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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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Percentage investment held by the managing member or general partner of the limited liability company (LLC) or limited partnership (LP).

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The number of each class of partnership units outstanding at the balance sheet date. Units represent shares of ownership of the general, limited, and preferred partners.

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The number of units sold in a private placement of each class of partners' capital account. Units represent shares of ownership of the general, limited, and preferred partners.

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- Definition

Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity.

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(Deficit) Equity (Details) - USD ($)	3 Months Ended
(Deficit) Equity (Details) - USD ($)	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Apr. 01, 2020	Dec. 31, 2019
Class of Stock [Line Items]
Partners' capital	$ (467,000,000)	$ (774,000,000)	$ (458,000,000)		$ (749,000,000)
Issuance of common units, maximum proceeds	$ 300,000,000
General Partner SPLC
Class of Stock [Line Items]
Capital units, publicly owned (in shares)				4,761,012
Common Units
Class of Stock [Line Items]
Units issued under the ATM Program (in shares)	1,000,000,000
Shell Pipeline Company L P \| General Partner SPLC
Class of Stock [Line Items]
Partners' capital		$ (4,014,000,000)		$ (4,000,000,000)	$ (4,014,000,000)
Shell Pipeline Company L P \| General Partner SPLC \| General Partner Interest
Class of Stock [Line Items]
Aggregate percentage of general partner interest		2.00%
Shell Pipeline Company L P \| Limited Partner \| Limited Partner Interest
Class of Stock [Line Items]
Aggregate percentage of general partner interest		98.00%
Shell Pipeline Company L P \| Common Units
Class of Stock [Line Items]
Capital units, publicly owned (in shares)	269,457,304