Revenue Recognition - Disaggregated Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Total Topic 606 revenue	$ 95	$ 111	$ 308	$ 335
Lease revenue – related parties	15	14
Total revenue	110	125	351	377
Related Parties
Disaggregation of Revenue [Line Items]
Lease revenue – related parties			43	42
Transportation Services | Third Parties
Disaggregation of Revenue [Line Items]
Total Topic 606 revenue	24	31	78	103
Transportation Services | Related Parties
Disaggregation of Revenue [Line Items]
Total Topic 606 revenue	31	55	127	156
Storage Services | Third Parties
Disaggregation of Revenue [Line Items]
Total Topic 606 revenue	2	2	6	6
Storage Services | Related Parties
Disaggregation of Revenue [Line Items]
Total Topic 606 revenue	2	1	6	5
Terminaling Services | Related Parties
Disaggregation of Revenue [Line Items]
Total Topic 606 revenue	31	12	73	35
Terminaling Services, Major Maintenance | Related Parties
Disaggregation of Revenue [Line Items]
Total Topic 606 revenue	0	0	4	0
Product Revenue | Third Parties
Disaggregation of Revenue [Line Items]
Total Topic 606 revenue	0	0	0	4
Product Revenue | Related Parties
Disaggregation of Revenue [Line Items]
Total Topic 606 revenue	5	10	14	26
Transportation Services, Non-lease Service | Related Parties
Disaggregation of Revenue [Line Items]
Total Topic 606 revenue	$ 2	$ 4	$ 2	$ 4