Property and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property and Equipment
Capitalized interest	$ 47	$ 57	$ 48
Property and equipment, gross	16,261	15,695
Accumulated depreciation	(2,371)	(2,202)
Property and equipment, net	13,890	13,493
Depreciation expense	471	381	321
Costs associated with discontinuation of capital projects	33
Impairments of long-lived assets	18	0	10
Pipelines and related facilities
Property and Equipment
Property and equipment, gross	$ 9,066	8,436
Pipelines and related facilities | Minimum
Property and Equipment
Estimated useful lives	10 years
Pipelines and related facilities | Maximum
Property and Equipment
Estimated useful lives	70 years
Storage, terminal and rail facilities
Property and Equipment
Property and equipment, gross	$ 5,305	5,012
Storage, terminal and rail facilities | Minimum
Property and Equipment
Estimated useful lives	30 years
Storage, terminal and rail facilities | Maximum
Property and Equipment
Estimated useful lives	70 years
Trucking equipment and other
Property and Equipment
Property and equipment, gross	$ 408	392
Trucking equipment and other | Minimum
Property and Equipment
Estimated useful lives	3 years
Trucking equipment and other | Maximum
Property and Equipment
Estimated useful lives	15 years
Construction in progress
Property and Equipment
Property and equipment, gross	$ 826	1,217
Office property and equipment
Property and Equipment
Property and equipment, gross	$ 222	196
Office property and equipment | Minimum
Property and Equipment
Estimated useful lives	2 years
Office property and equipment | Maximum
Property and Equipment
Estimated useful lives	50 years
Land and other
Property and Equipment
Property and equipment, gross	$ 434	442
Property, Plant and Equipment
Property and Equipment
Capitalized interest	34	$ 49	$ 48
Rail And Other Terminal Assets | Depreciation and amortization | Facilities
Property and Equipment
Non-cash impairment losses	$ 80