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