Revenue Recognition - Impact of Adoption (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customer	$ 107		$ 115		$ 224	$ 201
Lease revenue – related parties	14		14		28	28
Cost of product sold – third parties	2		1		3	1
Cost of product sold – related parties	5		1		13	8
Operations and maintenance – third parties	16		25		29	68
Operations and maintenance – related parties	16		13		30	26
Net income	119	$ 137	115	$ 65	256	180
Deferred revenue – related party	0				0		$ 3
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	119		115		256	180
Third Parties | Transportation, Terminaling and Storage Services
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customer	34		57		76	92
Third Parties | Product Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customer	3		1		4	1
Related Parties | Transportation, Terminaling and Storage Services
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customer	64		55		128	98
Related Parties | Product Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customer	$ 6		$ 2		$ 16	$ 10