Property, Plant and Equipment - Components of Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Land	$ 12	$ 11
Building and improvements	47	40
Pipeline and equipment	1,263	1,228
Other	34	33
Property, plant and equipment, gross	1,356	1,312
Accumulated depreciation, and amortization	(661)	(613)
Property plant and equipment excluding construction in progress	695	699
Construction in progress	4	27
Property, plant and equipment, net	699	726
Operating lease cost	0	0
Accumulated depreciation related to assets under operating leases	147	133
Accumulated depreciation related to assets under capital lease	$ 8	6
Building and Improvements | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	10 years
Building and Improvements | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	40 years
Pipeline and Equipment
Property Plant And Equipment [Line Items]
Operating lease cost	$ 372	369
Finance lease cost	$ 23	$ 23
Pipeline and Equipment | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	10 years
Pipeline and Equipment | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	30 years
Other | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	5 years
Other | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	25 years