Acquisitions and Other Transactions - April 2020 Transaction (Details)		3 Months Ended								9 Months Ended
	Apr. 01, 2020 USD ($) numberOfQuarters $ / shares shares	Sep. 30, 2020 USD ($) $ / shares shares	Jun. 30, 2020 $ / shares	Mar. 31, 2020 $ / shares	Dec. 31, 2019 USD ($) $ / shares	Sep. 30, 2019 $ / shares	Jun. 30, 2019 $ / shares	Mar. 31, 2019 $ / shares	Dec. 31, 2018 $ / shares	Sep. 30, 2020 USD ($) $ / shares shares	Sep. 30, 2019 $ / shares
Asset Acquisition [Line Items]
Equity method investments		$ 1,045,000,000			$ 926,000,000					$ 1,045,000,000
Financing receivables – related parties		300,000,000			0					300,000,000
Equity Method Investments And Other Assets	$ 720,000,000
Partners' capital		$ (437,000,000)			$ (775,000,000)					$ (437,000,000)
Common units (in units) | shares	393,289,537
Distributions paid per limited partner unit (in dollars per share) | $ / shares		$ 0.4600	$ 0.4600	$ 0.4600	$ 0.4600	$ 0.4450	$ 0.4300	$ 0.4150	$ 0.4000	$ 1.3800	$ 1.2900
Affiliated Entity | Norco Transaction | Valuation Technique, Discounted Cash Flow
Asset Acquisition [Line Items]
Measurement input	11.00%
Affiliated Entity | Mattox Transaction | Valuation Technique, Discounted Cash Flow
Asset Acquisition [Line Items]
Measurement input	14.00%
Affiliated Entity | GP/IDR Restructuring | Valuation Technique, Discounted Cash Flow
Asset Acquisition [Line Items]
Measurement input	20.00%
Mattox Pipeline Company LLC ("Mattox")
Asset Acquisition [Line Items]
Equity method investments	$ 174,000,000
April 2020 Transaction
Asset Acquisition [Line Items]
Contract asset - related parties					$ 0
April 2020 Transaction | Norco Transaction
Asset Acquisition [Line Items]
Financing receivables – related parties	302,000,000
April 2020 Transaction | Affiliated Entity | Norco Transaction
Asset Acquisition [Line Items]
Contract asset - related parties	244,000,000
Consideration allocated, fair value	$ 546,000,000
April 2020 Transaction | Terminaling Services | Affiliated Entity | Norco Transaction
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
Preferred Units
Asset Acquisition [Line Items]
Distributions paid per limited partner unit (in dollars per share) | $ / shares	$ 0.2363
General Partner SPLC
Asset Acquisition [Line Items]
Unit distribution (in units) | shares										(4,761,012)
Units canceled (in units) | shares	4,761,012
Partners' capital	$ (4,000,000,000)
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
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
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
Mattox Pipeline Company LLC ("Mattox")
Asset Acquisition [Line Items]
Ownership		79.00%								79.00%