Property, Plant and Equipment - Components of Property, Plant and Equipment (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Land	$ 12		$ 12
Building and improvements	47		47
Pipeline and equipment	1,260		1,263
Other	35		34
Property, plant and equipment, gross	1,354		1,356
Accumulated depreciation and amortization	(674)		(661)
Property plant and equipment excluding construction in progress	680		695
Construction in progress	6		4
Property, plant and equipment, net	686		699
Operating lease, accumulated depreciation	150		147
Finance lease, accumulated depreciation	8		8
Depreciation and amortization expense	13	$ 13
Impairment charge	3	$ 0
Auger Pipeline
Property Plant And Equipment [Line Items]
Impairment charge	$ 3
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		372
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