Revenue Recognition - Disaggregated Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Total Topic 606 revenue	$ 107	$ 117
Lease revenue	14	14
Total revenue	121	131
Transportation Services | Third Parties
Disaggregation of Revenue [Line Items]
Total Topic 606 revenue	29	40
Transportation Services | Related Parties
Disaggregation of Revenue [Line Items]
Total Topic 606 revenue	55	50
Storage Services | Third Parties
Disaggregation of Revenue [Line Items]
Total Topic 606 revenue	2	2
Storage Services | Related Parties
Disaggregation of Revenue [Line Items]
Total Topic 606 revenue	2	2
Terminaling Services | Related Parties
Disaggregation of Revenue [Line Items]
Total Topic 606 revenue	12	12
Product Revenue | Third Parties
Disaggregation of Revenue [Line Items]
Total Topic 606 revenue	0	1
Product Revenue | Related Parties
Disaggregation of Revenue [Line Items]
Total Topic 606 revenue	7	10
Transportation Services, Non-lease Service | Related Parties
Disaggregation of Revenue [Line Items]
Total Topic 606 revenue	$ 1	$ 1