Acquisitions Drop Down - Reconciliation of Combined Financial Statements (Details) - USD ($) $ in Millions		3 Months Ended					6 Months Ended
		Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018		Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues		$ 601		$ 569	[1],[2]		$ 1,231	$ 1,115	[1],[2]
NGL expense (excluding items shown separately below)		33		45	[2]		92	93	[2]
Operating expenses (excluding depreciation and amortization)		237		221	[2]		476	422	[2]
Depreciation and amortization expenses		104		93	[2]		205	182	[2],[3]
General and administrative expenses		18		29	[2]		38	60	[2]
Loss on asset disposals and impairments		2		1	[2]		2	1	[2],[3]
Operating Income		207		180	[1],[2]		418	357	[1],[2]
Interest and financing costs, net		(63)		(60)	[1],[2]		(124)	(115)	[1],[2]
Equity in earnings of equity method investments		9		10	[1],[2]		16	18	[1],[2]
Other income, net		7		2	[1],[2]		7	3	[1],[2]
Net Earnings		160		132	[1],[2],[4]		317	263	[1],[2],[3],[4]
Net Income (Loss) Attributable To Predecessors	[2]			16				24
Net Earnings Attributable to Partners		160	$ 157	148		$ 139	317	287
Preferred unitholders’ interest in net earnings		(10)		(10)			(20)	(24)
Limited Partners’ Interest in Net Earnings		150		138			297	263
Third Party
Revenues		177		180	[2]		363	399	[2]
Affiliated Entity
Revenues	[5]	$ 424		389	[2],[6]		$ 868	716	[2],[6]
Successors
Revenues				557				1,092
NGL expense (excluding items shown separately below)				45				93
Operating expenses (excluding depreciation and amortization)				201				391
Depreciation and amortization expenses				83				163
General and administrative expenses				25				52
Loss on asset disposals and impairments				1				1
Operating Income				202				392
Interest and financing costs, net				(58)				(112)
Equity in earnings of equity method investments				3				5
Other income, net				1				2
Net Earnings	[2]			148				287
Net Income (Loss) Attributable To Predecessors	[2]			0				0
Net Earnings Attributable to Partners				148				287
Preferred unitholders’ interest in net earnings				(10)				(24)
Limited Partners’ Interest in Net Earnings				138				263
Successors | Third Party
Revenues				176				393
Successors | Affiliated Entity
Revenues				381				699
Predecessors
Revenues				12				23
NGL expense (excluding items shown separately below)				0				0
Operating expenses (excluding depreciation and amortization)				20				31
Depreciation and amortization expenses				10				19
General and administrative expenses				4				8
Loss on asset disposals and impairments				0				0
Operating Income				(22)				(35)
Interest and financing costs, net				(2)				(3)
Equity in earnings of equity method investments				7				13
Other income, net				1				1
Net Earnings	[2]			(16)				(24)
Net Income (Loss) Attributable To Predecessors	[2]			16				24
Net Earnings Attributable to Partners				0				0
Preferred unitholders’ interest in net earnings				0				0
Limited Partners’ Interest in Net Earnings				0				0
Predecessors | Third Party
Revenues				4				6
Predecessors | Affiliated Entity
Revenues				$ 8				$ 17

[1] Adjusted to include the historical results of the Predecessors. See Note 1 for further discussion.

[2] Adjusted to include the historical results of the Predecessors. See Note 1 for further discussion.

[3] Adjusted to include the historical results of the Predecessors. See Note 1 for further discussion.

[4] Adjusted to include the historical results of the Predecessors. See Note 1 for further discussion.

[5] Represents 71% and 68% of our total revenues for the three months ended June 30, 2019 and 2018, respectively, and 71% and 64% of our total revenues for the six months ended June 30, 2019 and 2018, respectively.

[6] Adjusted to include the historical results of the Predecessors. See Note 1 for further discussion.