Equity Method Investments - Summary of Balance Sheet and Income Statement Data for Equity Method Investments (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Total revenue	$ 481,000,000	$ 503,000,000	$ 525,000,000
Total operating expenses	312,000,000	288,000,000	313,000,000
Operating income	169,000,000	215,000,000	212,000,000
Net income	556,000,000	546,000,000	482,000,000
Balance Sheets
Current assets	394,000,000	359,000,000
Total assets	2,347,000,000	2,019,000,000
Current liabilities	82,000,000	46,000,000
Non-current liabilities	2,723,000,000	2,722,000,000
Equity (Deficit)	(458,000,000)	(749,000,000)	(257,000,000)	$ (566,000,000)
Total liabilities and deficit	2,347,000,000	2,019,000,000
Outstanding Balance	2,692,000,000	2,692,000,000
Total Capacity	3,590,000,000	3,590,000,000
Available Capacity	896,000,000	896,000,000
Amberjack
Schedule of Equity Method Investments [Line Items]
Total revenue		315,000,000	204,000,000
Total operating expenses		73,000,000	47,000,000
Operating income		242,000,000	157,000,000
Net income		243,000,000	157,000,000
Balance Sheets
Current assets	44,000,000	56,000,000	46,000,000
Non-current assets	836,000,000	804,000,000	846,000,000
Total assets	880,000,000	860,000,000	892,000,000
Current liabilities	10,000,000	4,000,000	4,000,000
Non-current liabilities	124,000,000	32,000,000	4,000,000
Equity (Deficit)	746,000,000	824,000,000	884,000,000
Total liabilities and deficit	880,000,000	860,000,000	892,000,000
Amberjack | Equity Method Investment, Nonconsolidated Investee, Other
Schedule of Equity Method Investments [Line Items]
Total revenue	280,000,000
Total operating expenses	78,000,000
Operating income	202,000,000
Net income	201,000,000
Mars
Schedule of Equity Method Investments [Line Items]
Total revenue		282,000,000	241,000,000
Total operating expenses		104,000,000	87,000,000
Operating income		178,000,000	154,000,000
Net income		179,000,000	154,000,000
Balance Sheets
Current assets	47,000,000	57,000,000	53,000,000
Non-current assets	269,000,000	173,000,000	178,000,000
Total assets	316,000,000	230,000,000	231,000,000
Current liabilities	23,000,000	8,000,000	5,000,000
Non-current liabilities	103,000,000	22,000,000	18,000,000
Equity (Deficit)	190,000,000	200,000,000	208,000,000
Total liabilities and deficit	316,000,000	230,000,000	231,000,000
Mars | Equity Method Investment, Nonconsolidated Investee, Other
Schedule of Equity Method Investments [Line Items]
Total revenue	259,000,000
Total operating expenses	97,000,000
Operating income	162,000,000
Net income	163,000,000
Bengal
Schedule of Equity Method Investments [Line Items]
Total revenue		77,000,000	69,000,000
Total operating expenses		30,000,000	28,000,000
Operating income		47,000,000	41,000,000
Net income		47,000,000	41,000,000
Balance Sheets
Current assets	33,000,000	35,000,000	27,000,000
Non-current assets	161,000,000	157,000,000	156,000,000
Total assets	194,000,000	192,000,000	183,000,000
Current liabilities	7,000,000	6,000,000	9,000,000
Non-current liabilities	0	0	0
Equity (Deficit)	187,000,000	186,000,000	174,000,000
Total liabilities and deficit	194,000,000	192,000,000	183,000,000
Bengal | Equity Method Investment, Nonconsolidated Investee, Other
Schedule of Equity Method Investments [Line Items]
Total revenue	65,000,000
Total operating expenses	30,000,000
Operating income	35,000,000
Net income	35,000,000
Explorer
Schedule of Equity Method Investments [Line Items]
Total revenue		258,000,000
Total operating expenses		115,000,000
Operating income		143,000,000
Net income		111,000,000
Balance Sheets
Current assets	74,000,000	93,000,000
Non-current assets	537,000,000	530,000,000
Total assets	611,000,000	623,000,000
Current liabilities	49,000,000	44,000,000
Non-current liabilities	459,000,000	442,000,000
Equity (Deficit)	103,000,000	137,000,000
Total liabilities and deficit	611,000,000	623,000,000
Explorer | Equity Method Investment, Nonconsolidated Investee, Other
Schedule of Equity Method Investments [Line Items]
Total revenue	329,000,000
Total operating expenses	175,000,000
Operating income	154,000,000
Net income	119,000,000
Colonial
Schedule of Equity Method Investments [Line Items]
Total revenue		829,000,000
Total operating expenses		449,000,000
Operating income		380,000,000
Net income		255,000,000
Balance Sheets
Current assets	501,000,000	323,000,000
Non-current assets	3,105,000,000	2,920,000,000
Total assets	3,606,000,000	3,243,000,000
Current liabilities	245,000,000	519,000,000
Non-current liabilities	3,508,000,000	2,873,000,000
Equity (Deficit)	(147,000,000)	(149,000,000)
Total liabilities and deficit	3,606,000,000	3,243,000,000
Colonial | Equity Method Investment, Nonconsolidated Investee, Other
Schedule of Equity Method Investments [Line Items]
Total revenue	1,395,000,000
Total operating expenses	660,000,000
Operating income	735,000,000
Net income	473,000,000
Poseidon
Schedule of Equity Method Investments [Line Items]
Total revenue		132,000,000	116,000,000
Total operating expenses		35,000,000	35,000,000
Operating income		97,000,000	81,000,000
Net income		87,000,000	73,000,000
Balance Sheets
Current assets	31,000,000	30,000,000	19,000,000
Non-current assets	176,000,000	190,000,000	203,000,000
Total assets	207,000,000	220,000,000	222,000,000
Current liabilities	10,000,000	16,000,000	16,000,000
Non-current liabilities	238,000,000	246,000,000	243,000,000
Equity (Deficit)	(41,000,000)	(42,000,000)	(37,000,000)
Total liabilities and deficit	207,000,000	220,000,000	222,000,000
Poseidon | Equity Method Investment, Nonconsolidated Investee, Other
Schedule of Equity Method Investments [Line Items]
Total revenue	147,000,000
Total operating expenses	36,000,000
Operating income	111,000,000
Net income	105,000,000
Other
Schedule of Equity Method Investments [Line Items]
Total revenue		190,000,000	152,000,000
Total operating expenses		108,000,000	67,000,000
Operating income		82,000,000	85,000,000
Net income		73,000,000	76,000,000
Balance Sheets
Current assets	35,000,000	60,000,000	50,000,000
Non-current assets	920,000,000	917,000,000	876,000,000
Total assets	955,000,000	977,000,000	926,000,000
Current liabilities	56,000,000	73,000,000	65,000,000
Non-current liabilities	486,000,000	469,000,000	456,000,000
Equity (Deficit)	413,000,000	435,000,000	405,000,000
Total liabilities and deficit	955,000,000	977,000,000	926,000,000
Other | Equity Method Investment, Nonconsolidated Investee, Other
Schedule of Equity Method Investments [Line Items]
Total revenue	220,000,000
Total operating expenses	123,000,000
Operating income	97,000,000
Net income	88,000,000
Permian Basin
Schedule of Equity Method Investments [Line Items]
Total revenue	0
Total operating expenses		25,000,000
Operating income			28,000,000
Mattox
Balance Sheets
Current assets	13,000,000
Non-current assets	204,000,000
Total assets	217,000,000
Current liabilities	0
Non-current liabilities	12,000,000
Equity (Deficit)	205,000,000
Total liabilities and deficit	217,000,000
Mattox | Equity Method Investment, Nonconsolidated Investee, Other
Schedule of Equity Method Investments [Line Items]
Total revenue	66,000,000
Total operating expenses	9,000,000
Operating income	57,000,000
Net income	57,000,000
April 2020 Acquisition | Mattox
Schedule of Equity Method Investments [Line Items]
Total revenue	85,000,000
Total operating expenses	12,000,000
Operating income	$ 73,000,000
June 2019 Acquisition | Explorer
Schedule of Equity Method Investments [Line Items]
Total revenue		443,000,000
Total operating expenses		196,000,000
Operating income		247,000,000
June 2019 Acquisition | Colonial
Schedule of Equity Method Investments [Line Items]
Total revenue		1,437,000,000
Total operating expenses		735,000,000
Operating income		$ 702,000,000
May 2018 Acquisition | Amberjack
Schedule of Equity Method Investments [Line Items]
Total revenue			295,000,000
Total operating expenses			74,000,000
Operating income			$ 221,000,000