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Asset Acquisition, Consideration Transferred

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Asset Acquisition, Consideration Transferred, Common Units, Weighted Average Sales Price

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Asset Acquisition, Consideration Transferred, Equity Interests Issued and Issuable

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Asset Acquisition

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Equity Method Investment, Ownership Percentage Acquired

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Payments To Acquire Asset, Gross

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Number of common units issued of limited liability company (LLC).

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This element represents the aggregate cost of investments accounted for under the equity method of accounting.

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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The number of general partner units issued.

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The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

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Amount, after tax, of reclassification adjustment from accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan.

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Acquisitions and Other Transactions - June 2019 Acquisitions (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
	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%