Operating Segments Operating Segments, Results (Details) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)		Jun. 30, 2019 USD ($) segments	Jun. 30, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments | segments				3
Revenues	$ 601	$ 569	[1],[2]	$ 1,231	$ 1,115	[1],[2]
Operating Income	207	180	[1],[2]	418	357	[1],[2]
Segment Reporting Operating Income	217	187	[1]	437	372	[1]
Unallocated general and administrative expenses	(10)	(7)	[1]	(19)	(15)	[1]
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],[3]	317	263	[1],[2],[3],[4]
Depreciation and amortization expenses	104	93	[2]	205	182	[2],[4]
Additions to Other Assets, Amount	136	181	[5]	258	338	[5]
Operating Segments | Terminalling and Transportation
Segment Reporting Information [Line Items]
Revenues	297	250	[1]	590	482	[1]
Operating Income	146	107	[1]	298	211	[1]
Depreciation and amortization expenses	38	37	[5]	74	70	[5]
Additions to Other Assets, Amount	26	33	[5]	51	79	[5]
Operating Segments | Gathering and Processing
Segment Reporting Information [Line Items]
Revenues	284	301	[1]	605	600	[1]
Operating Income	59	69	[1]	122	146	[1]
Depreciation and amortization expenses	64	54	[5]	126	107	[5]
Additions to Other Assets, Amount	110	148	[5]	207	258	[5]
Operating Segments | Wholesale Segment
Segment Reporting Information [Line Items]
Revenues	23	25		45	42
Operating Income	12	11		17	15
Depreciation and amortization expenses	2	2		5	5
Additions to Other Assets, Amount	0	0		0	1
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenues	(3)	(7)		(9)	(9)
Terminalling revenues | Operating Segments | Terminalling and Transportation
Segment Reporting Information [Line Items]
Revenues	248	209	[1]	493	408	[1]
Pipeline transportation revenues | Operating Segments | Terminalling and Transportation
Segment Reporting Information [Line Items]
Revenues	47	40	[1]	93	71	[1]
Other Terminalling and Transportation Revenue | Operating Segments | Terminalling and Transportation
Segment Reporting Information [Line Items]
Revenues	2	1	[1]	4	3	[1]
Sales of natural gas, NGLS and condensate | Operating Segments | Gathering and Processing
Segment Reporting Information [Line Items]
Revenues	94	95	[1]	216	199	[1]
Gas gathering and processing | Operating Segments | Gathering and Processing
Segment Reporting Information [Line Items]
Revenues	75	82	[1]	145	167	[1]
Crude oil and water gathering | Operating Segments | Gathering and Processing
Segment Reporting Information [Line Items]
Revenues	79	80	[1]	176	155	[1]
Pass-thru and other revenue | Operating Segments | Gathering and Processing
Segment Reporting Information [Line Items]
Revenues	36	44	[1]	68	79	[1]
Fuel Sales | Operating Segments | Wholesale Segment
Segment Reporting Information [Line Items]
Revenues	17	15		29	24
Other Non-fuel | Operating Segments | Wholesale Segment
Segment Reporting Information [Line Items]
Revenues	$ 6	$ 10		$ 16	$ 18
PNAC
Segment Reporting Information [Line Items]
Equity Method Investment, Ownership Percentage	50.00%			50.00%

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