Variable Interest Entities (Consolidated Information of Variable Interest Entity) (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Variable Interest Entity [Line Items]
Cash and cash equivalents	$ 168	$ 452
Restricted cash and cash equivalents	27	24
Accounts receivable	1,161	931
Prepayments and other current assets	103	139
Plant, property, and equipment, net	22,340	22,352
Total assets	30,372	28,753
Accounts payable	949	875
Other current liabilities	170	156
Asset retirement obligations	747	628
Other non‑current liabilities	383	375
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Cash and cash equivalents	33	21
Restricted cash and cash equivalents	0	1
Accounts receivable	6	3
Prepayments and other current assets	3	2
Plant, property, and equipment, net	833	856
Total assets	875	883
Accounts payable	15	17
Other current liabilities	0	2
Asset retirement obligations	24	23
Other non‑current liabilities		4
Total liabilities	$ 39	$ 46