CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash Flows from Operating Activities
Net income	$ 1,221	$ 2,187	$ 510
Adjustments to reconcile net income to net cash provided by operating activities:
Distributions from and equity in earnings of unconsolidated affiliates	7	20	45
Depreciation and amortization	634	785	435
Accretion of asset retirement obligations	55	30	45
Provision for credit losses	11	698	108
Amortization of nuclear fuel	54	51	54
Amortization of financing costs and debt discounts	23	39	48
Loss on debt extinguishment	0	77	9
Amortization of in-the-money contracts and emission allowances	158	106	70
Amortization of unearned equity compensation	28	21	22
Net gain on sale of assets and disposal of assets	(102)	(261)	(23)
Impairment losses	206	544	93
Changes in derivative instruments	(3,221)	(3,626)	137
Changes in deferred income taxes and liability for uncertain tax benefits	382	604	228
Changes in collateral deposits in support of risk management activities	896	797	127
Changes in nuclear decommissioning trust liability	9	40	51
Oil lower of cost or market adjustment	0	0	29
Uplift securitization proceeds received/(receivable) from ERCOT	689	(689)	0
Cash (used)/provided by changes in other working capital, net of acquisition and disposition effects:
Accounts receivable - trade	(1,560)	(1,232)	0
Inventory	(252)	(61)	27
Prepayments and other current assets	17	31	4
Accounts payable	1,295	476	(56)
Accrued expenses and other current liabilities	(29)	(55)	(42)
Other assets and liabilities	(161)	(89)	(84)
Cash provided by operating activities	360	493	1,837
Cash Flows from Investing Activities
Payments for acquisitions of assets, businesses and leases	(62)	(3,559)	(284)
Capital expenditures	(367)	(269)	(230)
Net purchases of emissions allowances	(6)	0	(10)
Investments in nuclear decommissioning trust fund securities	(454)	(751)	(492)
Proceeds from sales of nuclear decommissioning trust fund securities	448	710	439
Proceeds from sale of assets, net of cash disposed and fees	109	830	81
Changes in investments in unconsolidated affiliates	0	0	2
Cash used by investing activities	(332)	(3,039)	(494)
Cash Flows from Financing Activities
Net receipts/(payments) from settlement of acquired derivatives that include financing elements	1,995	938	(7)
Payments for share repurchase activity	(606)	(48)	(229)
Payments of dividends to common stockholders	(332)	(319)	(295)
Proceeds from issuance of long-term debt	0	1,100	3,234
Payments for short and long-term debt	(5)	(1,861)	(335)
Payments for debt extinguishment costs	0	(65)	(5)
Payments of debt issuance costs	(9)	(18)	(75)
Repayments of Revolving Credit Facility	0	0	(83)
Proceeds from issuance of common stock	0	1	1
Purchase of and distributions to noncontrolling interests from subsidiaries	0	0	(2)
Cash provided/(used) by financing activities	1,043	(272)	2,204
Effect of exchange rate changes on cash and cash equivalents	(3)	(2)	(2)
Net Increase/(Decrease) in Cash and Cash Equivalents, Funds Deposited by Counterparties and Restricted Cash	1,068	(2,820)	3,545
Cash and Cash Equivalents, Funds Deposited by Counterparties and Restricted Cash at Beginning of Period	1,110	3,930	385
Cash and Cash Equivalents, Funds Deposited by Counterparties and Restricted Cash at End of Period	$ 2,178	$ 1,110	$ 3,930