of the acquisition date. Prior to the acquisition date, Explorer and Colonial were accounted for as Other investments without readily determinable fair values and were therefore carried at cost. Upon acquisition, we added our Parent’s historical carrying value of the equity interests transferred as a transaction between entities under common control, totaling $90 million, to the basis of our previously held interests of $60 million as this is the date these investments qualified for equity method accounting. Since the June 2019 Acquisition, we record distributions from these investments as reductions to the respective equity method investment balances for Explorer and Colonial as these amounts are no longer considered dividend income due to the change in the method of accounting. We recognize equity earnings for both Explorer and Colonial prospectively from the date of acquisition. For the years ended December 31, 2020, 2019 and 2018, distributions received from equity method investments were $541 million, $466 million and $301 million, respectively. Unamortized differences in the basis of the initial investments and our interest in the separate net assets within the financial statements of the investees are amortized into net income over the remaining useful lives of the underlying assets. As of December 31, 2020 and 2019, the unamortized basis differences included in our equity method investments are $84 million and $92 million, respectively. For the years ended 2020, 2019 and 2018, the net amortization expense was $8 million, $6 million and $4 million, respectively, which is included in Income from equity method investments. During the first quarter of 2018, the investment amount for Poseidon was reduced to zero due to distributions received that were in excess of our investment balance and we, therefore, suspended the equity method of accounting. As we have no commitments to provide further financial support to Poseidon, we have recorded excess distributions of $37 million, $33 million and $24 million in Other income for the years ended December 31, 2020, 2019 and 2018, respectively. Once our cumulative share of equity earnings becomes greater than the cumulative amount of distributions received, we will resume the equity method of accounting as long as the equity method investment balance remains greater than zero. Earnings from our equity method investments were as follows during the periods indicated: For the Year Ended December 31, 2020 2019 2018 Mattox (1) $ 45 $ — $ — Amberjack (2) 102 125 80 Mars 114 126 108 Bengal 18 24 21 Explorer (3) 44 41 — Colonial (3) 75 40 — Poseidon (4) — — 6 Other (5) 19 17 20 $ 417 $ 373 $ 235 (1) We acquired an interest in Mattox in the April 2020 Transaction. The acquisition of this interest has been accounted for prospectively. (2) We acquired an interest in Amberjack in the May 2018 Acquisition. The acquisition of this interest has been accounted for prospectively. (3) We acquired additional interests in Explorer and Colonial in the June 2019 Acquisition. The acquisition of these interests has been accounted for prospectively. (4) As stated above, the equity method of accounting has been suspended in 2018 for Poseidon and excess distributions are recorded in Other income. (5) Included in Other is the activity associated with our investments in Permian Basin, LOCAP, Proteus and Endymion. The adoption of the revenue standard for the majority of our equity method investments followed the non-public business entity adoption date of January 1, 2019 for their stand-alone financial statements, with the exception of Mars and Permian Basin, which both adopted on January 1, 2018. As a result of adopting the revenue standard January 1, 2019 and 2018 by Amberjack and Mars, respectively, we recognized our proportionate share of each investment’s cumulative effect transition adjustment increasing the opening deficit in the amounts of $9 million and $7 million, respectively. The Amberjack adjustment is related to its dedication and transportation agreements, which contain tiered pricing arrangements resulting in a deferral of revenue. The Mars adjustment related to its transportation and dedication agreement and method of recognition as a stand-ready obligation, which resulted in a deferral of the recognition of revenue over the life of the contract, whereas under previous GAAP revenue was recognized upon physical delivery. The adoption of the revenue standard by our other equity method investments was not material. Under the lease standard, the adoption date for our equity method investments will follow the non-public business entity adoption date of January 1, 2020 for their stand-alone financial statements, with the exception of Permian Basin, which adopted on January 1, 2019. There has been no material impact on the Partnership’s consolidated financial statements as a result of the adoption of the lease standard by our equity method investees. On October 23, 2019, we entered into a Settlement Agreement with SPLC (the “Settlement Agreement”) with respect to the storage revenue reimbursement provision contained in the Purchase and Sale Agreement entered into in 2016 under which we acquired an additional 20% interest in Mars. As a result of the Settlement Agreement, we received approximately $9 million during the fourth quarter of 2019 from SPLC that was recognized as an additional capital contribution. Pursuant to the Purchase and Sale Agreement, SPLC agreed to pay us up to $10 million if Mars inventory management fees do not meet certain levels for the calendar years 2017 through 2021. Based on our updated forecast and expectations of market conditions, we determined that there was a triggering event as of December 7, 2020 for our Permian Basin equity method investment that required us to update our impairment evaluation. The updated forecast had reductions in forecasted volumes gathered and processed by Permian Basin. Based on our evaluation, we determined that the fair value of our investment in Permian Basin was in excess of the carrying value as of December 7, 2020, and, therefore, there was no other-than-temporary impairment. However, if the facts and circumstances change in the near-term for Permian Basin and indicate a loss in value that is other-than-temporary, we will re-evaluate whether the carrying amount of this equity method investment may not be recoverable. The fair value of the Permian Basin investment was determined based upon applying both the discounted cash flow method, which is an income approach, and a market approach. The discounted cash flow fair value estimate is based on known and knowable information at the measurement date. The significant assumptions that were used to develop the estimate of fair value under the discounted cash flow method include management's best estimates of the expected future cash flows, including prices and volumes, the weighted average cost of capital and the long-term growth rate. Fair value determinations require considerable judgment and are sensitive to changes in underlying assumptions and factors. As a result, we cannot provide assurance that actual amounts will not vary significantly from estimated amounts. Due to the continuing effects of the COVID-19 pandemic, we also evaluated whether an impairment indicator existed as of December 31, 2020 for our other equity method investments. Based on our current forecast and expectations of market conditions, we determined that there was no triggering event that required us to update our impairment evaluation of these equity method investments. However, if the facts and circumstances change in the near-term and indicate a loss in value that is other-than-temporary, we will re-evaluate whether the carrying amount of our equity method investments may not be recoverable. Summarized Financial Information The following tables present aggregated selected balance sheet and income statement data for our equity method investments on a 100% basis. However, during periods in which an acquisition occurs, the selected balance sheet and income statement data reflects activity from the date of the acquisition. For the Year Ended December 31, 2020 Total revenues Total operating expenses Operating income Net income Statements of Income Mattox (1) $ 66 $ 9 $ 57 $ 57 Amberjack 280 78 202 201 Mars 259 97 162 163 Bengal 65 30 35 35 Explorer 329 175 154 119 Colonial 1,395 660 735 473 Poseidon 147 36 111 105 Other (2) 220 123 97 88 As of December 31, 2020 Current assets Non-current assets Total assets Current liabilities Non-current liabilities Equity (deficit) Total liabilities and equity (deficit) Balance Sheets Mattox (1) $ 13 $ 204 $ 217 $ — $ 12 $ 205 $ 217 Amberjack 44 836 880 10 124 746 880 Mars 47 269 316 23 103 190 316 Bengal 33 161 194 7 — 187 194 Explorer 74 537 611 49 459 103 611 Colonial 501 3,105 3,606 245 3,508 (147) 3,606 Poseidon 31 176 207 10 238 (41) 207 Other (2) 35 920 955 56 486 413 955 (1) Our interest in Mattox was acquired in the April 2020 Transaction. Mattox’s total revenues, total operating expenses and operating income (on a 100% basis) were $85 million, $12 million and $73 million, respectively. (2) Included in Other is the activity associated with our investments in Permian Basin, LOCAP, Proteus and Endymion. For the Year Ended December 31, 2019 Total revenues Total operating expenses Operating income Net income Statements of Income Amberjack $ 315 $ 73 $ 242 $ 243 Mars 282 104 178 179 Bengal 77 30 47 47 Explorer (1) 258 115 143 111 Colonial (2) 829 449 380 255 Poseidon 132 35 97 87 Other (3) 190 108 82 73 As of December 31, 2019 Current assets Non-current assets Total assets Current liabilities Non-current liabilities Equity (deficit) Total liabilities and equity (deficit) Balance Sheets Amberjack $ 56 $ 804 $ 860 $ 4 $ 32 $ 824 $ 860 Mars 57 173 230 8 22 200 230 Bengal 35 157 192 6 — 186 192 Explorer (1) 93 530 623 44 442 137 623 Colonial (2) 323 2,920 3,243 519 2,873 (149) 3,243 Poseidon 30 190 220 16 246 (42) 220 Other (3) 60 917 977 73 469 435 977 (1) Our interest in Explorer was acquired on June 6, 2019. Explorer total revenues, total operating expenses and operating income (on a 100% basis) was $443 million, $196 million and $247 million, respectively. (2) Our interest in Colonial was acquired on June 6, 2019. Colonial total revenues, total operating expenses and operating income (on a 100% basis) was $1,437 million, $735 million and $702 million, respectively. (3) Included in Other is the activity associated with our investments in Permian Basin, LOCAP, Proteus and Endymion. For the Year Ended December 31, 2018 Total revenues Total operating expenses Operating income Net income Statements of Income Amberjack (1) $ 204 $ 47 $ 157 $ 157 Mars 241 87 154 154 Bengal 69 28 41 41 Poseidon 116 35 81 73 Other (2) 152 67 85 76 As of December 31, 2018 Current assets Non-current assets Total assets Current liabilities Non-current liabilities Equity (deficit) Total liabilities and equity (deficit) Balance Sheets Amberjack (1) $ 46 $ 846 $ 892 $ 4 $ 4 $ 884 $ 892 Mars 53 178 231 5 18 208 231 Bengal 27 156 183 9 — 174 183 Poseidon 19 203 222 16 243 (37) 222 Other (2) 50 876 926 65 456 405 926 (1) Our interest in Amberjack was acquired on May 11, 2018. Amberjack total revenues, total operating expenses and operating income (on a 100% basis) was $295 million, $74 million and $221 million, respectively. (2) Included in Other is the activity associated with our investments in Permian Basin, LOCAP, Proteus and Endymion. Capital Contributions We make capital contributions for our pro rata interest in Permian Basin to fund capital and other expenditures. We made capital contributions to Permian Basin of zero, $25 million and $28 million in 2020, 2019 and 2018, respectively.

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
Property, Plant and Equipment	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment, net consists of the following as of the dates indicated: December 31, Depreciable Life 2020 2019 Land — $ 12 $ 11 Building and improvements 10 - 40 years 47 40 Pipeline and equipment (1) 10 - 30 years 1,263 1,228 Other 5 - 25 years 34 33 1,356 1,312 Accumulated depreciation and amortization (2) (661) (613) 695 699 Construction in progress 4 27 Property, plant and equipment, net $ 699 $ 726 (1) As of December 31, 2020 and 2019, includes cost of $372 million and $369 million, respectively, related to assets under operating leases (as lessor). As of both December 31, 2020 and 2019, includes cost of $23 million related to assets under capital lease (as lessee). (2) As of December 31, 2020 and 2019, includes accumulated depreciation of $147 million and $133 million, respectively, related to assets under operating leases (as lessor), which commenced in May 2017 and December 2017. As of December 31, 2020 and 2019, includes accumulated depreciation of $8 million and $6 million, respectively, related to assets under capital lease (as lessee). Depreciation and amortization expense on property, plant and equipment for 2020, 2019 and 2018 was $50 million, $49 million and $46 million, respectively, and is included in cost and expenses in the accompanying consolidated statements of income. Depreciation and amortization expense on property, plant and equipment includes amounts pertaining to assets under operating (as lessor) and capital leases (as lessee). We evaluate long-lived assets for potential impairment indicators whenever events or changes in circumstances indicate that the carrying amount of our assets may not be recoverable. Due to the continuing effects of the COVID-19 pandemic, we evaluated whether an impairment indicator existed during the year ended December 31, 2020. Based on our current forecast and expectations of market conditions, we determined that there was no triggering event that required us to update our impairment evaluation of property, plant and equipment. However, if current volatile market conditions deteriorate further or continue for an extended period of time, we may be required to assess the recoverability of our long-lived assets, which could result in an impairment.

Accrued Liabilities - Third Par

Accrued Liabilities - Third Parties	12 Months Ended
Accrued Liabilities - Third Parties	Dec. 31, 2020
Payables and Accruals [Abstract]
Accrued Liabilities – Third Parties	Accrued Liabilities – Third Parties Accrued liabilities – third parties consist of the following as of the dates indicated: December 31, 2020 2019 Project accruals $ 4 $ 5 Property taxes 5 4 Other accrued liabilities 1 3 Total accrued liabilities – third parties $ 10 $ 12 See Note 4 — Related Party Transactions for a discussion of Accrued liabilities – related parties.

Related Party Debt

Related Party Debt	12 Months Ended
Related Party Debt	Dec. 31, 2020
Debt Disclosure [Abstract]
Related Party Debt	Related Party Debt Consolidated related party debt obligations comprise the following as of the dates indicated: December 31, 2020 December 31, 2019 Outstanding Balance Total Capacity Available Capacity Outstanding Balance Total Capacity Available Capacity Ten Year Fixed Facility $ 600 $ 600 $ — $ 600 $ 600 $ — Seven Year Fixed Facility 600 600 — 600 600 — Five Year Revolver due July 2023 494 760 266 494 760 266 Five Year Revolver due December 2022 400 1,000 600 400 1,000 600 Five Year Fixed Facility 600 600 — 600 600 — 2019 Zydeco Revolver — 30 30 — 30 30 Unamortized debt issuance costs (2) n/a n/a (2) n/a n/a Debt payable – related party $ 2,692 $ 3,590 $ 896 $ 2,692 $ 3,590 $ 896 Interest and fee expenses associated with our borrowings, net of capitalized interest, were $90 million, $92 million and $61 million for 2020, 2019 and 2018, respectively, of which we paid $92 million, $88 million and $53 million, respectively. Borrowings under our revolving credit facilities approximate fair value as the interest rates are variable and reflective of market rates, which results in Level 2 instruments. The fair value of our fixed rate credit facilities is estimated based on the published market prices for issuances of similar risk and tenor and is categorized as Level 2 within the fair value hierarchy. As of December 31, 2020, the carrying amount and estimated fair value of total debt (before amortization of issuance costs) was $2,694 million and $2,928 million, respectively. As of December 31, 2019, the carrying amount and estimated fair value of total debt (before amortization of issuance costs) was $2,694 million and $2,825 million, respectively. The Ten The Seven Five On May 11, 2018, we funded the May 2018 Acquisition with $494 million in borrowings under the Five Five On February 6, 2018, we used net proceeds from sales of common units and from our general partner’s proportionate capital contribution to repay $247 million of borrowings outstanding under our Five Five Borrowings and repayments under our credit facilities for 2020, 2019 and 2018 are disclosed in our consolidated statements of cash flows. See Note 11 – (Deficit) Equity for additional information regarding the source of our repayments, if applicable to the period. Borrowings under the Five Year Revolver due July 2023, the Five Year Revolver due December 2022 and the 2019 Zydeco Revolver bear interest at the three-month LIBOR rate plus a margin or, in certain instances (including if LIBOR is discontinued) at an alternate interest rate as described in each respective revolver. Over the next few years, LIBOR will be discontinued globally, and as such, a new benchmark will take its place. We are in discussion with our Parent to further clarify the reference rate(s) applicable to our revolving credit facilities once LIBOR is discontinued, and we are evaluating any potential impact on our facilities. Credit Facility Agreements Ten On June 4, 2019, we entered into a ten Ten Ten Ten Seven On July 31, 2018, we entered into a seven Seven Seven The Seven Five On August 1, 2018, we amended and restated the five year revolving credit facility originally due October 2019 such that the facility will now mature on July 31, 2023 (the “Five Year Revolver due July 2023”). The Five As of December 31, 2020, the annualized weighted average interest rate for the Five The Five Five On December 1, 2017, we entered into a five year revolving credit facility with STCW (the “ Five Five the percentage rate per annum which is the rate notified to us by STCW in accordance with the terms of the Five . Additionally, we pay interest of 0.19% on any unused capacity. As of December 31, 2020, the weighted average interest rate for the Five Five Five On March 1, 2017, we entered into a Loan Facility Agreement with STCW with a borrowing capacity of $600 million (the “ Five Five The Five Five Zydeco Revolving Credit Facility Agreement On August 6, 2019, the senior unsecured revolving credit facility agreement between Zydeco and STCW, dated August 6, 2014, expired. On August 1, 2019, Zydeco entered into a senior unsecured revolving loan facility agreement with STCW, effective August 6, 2019 (the “2019 Zydeco Revolver”). The 2019 Zydeco Revolver has a borrowing capacity of $30 million and matures on August 6, 2024. Borrowings under the credit facility bear interest at the three-month LIBOR rate plus a margin, or, in certain instances, including if LIBOR is discontinued, STCW may specify another benchmark rate generally accepted in the loan market to apply in relation to the advances in place of LIBOR. No issuance fee was incurred in connection with the 2019 Zydeco Revolver. As of December 31, 2020, the interest rate for the 2019 Zydeco Revolver was 0.86%. Covenants Under the Ten Seven Five Five Five • to restrict additional indebtedness not loaned by STCW; • to give the applicable facility pari passu ranking with any new indebtedness; and • to refrain from securing our assets except as agreed with STCW. These facilities also contain customary events of default, such as nonpayment of principal, interest and fees when due and violation of covenants, as well as cross-default provisions under which a default under one credit facility may trigger an event of default in another facility with the same borrower. Any breach of covenants included in our debt agreements that could result in our related party lender demanding payment of the unpaid principal and interest balances will have a material adverse effect upon us and would likely require us to seek to renegotiate these debt arrangements with our related party lender and/or obtain new financing from other sources. As of December 31, 2020 and 2019, we were in compliance with the covenants contained in the Ten Seven Five Five Five Borrowings and repayments under our credit facilities for 2020, 2019 and 2018 are disclosed in our consolidated statements of cash flows. See Note 3 — Acquisitions and Other Transactions for additional information regarding our use of borrowings. See Note 11 — (Deficit) Equity

Leases

Leases	12 Months Ended
Leases	Dec. 31, 2020
Leases [Abstract]
Leases	Leases Adoption of ASC Topic 842 “Leases” On January 1, 2019, we adopted the lease standard by applying the modified retrospective approach to all leases on January 1, 2019. We elected the package of practical expedients upon transition that permits us to not reassess (1) whether any contracts entered into prior to adoption are or contain leases, (2) the lease classification of existing leases and (3) initial direct costs for any leases that existed prior to adoption. We also elected the practical expedient to not evaluate existing or expired land easements that were not accounted for as leases under previous guidance. Generally, we account for term-based land easements where we control the use of the land surface as leases. Upon adoption on January 1, 2019, we recognized operating lease right-of-use (“ROU”) assets and corresponding lease liabilities of $5 million. As lessor, the accounting for operating leases has not changed and the adoption did not have an impact on our existing transportation and terminaling services agreements that are considered operating leases. As lessee, the accounting for finance leases (capital leases) was substantially unchanged. Lessee accounting We determine if an arrangement is or contains a lease at inception. Our assessment is based on (1) whether the contract involves the use of a distinct identified asset, (2) whether we obtain the right to substantially all the economic benefit from the use of the asset throughout the period and (3) whether we have the right to direct the use of the asset. Leases are classified as either finance leases or operating leases. A lease is classified as a finance lease if any one of the following criteria are met: the lease transfers ownership of the asset by the end of the lease term, the lease contains an option to purchase the asset that is reasonably certain to be exercised, the lease term is for a major part of the remaining useful life of the asset or the present value of the lease payments equals or exceeds substantially all of the fair value of the asset. A lease is classified as an operating lease if it does not meet any one of these criteria. The lease classification affects the expense recognition in the income statement. Operating lease costs are recorded entirely in operating expenses. Finance lease costs are split, where amortization of the ROU asset is recorded in operating expenses and an implied interest component is recorded in interest expense. Under the lease standard, operating leases (as lessee) are included in Operating lease right-of-use assets, Accrued liabilities - third parties and Operating lease liabilities in our consolidated balance sheets. Finance leases (as lessee) are included in Property, plant and equipment, Accrued liabilities – third parties and Finance lease liabilities in our consolidated balance sheets. ROU assets and lease liabilities are recognized at commencement date based on the present value of the future minimum lease payments over the lease term. As most of our leases do not provide an implicit interest rate, we use our incremental borrowing rate (“IBR”) based on the information available at transition date in determining the present value of future payments. The ROU asset includes any lease payments made but excludes lease incentives and initial direct costs incurred, if any. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. We have long-term non-cancelable third-party operating leases for land. Several of the leases provide for renewal terms. We hold cancellable easements or rights-of-way arrangements from landowners permitting the use of land for the construction and operation of our pipeline systems. Obligations under these easements are not material to the results of our operations. In addition, Odyssey has a third-party operating lease for use of offshore platform space at Main Pass 289C. This lease will continue to be in effect until the continued operation of the platform is uneconomic. We are also obligated under two finance leases. We have a terminaling services agreement in which we took possession of certain storage tanks located in Port Neches, Texas and a lease of offshore platform space on the Garden Banks 128 “A” platform. Lease extensions. Many of our leases have options to either extend or terminate the lease. In determining the lease term, we considered all available contract extensions that are reasonably certain of occurring. Significant assumptions and judgments Incremental borrowing rate. We are generally not made aware of the interest rate implicit in a lease due to several reasons, including: (1) uncertainty as to the total amount of the costs incurred by the lessor in negotiating the lease or whether certain costs incurred by the lessor would qualify as initial direct costs and (2) uncertainty as to the lessor’s expectation of the residual value of the asset at the end of the lease. Therefore, we use our IBR at the commencement of the lease and estimate the IBR for each lease agreement taking into consideration lease contract term, collateral and entity credit ratings, and use sensitivity analyses to evaluate the reasonableness of the rates determined. Lease balances and costs The following tables summarize balance sheet data related to leases at December 31, 2020 and 2019 and our lease costs as of and for the year ended December 31, 2020 and 2019 : Leases Classification December 31, 2020 December 31, 2019 Assets Operating lease assets Operating lease right-of-use assets $ 4 $ 4 Finance lease assets Property, plant and equipment, net (1) 16 17 Total lease assets $ 20 $ 21 Liabilities Current Finance Accrued liabilities - third parties $ 1 $ 1 Noncurrent Operating Operating lease liabilities 4 4 Finance Finance lease liabilities 24 24 Total lease liabilities $ 29 $ 29 (1) Finance lease assets are recorded net of accumulated amortization of $8 million as of December 31, 2020 and $6 million as of December 31, 2019. Lease cost Classification December 31, 2020 December 31, 2019 Operating lease cost (1) Operations and maintenance - third parties $ — $ — Finance lease cost (cost resulting from lease payments): Amortization of leased assets Depreciation and amortization 1 1 Interest on lease liabilities Interest expense, net 4 4 Total lease cost $ 5 $ 5 (1) Amounts for each year ended December 31, 2020 and 2019 were less than $1 million. Other information December 31, 2020 December 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases (1) $ — $ — Operating cash flows from finance leases (3) (4) Financing cash flows from finance leases (1) (1) (1) Amounts for each year ended December 31, 2020 and 2019 were less than $1 million . December 31, 2020 December 31, 2019 Weighted-average remaining lease term (years): Operating leases 19 20 Finance leases 10 11 Weighted-average discount rate: Operating leases 5.8 % 5.8 % Finance leases 14.3 % 14.3 % Annual maturity analysis The future annual maturity of lease payments as of December 31, 2020 for the above lease obligations was: Maturity of lease liabilities Operating Leases (1) Finance Leases (2) Total 2021 $ — $ 4 $ 4 2022 1 4 5 2023 — 4 4 2024 1 4 5 2025 — 5 5 Remainder 5 28 33 Total lease payments 7 49 56 Less: Interest (3) (3) (24) (27) Present value of lease liabilities (4) $ 4 $ 25 $ 29 (1) Operating lease payments include $2 million related to options to extend lease terms that are reasonably certain of being exercised. (2) Includes $24 million in principal and excludes $8 million in executory costs. (3) Calculated using the interest rate for each lease. (4) Includes the current portion of $1 million for the finance lease. Lessor accounting We have certain transportation and terminaling services agreements with related parties entered into prior to the adoption date of January 1, 2019 that are considered operating leases and include both a lease component and an implied operation and maintenance service component (“non-lease service component”). Certain of these agreements were entered into for terms of ten years with the option to extend for two additional terms of five years each. One of these contracts was amended to include an option for the lessee to extend for a fourteen five one Note 12 — Revenue Recognition . Our risk management strategy for the residual assets is mitigated by the long-term nature of the underlying assets and the long-term nature of our lease agreements. Significant assumptions and judgments Lease and non-lease components. Certain of our revenues are accounted for under the lease standard, as the underlying contracts convey the right to control the use of the identified asset for a period of time. We allocate the arrangement consideration between the lease components that fall within the scope of the lease standard and any non-lease service components within the scope of the revenue standard based on the relative stand-alone selling price of each component. See Note 12 — Revenue Recognition for additional information regarding the allocation of the consideration in a contract between the lease and non-lease service components. Annual maturity analysis As of December 31, 2020, future annual maturity of lease payments to be received under the contract terms of these operating leases, which includes only the lease components of these leases, was estimated to be: Maturity of lease payments Operating leases (1) 2021 $ 56 2022 56 2023 56 2024 56 2025 56 Remainder 451 Total lease payments $ 731 (1) Operating lease payments include $366 million related to options to extend lease terms that are reasonably certain of being exercised. Other As of December 31, 2020 and 2019, we had short-term payment obligations relating to capital expenditures totaling $1 million and $5 million, respectively. These represent unconditional payment obligations to vendors for products and services delivered in connection with capital projects.
Leases	Leases Adoption of ASC Topic 842 “Leases” On January 1, 2019, we adopted the lease standard by applying the modified retrospective approach to all leases on January 1, 2019. We elected the package of practical expedients upon transition that permits us to not reassess (1) whether any contracts entered into prior to adoption are or contain leases, (2) the lease classification of existing leases and (3) initial direct costs for any leases that existed prior to adoption. We also elected the practical expedient to not evaluate existing or expired land easements that were not accounted for as leases under previous guidance. Generally, we account for term-based land easements where we control the use of the land surface as leases. Upon adoption on January 1, 2019, we recognized operating lease right-of-use (“ROU”) assets and corresponding lease liabilities of $5 million. As lessor, the accounting for operating leases has not changed and the adoption did not have an impact on our existing transportation and terminaling services agreements that are considered operating leases. As lessee, the accounting for finance leases (capital leases) was substantially unchanged. Lessee accounting We determine if an arrangement is or contains a lease at inception. Our assessment is based on (1) whether the contract involves the use of a distinct identified asset, (2) whether we obtain the right to substantially all the economic benefit from the use of the asset throughout the period and (3) whether we have the right to direct the use of the asset. Leases are classified as either finance leases or operating leases. A lease is classified as a finance lease if any one of the following criteria are met: the lease transfers ownership of the asset by the end of the lease term, the lease contains an option to purchase the asset that is reasonably certain to be exercised, the lease term is for a major part of the remaining useful life of the asset or the present value of the lease payments equals or exceeds substantially all of the fair value of the asset. A lease is classified as an operating lease if it does not meet any one of these criteria. The lease classification affects the expense recognition in the income statement. Operating lease costs are recorded entirely in operating expenses. Finance lease costs are split, where amortization of the ROU asset is recorded in operating expenses and an implied interest component is recorded in interest expense. Under the lease standard, operating leases (as lessee) are included in Operating lease right-of-use assets, Accrued liabilities - third parties and Operating lease liabilities in our consolidated balance sheets. Finance leases (as lessee) are included in Property, plant and equipment, Accrued liabilities – third parties and Finance lease liabilities in our consolidated balance sheets. ROU assets and lease liabilities are recognized at commencement date based on the present value of the future minimum lease payments over the lease term. As most of our leases do not provide an implicit interest rate, we use our incremental borrowing rate (“IBR”) based on the information available at transition date in determining the present value of future payments. The ROU asset includes any lease payments made but excludes lease incentives and initial direct costs incurred, if any. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. We have long-term non-cancelable third-party operating leases for land. Several of the leases provide for renewal terms. We hold cancellable easements or rights-of-way arrangements from landowners permitting the use of land for the construction and operation of our pipeline systems. Obligations under these easements are not material to the results of our operations. In addition, Odyssey has a third-party operating lease for use of offshore platform space at Main Pass 289C. This lease will continue to be in effect until the continued operation of the platform is uneconomic. We are also obligated under two finance leases. We have a terminaling services agreement in which we took possession of certain storage tanks located in Port Neches, Texas and a lease of offshore platform space on the Garden Banks 128 “A” platform. Lease extensions. Many of our leases have options to either extend or terminate the lease. In determining the lease term, we considered all available contract extensions that are reasonably certain of occurring. Significant assumptions and judgments Incremental borrowing rate. We are generally not made aware of the interest rate implicit in a lease due to several reasons, including: (1) uncertainty as to the total amount of the costs incurred by the lessor in negotiating the lease or whether certain costs incurred by the lessor would qualify as initial direct costs and (2) uncertainty as to the lessor’s expectation of the residual value of the asset at the end of the lease. Therefore, we use our IBR at the commencement of the lease and estimate the IBR for each lease agreement taking into consideration lease contract term, collateral and entity credit ratings, and use sensitivity analyses to evaluate the reasonableness of the rates determined. Lease balances and costs The following tables summarize balance sheet data related to leases at December 31, 2020 and 2019 and our lease costs as of and for the year ended December 31, 2020 and 2019 : Leases Classification December 31, 2020 December 31, 2019 Assets Operating lease assets Operating lease right-of-use assets $ 4 $ 4 Finance lease assets Property, plant and equipment, net (1) 16 17 Total lease assets $ 20 $ 21 Liabilities Current Finance Accrued liabilities - third parties $ 1 $ 1 Noncurrent Operating Operating lease liabilities 4 4 Finance Finance lease liabilities 24 24 Total lease liabilities $ 29 $ 29 (1) Finance lease assets are recorded net of accumulated amortization of $8 million as of December 31, 2020 and $6 million as of December 31, 2019. Lease cost Classification December 31, 2020 December 31, 2019 Operating lease cost (1) Operations and maintenance - third parties $ — $ — Finance lease cost (cost resulting from lease payments): Amortization of leased assets Depreciation and amortization 1 1 Interest on lease liabilities Interest expense, net 4 4 Total lease cost $ 5 $ 5 (1) Amounts for each year ended December 31, 2020 and 2019 were less than $1 million. Other information December 31, 2020 December 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases (1) $ — $ — Operating cash flows from finance leases (3) (4) Financing cash flows from finance leases (1) (1) (1) Amounts for each year ended December 31, 2020 and 2019 were less than $1 million . December 31, 2020 December 31, 2019 Weighted-average remaining lease term (years): Operating leases 19 20 Finance leases 10 11 Weighted-average discount rate: Operating leases 5.8 % 5.8 % Finance leases 14.3 % 14.3 % Annual maturity analysis The future annual maturity of lease payments as of December 31, 2020 for the above lease obligations was: Maturity of lease liabilities Operating Leases (1) Finance Leases (2) Total 2021 $ — $ 4 $ 4 2022 1 4 5 2023 — 4 4 2024 1 4 5 2025 — 5 5 Remainder 5 28 33 Total lease payments 7 49 56 Less: Interest (3) (3) (24) (27) Present value of lease liabilities (4) $ 4 $ 25 $ 29 (1) Operating lease payments include $2 million related to options to extend lease terms that are reasonably certain of being exercised. (2) Includes $24 million in principal and excludes $8 million in executory costs. (3) Calculated using the interest rate for each lease. (4) Includes the current portion of $1 million for the finance lease. Lessor accounting We have certain transportation and terminaling services agreements with related parties entered into prior to the adoption date of January 1, 2019 that are considered operating leases and include both a lease component and an implied operation and maintenance service component (“non-lease service component”). Certain of these agreements were entered into for terms of ten years with the option to extend for two additional terms of five years each. One of these contracts was amended to include an option for the lessee to extend for a fourteen five one Note 12 — Revenue Recognition . Our risk management strategy for the residual assets is mitigated by the long-term nature of the underlying assets and the long-term nature of our lease agreements. Significant assumptions and judgments Lease and non-lease components. Certain of our revenues are accounted for under the lease standard, as the underlying contracts convey the right to control the use of the identified asset for a period of time. We allocate the arrangement consideration between the lease components that fall within the scope of the lease standard and any non-lease service components within the scope of the revenue standard based on the relative stand-alone selling price of each component. See Note 12 — Revenue Recognition for additional information regarding the allocation of the consideration in a contract between the lease and non-lease service components. Annual maturity analysis As of December 31, 2020, future annual maturity of lease payments to be received under the contract terms of these operating leases, which includes only the lease components of these leases, was estimated to be: Maturity of lease payments Operating leases (1) 2021 $ 56 2022 56 2023 56 2024 56 2025 56 Remainder 451 Total lease payments $ 731 (1) Operating lease payments include $366 million related to options to extend lease terms that are reasonably certain of being exercised. Other As of December 31, 2020 and 2019, we had short-term payment obligations relating to capital expenditures totaling $1 million and $5 million, respectively. These represent unconditional payment obligations to vendors for products and services delivered in connection with capital projects.
Leases	Leases Adoption of ASC Topic 842 “Leases” On January 1, 2019, we adopted the lease standard by applying the modified retrospective approach to all leases on January 1, 2019. We elected the package of practical expedients upon transition that permits us to not reassess (1) whether any contracts entered into prior to adoption are or contain leases, (2) the lease classification of existing leases and (3) initial direct costs for any leases that existed prior to adoption. We also elected the practical expedient to not evaluate existing or expired land easements that were not accounted for as leases under previous guidance. Generally, we account for term-based land easements where we control the use of the land surface as leases. Upon adoption on January 1, 2019, we recognized operating lease right-of-use (“ROU”) assets and corresponding lease liabilities of $5 million. As lessor, the accounting for operating leases has not changed and the adoption did not have an impact on our existing transportation and terminaling services agreements that are considered operating leases. As lessee, the accounting for finance leases (capital leases) was substantially unchanged. Lessee accounting We determine if an arrangement is or contains a lease at inception. Our assessment is based on (1) whether the contract involves the use of a distinct identified asset, (2) whether we obtain the right to substantially all the economic benefit from the use of the asset throughout the period and (3) whether we have the right to direct the use of the asset. Leases are classified as either finance leases or operating leases. A lease is classified as a finance lease if any one of the following criteria are met: the lease transfers ownership of the asset by the end of the lease term, the lease contains an option to purchase the asset that is reasonably certain to be exercised, the lease term is for a major part of the remaining useful life of the asset or the present value of the lease payments equals or exceeds substantially all of the fair value of the asset. A lease is classified as an operating lease if it does not meet any one of these criteria. The lease classification affects the expense recognition in the income statement. Operating lease costs are recorded entirely in operating expenses. Finance lease costs are split, where amortization of the ROU asset is recorded in operating expenses and an implied interest component is recorded in interest expense. Under the lease standard, operating leases (as lessee) are included in Operating lease right-of-use assets, Accrued liabilities - third parties and Operating lease liabilities in our consolidated balance sheets. Finance leases (as lessee) are included in Property, plant and equipment, Accrued liabilities – third parties and Finance lease liabilities in our consolidated balance sheets. ROU assets and lease liabilities are recognized at commencement date based on the present value of the future minimum lease payments over the lease term. As most of our leases do not provide an implicit interest rate, we use our incremental borrowing rate (“IBR”) based on the information available at transition date in determining the present value of future payments. The ROU asset includes any lease payments made but excludes lease incentives and initial direct costs incurred, if any. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. We have long-term non-cancelable third-party operating leases for land. Several of the leases provide for renewal terms. We hold cancellable easements or rights-of-way arrangements from landowners permitting the use of land for the construction and operation of our pipeline systems. Obligations under these easements are not material to the results of our operations. In addition, Odyssey has a third-party operating lease for use of offshore platform space at Main Pass 289C. This lease will continue to be in effect until the continued operation of the platform is uneconomic. We are also obligated under two finance leases. We have a terminaling services agreement in which we took possession of certain storage tanks located in Port Neches, Texas and a lease of offshore platform space on the Garden Banks 128 “A” platform. Lease extensions. Many of our leases have options to either extend or terminate the lease. In determining the lease term, we considered all available contract extensions that are reasonably certain of occurring. Significant assumptions and judgments Incremental borrowing rate. We are generally not made aware of the interest rate implicit in a lease due to several reasons, including: (1) uncertainty as to the total amount of the costs incurred by the lessor in negotiating the lease or whether certain costs incurred by the lessor would qualify as initial direct costs and (2) uncertainty as to the lessor’s expectation of the residual value of the asset at the end of the lease. Therefore, we use our IBR at the commencement of the lease and estimate the IBR for each lease agreement taking into consideration lease contract term, collateral and entity credit ratings, and use sensitivity analyses to evaluate the reasonableness of the rates determined. Lease balances and costs The following tables summarize balance sheet data related to leases at December 31, 2020 and 2019 and our lease costs as of and for the year ended December 31, 2020 and 2019 : Leases Classification December 31, 2020 December 31, 2019 Assets Operating lease assets Operating lease right-of-use assets $ 4 $ 4 Finance lease assets Property, plant and equipment, net (1) 16 17 Total lease assets $ 20 $ 21 Liabilities Current Finance Accrued liabilities - third parties $ 1 $ 1 Noncurrent Operating Operating lease liabilities 4 4 Finance Finance lease liabilities 24 24 Total lease liabilities $ 29 $ 29 (1) Finance lease assets are recorded net of accumulated amortization of $8 million as of December 31, 2020 and $6 million as of December 31, 2019. Lease cost Classification December 31, 2020 December 31, 2019 Operating lease cost (1) Operations and maintenance - third parties $ — $ — Finance lease cost (cost resulting from lease payments): Amortization of leased assets Depreciation and amortization 1 1 Interest on lease liabilities Interest expense, net 4 4 Total lease cost $ 5 $ 5 (1) Amounts for each year ended December 31, 2020 and 2019 were less than $1 million. Other information December 31, 2020 December 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases (1) $ — $ — Operating cash flows from finance leases (3) (4) Financing cash flows from finance leases (1) (1) (1) Amounts for each year ended December 31, 2020 and 2019 were less than $1 million . December 31, 2020 December 31, 2019 Weighted-average remaining lease term (years): Operating leases 19 20 Finance leases 10 11 Weighted-average discount rate: Operating leases 5.8 % 5.8 % Finance leases 14.3 % 14.3 % Annual maturity analysis The future annual maturity of lease payments as of December 31, 2020 for the above lease obligations was: Maturity of lease liabilities Operating Leases (1) Finance Leases (2) Total 2021 $ — $ 4 $ 4 2022 1 4 5 2023 — 4 4 2024 1 4 5 2025 — 5 5 Remainder 5 28 33 Total lease payments 7 49 56 Less: Interest (3) (3) (24) (27) Present value of lease liabilities (4) $ 4 $ 25 $ 29 (1) Operating lease payments include $2 million related to options to extend lease terms that are reasonably certain of being exercised. (2) Includes $24 million in principal and excludes $8 million in executory costs. (3) Calculated using the interest rate for each lease. (4) Includes the current portion of $1 million for the finance lease. Lessor accounting We have certain transportation and terminaling services agreements with related parties entered into prior to the adoption date of January 1, 2019 that are considered operating leases and include both a lease component and an implied operation and maintenance service component (“non-lease service component”). Certain of these agreements were entered into for terms of ten years with the option to extend for two additional terms of five years each. One of these contracts was amended to include an option for the lessee to extend for a fourteen five one Note 12 — Revenue Recognition . Our risk management strategy for the residual assets is mitigated by the long-term nature of the underlying assets and the long-term nature of our lease agreements. Significant assumptions and judgments Lease and non-lease components. Certain of our revenues are accounted for under the lease standard, as the underlying contracts convey the right to control the use of the identified asset for a period of time. We allocate the arrangement consideration between the lease components that fall within the scope of the lease standard and any non-lease service components within the scope of the revenue standard based on the relative stand-alone selling price of each component. See Note 12 — Revenue Recognition for additional information regarding the allocation of the consideration in a contract between the lease and non-lease service components. Annual maturity analysis As of December 31, 2020, future annual maturity of lease payments to be received under the contract terms of these operating leases, which includes only the lease components of these leases, was estimated to be: Maturity of lease payments Operating leases (1) 2021 $ 56 2022 56 2023 56 2024 56 2025 56 Remainder 451 Total lease payments $ 731 (1) Operating lease payments include $366 million related to options to extend lease terms that are reasonably certain of being exercised. Other As of December 31, 2020 and 2019, we had short-term payment obligations relating to capital expenditures totaling $1 million and $5 million, respectively. These represent unconditional payment obligations to vendors for products and services delivered in connection with capital projects.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	12 Months Ended
Accumulated Other Comprehensive Loss	Dec. 31, 2020
Equity [Abstract]
Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive LossAs a result of the transactions contemplated by the June 2019 Acquisition, we recorded an accumulated other comprehensive loss related to pension and other post-retirement benefits provided by Explorer and Colonial to their employees. We are not a sponsor of these benefits plans. The June 2019 Acquisition is accounted for as a transaction between entities under common control on a prospective basis, and we have recorded the acquisition on our consolidated balance sheet at SPLC’s historical basis, which included accumulated other comprehensive loss. In 2020 and 2019, we recorded $1 million and $2 million, respectively, in other comprehensive loss related to remeasurements related to these pension and other post-retirement benefits.

(Deficit) Equity

(Deficit) Equity	12 Months Ended
(Deficit) Equity	Dec. 31, 2020
Equity [Abstract]
(Deficit) Equity	(Deficit) Equity General Partner and IDR Restructuring Prior to April 1, 2020, our capital accounts were comprised of a 2% general partner interest and 98% limited partner interests. On April 1, 2020, in connection with the closing of the April 2020 Transaction, we closed on the transactions contemplated by the Partnership Interests Restructuring Agreement, pursuant to which we eliminated all of the IDRs and converted the 2% economic general partner interest in the Partnership into a non-economic general partner interest. As a result, 4,761,012 general partner units and the IDRs were canceled and are no longer outstanding, and therefore, no longer participate in distributions of cash from the Partnership. Because the transaction was among entities under common control, our general partner’s negative equity balance of $4 billion at April 1, 2020 was transferred to SPLC’s equity accounts, allocated between its holdings of common units and preferred units, based on the relative fair value of the common units and preferred units issued as consideration in the April 2020 Transaction. Shelf Registrations We have a universal shelf registration statement on Form S-3 on file with the SEC under which we, as a well-known seasoned issuer, have the ability to issue and sell an indeterminate amount of common units and partnership securities representing limited partner units. We also have on file with the SEC a shelf registration statement on Form S-3 relating to $1,000,000,000 of common units and partnership securities representing limited partner units to be used in connection with the at-the-market equity distribution program, direct sales or other sales consistent with the plan of distribution set forth in the registration statement. Public Offerings and Private Placement On February 6, 2018, we completed the sale of 25,000,000 common units in a registered public offering for $673 million net proceeds ($680 million gross proceeds, or $27.20 per common unit, less $6 million of underwriter’s fees and $1 million of transaction fees). In connection with the issuance of common units, we issued 510,204 general partner units to our general partner for $14 million in order to maintain its 2% general partner interest in us. On February 6, 2018, we also completed the sale of 11,029,412 common units in a private placement with LP Holdings for an aggregate purchase price of $300 million, or $27.20 per common unit. In connection with the issuance of the common units, we issued 225,091 general partner units to our general partner for $6 million in order to maintain its 2% general partner interest in us. We used net proceeds from these sales to repay $247 million of borrowings outstanding under the Five Five At-the-Market Program We have an “at-the-market” equity distribution program pursuant to which we may issue and sell common units for up to $300 million in gross proceeds. We did not have any sales under this program during 2020, 2019 or 2018. Units Outstanding The changes in the number of units outstanding from December 31, 2018 through December 31, 2020 are as follows: (in units) SPLC Preferred Public SPLC General Balance as of December 31, 2018 — 123,832,233 99,979,548 4,567,588 June 2019 Acquisition — — 9,477,756 193,424 Balance as of December 31, 2019 — 123,832,233 109,457,304 4,761,012 April 2020 Acquisition 50,782,904 — 160,000,000 (4,761,012) Balance as of December 31, 2020 50,782,904 123,832,233 269,457,304 — Common units The common units represent limited partner interests in us. The holders of common units, both public and SPLC, are entitled to participate in partnership distributions and have limited rights of ownership as provided for under the Second Amended and Restated Partnership Agreement. As of December 31, 2020, we had 393,289,537 common units outstanding, of which 123,832,233 were publicly owned. SPLC owned 269,457,304 common units representing an aggregate 68.5% limited partner interest in us. Series A Preferred Units On April 1, 2020, as partial consideration for the April 2020 Transaction, we issued 50,782,904 Series A Preferred Units to SPLC at a price of $23.63 per preferred unit. The Series A Preferred Units are a new class of equity security that rank senior to all common units with respect to distribution rights and rights upon liquidation. The Series A Preferred Units have voting rights, distribution rights and certain redemption rights, and are also convertible (at the option of the Partnership and at the option of the holder, in each case under certain circumstances) and are otherwise subject to the terms and conditions as set forth in the Second Amended and Restated Partnership Agreement. We classified the Series A Preferred Units as permanent equity since they are not redeemable for cash or other assets 1) at a fixed or determinable price on a fixed or determinable date; 2) at the option of the holder; or 3) upon the occurrence of an event that is not solely within the control of the issuer. Conversion At the option of Series A Preferred Unitholder s. Beginning with the earlier of (1) January 1, 2022 and (2) immediately prior to the liquidation of the Partnership, the Series A Preferred Units are convertible by the preferred unitholders, at the preferred unitholders ’ option, into common units on a one-for-one basis, adjusted to give effect to any accrued and unpaid distributions on the applicable preferred units. At the option of the Partnership. The Partnership shall have the right to convert the Series A Preferred Units on a one-for-one basis, adjusted to give effect to any accrued and unpaid distributions on the applicable Series A Preferred Units, into common units at any time from and after January 1, 2023, if the closing price of the common units is greater than $33.082 per unit (140% of the Series A Preferred Unit Issue Price (as defined in the Second Amended and Restated Partnership Agreement)) for any 20 trading days during the 30 trading-day period immediately preceding notice of the conversion. The conversion rate for the Series A Preferred Units shall be the quotient of (a) the sum of (i) $23.63, plus (ii) any unpaid cash distributions on the applicable Series A Preferred Units , divided by (b) $23.63. Voting The Series A Preferred Units are entitled to vote on an as-converted basis with the common units and have certain other class voting rights with respect to any amendment to the Second Amended and Restated Partnership Agreement. In the event of any liquidation of the Partnership, the Series A Preferred Units are entitled to receive, out of the assets of the Partnership available for distribution to the partners or any assignees, prior and in preference to any distribution of any assets of any junior securities, the value in each holder ’ s capital account in respect of such Series A Preferred Units. Change of Control Upon the occurrence of certain events involving a change of control in which more than 90% of the consideration payable to the holders of the common units is payable in cash, the Series A Preferred Units will automatically convert into common units at the then-applicable conversion rate. Upon the occurrence of certain other events involving a change of control, the holders of the Series A Preferred Units may elect, among other potential elections, to convert the Series A Preferred Units to common units at the then-applicable conversion rate. Special Distribution Each Series A Preferred Unit has the right to share in any special distributions by the Partnership of cash, securities or other property pro rata with the common units or any other securities, on an as-converted basis, provided that special distributions shall not include regular quarterly distributions paid in the normal course of business on the common units. Distributions to our Unitholders In connection with the April 2020 Transaction, commencing with the quarter ending June 30, 2020, the holders of the Series A Preferred Units are entitled to cumulative quarterly distributions at a rate of $0.2363 per Series A Preferred Unit, payable quarterly in arrears no later than 60 days after the end of the applicable quarter. The Partnership will not be entitled to pay any distributions on any junior securities, including any of the common units, prior to paying the quarterly distribution payable to the Series A Preferred Units, including any previously accrued and unpaid distributions. For the year ended December 31, 2020, the aggregate and per unit amounts of cumulative preferred distributions paid were $36 million and $0.7089, respectively. Under the Second Amended and Restated Partnership Agreement, our general partner or its assignee has agreed to waive a portion of the distributions that would otherwise be payable on the common units issued to SPLC as part of the April 2020 Transaction, in an amount of $20 million per quarter for four consecutive fiscal quarters, beginning with the distribution made with respect to the second quarter of 2020. See Note 4 — Related Party Transactions for terms of the Second Amended and Restated Partnership Agreement. Under the Second Amendment, our general partner elected to waive $50 million of distributions with respect to the IDRs in 2019 to be used for future investment by the Partnership. See Note 4 — Related Party Transactions for terms of the Second Amendment. The following table details the distributions declared and/or paid for the periods presented: Date Paid or to be Paid Three Months Ended Public Common SPLC Preferred SPLC Common General Partner Distributions per Limited Partner Unit IDRs 2% Total (in millions, except per unit amounts) February 14, 2018 December 31, 2017 $ 33 $ — $ 30 $ 18 $ 2 $ 83 $ 0.33300 May 15, 2018 March 31, 2018 43 — 35 26 2 106 0.34800 August 14, 2018 June 30, 2018 46 — 36 29 2 113 0.36500 November 14, 2018 September 30, 2018 47 — 38 33 3 121 0.38200 February 14, 2019 December 31, 2018 49 — 40 37 3 129 0.40000 May 15, 2019 March 31, 2019 (1) 51 — 42 23 3 119 0.41500 August 14, 2019 June 30, 2019 (1) 53 — 47 28 3 131 0.43000 November 14, 2019 September 30, 2019 (1) 56 — 48 33 3 140 0.44500 February 14, 2020 December 31, 2019 57 — 50 52 3 162 0.46000 May 15, 2020 March 31, 2020 57 — 50 52 (3) 3 (4) 162 0.46000 August 14, 2020 June 30, 2020 (2) 57 12 104 — — 173 0.46000 November 13, 2020 September 30, 2020 (2) 57 12 104 — — 173 0.46000 February 12, 2021 December 31, 2020 (2)(5) 57 12 104 — — 173 0.46000 (1) Includes the impact of waived distributions to the holders of IDRs with respect to the Second Amendment as described above. (2) Includes the impact of waived distributions to SPLC with respect to the April 2020 Transaction as described above. (3) This amount represents the Final IDR Payment (as defined in the Partnership Interests Restructuring Agreement) to which our general partner (or its assignee) was entitled pursuant to the Partnership Interests Restructuring Agreement. Also pursuant to the Partnership Interests Restructuring Agreement, our general partner agreed (on its own behalf and on behalf of its assignees) to waive any distributions that it would otherwise be entitled to receive with respect to the newly-issued 160 million common units that it received in the April 2020 Transaction for the quarter in which it receives the Final IDR Payment. Our general partner is not entitled to any payments with respect to the IDRs going forward, as they have been cancelled as a part of the April 2020 Transaction. (4) This amount represents the final distribution payment on the 2% economic general partner interest. Our general partner is not entitled to any payments with respect to the economic general partner interest going forward, as it was converted into a non-economic general partner interest as a part of the April 2020 Transaction. (5) See Note 16 — Subsequent Event(s) for additional information. Distributions to Noncontrolling Interests Distributions to SPLC for its noncontrolling interest in Zydeco were $5 million, $4 million and $7 million in 2020, 2019 and 2018, respectively. Distributions to GEL for its noncontrolling interest in Odyssey were $11 million, $13 million and $9 million in 2020, 2019 and 2018, respectively. See Note 4 — Related Party Transactions for additional details.

Revenue Recognition

Revenue Recognition	12 Months Ended
Revenue Recognition	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue RecognitionThe revenue standard’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The revenue standard requires entities to recognize revenue through the application of a five-step model, which includes: identification of the contract; identification of the performance obligations; determination of the transaction price; allocation of the transaction price to the performance obligations; and recognition of revenue as the entity satisfies the performance obligations. Our revenues are primarily generated from the transportation, terminaling and storage of crude oil, refinery gas and refined petroleum products through our pipelines, terminals, storage tanks, docks, truck and rail racks. To identify the performance obligations, we considered all the products or services promised in the contracts with customers, whether explicitly stated or implied based on customary business practices. Revenue is recognized when each performance obligation is satisfied under the terms of the contract. Each barrel of product transported or day of services provided is considered a distinct service that represents a performance obligation that would be satisfied over time if it were accounted for separately. The services provided over the contract period are a series of distinct services that are substantially the same, have the same pattern of transfer to the customer, and, therefore, qualify as a single performance obligation. Since the customer simultaneously receives and consumes the benefits of services, we recognize revenue over time based on a measure of progress of volumes transported for transportation services contracts or number of days elapsed for storage and terminaling services contracts. Product revenue related to allowance oil sales is recognized at the point in time when the control of the oil transfers to the customer. For all performance obligations, payment is typically due in full within 30 days of the invoice date. Disaggregation of Revenue The following table provides information about disaggregated revenue by service type and customer type: 2020 2019 2018 Transportation services revenue – third parties $ 114 $ 134 $ 200 Transportation services revenue – related parties (1) 164 210 176 Storage services revenue – third parties 9 9 9 Storage services revenue – related parties 8 7 7 Terminaling services revenue – related parties (2) 103 47 46 Terminaling services revenue – major maintenance service – related parties (3) 7 — — Product revenue – third parties (4) — 5 2 Product revenue – related parties (4) 19 35 29 Total Topic 606 revenue 424 447 469 Lease revenue – related parties 57 56 56 Total revenue $ 481 $ 503 $ 525 (1) Transportation services revenue – related parties for each of 2020, 2019 and 2018 includes $5 million of non-lease service component in our transportation services contract. (2) Terminaling services revenue – related parties is comprised of the service components in our terminaling services contracts, including the operation and maintenance service components related to the Norco Assets in connection with the April 2020 Transaction. See Note 4 – Related Party Transactions for additional details. (3) Terminaling services revenue – major maintenance service – related parties is comprised of the service components related to providing required major maintenance to the Norco Assets in connection with the April 2020 Transaction. See Note 4 – Related Party Transactions for additional details. (4) Product revenue is comprised of allowance oil sales. Lease revenue Certain of our long-term transportation and terminaling services contracts with related parties are accounted for as operating leases. These agreements have both lease and non-lease service components. We allocate the arrangement consideration between the lease components and any non-lease service components based on the relative stand-alone selling price of each component. We estimate the stand-alone selling price of the lease and non-lease service components based on an analysis of service-related and lease-related costs for each contract, adjusted for a representative profit margin. The contracts have a minimum fixed monthly payment for both the lease and non-lease service components. We present the non-lease service components under the revenue standard within Transportation, terminaling and storage services – related parties in the consolidated statements of income. Revenues from the lease components of these agreements are recorded within Lease revenue – related parties in the consolidated statements of income. Some of these agreements were each entered into for terms of ten years, with the option for the lessee to extend for two additional five-year terms. One of these contracts was amended to include an option for the lessee to extend for a fourteen-month term prior to the original extension options. However, it is reasonably certain that the original extension options of the two additional five-year terms will not be exercised for this contract. Further, we have agreements with initial terms of ten years with the option for the lessee to extend for up to ten additional one-year terms. As of December 31, 2020, future minimum payments of both the lease and non-lease service components to be received under the ten-year contract term of these operating leases were estimated to be: Total Less than 1 year Years 2 to 3 Years 4 to 5 More than 5 years Operating leases $ 735 $ 111 $ 220 $ 220 $ 184 Transportation services revenue We have both long-term transportation contracts and month-to-month contracts for spot shippers that make nominations on our pipelines. Some of the long-term contracts entitle the customer to a specified amount of guaranteed capacity on the pipeline. Transportation services are charged at a per barrel rate or other applicable unit of measure. We apply the allocation exception guidance for variable consideration related to market indexing for long-term transportation contracts because (a) the variable payment relates specifically to our efforts to transfer the distinct service and (b) we allocate the variable amount of consideration entirely to the distinct service, which is consistent with the allocation objective. Except for guaranteed capacity payments as discussed below, transportation services are billed monthly as services are rendered. Our contracts and tariffs contain terms for the customer to reimburse us for losses from evaporation or other loss in transit in the form of allowance oil. Allowance oil represents the net difference between the tariff PLA volumes and the actual volumetric losses. We obtain control of the excess oil not lost during transportation, if any. Under the revenue standard, we include the excess oil retained during the period, if any, as non-cash consideration and include this amount in the transaction price for transportation services on a net basis. Our allowance oil revenue is valued at the average market price of the relevant type of crude oil during the month product was transported. Gains from pipeline operations that relate to allowance oil are recorded in Operations and maintenance expenses in the accompanying consolidated statements of income. As a result of FERC regulations, revenues we collect may be subject to refund. We establish reserves for these potential refunds based on actual expected refund amounts on the specific facts and circumstances. W e had no reserves for potential refunds as of December 31, 2020 and 2019. Storage and terminaling services revenue Storage and terminaling services are provided under short-term and long-term contracts, with a fixed price per month for committed storage and terminaling capacity, or under a monthly spot-rate for uncommitted storage or terminaling. Since the customer simultaneously receives and consumes the benefits of services, we recognize revenue over time based on the number of days elapsed. We apply the allocation exception guidance for variable consideration related to market indexing for long-term contracts because (a) the variable payment relates specifically to our efforts to transfer the distinct service and (b) we allocate the variable amount of consideration entirely to the distinct service, which is consistent with the allocation objective. Storage and terminaling services are billed monthly as services are rendered. Terminaling services revenue - Norco Assets In April 2020, the Partnership closed the April 2020 Transaction pursuant to which the Norco Assets were transferred from SOPUS and Shell Chemical to Triton. In connection with closing the April 2020 Transaction, Triton entered into terminaling service agreements with SOPUS and Shell Chemical related to the Norco Assets. These terminaling service agreements were entered into for an initial term of fifteen years, with the option to extend for additional five-year terms. The transfer of the Norco Assets, combined with the terminaling services agreements, were accounted for as a failed sale leaseback under the lease standard. The Partnership receives an annual net payment of $140 million, which is the total annual payment pursuant to the terminaling service agreements of $151 million, less $11 million, which primarily represents the allocated utility costs from SOPUS related to the Norco Assets. These agreements have components related to financing receivables, for which the interest income is recognized in the consolidated statements of income and principal payments are recognized as a reduction to the financing receivables in the consolidated balance sheet. Revenue related to the operation and maintenance service components and major maintenance service components are presented within Transportation, terminaling and storage services – related parties in the consolidated statements of income. The operation and maintenance service components consist of the Partnership’s obligation to operate the Norco Assets over the life of the agreements. It is considered a distinct service that represents a performance obligation that would be satisfied over time if it were accounted for separately. The services provided over the contract period are a series of distinct services that are substantially the same, have the same pattern of transfer to the customer, and, therefore, qualify as a single performance obligation. Since the customer simultaneously receives and consumes the benefits of services, we recognize revenue over time based on the number of days elapsed. The major maintenance service components consist of the Partnership’s obligation to provide major maintenance on the Norco Assets such that the current capacity available to the customers is maintained over the life of the agreements. It is considered a distinct service that represents a performance obligation that would be satisfied over time if it were accounted for separately. The services provided over the contract period are a series of distinct services that are substantially the same, have the same pattern of transfer to the customer, and, therefore, qualify as a single performance obligation. Since the customer simultaneously receives and consumes the benefits of services, we recognize revenue over time using the input method (cost-to-cost method) based on the ratio of actual major maintenance costs incurred to date to the total forecasted major maintenance costs over the contract term. We allocate the arrangement consideration between the components based on the relative stand-alone selling price of each component in accordance with the revenue standard. The Partnership established the stand-alone selling price for the financing components based off an expected return on the assets being financed. The Partnership established the stand-alone selling price for the service components using expected cost-plus margin approach based on the Partnership’s forecasted costs of satisfying the performance obligation plus an appropriate margin for the service. The key assumptions include forecasts of the future operation and maintenance costs and major maintenance costs and the expected margin with respect to the service components and the expected return on the assets with respect to the financing components. Deferred revenue Our FERC-approved transportation services agreements on Zydeco entitle the customer to a specified amount of guaranteed capacity on the pipeline. This capacity cannot be pro-rated even if the pipeline is oversubscribed. In exchange, the customer makes a specified monthly payment regardless of the volume transported. If the customer does not ship its full guaranteed volume in a given month, it makes the full monthly cash payment (i.e., deficiency payments) and it may ship the unused volume in a later month for no additional cash payment for up to 12 months, subject to availability on the pipeline. The cash payment received is recognized as deferred revenue, a contract liability under the revenue standard. If there is insufficient capacity on the pipeline to allow the unused volume to be shipped, the customer forfeits its right to ship such unused volume. We do not refund any cash payments relating to unused volumes. Under the revenue standard, we are required to estimate the likelihood that unused volumes will be shipped or forfeited at each reporting period based on additional data that becomes available and only to the extent that it is probable that a significant reversal of revenue will not occur. In some cases, this estimate could result in the earlier recognition of revenue. We also recognize deferred revenue on the major maintenance service components of the terminaling service agreement related to Norco Assets when we invoice SOPUS and Shell Chemical for the minimum volume commitment. Please refer to the T erminaling services revenues - Norco Assets section above for additional revenue recognition discussion. Reimbursements from customers Under certain transportation, terminaling and storage service contracts, we receive reimbursements from customers to recover costs of construction, maintenance or operating costs either under a tariff surcharge per volume shipped or under separate reimbursement payments. Because we consider these amounts as consideration from customers associated with ongoing services to be provided to customers, we defer these payments in deferred revenue and recognize amounts in revenue over the life of the associated revenue contract as performance obligations are satisfied under the contract. We consider these payments to be revenue because control of the long-lived assets does not transfer to our customer upon completion. Our financial statements were not materially impacted by adoption of the revenue standard related to reimbursements from customers. Product revenue We generate revenue by selling accumulated allowance oil inventory to customers. The sale of allowance oil is recorded as product revenue, with specific cost based on a weighted average price per barrel recorded as cost of product sold. Joint tariff Under a certain joint tariff, we record revenues on a gross basis within Transportation, terminaling and storage services – third parties or related parties because we control the transportation service before it is transferred to the customer and are therefore the principal. Contract Balances We perform our obligations under a contract with a customer by providing services in exchange for consideration from the customer. The timing of our performance may differ from the timing of the customer’s payment, which results in the recognition of a contract asset or a contract liability. We recognize a contract asset when we transfer goods or services to a customer and contractually bill an amount which is less than the revenue allocated to the related performance obligation. We recognize deferred revenue (contract liability) when the customer’s payment of consideration precedes our performance. The following table provides information about receivables and contract liabilities from contracts with customers: January 1, 2020 December 31, 2020 Receivables from contracts with customers – third parties $ 11 $ 19 Receivables from contracts with customers – related parties 24 18 Contract Assets - related parties — 233 Deferred revenue – third parties — 4 Deferred revenue – related parties (1) — 19 (1) Deferred revenue - related parties is related to deficiency credits from certain minimum volume commitment contracts and certain components of our terminaling service contracts on the Norco Assets. January 1, 2019 December 31, 2019 Receivables from contracts with customers – third parties $ 19 $ 11 Receivables from contracts with customers – related parties 21 24 Deferred revenue – third parties 8 — Deferred revenue – related parties 3 — In connection with the April 2020 Transaction, we also recorded contract assets in the amount of $244 million as of April 1, 2020 based on the difference between the consideration allocated to the Norco Transaction and the recognized financing receivables. The contract assets represent the excess of the fair value embedded within the terminaling services agreements transferred by the Partnership to SOPUS and Shell Chemical as part of entering into the terminaling services agreements. The contract assets balance is amortized in a pattern consistent with the recognition of revenue on the service components of the contract. The portion of the contract assets related to operations and maintenance is amortized on a straight-line basis over a fifteen-year period, and the portion related to major maintenance is amortized based on the ratio of actual major maintenance costs incurred to the total projected major maintenance costs over the fifteen year term. We recorded amortization as a component of Transportation, terminaling and storage services – related parties of $11 million for the year ended December 31, 2020. We had no contract assets recognized from the costs to obtain or fulfill a contract as of December 31, 2019. The estimated future amortization related to the contract assets for the next five years is as follows: 2021 2022 2023 2024 2025 Amortization $ 15 $ 16 $ 16 $ 17 $ 17 Significant changes in the deferred revenue balances with customers during the period are as follows: December 31, 2019 Additions (1) Reductions (2) December 31, 2020 Deferred revenue – third parties $ — $ 8 $ (4) $ 4 Deferred revenue – related parties — 21 (2) 19 (1) Deferred revenue additions resulted from $24 million deficiency payments from minimum volume commitment contracts and $5 million of deferred revenue related to the major maintenance service components of our terminaling service contracts on the Norco Assets. (2) Deferred revenue reductions resulted from revenue earned through the actual or estimated use and expiration of deficiency credits. December 31, 2018 Additions (1) Reductions (2) December 31, 2019 Deferred revenue – third parties $ 8 $ — $ (8) $ — Deferred revenue – related parties 3 — (3) — (1) Deferred revenue additions resulted from deficiency payments from minimum volume commitment contracts. (2) Deferred revenue reductions resulted from revenue earned through the actual or estimated use and expiration of deficiency credits. Remaining Performance Obligations The following table includes revenue expected to be recognized in the future related to performance obligations exceeding one year of their initial terms that are unsatisfied or partially unsatisfied as of December 31, 2020: Total 2021 2022 2023 2024 2025 and beyond Revenue expected to be recognized on multi-year committed shipper transportation contracts $ 472 $ 63 $ 63 $ 63 $ 57 $ 226 Revenue expected to be recognized on other multi-year transportation service contracts (1) 34 6 6 6 5 11 Revenue expected to be recognized on multi-year storage service contracts 17 4 4 4 5 — Revenue expected to be recognized on multi-year terminaling service contracts (1) 335 48 48 48 48 143 Revenue expected to be recognized on multi-year operation and major maintenance terminaling service contracts (2) 1,508 106 106 106 106 1,084 Total $ 2,366 $ 227 $ 227 $ 227 $ 221 $ 1,464 (1) Relates to the non-lease service components of certain of our long-term transportation and terminaling service contracts which are accounted for as operating leases. (2) Relates to the operation and maintenance service components and the major maintenance service components of our terminaling service contracts on the Norco Assets in connection with the April 2020 Transaction. As an exemption, we do not disclose the amount of remaining performance obligations for contracts with an original expected duration of one year or less or for variable consideration that is allocated entirely to a wholly unsatisfied promise to transfer a distinct service that forms part of a single performance obligation.

Net Income Per Limited Partner

Net Income Per Limited Partner Unit	12 Months Ended
Net Income Per Limited Partner Unit	Dec. 31, 2020
Partners' Capital Notes [Abstract]
Net Income Per Limited Partner Unit	Net Income Per Limited Partner Unit Net income per unit applicable to common limited partner units is computed by dividing the respective limited partners’ interest in net income attributable to the Partnership for the period by the weighted average number of common units outstanding for the period. Prior to April 1, 2020, the classes of participating securities included common units, general partner units and IDRs. Because we had more than one class of participating securities, we used the two-class method when calculating the net income per unit applicable to limited partners. Effective April 1, 2020, the classes of participating securities included only common units, as the general partner units and the IDRs were eliminated and the Series A Preferred Units are not considered a participating security. See Note 11 – (Deficit) Equity for a discussion of the elimination of our general partner’s IDRs and 2% economic interest effective April 1, 2020. For the year ended December 31, 2020, our Series A Preferred Units were dilutive to net income per limited partner unit. Basic and diluted net income per unit are the same for prior periods because we did not have any potentially dilutive units outstanding for those periods presented. Net income earned by the Partnership is allocated between the classes of participating securities in accordance with the terms of our partnership agreement as in effect on the date such calculation is performed, after giving effect to priority income allocations to the holders of the Series A Preferred Units if applicable. Earnings are allocated based on actual cash distributions declared to our unitholders, including those attributable to the IDRs prior to the second quarter of 2020, if applicable. To the extent net income attributable to the Partnership exceeds or is less than cash distributions, this difference is allocated based on the unitholders’ respective ownership percentages. For the diluted net income per limited partner unit calculation under the Second Amended and Restated Partnership Agreement, the Series A Preferred Units are assumed to be converted at the beginning of the period into common limited partner units on a one-for-one basis, and the distribution formula for available cash is recalculated using the available cash amount increased only for the preferred distributions, which would have been attributable to the common units after conversion. The following tables show the allocation of net income attributable to the Partnership to arrive at net income per limited partner unit: 2020 2019 2018 Net income $ 556 $ 546 $ 482 Less: Net income attributable to noncontrolling interests 13 18 18 Net income attributable to the Partnership 543 528 464 Less: General partner’s distribution declared (1) 55 148 135 Preferred unitholder’s interest in net income 36 — — Limited partners’ distribution declared on common units (2) 590 404 334 Distributions in excess of income $ (138) $ (24) $ (5) (1) For 2019, this includes the impact of waived distributions to the holders of the IDRs. See Note 4 — Related Party Transactions for additional information. (2) For 2020, this includes the impact of waived distributions to SPLC. See Note 4 — Related Party Transactions for additional information. 2020 General Partner Limited Partners’ Common Units Total (in millions of dollars, except per unit data) Distributions declared (1) $ 55 $ 590 $ 645 Distributions in excess of income — (138) (138) Net income attributable to the Partnership’s common unitholders (basic) $ 55 $ 452 $ 507 Dilutive effect of preferred units 36 Net income attributable to the Partnership’s common unitholders (diluted) $ 488 Weighted average units outstanding - Basic 353.5 Dilutive effect of preferred units 38.2 Weighted average units outstanding - Diluted 391.7 Net income per limited partner unit: Basic $ 1.28 Diluted $ 1.25 (1) This includes the impact of waived distributions to SPLC. See Note 4 — Related Party Transactions for additional information. 2019 General Partner Limited Partners’ Common Units Total (in millions of dollars, except per unit data) Distributions declared (1) $ 148 $ 404 $ 552 Distributions in excess of income (1) (23) (24) Net income attributable to the Partnership $ 147 $ 381 $ 528 Weighted average units outstanding: Basic and diluted 229.2 Net income per limited partner unit: Basic and diluted $ 1.66 (1) This includes the impact of waived distributions to the holders of the IDRs. See Note 4 — Related Party Transactions for additional information. 2018 General Partner Limited Partners’ Common Units Total (in millions of dollars, except per unit data) Distributions declared $ 135 $ 334 $ 469 Distributions in excess of income (1) (4) (5) Net income attributable to the Partnership $ 134 $ 330 $ 464 Weighted average units outstanding: Basic and diluted 220.3 Net income per limited partner unit: Basic and diluted $ 1.50

Transactions with Major Custome

Transactions with Major Customers and Concentration of Credit Risk	12 Months Ended
	Dec. 31, 2020
Risks and Uncertainties [Abstract]
Transactions with Major Customers and Concentration of Credit Risk	Transactions with Major Customers and Concentration of Credit Risk Our Parent and its affiliates accounted for approximately 75%, 70% and 60% of our total revenues for 2020, 2019 and 2018, respectively. There is no third-party customer that accounted for a 10% or greater share of consolidated revenues or net accounts receivable for the year ended December 31, 2020. We have a concentration of revenues and trade receivables due from customers in the same industry, our Parent’s affiliates, integrated oil companies, marketers and independent exploration, production and refining companies primarily within the Gulf Coast region of the United States. These concentrations of customers may impact our overall exposure to credit risk as they may be similarly affected by changes in economic, regulatory, regional and other factors. We are potentially exposed to concentration of credit risk primarily through our accounts receivable with our Parent. These receivables have payment terms of 30 days or less, and there has been no history of collectability issues. We monitor the creditworthiness of third-party major customers. We manage our exposure to credit risk through credit analysis, credit limit approvals and monitoring procedures, and for certain transactions, we may request letters of credit, prepayments or guarantees. As of December 31, 2020 and 2019, there were no such arrangements with customers.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and ContingenciesEnvironmental Matters We are subject to federal, state and local environmental laws and regulations. We routinely conduct reviews of potential environmental issues and claims that could impact our assets or operations. These reviews assist us in identifying environmental issues and estimating the costs and timing of remediation efforts. In making environmental liability estimations, we consider the material effect of environmental compliance, pending legal actions against us and potential third-party liability claims. Often, as the remediation evaluation and effort progresses, additional information is obtained, requiring revisions to estimated costs. These revisions are reflected in our income in the period in which they are probable and reasonably estimable. For both December 31, 2020 and 2019, these costs and any related liabilities are not material. Legal Proceedings We are named defendants in lawsuits and governmental proceedings that arise in the ordinary course of business. For each of our outstanding legal matters, we evaluate the merits of the case, our exposure to the matter, possible legal or settlement strategies and the likelihood of an unfavorable outcome. While there are still uncertainties related to the ultimate costs we may incur, based upon our evaluation and experience to date, we do not expect that the ultimate resolution of these matters will have a material adverse effect on our financial position, operating results or cash flows. Indemnification Under the 2019 Omnibus Agreement, certain tax liabilities are indemnified by SPLC. See Note 4 — Related Party Transactions for additional information. Other Commitments Odyssey entered into a tie-in agreement effective January 2012 with a third party, which allowed producers to install the tie-in connection facilities and tying into the system. The agreement will continue to be in effect until the continued operation of the platform is uneconomic. We hold cancellable easements or rights-of-way arrangements from landowners permitting the use of land for the construction and operation of our pipeline systems. Obligations under these easements are not material to the results of our operations.

Subsequent Event(s)

Subsequent Event(s)	12 Months Ended
Subsequent Event(s)	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Event(s)	Subsequent Event(s) We have evaluated events that occurred after December 31, 2020 through the issuance of these consolidated financial statements. Any material subsequent events that occurred during this time have been properly recognized or disclosed in the consolidated financial statements and accompanying notes. Distribution On January 20, 2021, the Board declared a cash distribution of $0.4600 per limited partner unit and $0.2363 per limited partner preferred unit for the three months ended December 31, 2020. The distribution was paid on February 12, 2021 to unitholders of record as of February 2, 2021. Assets Held for Sale On January 25, 2021, we executed an agreement to divest the 12” segment of the Auger pipeline, effective March 1, 2021. The remainder of the Auger pipeline will continue to operate under the ownership of Pecten. As a result of the divestment, we expect to record an impairment charge of approximately $3 million during the first quarter of 2021. 2019 Omnibus Agreement On February 16, 2021, pursuant to the 2019 Omnibus Agreement, the Board approved a decrease to the annual general and administrative fee for 2021 based on a change in the cost of the services provided. The annual fee for 2021 will be $10 million for the provision of certain services provided by SPLC to us.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2020
Accounting Policies [Abstract]
Description of Business	Description of the Business We own, operate, develop and acquire pipelines and other midstream and logistics assets. As of December 31, 2020, our assets include interests in entities that own (a) crude oil and refined products pipelines and terminals that serve as key infrastructure to transport onshore and offshore crude oil production to Gulf Coast and Midwest refining markets and deliver refined products from those markets to major demand centers and (b) storage tanks and financing receivables that are secured by pipelines, storage tanks, docks, truck and rail racks and other infrastructure used to stage and transport intermediate and finished products. The Partnership’s assets also include interests in entities that own natural gas and refinery gas pipelines that transport offshore natural gas to market hubs and deliver refinery gas from refineries and plants to chemical sites along the Gulf Coast.
Basis of Presentation	Basis of Presentation Our consolidated financial statements include all subsidiaries required to be consolidated under generally accepted accounting principles in the United States (“GAAP”). Our reporting currency is U.S. dollars, and all references to dollars are U.S. dollars. The accompanying consolidated financial statements and related notes have been prepared under the rules and regulations of the Securities and Exchange Commission (the “SEC”). These rules and regulations conform to the accounting principles contained in the Financial Accounting Standards Board’s (“FASB”) Accounting Standards Codification, the single source of GAAP. Our consolidated subsidiaries include Pecten, Sand Dollar, Triton, Zydeco, Odyssey and the Operating Company. Asset acquisitions of additional interests in previously consolidated subsidiaries and interests in equity method and other investments are included in the financial statements prospectively from the effective date of each acquisition. In cases where these types of acquisitions are considered acquisitions of businesses under common control, the financial statements are retrospectively adjusted. Expense Allocations. Our consolidated statements of income also include expense allocations for certain functions performed by SPLC and Shell on our behalf. Such costs are included in either general and administrative expenses or operations and maintenance expenses in the accompanying consolidated statements of income, depending on the nature of the employee’s role in our operations. The expense allocations have been determined on a basis that we, SPLC and Shell consider to be a reasonable reflection of the utilization of the services provided or the benefit received during the periods presented. See Note 4 — Related Party Transactions for details of operating agreements impacting expense allocations, as well as details of related party transactions.
Principles of Consolidation	Principles of Consolidation Our consolidated financial statements include all subsidiaries where we have control. The assets and liabilities in the accompanying consolidated financial statements have been reflected on a historical basis. All significant intercompany accounts and transactions are eliminated upon consolidation.
Regulation	Regulation Certain businesses are subject to regulation by various authorities including, but not limited to, FERC. Regulatory bodies exercise statutory authority over matters such as construction, rates and ratemaking and agreements with customers.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported of assets, liabilities, revenues and expenses in the accompanying consolidated financial statements and notes. Actual results could differ from those estimates.
Common Control Transactions	Common Control Transactions Assets and businesses acquired from our Parent and its subsidiaries are accounted for as common control transactions whereby the net assets acquired are combined with ours at our Parent’s historical carrying value. If any recognized consideration transferred in such a transaction exceeds the carrying value of the net assets acquired, the excess is treated as a capital distribution to our general partner, similar to a dividend. If the carrying value of the net assets acquired exceeds any recognized consideration transferred including, if applicable, the fair value of any limited partner units issued, then our Parent would record an impairment, and our net assets acquired would be recorded at fair value. Cash consideration up to the carrying value of net assets acquired is presented as an investing activity in our consolidated statement of cash flows. Cash consideration in excess of the carrying value of net assets acquired is presented as a financing activity in our consolidated statement of cash flows. Assets and businesses sold to our Parent are also common control transactions accounted for using historical carrying value with any resulting gain treated as a contribution from Parent.
Revenue Recognition	Revenue Recognition Our revenues are primarily generated from the transportation, terminaling and storage of crude oil, refined gas and refined petroleum products through our pipelines, terminals, storage tanks, docks, truck and rail racks. We recognize revenue when we transfer promised goods or services to customers in an amount that reflects the consideration to which we expect to be entitled in exchange for those goods or services. We recognize revenue through the application of a five-step model, which includes: identification of the contract; identification of the performance obligations; determination of the transaction price; allocation of the transaction price to the performance obligations; and recognition of revenue as the entity satisfies the performance obligations.
Leases, Sale Leaseback	Leases, Sale Leaseback When entering into sale-leaseback transactions as a buyer-lessor, the requirements in Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers, and all related accounting standards updates to such Topic (collectively, “the revenue standard”) are applied in determining whether the transfer of an asset shall be accounted for as a sale of the asset by assessing whether it satisfies a performance obligation under the contract by transferring control of an asset. If the seller-lessee transfers control of an asset to us, we account for the transfer of the asset as a purchase and recognize the transferred asset. The subsequent leaseback of the asset is accounted for in accordance with ASC Topic 842, Leases (the “lease standard”), in the same manner as any other lease. If the seller-lessee does not transfer the control of an asset to us, the failed sale-leaseback transaction is accounted for as a financing arrangement. Transactions in which control of an asset is not transferred are accounted for as financing receivables in accordance with ASC Topic 310, Receivables. Since the seller-lessee did not transfer the control of assets to us in the April 2020 Transaction (defined in Note 3 — Acquisitions and Other Transactions below), we did not recognize the transferred assets, and instead they were accounted for as financing receivables. Receivables issued in exchange for the Partnership’s capital stock are presented as a component of the partners’ (deficit) equity. Since the Partnership issued common units and preferred units as consideration in exchange for the financing receivables in the April 2020 Transaction, we recorded the financing receivables as contra-equity. Refer to Note 3 — Acquisitions and Other Transactions and Note 11 – (Deficit) Equity for additional details. We recognize interest income on the financing receivables on the basis of the imputed interest rate determined in accordance with ASC Topic 835, Interest.
Cash and Cash Equivalents	Cash and Cash Equivalents Our cash and cash equivalents includes cash and short-term highly liquid overnight deposits.
Accounts Receivable and Allowance for Doubtful Accounts	Accounts Receivable and Allowance for Doubtful AccountsAccounts receivable represent valid claims against customers for products sold or services rendered, net of allowances for doubtful accounts. We assess the creditworthiness of our counterparties on an ongoing basis and require security, including prepayments and other forms of collateral, when appropriate. We establish provisions for losses on third-party accounts receivable due from shippers and operators based on current expected credit losses.
Other Investments	Equity Method Investments We account for investments where we have the ability to exercise significant influence, but not control, under the equity method of accounting. Income from equity method investments represents our proportionate share of net income generated by the equity method investees. Differences in the basis of the investments and the underlying net asset value of the investees, if any, are amortized into net income over the remaining useful lives of the underlying assets. Equity method investments are assessed for impairment whenever changes in the facts and circumstances indicate a loss in value has occurred, if the loss is deemed to be other-than-temporary. When the loss is deemed to be other-than-temporary, the carrying value of the equity method investment is written down to fair value.
Property, Plant and Equipment	Property, Plant and Equipment Our property, plant and equipment is recorded at its historical cost of construction or, upon acquisition, at either the fair value of the assets acquired or the historical carrying value to the entity that placed the asset in service. Expenditures for major renewals and betterments are capitalized while those minor replacement, maintenance and repairs that do not improve or extend asset life are expensed when incurred. For constructed assets, we capitalize all construction-related direct labor and material costs, as well as indirect construction costs. We capitalize interest on certain projects. For 2020, 2019 and 2018, the total amount of interest capitalized was immaterial.
Impairment of Long-lived Assets	Impairment of Long-lived Assets We evaluate long-lived assets of identifiable business activities for impairment when events or changes in circumstances indicate, in our management’s judgment, that the carrying value of such assets may not be recoverable. These events include a significant decrease in the market value of the asset, changes in the manner in which we intend to use a long-lived asset, decisions to sell an asset and adverse changes in the legal or business environment such as adverse actions by regulators. If an event occurs, which is a determination that involves judgment, we perform an impairment assessment by comparing estimated undiscounted future cash flows associated with the asset to the asset’s net book value. If the net book value exceeds our estimate of undiscounted future cash flows, an impairment is calculated as the amount the net book value exceeds the estimated fair value associated with the asset.
Income Taxes	Income Taxes We are not a taxable entity for U.S. federal income tax purposes or for the majority of states that impose an income tax. Taxes on our net income are generally borne by our partners through the allocation of taxable income. Our income tax expense results from partnership activity in the state of Texas, as conducted by Zydeco, Sand Dollar and Triton. Income tax expense for 2020, 2019 and 2018 was immaterial.
Other Investments	Other Investments We account for equity investments in entities where we do not have control or significant influence at fair value with changes in fair value recognized in net income when the fair value is readily determinable. For investments without readily determinable fair values, we carry such investments at cost less impairments, if any. These investments are remeasured either upon the
Asset Retirement Obligations	Asset Retirement Obligations AROs represent contractual or regulatory obligations associated with the retirement of long-lived assets that result from the acquisition, construction, development and/or normal use of the asset. Our AROs were zero as of both December 31, 2020 and 2019. Our assets include pipelines and terminals that have contractual or regulatory obligations that will need to be settled at retirement. The settlement date of these obligations will depend mostly on the various supply sources that connect to our systems and the ongoing demand for usage in the markets we serve. We expect these supply sources and market demands to continue for the foreseeable future. As the settlement dates of obligations are indeterminate, there is not sufficient information to make a reasonable estimate of the ARO of our remaining assets as of December 31, 2020 and 2019. We re-evaluate our AROs in each reporting period, and future developments could impact the amounts we record.
Pensions and Other Postretirement Benefits	Pensions and Other Postretirement Benefits We do not have our own employees. Employees that work on our pipelines or terminals are employees of SPLC, and we share employees with other SPLC-controlled and non-controlled entities. For presentation of these accompanying consolidated financial statements, our portion of payroll costs and employee benefit plan costs have been allocated as a charge to us by SPLC and Shell Oil Company. Shell Oil Company sponsors various employee pension and postretirement health and life insurance plans. For purposes of these accompanying consolidated financial statements, we are considered to be participating in the benefit plans of Shell Oil Company. We participate in the following defined benefits plans: Shell Oil Pension Plan, Shell Oil Retiree Health Care Plan and Pennzoil-Quaker State Retiree Medical & Life Insurance. As a participant in these benefit plans, we recognize as expense in each period an allocation from Shell Oil Company, and we do not recognize any employee benefit plan assets or liabilities. See Note 4 — Related Party Transactions
Legal	Legal We are subject to litigation and regulatory proceedings as the result of our business operations and transactions. We use both internal and external counsel in evaluating our potential exposure to adverse outcomes from orders, judgments or settlements. In general, we expense legal costs as incurred. When we identify specific litigation that is expected to continue for a significant period of time, is probable to occur and may require substantial expenditures, we identify a range of possible costs expected to be required to litigate the matter to a conclusion or reach an acceptable settlement, and we accrue for the most probable outcome. To the extent that actual outcomes differ from our estimates, or additional facts and circumstances cause us to revise our estimates, our earnings will be affected.
Environmental Matters	Environmental Matters We are subject to federal, state, and local environmental laws and regulations. Environmental expenditures are expensed or capitalized depending on their economic benefit. We expense costs such as permits, compliance with existing environmental regulations, remedial investigations, soil sampling, testing and monitoring costs to meet applicable environmental laws and regulations where prudently incurred or determined to be reasonably possible in the ordinary course of business. We are permitted to recover such expenditures through tariff rates charged to customers. We also expense costs that relate to an existing condition caused by past environmental incidents, which do not contribute to current or future revenue generation. We record environmental liabilities when environmental assessments and/or remedial efforts are probable and we can reasonably estimate the costs. Generally, our recording of these accruals coincides with our completion of a feasibility study or our commitment to a formal plan of action. We recognize receivables for anticipated associated insurance recoveries when such recoveries are deemed to be probable. For 2020, 2019 and 2018, the environmental cleanup costs incurred were immaterial. At both December 31, 2020 and 2019, the accruals for environmental clean-up costs pursuant to a Consent Decree issued in 1998 by the State of Washington Department of Ecology with respect to our products terminal located in Seattle, Washington were immaterial. The costs relate to ongoing groundwater compliance monitoring and other remedial activities. Refer to Note 4 — Related Party Transactions under the Omnibus Agreement (defined below) for additional details.
Other Contingencies	Other Contingencies We recognize liabilities for other contingencies when we have an exposure that indicates it is both probable that a liability has been incurred and the amount of loss can be reasonably estimated. Where the most likely outcome of a contingency can be reasonably estimated, we accrue a liability for that amount. Where the most likely outcome cannot be estimated, a range of potential losses is established and if no one amount in that range is more likely than any other, the lower end of the range is accrued.
Fair Value Estimates	Fair Value Estimates We measure assets and liabilities requiring fair value presentation or disclosure using an exit price ( i.e. , the price that would be received to sell an asset or paid to transfer a liability) and disclose such amounts according to the quality of valuation inputs under the following hierarchy: Level 1: Quoted prices in an active market for identical assets or liabilities. Level 2: Inputs other than quoted prices that are directly or indirectly observable. Level 3: Unobservable inputs that are significant to the fair value of assets or liabilities. We classify the fair value of an asset or liability based on the lowest level of input significant to its measurement. A fair value initially reported as Level 3 will be subsequently reported as Level 2 if the unobservable inputs become inconsequential to its measurement or corroborating market data becomes available. Asset and liability fair values initially reported as Level 2 will be subsequently reported as Level 3 if corroborating market data becomes unavailable.
Net Income per Limited Partner Unit	Net income per limited partner unitPrior to the April 2020 Transaction, we used the two-class method when calculating the net income per unit applicable to limited partners as there were different participating securities included in the calculation – including common units, general partner units and IDRs. After the April 2020 Transaction, the IDRs were eliminated, the 2% general partner economic interest was converted into a non-economic general partner interest in the Partnership and the newly issued Series A Preferred Units did not qualify as participating securities. Since the transaction occurred during 2020, the two-class method was still applied to the year-to-date calculation but was not applied to calculations for any quarterly periods beginning with the second quarter of 2020.
Reclassifications	ReclassificationsCertain reclassifications have been made to prior period amounts in our consolidated statements of income and consolidated balance sheets to conform to the current period presentation. The net effect of these reclassifications was not material to our consolidated financial statements.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Standards Adopted as of January 1, 2020 In June 2016, the FASB issued Accounting Standards Update (“ASU”) 2016-13 to Topic 326, Financial Instruments — Credit Losses: Measurement of Credit Losses on Financial Instruments, which replaces the current incurred loss impairment method with a method that reflects expected credit losses on financial instruments. The measurement of current expected credit losses under the new guidance is applicable to financial assets measured at amortized cost, including third-party trade receivables. We adopted the new standard effective January 1, 2020, using the modified retrospective method for all financial assets measured. No cumulative-effect adjustment to retained earnings was required upon adoption. The adoption of ASU 2016-13 did not have a material impact on our consolidated financial statements. Standards Not Adopted as of December 31, 2020 In August 2020, the FASB issued ASU 2020-06, Debt — Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging — Contracts in Entity’s Own Equity. The update will simplify the accounting for convertible instruments by reducing the number of accounting models for convertible debt instruments and convertible preferred stock. Limiting the accounting models may result in fewer embedded conversion features being separately recognized from the host contract as compared with current GAAP. This update also amends the guidance for the derivatives scope exception for contracts in an entity’s own equity to reduce form-over-substance-based accounting conclusions. The update is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2021 for SEC filers, excluding smaller reporting companies. Early adoption is permitted, but not earlier than January 1, 2021, including interim periods within that year. Management is currently evaluating the appropriate date of adoption and the effect of the adoption of this update on our consolidated financial statements. The effect will largely depend on the composition and terms of our financial instruments at the time of adoption.

Description of the Business a_2

Description of the Business and Basis of Presentation (Tables)	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Ownership Percentage	The following table reflects our ownership interests as of December 31, 2020: SHLX Ownership Pecten Midstream LLC (“Pecten”) 100.0 % Sand Dollar Pipeline LLC (“Sand Dollar”) 100.0 % Triton West LLC (“Triton”) 100.0 % Zydeco Pipeline Company LLC (“Zydeco”) (1) 92.5 % Mattox Pipeline Company LLC (“Mattox”) 79.0 % Amberjack Pipeline Company LLC (“Amberjack”) – Series A/Series B 75.0% / 50.0% Mars Oil Pipeline Company LLC (“Mars”) 71.5 % Odyssey Pipeline L.L.C. (“Odyssey”) 71.0 % Bengal Pipeline Company LLC (“Bengal”) 50.0 % Crestwood Permian Basin LLC (“Permian Basin”) 50.0 % LOCAP LLC (“LOCAP”) 41.48 % Explorer Pipeline Company (“Explorer”) 38.59 % Poseidon Oil Pipeline Company, L.L.C. (“Poseidon”) 36.0 % Colonial Enterprises, Inc. (“Colonial”) 16.125 % Proteus Oil Pipeline Company, LLC (“Proteus”) 10.0 % Endymion Oil Pipeline Company, LLC (“Endymion”) 10.0 % Cleopatra Gas Gathering Company, LLC (“Cleopatra”) 1.0 % (1) SPLC owns the remaining 7.5% ownership interest in Zydeco.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
Summary of Significant Accounting Policies (Tables)	Dec. 31, 2020
Accounting Policies [Abstract]
Schedule of Cost Method Investments	Our equity investments which are accounted for at cost as they do not have readily determinable fair values, consist of: December 31, 2020 December 31, 2019 Ownership Amount Ownership Amount Cleopatra 1.0 % $ 2 1.0 % $ 2

Acquisitions and Other Transact

Acquisitions and Other Transactions (Tables)	12 Months Ended
Acquisitions and Other Transactions (Tables)	Dec. 31, 2020
Business Combinations [Abstract]
Schedule Of Balances In Equity Transaction	In connection with the April 2020 Transaction, the Partnership recorded the following balances as of April 1, 2020: Equity method investment (1) $ 174 Financing receivables – related parties (2) 302 Contract assets - related parties (3) 244 April 2020 Transaction $ 720 (1) Equity method investment was recorded at SGOM’s historical carrying value of the 79% interest in Mattox. See more discussion in the section entitled “Mattox Transaction” below. (2) Financing receivables under the failed sale leaseback were recorded at the fair value of the property, plant and equipment of the Norco Assets transferred by SOPUS and Shell Chemical and recognized as a component of the Partners’ deficit. See more discussion in the section entitled “Norco Transaction” below. (3) Contract assets were recorded based on the difference between the consideration allocated to the Norco Transaction and the financing receivables. See more discussion in the section entitled “Norco Transaction” below.

Related Party Transactions (Tab

Related Party Transactions (Tables)	12 Months Ended
Related Party Transactions (Tables)	Dec. 31, 2020
Related Party Transactions [Abstract]
Schedule of Other Related Party Balances	Other related party balances consist of the following: December 31, 2020 2019 Accounts receivable $ 21 $ 29 Prepaid expenses 22 15 Other assets 2 2 Contract assets (1) 233 — Accounts payable (2) 16 10 Deferred revenue 19 — Accrued liabilities (3) 28 19 Debt payable (4) 2,692 2,692 Financing receivables (1) 298 — (1) Contract assets and Financing receivables were recognized in connection with the April 2020 Transaction. Refer to the section entitled “Sale Leaseback” below for additional details. Financing receivables were presented as a component of (deficit) equity. (2) Accounts payable reflects amounts owed to SPLC for reimbursement of third-party expenses incurred by SPLC for our benefit. (3) As of December 31, 2020, Accrued liabilities reflects $16 million accrued interest and $12 million other accrued liabilities, which are primarily related to the accrued operation and maintenance expenses on the Norco Assets. As of December 31, 2019, Accrued liabilities reflects $18 million accrued interest and $1 million other accrued liabilities. (4) Debt payable reflects borrowings outstanding net of unamortized debt issuance costs of $2 million as of both December 31, 2020 and December 31, 2019.
Schedule of Related Party Expenses Including Personnel Costs	The following table shows related party expenses, including certain personnel costs, incurred by Shell and SPLC on our behalf that are reflected in the accompanying consolidated statements of income for the indicated periods. Included in these amounts, and disclosed below, is our share of operating and general corporate expenses, as well as the fees paid to SPLC under certain agreements. 2020 2019 2018 Allocated operating expenses $ 45 $ 18 $ 15 Major maintenance costs (1) 6 — — Insurance expense (2) 20 18 15 Other (3) 43 23 24 Operations and maintenance – related parties $ 114 $ 59 $ 54 Allocated general corporate expenses $ 29 $ 28 $ 33 Management Agreement fee 9 9 9 Omnibus Agreement fee 11 11 9 Other — 1 1 General and administrative – related parties $ 49 $ 49 $ 52 (1) Major maintenance costs are expensed as incurred in connection with the maintenance services of the Norco Assets. Refer to section entitled “Sale Leaseback” below for additional details. (2) The majority of our insurance coverage is provided by a wholly owned subsidiary of Shell. The remaining coverage is provided by third-party insurers. (3) Other expenses primarily relate to salaries and wages, other payroll expenses and special maintenance.
Schedule Of Interest Income, Reduction In Financing Receivables, Cash Payments For Interest Income And Principal Repayment Of Financing Receivable	The following table shows the interest income, reduction in the financing receivables, as well as the cash payments received for interest income and cash principal payments received on financing receivables for the year ended December 31, 2020: For the Year Ended December 31, 2020 Interest income $ 23 Reduction in the financing receivables 3 Cash payments received for interest income 20 Cash principal payments received on financing receivables 3

Equity Method Investments (Tabl

Equity Method Investments (Tables)	12 Months Ended
Equity Method Investments (Tables)	Dec. 31, 2020
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Equity Investments in Affiliates	Equity method investments comprise the following as of the dates indicated: December 31, 2020 2019 Ownership Amount Ownership Amount Mattox (1) 79% $ 163 — $ — Amberjack – Series A / Series B 75.0% / 50.0% 382 75.0% / 50.0% 426 Mars 71.5% 152 71.5% 161 Bengal 50.0% 88 50.0% 88 Permian Basin 50.0% 83 50.0% 91 LOCAP 41.48% 12 41.48% 9 Explorer (2) 38.59% 73 38.59% 88 Poseidon 36.0% — 36.0% — Colonial (2) 16.125% 29 16.125% 30 Proteus 10.0% 14 10.0% 15 Endymion 10.0% 17 10.0% 18 $ 1,013 $ 926 (1) Mattox was acquired as part of the April 2020 Transaction. This interest has been accounted for on a prospective basis. See below for additional information. (2) As part of the June 2019 Acquisition, these interests have been accounted for prospectively. See below for additional information.
Schedule Of Equity Investments In Affiliates Balance Affected Table	Earnings from our equity method investments were as follows during the periods indicated: For the Year Ended December 31, 2020 2019 2018 Mattox (1) $ 45 $ — $ — Amberjack (2) 102 125 80 Mars 114 126 108 Bengal 18 24 21 Explorer (3) 44 41 — Colonial (3) 75 40 — Poseidon (4) — — 6 Other (5) 19 17 20 $ 417 $ 373 $ 235 (1) We acquired an interest in Mattox in the April 2020 Transaction. The acquisition of this interest has been accounted for prospectively. (2) We acquired an interest in Amberjack in the May 2018 Acquisition. The acquisition of this interest has been accounted for prospectively. (3) We acquired additional interests in Explorer and Colonial in the June 2019 Acquisition. The acquisition of these interests has been accounted for prospectively. (4) As stated above, the equity method of accounting has been suspended in 2018 for Poseidon and excess distributions are recorded in Other income.
Summary of Balance Sheet and Income Statement Data for Equity Method Investments	The following tables present aggregated selected balance sheet and income statement data for our equity method investments on a 100% basis. However, during periods in which an acquisition occurs, the selected balance sheet and income statement data reflects activity from the date of the acquisition. For the Year Ended December 31, 2020 Total revenues Total operating expenses Operating income Net income Statements of Income Mattox (1) $ 66 $ 9 $ 57 $ 57 Amberjack 280 78 202 201 Mars 259 97 162 163 Bengal 65 30 35 35 Explorer 329 175 154 119 Colonial 1,395 660 735 473 Poseidon 147 36 111 105 Other (2) 220 123 97 88 As of December 31, 2020 Current assets Non-current assets Total assets Current liabilities Non-current liabilities Equity (deficit) Total liabilities and equity (deficit) Balance Sheets Mattox (1) $ 13 $ 204 $ 217 $ — $ 12 $ 205 $ 217 Amberjack 44 836 880 10 124 746 880 Mars 47 269 316 23 103 190 316 Bengal 33 161 194 7 — 187 194 Explorer 74 537 611 49 459 103 611 Colonial 501 3,105 3,606 245 3,508 (147) 3,606 Poseidon 31 176 207 10 238 (41) 207 Other (2) 35 920 955 56 486 413 955 (1) Our interest in Mattox was acquired in the April 2020 Transaction. Mattox’s total revenues, total operating expenses and operating income (on a 100% basis) were $85 million, $12 million and $73 million, respectively. (2) Included in Other is the activity associated with our investments in Permian Basin, LOCAP, Proteus and Endymion. For the Year Ended December 31, 2019 Total revenues Total operating expenses Operating income Net income Statements of Income Amberjack $ 315 $ 73 $ 242 $ 243 Mars 282 104 178 179 Bengal 77 30 47 47 Explorer (1) 258 115 143 111 Colonial (2) 829 449 380 255 Poseidon 132 35 97 87 Other (3) 190 108 82 73 As of December 31, 2019 Current assets Non-current assets Total assets Current liabilities Non-current liabilities Equity (deficit) Total liabilities and equity (deficit) Balance Sheets Amberjack $ 56 $ 804 $ 860 $ 4 $ 32 $ 824 $ 860 Mars 57 173 230 8 22 200 230 Bengal 35 157 192 6 — 186 192 Explorer (1) 93 530 623 44 442 137 623 Colonial (2) 323 2,920 3,243 519 2,873 (149) 3,243 Poseidon 30 190 220 16 246 (42) 220 Other (3) 60 917 977 73 469 435 977 (1) Our interest in Explorer was acquired on June 6, 2019. Explorer total revenues, total operating expenses and operating income (on a 100% basis) was $443 million, $196 million and $247 million, respectively. (2) Our interest in Colonial was acquired on June 6, 2019. Colonial total revenues, total operating expenses and operating income (on a 100% basis) was $1,437 million, $735 million and $702 million, respectively. (3) Included in Other is the activity associated with our investments in Permian Basin, LOCAP, Proteus and Endymion. For the Year Ended December 31, 2018 Total revenues Total operating expenses Operating income Net income Statements of Income Amberjack (1) $ 204 $ 47 $ 157 $ 157 Mars 241 87 154 154 Bengal 69 28 41 41 Poseidon 116 35 81 73 Other (2) 152 67 85 76 As of December 31, 2018 Current assets Non-current assets Total assets Current liabilities Non-current liabilities Equity (deficit) Total liabilities and equity (deficit) Balance Sheets Amberjack (1) $ 46 $ 846 $ 892 $ 4 $ 4 $ 884 $ 892 Mars 53 178 231 5 18 208 231 Bengal 27 156 183 9 — 174 183 Poseidon 19 203 222 16 243 (37) 222 Other (2) 50 876 926 65 456 405 926 (1) Our interest in Amberjack was acquired on May 11, 2018. Amberjack total revenues, total operating expenses and operating income (on a 100% basis) was $295 million, $74 million and $221 million, respectively. (2) Included in Other is the activity associated with our investments in Permian Basin, LOCAP, Proteus and Endymion.

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
Property, Plant and Equipment (Tables)	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Components of Property, Plant and Equipment	Property, plant and equipment, net consists of the following as of the dates indicated: December 31, Depreciable Life 2020 2019 Land — $ 12 $ 11 Building and improvements 10 - 40 years 47 40 Pipeline and equipment (1) 10 - 30 years 1,263 1,228 Other 5 - 25 years 34 33 1,356 1,312 Accumulated depreciation and amortization (2) (661) (613) 695 699 Construction in progress 4 27 Property, plant and equipment, net $ 699 $ 726 (1) As of December 31, 2020 and 2019, includes cost of $372 million and $369 million, respectively, related to assets under operating leases (as lessor). As of both December 31, 2020 and 2019, includes cost of $23 million related to assets under capital lease (as lessee). (2) As of December 31, 2020 and 2019, includes accumulated depreciation of $147 million and $133 million, respectively, related to assets under operating leases (as lessor), which commenced in May 2017 and December 2017. As of December 31, 2020 and 2019, includes accumulated depreciation of $8 million and $6 million, respectively, related to assets under capital lease (as lessee).

Accrued Liabilities - Third P_2

Accrued Liabilities - Third Parties (Tables)	12 Months Ended
Accrued Liabilities - Third Parties (Tables)	Dec. 31, 2020
Payables and Accruals [Abstract]
Schedule of Accrued Liabilities - Third Parties	Accrued liabilities – third parties consist of the following as of the dates indicated: December 31, 2020 2019 Project accruals $ 4 $ 5 Property taxes 5 4 Other accrued liabilities 1 3 Total accrued liabilities – third parties $ 10 $ 12

Related Party Debt (Tables)

Related Party Debt (Tables)	12 Months Ended
Related Party Debt (Tables)	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule of Consolidated Related Party Debt Obligations	Consolidated related party debt obligations comprise the following as of the dates indicated: December 31, 2020 December 31, 2019 Outstanding Balance Total Capacity Available Capacity Outstanding Balance Total Capacity Available Capacity Ten Year Fixed Facility $ 600 $ 600 $ — $ 600 $ 600 $ — Seven Year Fixed Facility 600 600 — 600 600 — Five Year Revolver due July 2023 494 760 266 494 760 266 Five Year Revolver due December 2022 400 1,000 600 400 1,000 600 Five Year Fixed Facility 600 600 — 600 600 — 2019 Zydeco Revolver — 30 30 — 30 30 Unamortized debt issuance costs (2) n/a n/a (2) n/a n/a Debt payable – related party $ 2,692 $ 3,590 $ 896 $ 2,692 $ 3,590 $ 896

Leases (Tables)

Leases (Tables)	12 Months Ended
Leases (Tables)	Dec. 31, 2020
Leases [Abstract]
Assets And Liabilities, Lessee	The following tables summarize balance sheet data related to leases at December 31, 2020 and 2019 and our lease costs as of and for the year ended December 31, 2020 and 2019 : Leases Classification December 31, 2020 December 31, 2019 Assets Operating lease assets Operating lease right-of-use assets $ 4 $ 4 Finance lease assets Property, plant and equipment, net (1) 16 17 Total lease assets $ 20 $ 21 Liabilities Current Finance Accrued liabilities - third parties $ 1 $ 1 Noncurrent Operating Operating lease liabilities 4 4 Finance Finance lease liabilities 24 24 Total lease liabilities $ 29 $ 29 (1) Finance lease assets are recorded net of accumulated amortization of $8 million as of December 31, 2020 and $6 million as of December 31, 2019.
Lease, Cost	Lease cost Classification December 31, 2020 December 31, 2019 Operating lease cost (1) Operations and maintenance - third parties $ — $ — Finance lease cost (cost resulting from lease payments): Amortization of leased assets Depreciation and amortization 1 1 Interest on lease liabilities Interest expense, net 4 4 Total lease cost $ 5 $ 5
Supplemental Cash Flows, Lessee	December 31, 2020 December 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases (1) $ — $ — Operating cash flows from finance leases (3) (4) Financing cash flows from finance leases (1) (1) (1) Amounts for each year ended December 31, 2020 and 2019 were less than $1 million . December 31, 2020 December 31, 2019 Weighted-average remaining lease term (years): Operating leases 19 20 Finance leases 10 11 Weighted-average discount rate: Operating leases 5.8 % 5.8 % Finance leases 14.3 % 14.3 %
Lessee, Operating Lease, Liability, Maturity	The future annual maturity of lease payments as of December 31, 2020 for the above lease obligations was: Maturity of lease liabilities Operating Leases (1) Finance Leases (2) Total 2021 $ — $ 4 $ 4 2022 1 4 5 2023 — 4 4 2024 1 4 5 2025 — 5 5 Remainder 5 28 33 Total lease payments 7 49 56 Less: Interest (3) (3) (24) (27) Present value of lease liabilities (4) $ 4 $ 25 $ 29 (1) Operating lease payments include $2 million related to options to extend lease terms that are reasonably certain of being exercised. (2) Includes $24 million in principal and excludes $8 million in executory costs. (3) Calculated using the interest rate for each lease. (4) Includes the current portion of $1 million for the finance lease.
Finance Lease, Liability, Maturity	The future annual maturity of lease payments as of December 31, 2020 for the above lease obligations was: Maturity of lease liabilities Operating Leases (1) Finance Leases (2) Total 2021 $ — $ 4 $ 4 2022 1 4 5 2023 — 4 4 2024 1 4 5 2025 — 5 5 Remainder 5 28 33 Total lease payments 7 49 56 Less: Interest (3) (3) (24) (27) Present value of lease liabilities (4) $ 4 $ 25 $ 29 (1) Operating lease payments include $2 million related to options to extend lease terms that are reasonably certain of being exercised. (2) Includes $24 million in principal and excludes $8 million in executory costs. (3) Calculated using the interest rate for each lease. (4) Includes the current portion of $1 million for the finance lease.
Lessor, Operating Lease, Payments to be Received, Maturity	As of December 31, 2020, future annual maturity of lease payments to be received under the contract terms of these operating leases, which includes only the lease components of these leases, was estimated to be: Maturity of lease payments Operating leases (1) 2021 $ 56 2022 56 2023 56 2024 56 2025 56 Remainder 451 Total lease payments $ 731 (1) Operating lease payments include $366 million related to options to extend lease terms that are reasonably certain of being exercised.

(Deficit) Equity (Tables)

(Deficit) Equity (Tables)	12 Months Ended
(Deficit) Equity (Tables)	Dec. 31, 2020
Equity [Abstract]
Schedule of Capital Units	The changes in the number of units outstanding from December 31, 2018 through December 31, 2020 are as follows: (in units) SPLC Preferred Public SPLC General Balance as of December 31, 2018 — 123,832,233 99,979,548 4,567,588 June 2019 Acquisition — — 9,477,756 193,424 Balance as of December 31, 2019 — 123,832,233 109,457,304 4,761,012 April 2020 Acquisition 50,782,904 — 160,000,000 (4,761,012) Balance as of December 31, 2020 50,782,904 123,832,233 269,457,304 —
Schedule of Distributions Declared and/or Paid	The following table details the distributions declared and/or paid for the periods presented: Date Paid or to be Paid Three Months Ended Public Common SPLC Preferred SPLC Common General Partner Distributions per Limited Partner Unit IDRs 2% Total (in millions, except per unit amounts) February 14, 2018 December 31, 2017 $ 33 $ — $ 30 $ 18 $ 2 $ 83 $ 0.33300 May 15, 2018 March 31, 2018 43 — 35 26 2 106 0.34800 August 14, 2018 June 30, 2018 46 — 36 29 2 113 0.36500 November 14, 2018 September 30, 2018 47 — 38 33 3 121 0.38200 February 14, 2019 December 31, 2018 49 — 40 37 3 129 0.40000 May 15, 2019 March 31, 2019 (1) 51 — 42 23 3 119 0.41500 August 14, 2019 June 30, 2019 (1) 53 — 47 28 3 131 0.43000 November 14, 2019 September 30, 2019 (1) 56 — 48 33 3 140 0.44500 February 14, 2020 December 31, 2019 57 — 50 52 3 162 0.46000 May 15, 2020 March 31, 2020 57 — 50 52 (3) 3 (4) 162 0.46000 August 14, 2020 June 30, 2020 (2) 57 12 104 — — 173 0.46000 November 13, 2020 September 30, 2020 (2) 57 12 104 — — 173 0.46000 February 12, 2021 December 31, 2020 (2)(5) 57 12 104 — — 173 0.46000 (1) Includes the impact of waived distributions to the holders of IDRs with respect to the Second Amendment as described above. (2) Includes the impact of waived distributions to SPLC with respect to the April 2020 Transaction as described above. (3) This amount represents the Final IDR Payment (as defined in the Partnership Interests Restructuring Agreement) to which our general partner (or its assignee) was entitled pursuant to the Partnership Interests Restructuring Agreement. Also pursuant to the Partnership Interests Restructuring Agreement, our general partner agreed (on its own behalf and on behalf of its assignees) to waive any distributions that it would otherwise be entitled to receive with respect to the newly-issued 160 million common units that it received in the April 2020 Transaction for the quarter in which it receives the Final IDR Payment. Our general partner is not entitled to any payments with respect to the IDRs going forward, as they have been cancelled as a part of the April 2020 Transaction. (4) This amount represents the final distribution payment on the 2% economic general partner interest. Our general partner is not entitled to any payments with respect to the economic general partner interest going forward, as it was converted into a non-economic general partner interest as a part of the April 2020 Transaction. (5) See Note 16 — Subsequent Event(s) for additional information.

Revenue Recognition (Tables)

Revenue Recognition (Tables)	12 Months Ended
Revenue Recognition (Tables)	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table provides information about disaggregated revenue by service type and customer type: 2020 2019 2018 Transportation services revenue – third parties $ 114 $ 134 $ 200 Transportation services revenue – related parties (1) 164 210 176 Storage services revenue – third parties 9 9 9 Storage services revenue – related parties 8 7 7 Terminaling services revenue – related parties (2) 103 47 46 Terminaling services revenue – major maintenance service – related parties (3) 7 — — Product revenue – third parties (4) — 5 2 Product revenue – related parties (4) 19 35 29 Total Topic 606 revenue 424 447 469 Lease revenue – related parties 57 56 56 Total revenue $ 481 $ 503 $ 525 (1) Transportation services revenue – related parties for each of 2020, 2019 and 2018 includes $5 million of non-lease service component in our transportation services contract. (2) Terminaling services revenue – related parties is comprised of the service components in our terminaling services contracts, including the operation and maintenance service components related to the Norco Assets in connection with the April 2020 Transaction. See Note 4 – Related Party Transactions for additional details. (3) Terminaling services revenue – major maintenance service – related parties is comprised of the service components related to providing required major maintenance to the Norco Assets in connection with the April 2020 Transaction. See Note 4 – Related Party Transactions for additional details. (4) Product revenue is comprised of allowance oil sales.
Schedule of New Accounting Pronouncements and Changes in Accounting Principles
Contract with Customer, Asset and Liability	The following table provides information about receivables and contract liabilities from contracts with customers: January 1, 2020 December 31, 2020 Receivables from contracts with customers – third parties $ 11 $ 19 Receivables from contracts with customers – related parties 24 18 Contract Assets - related parties — 233 Deferred revenue – third parties — 4 Deferred revenue – related parties (1) — 19 (1) Deferred revenue - related parties is related to deficiency credits from certain minimum volume commitment contracts and certain components of our terminaling service contracts on the Norco Assets. January 1, 2019 December 31, 2019 Receivables from contracts with customers – third parties $ 19 $ 11 Receivables from contracts with customers – related parties 21 24 Deferred revenue – third parties 8 — Deferred revenue – related parties 3 —
Contract With Customer, Estimated Future Amortization	The estimated future amortization related to the contract assets for the next five years is as follows: 2021 2022 2023 2024 2025 Amortization $ 15 $ 16 $ 16 $ 17 $ 17
Contract With Customer, Deferred Revenue Activity	Significant changes in the deferred revenue balances with customers during the period are as follows: December 31, 2019 Additions (1) Reductions (2) December 31, 2020 Deferred revenue – third parties $ — $ 8 $ (4) $ 4 Deferred revenue – related parties — 21 (2) 19 (1) Deferred revenue additions resulted from $24 million deficiency payments from minimum volume commitment contracts and $5 million of deferred revenue related to the major maintenance service components of our terminaling service contracts on the Norco Assets. (2) Deferred revenue reductions resulted from revenue earned through the actual or estimated use and expiration of deficiency credits. December 31, 2018 Additions (1) Reductions (2) December 31, 2019 Deferred revenue – third parties $ 8 $ — $ (8) $ — Deferred revenue – related parties 3 — (3) — (1) Deferred revenue additions resulted from deficiency payments from minimum volume commitment contracts.
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction	The following table includes revenue expected to be recognized in the future related to performance obligations exceeding one year of their initial terms that are unsatisfied or partially unsatisfied as of December 31, 2020: Total 2021 2022 2023 2024 2025 and beyond Revenue expected to be recognized on multi-year committed shipper transportation contracts $ 472 $ 63 $ 63 $ 63 $ 57 $ 226 Revenue expected to be recognized on other multi-year transportation service contracts (1) 34 6 6 6 5 11 Revenue expected to be recognized on multi-year storage service contracts 17 4 4 4 5 — Revenue expected to be recognized on multi-year terminaling service contracts (1) 335 48 48 48 48 143 Revenue expected to be recognized on multi-year operation and major maintenance terminaling service contracts (2) 1,508 106 106 106 106 1,084 Total $ 2,366 $ 227 $ 227 $ 227 $ 221 $ 1,464 (1) Relates to the non-lease service components of certain of our long-term transportation and terminaling service contracts which are accounted for as operating leases. (2) Relates to the operation and maintenance service components and the major maintenance service components of our terminaling service contracts on the Norco Assets in connection with the April 2020 Transaction.
Operating Lease, Lease Income	As of December 31, 2020, future minimum payments of both the lease and non-lease service components to be received under the ten-year contract term of these operating leases were estimated to be: Total Less than 1 year Years 2 to 3 Years 4 to 5 More than 5 years Operating leases $ 735 $ 111 $ 220 $ 220 $ 184

Net Income Per Limited Partne_2

Net Income Per Limited Partner Unit (Tables)	12 Months Ended
Net Income Per Limited Partner Unit (Tables)	Dec. 31, 2020
Partners' Capital Notes [Abstract]
Schedule of Allocation of Net Income to Arrive at Net Income Per Limited Partner Unit	The following tables show the allocation of net income attributable to the Partnership to arrive at net income per limited partner unit: 2020 2019 2018 Net income $ 556 $ 546 $ 482 Less: Net income attributable to noncontrolling interests 13 18 18 Net income attributable to the Partnership 543 528 464 Less: General partner’s distribution declared (1) 55 148 135 Preferred unitholder’s interest in net income 36 — — Limited partners’ distribution declared on common units (2) 590 404 334 Distributions in excess of income $ (138) $ (24) $ (5) (1) For 2019, this includes the impact of waived distributions to the holders of the IDRs. See Note 4 — Related Party Transactions for additional information. (2) For 2020, this includes the impact of waived distributions to SPLC. See Note 4 — Related Party Transactions for additional information.
Schedule of Basic and Diluted Net Income Per Unit	2020 General Partner Limited Partners’ Common Units Total (in millions of dollars, except per unit data) Distributions declared (1) $ 55 $ 590 $ 645 Distributions in excess of income — (138) (138) Net income attributable to the Partnership’s common unitholders (basic) $ 55 $ 452 $ 507 Dilutive effect of preferred units 36 Net income attributable to the Partnership’s common unitholders (diluted) $ 488 Weighted average units outstanding - Basic 353.5 Dilutive effect of preferred units 38.2 Weighted average units outstanding - Diluted 391.7 Net income per limited partner unit: Basic $ 1.28 Diluted $ 1.25 (1) This includes the impact of waived distributions to SPLC. See Note 4 — Related Party Transactions for additional information. 2019 General Partner Limited Partners’ Common Units Total (in millions of dollars, except per unit data) Distributions declared (1) $ 148 $ 404 $ 552 Distributions in excess of income (1) (23) (24) Net income attributable to the Partnership $ 147 $ 381 $ 528 Weighted average units outstanding: Basic and diluted 229.2 Net income per limited partner unit: Basic and diluted $ 1.66 (1) This includes the impact of waived distributions to the holders of the IDRs. See Note 4 — Related Party Transactions for additional information. 2018 General Partner Limited Partners’ Common Units Total (in millions of dollars, except per unit data) Distributions declared $ 135 $ 334 $ 469 Distributions in excess of income (1) (4) (5) Net income attributable to the Partnership $ 134 $ 330 $ 464 Weighted average units outstanding: Basic and diluted 220.3 Net income per limited partner unit: Basic and diluted $ 1.50

Description of the Business a_3

Description of the Business and Basis of Presentation (Details)	12 Months Ended
	Dec. 31, 2020segmentshares	Apr. 01, 2020shares	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Common units (in units)		393,289,537
Number of segments \| segment	1
Limited Partner \| Partnership Interests Restructuring Agreement \| Series A Perpetual Convertible Preferred Units
Schedule of Equity Method Investments [Line Items]
Unit distribution (in units)	50,782,904
Economic Interest \| General Partner SPLC
Schedule of Equity Method Investments [Line Items]
Noncontrolling interest	2.00%
Shell Pipeline Company L P \| Limited Partner
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percentage)	68.50%
Common units (in units)	269,457,304
Shell Pipeline Company L P \| Limited Partner \| Common Units And Series A Perpetual Convertible Preferred Units
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percentage)	72.00%
Pecten Midstream LLC (“Pecten”)
Schedule of Equity Method Investments [Line Items]
Ownership	100.00%
Sand Dollar Pipeline LLC (“Sand Dollar”)
Schedule of Equity Method Investments [Line Items]
Ownership	100.00%
Triton West LLC (“Triton”)
Schedule of Equity Method Investments [Line Items]
Ownership	100.00%
Zydeco Pipeline Company LLC (“Zydeco”)
Schedule of Equity Method Investments [Line Items]
Ownership	92.50%
Zydeco Pipeline Company LLC (“Zydeco”) \| Zydeco Pipeline Company LLC (“Zydeco”)
Schedule of Equity Method Investments [Line Items]
Shell's Retained Ownership	7.50%
Mattox Pipeline Company LLC (“Mattox”)
Schedule of Equity Method Investments [Line Items]
Ownership	79.00%
Amberjack Pipeline Company LLC - Series A
Schedule of Equity Method Investments [Line Items]
Ownership	75.00%		75.00%
Amberjack Pipeline Company LLC - Series B
Schedule of Equity Method Investments [Line Items]
Ownership	50.00%		50.00%
Mars Oil Pipeline Company LLC (“Mars”)
Schedule of Equity Method Investments [Line Items]
Ownership	71.50%		71.50%
Odyssey Pipeline L.L.C. (“Odyssey”)
Schedule of Equity Method Investments [Line Items]
Ownership	71.00%
Bengal Pipeline Company LLC (“Bengal”)
Schedule of Equity Method Investments [Line Items]
Ownership	50.00%		50.00%
Crestwood Permian Basin LLC (“Permian Basin”)
Schedule of Equity Method Investments [Line Items]
Ownership	50.00%
LOCAP LLC (“LOCAP”)
Schedule of Equity Method Investments [Line Items]
Ownership	41.48%		41.48%
Explorer Pipeline Company (“Explorer”)
Schedule of Equity Method Investments [Line Items]
Ownership	38.59%		38.59%
Poseidon Oil Pipeline Company, L.L.C. (“Poseidon”)
Schedule of Equity Method Investments [Line Items]
Ownership	36.00%		36.00%
Colonial Enterprises, Inc. (“Colonial”)
Schedule of Equity Method Investments [Line Items]
Ownership	16.125%		16.125%
Proteus Oil Pipeline Company, LLC (“Proteus”)
Schedule of Equity Method Investments [Line Items]
Ownership	10.00%		10.00%
Endymion Oil Pipeline Company, LLC (“Endymion”)
Schedule of Equity Method Investments [Line Items]
Ownership	10.00%		10.00%
Cleopatra Gas Gathering Company, LLC (“Cleopatra”)
Schedule of Equity Method Investments [Line Items]
Ownership	1.00%

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Asset retirement obligation	$ 0	$ 0

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Investments (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Other investments	$ 2	$ 2
Cleopatra
Schedule of Equity Method Investments [Line Items]
Ownership	1.00%	1.00%
Other investments	$ 2	$ 2
Economic Interest \| General Partner SPLC
Schedule of Equity Method Investments [Line Items]
Noncontrolling interest	2.00%

Acquisitions and Other Transa_2

Acquisitions and Other Transactions - April 2020 Transaction (Details)	Apr. 01, 2020USD ($)numberOfQuarters$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares	Sep. 30, 2020$ / shares	Jun. 30, 2020$ / shares	Mar. 31, 2020$ / shares	Dec. 31, 2019USD ($)$ / sharesshares	Sep. 30, 2019$ / shares	Jun. 30, 2019$ / shares	Mar. 31, 2019$ / shares	Dec. 31, 2018$ / sharesshares	Sep. 30, 2018$ / shares	Jun. 30, 2018$ / shares	Mar. 31, 2018$ / shares	Dec. 31, 2017$ / shares	Dec. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2018$ / sharesshares
Asset Acquisition [Line Items]
Equity method investments		$ 1,013,000,000				$ 926,000,000									$ 1,013,000,000	$ 926,000,000
Financing receivables – related parties		298,000,000				0									298,000,000	0
Equity method investments and other assets	$ 720,000,000
Partners' capital		$ (481,000,000)				$ (775,000,000)									$ (481,000,000)	$ (775,000,000)
Common units (in units) \| shares	393,289,537
Distributions per Limited Partner unit (in dollars per share) \| $ / shares		$ 0.46000	$ 0.46000	$ 0.46000	$ 0.46000	$ 0.46000	$ 0.44500	$ 0.43000	$ 0.41500	$ 0.40000	$ 0.38200	$ 0.36500	$ 0.34800	$ 0.33300	$ 1.8400	$ 1.7500	$ 1.4950
April 2020 Transaction
Asset Acquisition [Line Items]
Contract assets - related parties						$ 0										$ 0
Norco Transaction \| Affiliated Entity \| Valuation Technique, Discounted Cash Flow
Asset Acquisition [Line Items]
Measurement input	11.00%
Norco Transaction \| April 2020 Transaction
Asset Acquisition [Line Items]
Financing receivables – related parties	$ 302,000,000
Norco Transaction \| April 2020 Transaction \| Affiliated Entity
Asset Acquisition [Line Items]
Contract assets - related parties	244,000,000
Consideration allocated, fair value	$ 546,000,000
Norco Transaction \| April 2020 Transaction \| Affiliated Entity \| Revenue expected to be recognized on multi-year terminaling service contracts in place as of September 30, 2019
Asset Acquisition [Line Items]
Annual payments receivable		$ 140,000,000													$ 140,000,000
Annual payments receivable, gross		151,000,000													151,000,000
Annual payments receivable, net		$ 11,000,000													$ 11,000,000
Mattox Transaction \| Affiliated Entity \| Valuation Technique, Discounted Cash Flow
Asset Acquisition [Line Items]
Measurement input	14.00%
GP/IDR Restructuring \| Affiliated Entity \| Valuation Technique, Discounted Cash Flow
Asset Acquisition [Line Items]
Measurement input	20.00%
Preferred Units
Asset Acquisition [Line Items]
Distributions per Limited Partner unit (in dollars per share) \| $ / shares	$ 0.2363														$ 0.7089
General Partner SPLC
Asset Acquisition [Line Items]
Unit distribution (in units) \| shares															(4,761,012)
Units canceled (in units) \| shares		0				4,761,012				4,567,588					0	4,761,012	4,567,588
Partners' capital	$ (4,000,000,000)
Economic Interest \| General Partner SPLC
Asset Acquisition [Line Items]
Noncontrolling interest		2.00%													2.00%
Shell Pipeline Company L P \| Limited Partner
Asset Acquisition [Line Items]
Common units (in units) \| shares		269,457,304													269,457,304
Ownership interest (in percentage)															68.50%
Mattox Pipeline Company LLC (“Mattox”)
Asset Acquisition [Line Items]
Equity method investments	$ 174,000,000
Purchase And Sale Agreement \| Mattox Pipeline Company LLC (“Mattox”)
Asset Acquisition [Line Items]
Equity method investment, ownership interest acquired	79.00%
Partnership Interests Restructuring Agreement \| General Partner SPLC
Asset Acquisition [Line Items]
Distributions payable, amount waved	$ 20,000,000
Distribution payable, number of consecutive quarters \| numberOfQuarters	4
Partnership Interests Restructuring Agreement \| Limited Partner \| Series A Perpetual Convertible Preferred Units
Asset Acquisition [Line Items]
Unit distribution (in units) \| shares		50,782,904													50,782,904
Unit distribution (in dollars per unit) \| $ / shares	$ 23.63
Partnership Interests Restructuring Agreement \| Limited Partner \| Common Units
Asset Acquisition [Line Items]
Unit distribution (in units) \| shares	160,000,000

Acquisitions and Other Transa_3

Acquisitions and Other Transactions - June 2019 Acquisitions (Details) - USD ($) $ / shares in Units, $ in Millions	Jun. 06, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Asset Acquisition [Line Items]
Remeasurements of pension and other postretirement benefits related to equity method investments, net of tax		$ 1	$ 2	$ 0
June 2019 Acquisition
Asset Acquisition [Line Items]
Consideration transferred	$ 800
Equity method investment, aggregate cost	90
Remeasurements of pension and other postretirement benefits related to equity method investments, net of tax	6
Capital distribution to general partner	510
Non-cash equity consideration	$ 200
Common units, weighted average sales price (in dollars per share)	$ 20.68
General partners' capital account, units issued (in units)	193,424
General Partner SPLC \| June 2019 Acquisition \| Shell Midstream Partners L.P.
Asset Acquisition [Line Items]
Noncontrolling interest	2.00%
Subsidiary \| Shell Midstream LP Holdings LLC \| June 2019 Acquisition
Asset Acquisition [Line Items]
Common units issued (in shares)	9,477,756
Revolving Credit Facility \| Shell Treasury Center West Inc \| Ten Year Fixed Facility \| June 2019 Acquisition
Asset Acquisition [Line Items]
Consideration, cash on hand	$ 600
Explorer
Asset Acquisition [Line Items]
Ownership		38.59%	38.59%
Explorer \| June 2019 Acquisition
Asset Acquisition [Line Items]
Equity method investments, ownership interest acquired	25.97%
Ownership		38.59%
Colonial
Asset Acquisition [Line Items]
Ownership		16.125%	16.125%
Colonial \| June 2019 Acquisition
Asset Acquisition [Line Items]
Equity method investments, ownership interest acquired	10.125%
Ownership		16.125%

Acquisitions and Other Transa_4

Acquisitions and Other Transactions - May 2018 Acquisitions (Details) - USD ($) $ in Millions	May 11, 2018	Dec. 31, 2020
May 2018 Acquisition
Asset Acquisition [Line Items]
Consideration transferred	$ 1,220
Consideration in excess of book value of net assets acquired	738
Equity method investment, aggregate cost	482
Five Year Revolver due July 2023
Asset Acquisition [Line Items]
Debt instrument term		5 years
Five Year Revolver Due December 2022
Asset Acquisition [Line Items]
Debt instrument term		5 years
Revolving Credit Facility \| Five Year Revolver due July 2023
Asset Acquisition [Line Items]
Debt instrument term		5 years
Shell Treasury Center West Inc \| Revolving Credit Facility \| Five Year Revolver due July 2023
Asset Acquisition [Line Items]
Debt instrument term		5 years
Shell Treasury Center West Inc \| Revolving Credit Facility \| Five Year Revolver due July 2023 \| May 2018 Acquisition
Asset Acquisition [Line Items]
Consideration transferred	$ 494
Debt instrument term	5 years
Shell Treasury Center West Inc \| Revolving Credit Facility \| Five Year Revolver Due December 2022
Asset Acquisition [Line Items]
Debt instrument term		5 years
Shell Treasury Center West Inc \| Revolving Credit Facility \| Five Year Revolver Due December 2022 \| May 2018 Acquisition
Asset Acquisition [Line Items]
Consideration transferred	$ 726
Debt instrument term	5 years
Amberjack Pipeline Company LLC - Series A \| May 2018 Acquisition
Asset Acquisition [Line Items]
Voting interest acquired	75.00%
Amberjack Pipeline Company LLC - Series B \| May 2018 Acquisition
Asset Acquisition [Line Items]
Voting interest acquired	50.00%

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) $ in Millions	Feb. 18, 2020	Nov. 03, 2014USD ($)	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2020USD ($)credit_facility	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Apr. 01, 2020USD ($)numberOfQuarters
Related Party Transaction [Line Items]
Inflationary increase in general and administrative fee, percent	3.00%
Number of days within combined tax filing submission						15 days
Distribution to holders of incentive distribution rights waived			$ 16	$ 17	$ 17	$ 50
Health and life insurance costs						5	$ 6	$ 6
Defined contribution benefit costs						2	$ 2	3
Severance Costs						$ 7		$ 3
Five Year Revolver due July 2023
Related Party Transaction [Line Items]
Debt instrument term						5 years
Five Year Revolver Due December 2022
Related Party Transaction [Line Items]
Debt instrument term						5 years
Revolving Credit Facility \| Ten Year Fixed Facility
Related Party Transaction [Line Items]
Debt instrument term						10 years
Revolving Credit Facility \| Seven Year Fixed Facility
Related Party Transaction [Line Items]
Debt instrument term						7 years
Revolving Credit Facility \| Five Year Revolver due July 2023
Related Party Transaction [Line Items]
Debt instrument term						5 years
Revolving Credit Facility \| Five Year Fixed Facility
Related Party Transaction [Line Items]
Debt instrument term						5 years
Shell Treasury Center West Inc
Related Party Transaction [Line Items]
Number of revolving credit facilities \| credit_facility						5
Shell Treasury Center West Inc \| Revolving Credit Facility \| Ten Year Fixed Facility
Related Party Transaction [Line Items]
Debt instrument term						10 years
Shell Treasury Center West Inc \| Revolving Credit Facility \| Seven Year Fixed Facility
Related Party Transaction [Line Items]
Debt instrument term						7 years
Shell Treasury Center West Inc \| Revolving Credit Facility \| Five Year Revolver due July 2023
Related Party Transaction [Line Items]
Debt instrument term						5 years
Shell Treasury Center West Inc \| Revolving Credit Facility \| Five Year Revolver Due December 2022
Related Party Transaction [Line Items]
Debt instrument term						5 years
Shell Treasury Center West Inc \| Revolving Credit Facility \| Five Year Fixed Facility
Related Party Transaction [Line Items]
Debt instrument term						5 years
Partnership Interests Restructuring Agreement \| General Partner SPLC
Related Party Transaction [Line Items]
Distributions payable, amount waved									$ 20
Distribution payable, number of consecutive quarters \| numberOfQuarters									4
Zydeco Pipeline Company LLC (“Zydeco”) \| Shell Pipeline Company L P
Related Party Transaction [Line Items]
Noncontrolling interest						7.50%	7.50%	7.50%
Odyssey Pipeline L.L.C. (“Odyssey”) \| GEL Offshore Pipeline LLC
Related Party Transaction [Line Items]
Noncontrolling interest						29.00%	29.00%	29.00%
Omnibus Agreement
Related Party Transaction [Line Items]
Statute of limitations expirations, number of days						60 days
Omnibus Agreement \| Shell Pipeline Company L P
Related Party Transaction [Line Items]
Payment of general and administrative fee		$ 11

Related Party Transactions - Sc

Related Party Transactions - Schedule of Other Related Party Balances (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Related Party Transaction [Line Items]
Accounts receivable	$ 21	$ 29
Prepaid expenses	22	15
Other assets	2	2
Contract assets	233	0
Accounts payable	16	10
Deferred revenue	19	0
Accrued liabilities	28	19
Debt payable	2,692	2,692
Financing receivables – related parties	298	0
Accrued interest, related parties	16	18
Other accrued liabilities, related parties	12	1
Unamortized debt issuance expense	2	$ 2
Affiliated Entity
Related Party Transaction [Line Items]
Unamortized debt issuance expense	$ 2

Related Party Transactions - _2

Related Party Transactions - Schedule of Condensed Combined Statement of Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Related Party Transactions [Abstract]
Allocated operating expenses	$ 45	$ 18	$ 15
Major maintenance costs	6	0	0
Insurance expense	20	18	15
Other	43	23	24
Operations and maintenance – related parties	114	59	54
Allocated general corporate expenses	29	28	33
Management Agreement fee	9	9	9
Omnibus Agreement fee	11	11	9
Other	0	1	1
General and administrative – related parties	$ 49	$ 49	$ 52

Related Party Transactions - _3

Related Party Transactions - Schedule of Reimbursement from Parent and Sale Leaseback (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Apr. 01, 2020
Related Party Transaction [Line Items]
Financing receivables – related parties	$ 298,000,000	$ 298,000,000	$ 0
April 2020 Transaction
Related Party Transaction [Line Items]
Contract assets - related parties			0
April 2020 Transaction \| Norco Transaction
Related Party Transaction [Line Items]
Financing receivables – related parties					$ 302,000,000
Affiliated Entity \| April 2020 Transaction \| Norco Transaction
Related Party Transaction [Line Items]
Contract assets - related parties					$ 244,000,000
Affiliated Entity \| Revenue expected to be recognized on multi-year terminaling service contracts in place as of September 30, 2019 \| April 2020 Transaction
Related Party Transaction [Line Items]
Interest income		23,000,000
Increase (Decrease) in Finance Receivables		3,000,000
Cash payments received for interest income		20,000,000
Cash principal payments received on financing receivables		3,000,000
Affiliated Entity \| Revenue expected to be recognized on multi-year terminaling service contracts in place as of September 30, 2019 \| April 2020 Transaction \| Norco Transaction
Related Party Transaction [Line Items]
Annual payments receivable	140,000,000	140,000,000
Annual payments receivable, gross	151,000,000	151,000,000
Annual payments receivable, net	11,000,000	$ 11,000,000
Affiliated Entity \| Revenue expected to be recognized on multi-year terminaling service contracts in place as of September 30, 2019 \| April 2020 Transaction \| Shell Oil Products (SOPUS)
Related Party Transaction [Line Items]
Financing Receivable, Imputed Interest Rate		11.10%
Affiliated Entity \| Revenue expected to be recognized on multi-year terminaling service contracts in place as of September 30, 2019 \| April 2020 Transaction \| Shell Chemical
Related Party Transaction [Line Items]
Financing Receivable, Imputed Interest Rate		7.40%
Shell Pipeline Company L P
Related Party Transaction [Line Items]
Reimbursement related to cost and expenses for maintenance projects			$ 19,000,000	$ 12,000,000
Mars \| Shell Pipeline Company L P
Related Party Transaction [Line Items]
Cash received	$ 9,000,000

Equity Method Investments - Sch

Equity Method Investments - Schedule of Equity Investments in Affiliates (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Jun. 30, 2019
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 1,013,000,000	$ 926,000,000
Mattox
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percentage)	79.00%	0.00%
Equity method investments	$ 163,000,000	$ 0
Amberjack
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 382,000,000	$ 426,000,000
Amberjack Pipeline Company LLC - Series A
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percentage)	75.00%	75.00%
Amberjack Pipeline Company LLC - Series B
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percentage)	50.00%	50.00%
Mars
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percentage)	71.50%	71.50%
Equity method investments	$ 152,000,000	$ 161,000,000
Bengal Pipeline Company LLC (“Bengal”)
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percentage)	50.00%	50.00%
Equity method investments	$ 88,000,000	$ 88,000,000
Permian Basin
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percentage)	50.00%	50.00%
Equity method investments	$ 83,000,000	$ 91,000,000
LOCAP
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percentage)	41.48%	41.48%
Equity method investments	$ 12,000,000	$ 9,000,000
Explorer
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percentage)	38.59%	38.59%
Equity method investments	$ 73,000,000	$ 88,000,000
Poseidon Oil Pipeline Company, L.L.C. (“Poseidon”)
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percentage)	36.00%	36.00%
Equity method investments	$ 0	$ 0	$ 0
Colonial
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percentage)	16.125%	16.125%
Equity method investments	$ 29,000,000	$ 30,000,000
Proteus
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percentage)	10.00%	10.00%
Equity method investments	$ 14,000,000	$ 15,000,000
Endymion Oil Pipeline Company, LLC (“Endymion”)
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percentage)	10.00%	10.00%
Equity method investments	$ 17,000,000	$ 18,000,000

Equity Method Investments - Add

Equity Method Investments - Additional Information (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Apr. 01, 2020	Jun. 30, 2019	Jun. 06, 2019	Jun. 05, 2019	Jan. 01, 2019	Jan. 01, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 1,013,000,000	$ 1,013,000,000	$ 926,000,000
Distributions received from equity method investments		541,000,000	466,000,000	$ 301,000,000
Unamortized basis differences included in equity investments	84,000,000	84,000,000	92,000,000
Amortization expense		8,000,000	6,000,000	4,000,000
Income from equity method investments		417,000,000	373,000,000	235,000,000
Mattox Pipeline Company LLC (“Mattox”)
Schedule of Equity Method Investments [Line Items]
Equity method investments					$ 174,000,000
Purchase And Sale Agreement \| Mattox Pipeline Company LLC (“Mattox”)
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership interest acquired					79.00%
Mars Oil Pipeline Company LLC (“Mars”) \| Shell Pipeline Company L P
Schedule of Equity Method Investments [Line Items]
Equity method investments, ownership interest acquired											20.00%
Consideration to be received if inventory management fees do now meet certain levels											$ 10,000,000
June 2019 Acquisition
Schedule of Equity Method Investments [Line Items]
Equity method investments							$ 90,000,000
Poseidon Oil Pipeline Company, L.L.C. (“Poseidon”)
Schedule of Equity Method Investments [Line Items]
Equity method investments	0	0	0			$ 0
Investment, excess distribution		37,000,000	33,000,000	24,000,000
Income from equity method investments		0	0	6,000,000
Amberjack
Schedule of Equity Method Investments [Line Items]
Equity method investments	382,000,000	382,000,000	426,000,000
Income from equity method investments		102,000,000	125,000,000	80,000,000
Amberjack \| Accounting Standards Update 2014-09 \| Cumulative Effect, Period of Adoption, Adjustment
Schedule of Equity Method Investments [Line Items]
Accumulated deficit									$ 9,000,000	$ 7,000,000
Mars Oil Pipeline Company LLC (“Mars”)
Schedule of Equity Method Investments [Line Items]
Equity method investments	152,000,000	152,000,000	161,000,000
Income from equity method investments		114,000,000	126,000,000	108,000,000
Mars Oil Pipeline Company LLC (“Mars”) \| Shell Pipeline Company L P
Schedule of Equity Method Investments [Line Items]
Cash received	9,000,000
Bengal
Schedule of Equity Method Investments [Line Items]
Equity method investments	88,000,000	88,000,000	88,000,000
Income from equity method investments		18,000,000	24,000,000	21,000,000
Explorer
Schedule of Equity Method Investments [Line Items]
Equity method investments	73,000,000	73,000,000	88,000,000
Income from equity method investments		44,000,000	41,000,000	0
Explorer \| June 2019 Acquisition
Schedule of Equity Method Investments [Line Items]
Equity method investments, ownership interest acquired							25.97%
Colonial
Schedule of Equity Method Investments [Line Items]
Equity method investments	29,000,000	29,000,000	30,000,000
Income from equity method investments		75,000,000	40,000,000	0
Colonial \| June 2019 Acquisition
Schedule of Equity Method Investments [Line Items]
Equity method investments, ownership interest acquired							10.125%
Permian Basin
Schedule of Equity Method Investments [Line Items]
Equity method investments	83,000,000	83,000,000	91,000,000
Other
Schedule of Equity Method Investments [Line Items]
Income from equity method investments		19,000,000	17,000,000	20,000,000
Explorer And Colonial
Schedule of Equity Method Investments [Line Items]
Other Investments								$ 60,000,000
Mattox
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 163,000,000	163,000,000	0
Income from equity method investments		$ 45,000,000	$ 0	$ 0

Equity Method Investments - Sum

Equity Method Investments - Summary of Balance Sheet and Income Statement Data for Equity Method Investments (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Total revenue	$ 481,000,000	$ 503,000,000	$ 525,000,000
Total operating expenses	312,000,000	288,000,000	313,000,000
Operating income	169,000,000	215,000,000	212,000,000
Net income	556,000,000	546,000,000	482,000,000
Balance Sheets
Current assets	394,000,000	359,000,000
Total assets	2,347,000,000	2,019,000,000
Current liabilities	82,000,000	46,000,000
Non-current liabilities	2,723,000,000	2,722,000,000
Equity (Deficit)	(458,000,000)	(749,000,000)	(257,000,000)	$ (566,000,000)
Total liabilities and deficit	2,347,000,000	2,019,000,000
Outstanding Balance	2,692,000,000	2,692,000,000
Total Capacity	3,590,000,000	3,590,000,000
Available Capacity	896,000,000	896,000,000
Amberjack
Schedule of Equity Method Investments [Line Items]
Total revenue		315,000,000	204,000,000
Total operating expenses		73,000,000	47,000,000
Operating income		242,000,000	157,000,000
Net income		243,000,000	157,000,000
Balance Sheets
Current assets	44,000,000	56,000,000	46,000,000
Non-current assets	836,000,000	804,000,000	846,000,000
Total assets	880,000,000	860,000,000	892,000,000
Current liabilities	10,000,000	4,000,000	4,000,000
Non-current liabilities	124,000,000	32,000,000	4,000,000
Equity (Deficit)	746,000,000	824,000,000	884,000,000
Total liabilities and deficit	880,000,000	860,000,000	892,000,000
Amberjack \| Equity Method Investment, Nonconsolidated Investee, Other
Schedule of Equity Method Investments [Line Items]
Total revenue	280,000,000
Total operating expenses	78,000,000
Operating income	202,000,000
Net income	201,000,000
Mars
Schedule of Equity Method Investments [Line Items]
Total revenue		282,000,000	241,000,000
Total operating expenses		104,000,000	87,000,000
Operating income		178,000,000	154,000,000
Net income		179,000,000	154,000,000
Balance Sheets
Current assets	47,000,000	57,000,000	53,000,000
Non-current assets	269,000,000	173,000,000	178,000,000
Total assets	316,000,000	230,000,000	231,000,000
Current liabilities	23,000,000	8,000,000	5,000,000
Non-current liabilities	103,000,000	22,000,000	18,000,000
Equity (Deficit)	190,000,000	200,000,000	208,000,000
Total liabilities and deficit	316,000,000	230,000,000	231,000,000
Mars \| Equity Method Investment, Nonconsolidated Investee, Other
Schedule of Equity Method Investments [Line Items]
Total revenue	259,000,000
Total operating expenses	97,000,000
Operating income	162,000,000
Net income	163,000,000
Bengal
Schedule of Equity Method Investments [Line Items]
Total revenue		77,000,000	69,000,000
Total operating expenses		30,000,000	28,000,000
Operating income		47,000,000	41,000,000
Net income		47,000,000	41,000,000
Balance Sheets
Current assets	33,000,000	35,000,000	27,000,000
Non-current assets	161,000,000	157,000,000	156,000,000
Total assets	194,000,000	192,000,000	183,000,000
Current liabilities	7,000,000	6,000,000	9,000,000
Non-current liabilities	0	0	0
Equity (Deficit)	187,000,000	186,000,000	174,000,000
Total liabilities and deficit	194,000,000	192,000,000	183,000,000
Bengal \| Equity Method Investment, Nonconsolidated Investee, Other
Schedule of Equity Method Investments [Line Items]
Total revenue	65,000,000
Total operating expenses	30,000,000
Operating income	35,000,000
Net income	35,000,000
Explorer
Schedule of Equity Method Investments [Line Items]
Total revenue		258,000,000
Total operating expenses		115,000,000
Operating income		143,000,000
Net income		111,000,000
Balance Sheets
Current assets	74,000,000	93,000,000
Non-current assets	537,000,000	530,000,000
Total assets	611,000,000	623,000,000
Current liabilities	49,000,000	44,000,000
Non-current liabilities	459,000,000	442,000,000
Equity (Deficit)	103,000,000	137,000,000
Total liabilities and deficit	611,000,000	623,000,000
Explorer \| Equity Method Investment, Nonconsolidated Investee, Other
Schedule of Equity Method Investments [Line Items]
Total revenue	329,000,000
Total operating expenses	175,000,000
Operating income	154,000,000
Net income	119,000,000
Colonial
Schedule of Equity Method Investments [Line Items]
Total revenue		829,000,000
Total operating expenses		449,000,000
Operating income		380,000,000
Net income		255,000,000
Balance Sheets
Current assets	501,000,000	323,000,000
Non-current assets	3,105,000,000	2,920,000,000
Total assets	3,606,000,000	3,243,000,000
Current liabilities	245,000,000	519,000,000
Non-current liabilities	3,508,000,000	2,873,000,000
Equity (Deficit)	(147,000,000)	(149,000,000)
Total liabilities and deficit	3,606,000,000	3,243,000,000
Colonial \| Equity Method Investment, Nonconsolidated Investee, Other
Schedule of Equity Method Investments [Line Items]
Total revenue	1,395,000,000
Total operating expenses	660,000,000
Operating income	735,000,000
Net income	473,000,000
Poseidon
Schedule of Equity Method Investments [Line Items]
Total revenue		132,000,000	116,000,000
Total operating expenses		35,000,000	35,000,000
Operating income		97,000,000	81,000,000
Net income		87,000,000	73,000,000
Balance Sheets
Current assets	31,000,000	30,000,000	19,000,000
Non-current assets	176,000,000	190,000,000	203,000,000
Total assets	207,000,000	220,000,000	222,000,000
Current liabilities	10,000,000	16,000,000	16,000,000
Non-current liabilities	238,000,000	246,000,000	243,000,000
Equity (Deficit)	(41,000,000)	(42,000,000)	(37,000,000)
Total liabilities and deficit	207,000,000	220,000,000	222,000,000
Poseidon \| Equity Method Investment, Nonconsolidated Investee, Other
Schedule of Equity Method Investments [Line Items]
Total revenue	147,000,000
Total operating expenses	36,000,000
Operating income	111,000,000
Net income	105,000,000
Other
Schedule of Equity Method Investments [Line Items]
Total revenue		190,000,000	152,000,000
Total operating expenses		108,000,000	67,000,000
Operating income		82,000,000	85,000,000
Net income		73,000,000	76,000,000
Balance Sheets
Current assets	35,000,000	60,000,000	50,000,000
Non-current assets	920,000,000	917,000,000	876,000,000
Total assets	955,000,000	977,000,000	926,000,000
Current liabilities	56,000,000	73,000,000	65,000,000
Non-current liabilities	486,000,000	469,000,000	456,000,000
Equity (Deficit)	413,000,000	435,000,000	405,000,000
Total liabilities and deficit	955,000,000	977,000,000	926,000,000
Other \| Equity Method Investment, Nonconsolidated Investee, Other
Schedule of Equity Method Investments [Line Items]
Total revenue	220,000,000
Total operating expenses	123,000,000
Operating income	97,000,000
Net income	88,000,000
Permian Basin
Schedule of Equity Method Investments [Line Items]
Total revenue	0
Total operating expenses		25,000,000
Operating income			28,000,000
Mattox
Balance Sheets
Current assets	13,000,000
Non-current assets	204,000,000
Total assets	217,000,000
Current liabilities	0
Non-current liabilities	12,000,000
Equity (Deficit)	205,000,000
Total liabilities and deficit	217,000,000
Mattox \| Equity Method Investment, Nonconsolidated Investee, Other
Schedule of Equity Method Investments [Line Items]
Total revenue	66,000,000
Total operating expenses	9,000,000
Operating income	57,000,000
Net income	57,000,000
April 2020 Acquisition \| Mattox
Schedule of Equity Method Investments [Line Items]
Total revenue	85,000,000
Total operating expenses	12,000,000
Operating income	$ 73,000,000
June 2019 Acquisition \| Explorer
Schedule of Equity Method Investments [Line Items]
Total revenue		443,000,000
Total operating expenses		196,000,000
Operating income		247,000,000
June 2019 Acquisition \| Colonial
Schedule of Equity Method Investments [Line Items]
Total revenue		1,437,000,000
Total operating expenses		735,000,000
Operating income		$ 702,000,000
May 2018 Acquisition \| Amberjack
Schedule of Equity Method Investments [Line Items]
Total revenue			295,000,000
Total operating expenses			74,000,000
Operating income			$ 221,000,000

Property, Plant and Equipment -

Property, Plant and Equipment - Components of Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Land	$ 12	$ 11
Building and improvements	47	40
Pipeline and equipment	1,263	1,228
Other	34	33
Property, plant and equipment, gross	1,356	1,312
Accumulated depreciation, and amortization	(661)	(613)
Property plant and equipment excluding construction in progress	695	699
Construction in progress	4	27
Property, plant and equipment, net	699	726
Operating lease cost	0	0
Accumulated depreciation related to assets under operating leases	147	133
Accumulated depreciation related to assets under capital lease	$ 8	6
Building and Improvements \| Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	10 years
Building and Improvements \| Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	40 years
Pipeline and Equipment
Property Plant And Equipment [Line Items]
Operating lease cost	$ 372	369
Finance lease cost	$ 23	$ 23
Pipeline and Equipment \| Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	10 years
Pipeline and Equipment \| Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	30 years
Other \| Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	5 years
Other \| Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	25 years

Property, Plant and Equipment_2

Property, Plant and Equipment - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Depreciation, amortization and accretion	$ 50	$ 49	$ 46

Accrued Liabilities - Third P_3

Accrued Liabilities - Third Parties (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Payables and Accruals [Abstract]
Project accruals	$ 4	$ 5
Property taxes	5	4
Other accrued liabilities	1	3
Accrued liabilities - third parties	$ 10	$ 12

Related Party Debt - Schedule o

Related Party Debt - Schedule of Consolidated Related Party Debt Obligations (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Aug. 01, 2018
Line Of Credit Facility [Line Items]
Outstanding Balance	$ 2,692,000,000	$ 2,692,000,000
Unamortized debt issuance costs	(2,000,000)	(2,000,000)
Total Capacity	3,590,000,000	3,590,000,000
Available Capacity	$ 896,000,000	896,000,000
Five Year Revolver due July 2023
Line Of Credit Facility [Line Items]
Debt instrument term	5 years
Revolving Credit Facility \| Ten Year Fixed Facility
Line Of Credit Facility [Line Items]
Debt instrument term	10 years
Outstanding Balance	$ 600,000,000	600,000,000
Total Capacity	600,000,000	600,000,000
Available Capacity	$ 0	0
Revolving Credit Facility \| Seven Year Fixed Facility
Line Of Credit Facility [Line Items]
Debt instrument term	7 years
Outstanding Balance	$ 600,000,000	600,000,000
Total Capacity	600,000,000	600,000,000
Available Capacity	$ 0	0
Revolving Credit Facility \| Five Year Revolver due July 2023
Line Of Credit Facility [Line Items]
Debt instrument term	5 years
Outstanding Balance	$ 494,000,000	494,000,000
Total Capacity	760,000,000	760,000,000	$ 760,000,000
Available Capacity	$ 266,000,000	266,000,000
Revolving Credit Facility \| Five Year Revolver due December 2022
Line Of Credit Facility [Line Items]
Debt instrument term	5 years
Outstanding Balance	$ 400,000,000	400,000,000
Total Capacity	1,000,000,000	1,000,000,000
Available Capacity	$ 600,000,000	600,000,000
Revolving Credit Facility \| Five Year Fixed Facility
Line Of Credit Facility [Line Items]
Debt instrument term	5 years
Outstanding Balance	$ 600,000,000	600,000,000
Total Capacity	600,000,000	600,000,000
Available Capacity	0	0
Revolving Credit Facility \| 2019 Zydeco Revolver
Line Of Credit Facility [Line Items]
Outstanding Balance	0	0
Total Capacity	30,000,000	30,000,000
Available Capacity	$ 30,000,000	$ 30,000,000

Related Party Debt - Additional

Related Party Debt - Additional Information (Details) - USD ($)	May 11, 2018	Feb. 06, 2018	Dec. 01, 2017	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Aug. 06, 2019	Aug. 01, 2018	Jul. 31, 2018	Mar. 01, 2017
Line Of Credit Facility [Line Items]
Interest and fee expenses associated with borrowings				$ 90,000,000	$ 92,000,000	$ 61,000,000
Interest paid				92,000,000	88,000,000	53,000,000
Long-term debt, carrying value				2,694,000,000	2,694,000,000
Long-term debt, fair value				2,928,000,000	2,825,000,000
Repayments of credit facilities				0	0	$ 1,573,000,000
Maximum borrowing capacity				$ 3,590,000,000	3,590,000,000
Seven Year Fixed Facility \| Revolving Credit Facility
Line Of Credit Facility [Line Items]
Debt instrument term				7 years
Maximum borrowing capacity				$ 600,000,000	600,000,000
Fixed interest rate				4.06%
Debt issuance costs									$ 1,000,000
Five Year Revolver due July 2023
Line Of Credit Facility [Line Items]
Debt instrument term				5 years
Five Year Revolver due July 2023 \| Revolving Credit Facility
Line Of Credit Facility [Line Items]
Debt instrument term				5 years
Repayments of credit facilities		$ 247,000,000
Maximum borrowing capacity				$ 760,000,000	760,000,000			$ 760,000,000
Fixed interest rate								0.19%
Weighted average interest rate				2.06%
Five Year Revolver due December 2022 \| Revolving Credit Facility
Line Of Credit Facility [Line Items]
Debt instrument term				5 years
Repayments of credit facilities		$ 726,000,000
Maximum borrowing capacity				$ 1,000,000,000	1,000,000,000
Five Year Revolver due December 2022 \| Revolving Credit Facility \| Affiliated Entity \| Shell Treasury Center West Inc
Line Of Credit Facility [Line Items]
Unused capacity commitment fee percentage			0.19%
Maximum borrowing capacity			$ 1,000,000,000
Debt issuance costs			$ 2,000,000
Weighted average interest rate				2.26%
2019 Zydeco Revolver \| Revolving Credit Facility
Line Of Credit Facility [Line Items]
Maximum borrowing capacity				$ 30,000,000	30,000,000
2019 Zydeco Revolver \| Revolving Credit Facility \| Affiliated Entity \| Shell Treasury Center West Inc
Line Of Credit Facility [Line Items]
Maximum borrowing capacity							$ 30,000,000
Fixed interest rate				0.86%
Five Year Fixed Facility \| Revolving Credit Facility
Line Of Credit Facility [Line Items]
Debt instrument term				5 years
Maximum borrowing capacity				$ 600,000,000	600,000,000
Five Year Fixed Facility \| Revolving Credit Facility \| Affiliated Entity \| Shell Treasury Center West Inc
Line Of Credit Facility [Line Items]
Maximum borrowing capacity										$ 600,000,000
Fixed interest rate				3.23%
Debt issuance costs										$ 1,000,000
Ten Year Fixed Facility \| Revolving Credit Facility
Line Of Credit Facility [Line Items]
Debt instrument term				10 years
Maximum borrowing capacity				$ 600,000,000	$ 600,000,000
Ten Year Fixed Facility \| Revolving Credit Facility \| Affiliated Entity \| Shell Treasury Center West Inc
Line Of Credit Facility [Line Items]
Maximum borrowing capacity				$ 600,000,000
Fixed interest rate				4.18%
May 2018 Acquisition
Line Of Credit Facility [Line Items]
Consideration transferred	$ 1,220,000,000
May 2018 Acquisition \| Five Year Revolver due July 2023 \| Revolving Credit Facility \| Affiliated Entity \| Shell Treasury Center West Inc
Line Of Credit Facility [Line Items]
Consideration transferred	494,000,000
May 2018 Acquisition \| Five Year Revolver due December 2022 \| Revolving Credit Facility \| Affiliated Entity \| Shell Treasury Center West Inc
Line Of Credit Facility [Line Items]
Consideration transferred	$ 726,000,000

Leases - Additional Information

Leases - Additional Information (Details) $ in Millions	12 Months Ended
Leases - Additional Information (Details) $ in Millions	Dec. 31, 2020USD ($)leaserenewal_option	Dec. 31, 2019USD ($)	Jan. 01, 2019USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets	$ 4	$ 4
Number of finance leases \| lease	2
Present value of lease liabilities	$ 4
Unconditional payment obligations	$ 1	$ 5
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets			$ 5
Present value of lease liabilities			$ 5
Ten Year Agreement, Five Year Renewal Option
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Initial term	10 years
Additional term	5 years
Extension term prior to original extension option	14 months
Number of renewal options \| renewal_option	2
Ten Year Agreement, One Year Renewal Option
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Additional term	1 year
Number of renewal options \| renewal_option	10

Leases - Assets and Liabilities

Leases - Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease right-of-use assets	$ 4	$ 4
Finance lease assets	16	17
Total lease assets	20	21
Current finance lease liabilities	1	1
Operating lease liabilities	4	4
Finance lease liabilities	24	24
Total lease liabilities	29	29
Finance lease, accumulated amortization	$ 8	$ 6
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentNet	us-gaap:PropertyPlantAndEquipmentNet
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent	us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent

Leases - Lease Cost (Details)

Leases - Lease Cost (Details) - USD ($) $ in Millions	12 Months Ended
Leases - Lease Cost (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease cost	$ 0	$ 0
Finance lease cost, amortization of leased assets	1	1
Finance lease cost, interest on lease liabilities	4	4
Total lease cost	$ 5	$ 5

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Operating cash flows from operating leases	$ 0	$ 0
Operating cash flows from finance leases	(3)	(4)
Financing cash flows from finance leases	$ (1)	$ (1)	$ 0
Weighted-average remaining lease term - operating leases	19 years	20 years
Weighted-average remaining lease term - finance leases	10 years	11 years
Weighted-average discount rate - operating leases	5.80%	5.80%
Weighted-average discount rate - finance leases	14.30%	14.30%

Leases - Maturities of Operatin

Leases - Maturities of Operating and Financing Lease Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2021	$ 0
2022	1
2023	0
2024	1
2025	0
Remainder	5
Total lease payments	7
Less: Interest	(3)
Present value of lease liabilities	4
Operating lease, payments due, related to options to extend	2
Finance Lease, Liability, Payment, Due [Abstract]
2021	4
2022	4
2023	4
2024	4
2025	5
Remainder	28
Total lease payments	49
Less: Interest	(24)
Present value of lease liabilities	25
Finance lease, liability, payments due, principal amounts	24
Finance lease, liability, payments due, executory costs	8
Current finance lease liabilities	1	$ 1
Operating And Finance Lease, Liabilities, Payments Due [Abstract]
2021	4
2022	5
2023	4
2024	5
2025	5
Remainder	33
Total lease payments	56
Less: Interest	(27)
Present value of lease liabilities	$ 29

Leases - Maturity of Lease Paym

Leases - Maturity of Lease Payments to be Received (Details) $ in Millions	Dec. 31, 2020USD ($)
Leases [Abstract]
2021	$ 56
2022	56
2023	56
2024	56
2025	56
Remainder	451
Total lease payments	731
Operating lease, payments to be received, related to options to extend	$ 366

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Equity [Abstract]
Other comprehensive income (loss)	$ 1	$ 2

(Deficit) Equity - Additional I

(Deficit) Equity - Additional Information (Details) - USD ($) $ in Millions	Feb. 06, 2018	Dec. 31, 2020	Apr. 01, 2020	Dec. 31, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Partners' capital		$ (481)		$ (775)
General Partner SPLC
Class of Stock [Line Items]
Units canceled (in units)		0		4,761,012	4,567,588
Partners' capital			$ (4,000)
Units issued in connection with private placement (in units)	225,091
General Partner SPLC \| Shell Pipeline Company L P \| General Partner Interest
Class of Stock [Line Items]
Aggregate percentage of interest	2.00%	2.00%
Limited Partner \| Shell Pipeline Company L P \| Limited Partner Interest
Class of Stock [Line Items]
Aggregate percentage of interest		98.00%
Common Units
Class of Stock [Line Items]
Units issued in connection with private placement (in units)	11,029,412	1,000,000,000
Common Units \| Shell Pipeline Company L P
Class of Stock [Line Items]
Units canceled (in units)		269,457,304		109,457,304	99,979,548

(Deficit) Equity - Public Offer

(Deficit) Equity - Public Offerings and Private Placement (Details) - USD ($) $ / shares in Units, $ in Millions	Feb. 06, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Net proceeds from equity offerings				$ 973
Underwriter fees		$ 2	$ 0	0
Contributions from general partner	$ 14			20
Consideration for units issued in connection with private placement		$ 0	$ 0	20
Five Year Revolver Due December 2022
Class of Stock [Line Items]
Debt instrument term		5 years
Repayments of Debt		$ 726
Five Year Revolver due July 2023
Class of Stock [Line Items]
Debt instrument term		5 years
Repayments of Debt		$ 247
Common Units
Class of Stock [Line Items]
Units issued in connection with private placement (in units)	11,029,412	1,000,000,000
Common units per share (in units per share)	$ 27.20
Payment of equity issuance costs	$ 300
Consideration for units issued in connection with private placement	$ 6
Common Units \| General Public
Class of Stock [Line Items]
Units issued in connection with public offering (in units)	25,000,000
Net proceeds from equity offerings	$ 673
Gross proceeds from public offering	$ 680
Common units per share (in units per share)	$ 27.20
Underwriter fees	$ 6
Placement fees	$ 1
General Partner SPLC
Class of Stock [Line Items]
Units issued in connection with public offering (in units)	510,204
Units issued in connection with private placement (in units)	225,091
General Partner SPLC \| Shell Pipeline Company L P
Class of Stock [Line Items]
Contributions from general partner				$ 20
General Partner SPLC \| Shell Pipeline Company L P \| General Partner Interest
Class of Stock [Line Items]
Aggregate percentage of interest	2.00%	2.00%

(Deficit) Equity - At-the-Marke

(Deficit) Equity - At-the-Market Program (Details)	12 Months Ended
(Deficit) Equity - At-the-Market Program (Details)	Dec. 31, 2020USD ($)
Equity [Abstract]
Issuance of common units, maximum (in units)	$ 300,000,000

(Deficit) Equity - Schedule of

(Deficit) Equity - Schedule of Number of Units Outstanding (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
General Partner SPLC
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)	4,761,012	4,567,588
June 2019 Acquisition (in units)		193,424
Unit distribution (in units)	(4,761,012)
Ending balance (in units)	0	4,761,012
Preferred Partner
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)	0	0
June 2019 Acquisition (in units)		0
Unit distribution (in units)	50,782,904
Ending balance (in units)	50,782,904	0
General Public \| Common Units
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)	123,832,233	123,832,233
June 2019 Acquisition (in units)		0
Unit distribution (in units)	0
Ending balance (in units)	123,832,233	123,832,233
Shell Pipeline Company L P \| Common Units
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)	109,457,304	99,979,548
June 2019 Acquisition (in units)		9,477,756
Unit distribution (in units)	160,000,000
Ending balance (in units)	269,457,304	109,457,304

(Deficit) Equity - Units Outsta

(Deficit) Equity - Units Outstanding (Details)	Apr. 01, 2020$ / shares	Dec. 31, 2020shares	Dec. 31, 2019shares	Dec. 31, 2018shares
Class of Stock [Line Items]
Common unitholders' capital account, units outstanding (in shares)		393,289,537
Percent of consideration payable in cash	90.00%
Common Units
Class of Stock [Line Items]
Common unitholders' capital account, units outstanding (in shares)		123,832,233	123,832,233
Limited Partner \| Partnership Interests Restructuring Agreement \| Series A Perpetual Convertible Preferred Units
Class of Stock [Line Items]
Unit distribution (in units)		50,782,904
Unit distribution (in dollars per unit) \| $ / shares	$ 23.63
Preferred Partner
Class of Stock [Line Items]
Units canceled (in units)		50,782,904	0	0
Preferred Partner \| Series A Perpetual Convertible Preferred Units
Class of Stock [Line Items]
Conversion ratio	1
General Public \| Common Units
Class of Stock [Line Items]
Units canceled (in units)		123,832,233	123,832,233	123,832,233
Shell Pipeline Company L P
Class of Stock [Line Items]
Unit distribution (in units)		50,782,904	0
Shell Pipeline Company L P \| Series A Perpetual Convertible Preferred Units
Class of Stock [Line Items]
Conversion ratio	1
Closing price per share, threshold (in dollars per share) \| $ / shares	$ 33.082
Closing price per share, percent of issuance price, threshold	140.00%
Closing price per share, number of trading days threshold	20 days
Closing price per share, number of trading days preceding notice of conversion	30 days
Shell Pipeline Company L P \| Common Units
Class of Stock [Line Items]
Common unitholders' capital account, units outstanding (in shares)		269,457,304	109,457,304
Units canceled (in units)		269,457,304	109,457,304	99,979,548
Shell Pipeline Company L P \| Limited Partner \| Limited Partner Interest
Class of Stock [Line Items]
Ownership interest (in percentage)		68.50%

(Deficit) Equity - Schedule o_2

(Deficit) Equity - Schedule of Distributions Declared and/or Paid (Details) - USD ($) $ / shares in Units, $ in Millions	Apr. 01, 2020	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Distribution Made To Limited Partner [Line Items]
Distributions per Limited Partner unit (in dollars per share)		$ 0.46000	$ 0.46000	$ 0.46000	$ 0.46000	$ 0.46000	$ 0.44500	$ 0.43000	$ 0.41500	$ 0.40000	$ 0.38200	$ 0.36500	$ 0.34800	$ 0.33300	$ 1.8400	$ 1.7500	$ 1.4950
Preferred unitholder’s interest in net income		$ 36													$ 36	$ 0	$ 0
Distribution to holders of incentive distribution rights waived			$ 16	$ 17	$ 17										$ 50
Distributions declared and/or paid		173	173	173	162	$ 162	$ 140	$ 131	$ 119	$ 129	$ 121	$ 113	$ 106	$ 83
Preferred Units
Distribution Made To Limited Partner [Line Items]
Distributions per Limited Partner unit (in dollars per share)	$ 0.2363														$ 0.7089
Shell Midstream Partners L.P.
Distribution Made To Limited Partner [Line Items]
Aggregate percentage of interest															200.00%
Common Units \| General Public
Distribution Made To Limited Partner [Line Items]
Distributions declared and/or paid		57	57	57	57	57	56	53	51	49	47	46	43	33
Unit distribution (in units)															0
Common Units \| Shell Pipeline Company L P
Distribution Made To Limited Partner [Line Items]
Distributions declared and/or paid		104	104	104	50	50	48	47	42	40	38	36	35	30
Unit distribution (in units)															160,000,000
General Partner SPLC
Distribution Made To Limited Partner [Line Items]
Distributions declared and/or paid		$ 0	0	0	3	3	3	3	3	3	3	2	2	2
Unit distribution (in units)															(4,761,012)
General Partner SPLC \| Partnership Interests Restructuring Agreement
Distribution Made To Limited Partner [Line Items]
Distributions payable, amount waved	$ 20
General Partner SPLC \| Economic Interest
Distribution Made To Limited Partner [Line Items]
Noncontrolling interest		2.00%													2.00%
General Partner SPLC \| General Partner IDR's
Distribution Made To Limited Partner [Line Items]
Distributions declared and/or paid		$ 0	0	0	52	52	33	28	23	37	33	29	26	18
Preferred Units \| Shell Pipeline Company L P
Distribution Made To Limited Partner [Line Items]
Distributions declared and/or paid		$ 12	$ 12	$ 12	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0

(Deficit) Equity - Distribution

(Deficit) Equity - Distributions to Noncontroling Interest (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Zydeco Pipeline Company LLC (“Zydeco”)
Class of Stock [Line Items]
Distributions to noncontrolling interest	$ 5	$ 4	$ 7
Odyssey Pipeline L.L.C.
Class of Stock [Line Items]
Distributions to noncontrolling interest	$ 11	$ 13	$ 9

Revenue Recognition - Disaggreg

Revenue Recognition - Disaggregated Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total Topic 606 revenue	$ 424	$ 447	$ 469
Total revenue	481	503	525
Third Parties \| Revenue expected to be recognized on multi-year committed shipper transportation contracts
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total Topic 606 revenue	114	134	200
Third Parties \| Revenue expected to be recognized on multi-year storage service contracts
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total Topic 606 revenue	9	9	9
Third Parties \| Product Revenue
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total Topic 606 revenue	0	5	2
Related Parties
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Lease revenue – related parties	57	56	56
Related Parties \| Revenue expected to be recognized on multi-year committed shipper transportation contracts
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total Topic 606 revenue	164	210	176
Related Parties \| Revenue expected to be recognized on multi-year storage service contracts
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total Topic 606 revenue	8	7	7
Related Parties \| Revenue expected to be recognized on multi-year terminaling service contracts in place as of September 30, 2019
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total Topic 606 revenue	103	47	46
Related Parties \| Terminaling Services, Major Maintenance
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total Topic 606 revenue	7	0	0
Related Parties \| Product Revenue
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total Topic 606 revenue	19	35	29
Related Parties \| Transportation Services Nonlease Service
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total Topic 606 revenue	$ 5	$ 5	$ 5

Revenue Recognition - Future Mi

Revenue Recognition - Future Minimum Payments Receivable (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)term
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total lease payments	$ 731
Less than 1 year	56
More than 5 years	$ 451
Transportation Services Operating Leases Five Year Terms
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Initial term	10 years
Number of additional terms \| term	2
Additional term	5 years
Transportation Services Operating Leases Amended
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Additional term	14 months
Transportation Services Operating Leases One Year Terms
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Initial term	10 years
Number of additional terms \| term	10
Additional term	1 year
Transportation Services Operating Leases
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Initial term	10 years
Lease And Non-Lease Service Components
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total lease payments	$ 735
Less than 1 year	111
Years 2 to 3	220
Years 4 to 5	220
More than 5 years	$ 184

Revenue Recognition - Terminali

Revenue Recognition - Terminaling Service (Details) - Revenue expected to be recognized on multi-year terminaling service contracts in place as of September 30, 2019 $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Disaggregation of Revenue [Line Items]
Agreement term	15 years
Agreement term extension	5 years
Norco Transaction \| Affiliated Entity \| April 2020 Transaction
Disaggregation of Revenue [Line Items]
Annual payments receivable	$ 140
Annual payments receivable, gross	151
Annual payments receivable, net	$ 11

Revenue Recognition - Receivabl

Revenue Recognition - Receivables and Contract Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Jan. 01, 2018
Disaggregation of Revenue [Line Items]
Accounts receivable – third parties, net	$ 20	$ 12
Contract assets – related parties	233	0
Deferred revenue	4	0
Third Parties
Disaggregation of Revenue [Line Items]
Accounts receivable – third parties, net	19	11	$ 11		$ 19
Deferred revenue	4	0	0	$ 8	8
Related Parties
Disaggregation of Revenue [Line Items]
Accounts receivable – third parties, net	18	24	24		21
Contract assets – related parties	233		0
Deferred revenue	$ 19	$ 0	$ 0	$ 3	$ 3

Revenue Recognition - Contract

Revenue Recognition - Contract Balances (Details) - USD ($)	3 Months Ended	12 Months Ended
Revenue Recognition - Contract Balances (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Apr. 01, 2020	Jan. 01, 2019	Dec. 31, 2018	Jan. 01, 2018
Movement in Deferred Revenue [Roll Forward]
Deferred revenue, ending balance	$ 4,000,000	$ 4,000,000	$ 0
Contract With Customer, Estimated Future Amortization [Abstract]
2021	15,000,000	15,000,000
2022	16,000,000	16,000,000
2023	16,000,000	16,000,000
2024	17,000,000	17,000,000
2025	17,000,000	17,000,000
Minimum Volume Commitment
Movement in Deferred Revenue [Roll Forward]
Additions		24,000,000
Third Parties
Movement in Deferred Revenue [Roll Forward]
Deferred revenue, ending balance	4,000,000	4,000,000	0		$ 0	$ 8,000,000	$ 8,000,000
Additions		8,000,000	0
Reductions		(4,000,000)	(8,000,000)
Related Parties
Movement in Deferred Revenue [Roll Forward]
Deferred revenue, ending balance	19,000,000	19,000,000	0		$ 0	$ 3,000,000	$ 3,000,000
Additions		21,000,000	0
Reductions		(2,000,000)	(3,000,000)
Revenue expected to be recognized on multi-year terminaling service contracts in place as of September 30, 2019
Movement in Deferred Revenue [Roll Forward]
Additions		$ 5,000,000
Agreement term		15 years
Capitalized contract cost, amortization	$ 11,000,000
April 2020 Transaction
Movement in Deferred Revenue [Roll Forward]
Contract assets - related parties			$ 0
April 2020 Transaction \| Norco Transaction \| Affiliated Entity
Movement in Deferred Revenue [Roll Forward]
Contract assets - related parties				$ 244,000,000

Revenue Recognition - Remaining

Revenue Recognition - Remaining Performance Obligations (Details) $ in Millions	Dec. 31, 2020USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 2,366
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 227
Remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 227
Remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 227
Remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 221
Remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 1,464
Remaining performance obligation, expected timing of satisfaction, period
Revenue expected to be recognized on multi-year committed shipper transportation contracts
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 472
Revenue expected to be recognized on multi-year committed shipper transportation contracts \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	63
Revenue expected to be recognized on multi-year committed shipper transportation contracts \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	63
Revenue expected to be recognized on multi-year committed shipper transportation contracts \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	63
Revenue expected to be recognized on multi-year committed shipper transportation contracts \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	57
Revenue expected to be recognized on multi-year committed shipper transportation contracts \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	226
Revenue expected to be recognized on other multi-year transportation service contracts in place as of September 30, 2019
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	34
Revenue expected to be recognized on other multi-year transportation service contracts in place as of September 30, 2019 \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	6
Revenue expected to be recognized on other multi-year transportation service contracts in place as of September 30, 2019 \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	6
Revenue expected to be recognized on other multi-year transportation service contracts in place as of September 30, 2019 \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	6
Revenue expected to be recognized on other multi-year transportation service contracts in place as of September 30, 2019 \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	5
Revenue expected to be recognized on other multi-year transportation service contracts in place as of September 30, 2019 \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	11
Revenue expected to be recognized on multi-year storage service contracts
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	17
Revenue expected to be recognized on multi-year storage service contracts \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	4
Revenue expected to be recognized on multi-year storage service contracts \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	4
Revenue expected to be recognized on multi-year storage service contracts \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	4
Revenue expected to be recognized on multi-year storage service contracts \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	5
Revenue expected to be recognized on multi-year storage service contracts \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	0
Revenue expected to be recognized on multi-year terminaling service contracts in place as of September 30, 2019
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	335
Revenue expected to be recognized on multi-year terminaling service contracts in place as of September 30, 2019 \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	48
Revenue expected to be recognized on multi-year terminaling service contracts in place as of September 30, 2019 \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	48
Revenue expected to be recognized on multi-year terminaling service contracts in place as of September 30, 2019 \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	48
Revenue expected to be recognized on multi-year terminaling service contracts in place as of September 30, 2019 \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	48
Revenue expected to be recognized on multi-year terminaling service contracts in place as of September 30, 2019 \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	143
Revenue expected to be recognized on multi-year operation and major maintenance terminaling service contracts
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	1,508
Revenue expected to be recognized on multi-year operation and major maintenance terminaling service contracts \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	106
Revenue expected to be recognized on multi-year operation and major maintenance terminaling service contracts \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	106
Revenue expected to be recognized on multi-year operation and major maintenance terminaling service contracts \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	106
Revenue expected to be recognized on multi-year operation and major maintenance terminaling service contracts \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	106
Revenue expected to be recognized on multi-year operation and major maintenance terminaling service contracts \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 1,084

Net Income Per Limited Partne_3

Net Income Per Limited Partner Unit - Schedule of Allocation of Net Income to Arrive at Net Income Per Limited Partner Unit (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Limited Partners Capital Account [Line Items]
Net income		$ 556	$ 546	$ 482
Net income attributable to noncontrolling interests		13	18	18
Net income attributable to the Partnership		543	528	464
Partner distribution declared		645	552	469
Preferred unitholder’s interest in net income	$ 36	36	0	0
Income (less than)/in excess of distributions		(138)	(24)	(5)
General Partner SPLC
Limited Partners Capital Account [Line Items]
Net income attributable to the Partnership			147	134
Partner distribution declared		55	148	135
Income (less than)/in excess of distributions		$ 0	(1)	(1)
General Partner SPLC \| Economic Interest
Limited Partners Capital Account [Line Items]
Noncontrolling interest	2.00%	2.00%
Limited Partners Common Units
Limited Partners Capital Account [Line Items]
Net income attributable to the Partnership			381	330
Partner distribution declared		$ 590	404	334
Income (less than)/in excess of distributions		(138)	(23)	(4)
Preferred Partner
Limited Partners Capital Account [Line Items]
Preferred unitholder’s interest in net income		$ 36	$ 0	$ 0

Net Income Per Limited Partne_4

Net Income Per Limited Partner Unit - Schedule of Basic and Diluted Net Income Per Unit (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Distribution Made To Limited Partner [Line Items]
Distributions declared	$ 645	$ 552	$ 469
Income (less than)/in excess of distributions	(138)	(24)	(5)
Net income attributable to the Partnership	543	528	464
Net income attributable to the Partnership’s common unitholders (basic)	507
General Partner SPLC
Distribution Made To Limited Partner [Line Items]
Distributions declared	55	148	135
Income (less than)/in excess of distributions	0	(1)	(1)
Net income attributable to the Partnership		147	134
Net income attributable to the Partnership’s common unitholders (basic)	55
Limited Partners Common Units
Distribution Made To Limited Partner [Line Items]
Distributions declared	590	404	334
Income (less than)/in excess of distributions	(138)	(23)	(4)
Net income attributable to the Partnership		$ 381	$ 330
Net income attributable to the Partnership’s common unitholders (basic)	452
Dilutive effect of preferred units	36
Net income attributable to the Partnership’s common unitholders (diluted)	$ 488
Weighted average units outstanding:
Weighted average units outstanding - Basic (in shares)	353.5
Dilutive effect of preferred units (in shares)	38.2	229.2	220.3
Weighted average units outstanding - Diluted (in shares)	391.7
Net income per limited partner unit:
Basic and diluted (in dollars per share)	$ 1.28	$ 1.66	$ 1.50
Common - Diluted (in dollars per share)	$ 1.25	$ 1.66	$ 1.50

Transactions with Major Custo_2

Transactions with Major Customers and Concentration of Credit Risk - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Concentration Risk [Line Items]
Cash and cash equivalents in excess of FDIC limits	$ 320	$ 289
Maximum
Concentration Risk [Line Items]
Receivables payment terms	30 days
Sales Revenue Net \| Parent and Affiliates
Concentration Risk [Line Items]
Revenue with parent as percentage of total revenues	75.00%	70.00%	60.00%

Subsequent Events (Details)

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

Jan. 20, 2021

Mar. 31, 2021

Dec. 31, 2020

Sep. 30, 2020

Jun. 30, 2020

Mar. 31, 2020

Dec. 31, 2019

Sep. 30, 2019

Jun. 30, 2019

Mar. 31, 2019

Dec. 31, 2018

Sep. 30, 2018

Jun. 30, 2018

Mar. 31, 2018

Dec. 31, 2017

Dec. 31, 2021

Dec. 31, 2020

Dec. 31, 2019

Dec. 31, 2018

Subsequent Event [Line Items]

Distributions per Limited Partner unit (in dollars per share)

$ 0.46000

$ 0.44500

$ 0.43000

$ 0.41500

$ 0.40000

$ 0.38200

$ 0.36500

$ 0.34800

$ 0.33300

$ 1.8400

$ 1.7500

$ 1.4950

Scenario, Forecast

Subsequent Event [Line Items]

General and administrative fee

$ 10

Scenario, Forecast | Auger Pipeline

Subsequent Event [Line Items]

Asset impairments

$ 3

Subsequent Event | Cash Distribution

Subsequent Event [Line Items]

Distributions per Limited Partner unit (in dollars per share)

$ 0.4600

Subsequent Event | Preferred Unit Distribution

Subsequent Event [Line Items]

Distributions per Limited Partner unit (in dollars per share)

$ 0.2363

Uncategorized Items - shlx-2020

Label	Element	Value
Accounting Standards Update [Extensible List]	us-gaap_AccountingStandardsUpdateExtensibleList	Accounting Standards Update 2014-09 [Member]