Reportable Segments - Schedule of Financial Data for Business Segments and Services (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($) segment	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	2
Total Revenues	$ 648	$ 795
Cost of natural gas and natural gas liquids (excluding depreciation and amortization shown separately)	226	378
Operation and maintenance, General and administrative	126	129
Depreciation and amortization	104	105
Impairments	28	0
Taxes other than income tax	18	18
Operating Income	146	165
Capital expenditures	54	143
Total assets	12,117		$ 12,266
Operating Segments | Gathering and Processing
Segment Reporting Information [Line Items]
Total Revenues	477	630
Cost of natural gas and natural gas liquids (excluding depreciation and amortization shown separately)	211	360
Operation and maintenance, General and administrative	81	84
Depreciation and amortization	74	74
Impairments	28
Taxes other than income tax	11	11
Operating Income	72	101
Capital expenditures	34	107
Total assets	9,659		9,739
Operating Segments | Transportation and Storage
Segment Reporting Information [Line Items]
Total Revenues	234	316
Cost of natural gas and natural gas liquids (excluding depreciation and amortization shown separately)	78	169
Operation and maintenance, General and administrative	45	45
Depreciation and amortization	30	31
Impairments	0
Taxes other than income tax	7	7
Operating Income	74	64
Capital expenditures	20	36
Total assets	5,702		5,886
Eliminations
Segment Reporting Information [Line Items]
Total Revenues	(63)	(151)
Cost of natural gas and natural gas liquids (excluding depreciation and amortization shown separately)	(63)	(151)
Operation and maintenance, General and administrative	0	0
Depreciation and amortization	0	0
Impairments	0
Taxes other than income tax	0	0
Operating Income	0	0
Capital expenditures	0	0
Total assets	(3,244)		$ (3,359)
Product
Segment Reporting Information [Line Items]
Total Revenues	288	443
Product | Operating Segments | Gathering and Processing
Segment Reporting Information [Line Items]
Total Revenues	275	423
Product | Operating Segments | Transportation and Storage
Segment Reporting Information [Line Items]
Total Revenues	75	167
Product | Eliminations
Segment Reporting Information [Line Items]
Total Revenues	(62)	(147)
Natural Gas, Gathering, Transportation, Marketing and Processing
Segment Reporting Information [Line Items]
Total Revenues	360	352
Natural Gas, Gathering, Transportation, Marketing and Processing | Operating Segments | Gathering and Processing
Segment Reporting Information [Line Items]
Total Revenues	202	207
Natural Gas, Gathering, Transportation, Marketing and Processing | Operating Segments | Transportation and Storage
Segment Reporting Information [Line Items]
Total Revenues	159	149
Natural Gas, Gathering, Transportation, Marketing and Processing | Eliminations
Segment Reporting Information [Line Items]
Total Revenues	$ (1)	$ (4)