Acquisitions and Divestitures - (Schedule of the Allocation of Purchase Price of GEPH) (Details) - GEPH Merger $ in Millions	Dec. 31, 2021 USD ($)
Consideration:
Total consideration	$ 1,732
Fair Value of Assets Acquired:
Cash and cash equivalents	11
Accounts receivable	171
Other current assets	3
Derivative assets	56
Evaluated natural gas and oil properties	1,783
Unevaluated natural gas and oil properties	59
Other property, plant and equipment	2
Other long-term assets	3
Total assets acquired	2,088
Fair Value of Liabilities Assumed:
Accounts payable	170
Other current liabilities	1
Derivative liabilities	75
Revolving credit facility	81
Asset retirement obligations	24
Other long-term liabilities	5
Total liabilities assumed	356
Net assets acquired and liabilities assumed	$ 1,732