Summary Of Significant Accounting Policies (Narrative) (Details) shares in Millions, $ in Millions	1 Months Ended	9 Months Ended		12 Months Ended
	Dec. 31, 2018 shares	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Dec. 31, 2020 USD ($) gas_processing_plant segment	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jan. 01, 2021 USD ($)	Jan. 01, 2019 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Allowances for doubtful accounts				$ 3	$ 2
Number of Gas Processing Plants | gas_processing_plant				11
Revenue - service revenue				$ 7,024	$ 9,671
Stock-based compensation awards general vesting period				3 years	3 years
Reportable operating segments | segment				1
Operating lease right-of-use assets				$ 197	$ 280
Present value of lease liabilities				210	306			$ 325
Total lease payments				223
Issuance costs and discounts				248	11
Accounting Standards Update 2020-06 | Cumulative Effect, Period of Adoption, Adjustment
Summary Of Significant Accounting Policies [Line Items]
Issuance costs and discounts							$ 202
ProPetro
Summary Of Significant Accounting Policies [Line Items]
Revenue - service revenue		$ 635	$ 1,618
Third party expenses, processing plants and treating facilities		$ 469	$ 1,165
Pressure pumping assets | Sale assets | ProPetro
Summary Of Significant Accounting Policies [Line Items]
Shares received | shares	16.6
Short-term receivables				$ 110
Minimum | Buildings
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life				20 years
Minimum | Equipment, vehicles, furniture and fixtures and information technology
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life				3 years
Minimum | Water infrastructure
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life				3 years
Maximum | Buildings
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life				39 years
Maximum | Equipment, vehicles, furniture and fixtures and information technology
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life				10 years
Maximum | Water infrastructure
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life				50 years
Natural Gas, Gathering, Transportation, Marketing and Processing [Member]
Summary Of Significant Accounting Policies [Line Items]
Revenue - service revenue				$ 178	140	$ 124
Third party expenses, processing plants and treating facilities				$ 76	$ 65	$ 75
ProPetro | ProPetro
Summary Of Significant Accounting Policies [Line Items]
Shares acquired				16.00%