Operating Segments Operating Segments, Results (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016		Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Revenue, Net	$ 444	$ 308		$ 1,277	$ 901
Operating Income	151	127	[1]	467	364	[1]
Segment Reporting Operating Income	157	134		489	384
Unallocated general and administrative expenses	(6)	(7)		(22)	(20)
Interest and financing costs, net	(59)	(49)	[1]	(178)	(138)	[1]
Equity in earnings of equity method investments	2	3	[1]	7	10	[1]
Other income, net	3	0	[1]	3	6	[1]
Net Earnings	97	81	[1]	299	242	[1]
Additions to Other Assets, Amount	51	61		141	181
Operating Segments [Member] | Terminalling and Transportation
Segment Reporting Information [Line Items]
Revenue, Net	189	157		544	438
Operating Income	110	80		329	211
Additions to Other Assets, Amount	26	38		77	99
Operating Segments [Member] | Gathering and Processing
Segment Reporting Information [Line Items]
Revenue, Net	255	151		733	463
Operating Income	47	54		160	173
Additions to Other Assets, Amount	25	23		64	82
Terminalling revenues [Member] | Operating Segments [Member] | Terminalling and Transportation
Segment Reporting Information [Line Items]
Revenue, Net	155	125		447	345
Pipeline transportation revenues [Member] | Operating Segments [Member] | Terminalling and Transportation
Segment Reporting Information [Line Items]
Revenue, Net	34	32		97	93
Sales of natural gas, NGLS and condensate [Member] | Operating Segments [Member] | Gathering and Processing
Segment Reporting Information [Line Items]
Revenue, Net	90	24		254	78
Gas gathering and processing [Member] | Operating Segments [Member] | Gathering and Processing
Segment Reporting Information [Line Items]
Revenue, Net	85	67		252	198
Crude oil and water gathering [Member] | Operating Segments [Member] | Gathering and Processing
Segment Reporting Information [Line Items]
Revenue, Net	43	33		116	100
Pass-thru and other revenue [Member] | Operating Segments [Member] | Gathering and Processing
Segment Reporting Information [Line Items]
Revenue, Net	$ 37	$ 27		$ 111	$ 87

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