Leases, Total Lease Cost by Class of Underlying Asset (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Finance lease cost:
Amortization of ROU assets	$ 10
Interest on lease liabilities	11
Lease cost:
Operating lease cost	105
Variable lease cost	28
Short-term lease cost	23
Sublease income	(2)
Total lease cost	175
Pipelines, Terminals, and Tanks [Member]
Finance lease cost:
Amortization of ROU assets	8
Interest on lease liabilities	10
Lease cost:
Operating lease cost	47
Variable lease cost	18
Short-term lease cost	3
Sublease income	0
Total lease cost	86
Transportation, Marine [Member]
Finance lease cost:
Amortization of ROU assets	0
Interest on lease liabilities	0
Lease cost:
Operating lease cost	34
Variable lease cost	10
Short-term lease cost	14
Sublease income	(1)
Total lease cost	57
Transportation, Rail [Member]
Finance lease cost:
Amortization of ROU assets	0
Interest on lease liabilities	0
Lease cost:
Operating lease cost	11
Variable lease cost	0
Short-term lease cost	0
Sublease income	0
Total lease cost	11
Feedstock Processing Equipment [Member]
Finance lease cost:
Amortization of ROU assets	1
Interest on lease liabilities	0
Lease cost:
Operating lease cost	7
Variable lease cost	0
Short-term lease cost	6
Sublease income	0
Total lease cost	14
Energy and Gases [Member]
Finance lease cost:
Amortization of ROU assets	1
Interest on lease liabilities	1
Lease cost:
Operating lease cost	2
Variable lease cost	0
Short-term lease cost	0
Sublease income	0
Total lease cost	4
Real Estate [Member]
Finance lease cost:
Amortization of ROU assets	0
Interest on lease liabilities	0
Lease cost:
Operating lease cost	4
Variable lease cost	0
Short-term lease cost	0
Sublease income	(1)
Total lease cost	$ 3