Related-Party Transactions Related-Party Transactions, Summary of Affiliate Transactions (Details) - USD ($) $ in Millions		3 Months Ended			6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018		Jun. 30, 2019	Jun. 30, 2018
Revenues		$ 601	$ 569	[1],[2]	$ 1,231	$ 1,115	[1],[2]
Concentration Risk, Percentage		71.00%	68.00%		71.00%	64.00%
Related Party Transactions, Operating Expenses	[3]	$ 113	$ 72	[4]	$ 217	$ 134	[4]
Related Party Transactions, General and Administrative Expenses		15	22	[4]	29	46	[4]
Recovery of Direct Costs		7	3		10	10
Affiliated Entity
Revenues	[5]	$ 424	$ 389	[2],[4]	$ 868	$ 716	[2],[4]

[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] Excludes reimbursements from our Sponsor pursuant to the Amended Omnibus Agreement, the Carson Assets Indemnity Agreement and other affiliate agreements of $7 million and $3 million for the three months ended June 30, 2019 and 2018, respectively, and $10 million for both the six months ended June 30, 2019 and 2018.

[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.