Leases, Total Lease Cost by Class of Underlying Asset (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Finance lease cost:
Amortization of ROU assets	$ 14	$ 24
Interest on lease liabilities	14	25
Lease cost:
Operating lease cost	113	218
Variable lease cost	22	50
Short-term lease cost	24	47
Sublease income	(16)	(18)
Total lease cost	171	346
Pipelines, Terminals, and Tanks [Member]
Finance lease cost:
Amortization of ROU assets	12	20
Interest on lease liabilities	12	22
Lease cost:
Operating lease cost	47	94
Variable lease cost	15	33
Short-term lease cost	4	7
Sublease income	0	0
Total lease cost	90	176
Transportation, Marine [Member]
Finance lease cost:
Amortization of ROU assets	0	0
Interest on lease liabilities	0	0
Lease cost:
Operating lease cost	34	68
Variable lease cost	7	17
Short-term lease cost	12	26
Sublease income	(15)	(16)
Total lease cost	38	95
Transportation, Rail [Member]
Finance lease cost:
Amortization of ROU assets	0	0
Interest on lease liabilities	0	0
Lease cost:
Operating lease cost	13	24
Variable lease cost	0	0
Short-term lease cost	0	0
Sublease income	0	0
Total lease cost	13	24
Feedstock Processing Equipment [Member]
Finance lease cost:
Amortization of ROU assets	1	2
Interest on lease liabilities	1	1
Lease cost:
Operating lease cost	5	12
Variable lease cost	0	0
Short-term lease cost	8	14
Sublease income	0	0
Total lease cost	15	29
Energy and Gases [Member]
Finance lease cost:
Amortization of ROU assets	1	2
Interest on lease liabilities	1	2
Lease cost:
Operating lease cost	2	4
Variable lease cost	0	0
Short-term lease cost	0	0
Sublease income	0	0
Total lease cost	4	8
Real Estate [Member]
Finance lease cost:
Amortization of ROU assets	0	0
Interest on lease liabilities	0	0
Lease cost:
Operating lease cost	10	14
Variable lease cost	0	0
Short-term lease cost	0	0
Sublease income	(1)	(2)
Total lease cost	9	12
Other [Member]
Finance lease cost:
Amortization of ROU assets	0	0
Interest on lease liabilities	0	0
Lease cost:
Operating lease cost	2	2
Variable lease cost	0	0
Short-term lease cost	0	0
Sublease income	0	0
Total lease cost	$ 2	$ 2