Variable Interest Entities (Consolidated Information of Variable Interest Entity) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Variable Interest Entity [Line Items]
Cash and cash equivalents	$ 389	$ 164
Prepayments and other current assets	125	113
Plant, property, and equipment, net	24,264	22,713
Total assets	32,265	31,353
Asset retirement obligations	759	746
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Cash and cash equivalents	22	28
Accounts receivable	4	7
Prepayments and other current assets	4	3
Plant, property, and equipment, net	810	825
Total assets	840	863
Accounts payable	7	15
Asset retirement obligations	24	24
Total liabilities	$ 31	$ 39