Revenue Recognition - Disaggregated Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total Topic 606 revenue	$ 424	$ 447	$ 469
Total revenue	481	503	525
Third Parties | Revenue expected to be recognized on multi-year committed shipper transportation contracts
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total Topic 606 revenue	114	134	200
Third Parties | Revenue expected to be recognized on multi-year storage service contracts
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total Topic 606 revenue	9	9	9
Third Parties | Product Revenue
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total Topic 606 revenue	0	5	2
Related Parties
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Lease revenue – related parties	57	56	56
Related Parties | Revenue expected to be recognized on multi-year committed shipper transportation contracts
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total Topic 606 revenue	164	210	176
Related Parties | Revenue expected to be recognized on multi-year storage service contracts
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total Topic 606 revenue	8	7	7
Related Parties | Revenue expected to be recognized on multi-year terminaling service contracts in place as of September 30, 2019
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total Topic 606 revenue	103	47	46
Related Parties | Terminaling Services, Major Maintenance
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total Topic 606 revenue	7	0	0
Related Parties | Product Revenue
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total Topic 606 revenue	19	35	29
Related Parties | Transportation Services Nonlease Service
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total Topic 606 revenue	$ 5	$ 5	$ 5