Equity Method Investments - Schedule of Equity Investments in Affiliates (Details) - USD ($)	Sep. 30, 2020	Dec. 31, 2019	Jun. 30, 2018
Schedule of Equity Method Investments [Line Items]
Investment Amount	$ 1,045,000,000	$ 926,000,000
Mattox
Schedule of Equity Method Investments [Line Items]
Ownership	79.00%	0.00%
Investment Amount	$ 166,000,000	$ 0
Amberjack – Series A / Series B
Schedule of Equity Method Investments [Line Items]
Investment Amount	$ 395,000,000	$ 426,000,000
Amberjack Pipeline Company LLC (“Amberjack”) - Series A
Schedule of Equity Method Investments [Line Items]
Ownership	75.00%	75.00%
Amberjack Pipeline Company LLC (“Amberjack”) - Series B
Schedule of Equity Method Investments [Line Items]
Ownership	50.00%	50.00%
Mars
Schedule of Equity Method Investments [Line Items]
Ownership	71.50%	71.50%
Investment Amount	$ 156,000,000	$ 161,000,000
Bengal
Schedule of Equity Method Investments [Line Items]
Ownership	50.00%	50.00%
Investment Amount	$ 89,000,000	$ 88,000,000
Crestwood Permian Basin LLC (“Permian Basin”)
Schedule of Equity Method Investments [Line Items]
Ownership	50.00%	50.00%
Investment Amount	$ 88,000,000	$ 91,000,000
LOCAP
Schedule of Equity Method Investments [Line Items]
Ownership	41.48%	41.48%
Investment Amount	$ 12,000,000	$ 9,000,000
Explorer
Schedule of Equity Method Investments [Line Items]
Ownership	38.59%	38.59%
Investment Amount	$ 79,000,000	$ 88,000,000
Poseidon
Schedule of Equity Method Investments [Line Items]
Ownership	36.00%	36.00%
Investment Amount	$ 0	$ 0	$ 0
Colonial Pipeline Company (“Colonial”)
Schedule of Equity Method Investments [Line Items]
Ownership	16.125%	16.125%
Investment Amount	$ 28,000,000	$ 30,000,000
Proteus
Schedule of Equity Method Investments [Line Items]
Ownership	10.00%	10.00%
Investment Amount	$ 14,000,000	$ 15,000,000
Endymion
Schedule of Equity Method Investments [Line Items]
Ownership	10.00%	10.00%
Investment Amount	$ 18,000,000	$ 18,000,000