Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	$ 268	$ 453
Gain (loss) on derivative activity	20	(10)
Total Revenues	648	795
Natural gas
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	69	149
Natural gas liquids
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	172	270
Condensate Natural Gas
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	27	34
Product
Disaggregation of Revenue [Line Items]
Total Revenues	288	443
Demand Service Revenue
Disaggregation of Revenue [Line Items]
Total Revenues	181	191
Volume Dependant Service Revenue
Disaggregation of Revenue [Line Items]
Total Revenues	179	161
Natural Gas, Gathering, Transportation, Marketing and Processing
Disaggregation of Revenue [Line Items]
Total Revenues	360	352
Operating Segments | Gathering and Processing
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	255	432
Gain (loss) on derivative activity	20	(9)
Total Revenues	477	630
Operating Segments | Gathering and Processing | Natural gas
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	56	128
Operating Segments | Gathering and Processing | Natural gas liquids
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	172	270
Operating Segments | Gathering and Processing | Condensate Natural Gas
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	27	34
Operating Segments | Gathering and Processing | Product
Disaggregation of Revenue [Line Items]
Total Revenues	275	423
Operating Segments | Gathering and Processing | Demand Service Revenue
Disaggregation of Revenue [Line Items]
Total Revenues	39	60
Operating Segments | Gathering and Processing | Volume Dependant Service Revenue
Disaggregation of Revenue [Line Items]
Total Revenues	163	147
Operating Segments | Gathering and Processing | Natural Gas, Gathering, Transportation, Marketing and Processing
Disaggregation of Revenue [Line Items]
Total Revenues	202	207
Operating Segments | Transportation and Storage
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	75	168
Gain (loss) on derivative activity	0	(1)
Total Revenues	234	316
Operating Segments | Transportation and Storage | Natural gas
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	73	162
Operating Segments | Transportation and Storage | Natural gas liquids
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	2	6
Operating Segments | Transportation and Storage | Condensate Natural Gas
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	0	0
Operating Segments | Transportation and Storage | Product
Disaggregation of Revenue [Line Items]
Total Revenues	75	167
Operating Segments | Transportation and Storage | Demand Service Revenue
Disaggregation of Revenue [Line Items]
Total Revenues	142	131
Operating Segments | Transportation and Storage | Volume Dependant Service Revenue
Disaggregation of Revenue [Line Items]
Total Revenues	17	18
Operating Segments | Transportation and Storage | Natural Gas, Gathering, Transportation, Marketing and Processing
Disaggregation of Revenue [Line Items]
Total Revenues	159	149
Eliminations
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	(62)	(147)
Gain (loss) on derivative activity	0	0
Total Revenues	(63)	(151)
Eliminations | Natural gas
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	(60)	(141)
Eliminations | Natural gas liquids
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	(2)	(6)
Eliminations | Condensate Natural Gas
Disaggregation of Revenue [Line Items]
Total revenues from natural gas, natural gas liquids, and condensate	0	0
Eliminations | Product
Disaggregation of Revenue [Line Items]
Total Revenues	(62)	(147)
Eliminations | Demand Service Revenue
Disaggregation of Revenue [Line Items]
Total Revenues	0	0
Eliminations | Volume Dependant Service Revenue
Disaggregation of Revenue [Line Items]
Total Revenues	(1)	(4)
Eliminations | Natural Gas, Gathering, Transportation, Marketing and Processing
Disaggregation of Revenue [Line Items]
Total Revenues	$ (1)	$ (4)