Statements of Cash Flows (Unaudited) - MEC - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities:
Net income	$ 653	$ 989
Adjustments to reconcile net income (loss) to net cash flows from operating activities:
Allowance for equity funds	(83)	(49)
Deferred income taxes and investment tax credits, net	(81)	(11)
Other, net	(8)	15
Changes in other operating assets and liabilities, net of effects from acquisitions:
Trade receivables and other assets	67	161
Pension and other postretirement benefit plans	(2)	(7)
Accrued property, income and other taxes, net	(353)	(177)
Accounts payable and other liabilities	113	(106)
Net cash flows from operating activities	1,986	1,095
Cash flows from investing activities:
Capital expenditures	(2,153)	(1,848)
Purchases of marketable securities	(100)	(106)
Proceeds from sales of marketable securities	108	1,091
Other, net	13	0
Net cash flows from investing activities	(2,149)	(1,778)
Cash flows from financing activities:
Net (repayments of) proceeds from short-term debt	(2,618)	699
Other, net	(10)	(17)
Net cash flows from financing activities	2,313	20
Net change in cash and cash equivalents and restricted cash and cash equivalents	2,148	(662)
Cash and cash equivalents and restricted cash and cash equivalents at beginning of period	1,811	1,817
Cash and cash equivalents and restricted cash and cash equivalents at end of period	3,959	1,155
MEC
Cash flows from operating activities:
Net income	238	242
Adjustments to reconcile net income (loss) to net cash flows from operating activities:
Depreciation and amortization	227	234
Amortization of utility plant to other operating expenses	9	8
Allowance for equity funds	(16)	(11)
Deferred income taxes and investment tax credits, net	65	32
Settlements of asset retirement obligations	0	(6)
Other, net	(9)	8
Changes in other operating assets and liabilities, net of effects from acquisitions:
Trade receivables and other assets	(36)	131
Inventories	6	(3)
Pension and other postretirement benefit plans	0	(3)
Accrued property, income and other taxes, net	(137)	(263)
Accounts payable and other liabilities	(79)	(81)
Net cash flows from operating activities	268	288
Cash flows from investing activities:
Capital expenditures	(428)	(382)
Purchases of marketable securities	(81)	(48)
Proceeds from sales of marketable securities	76	42
Other, net	8	4
Net cash flows from investing activities	(425)	(384)
Cash flows from financing activities:
Common stock dividends	(425)	(100)
Proceeds from long-term debt	592	0
Repayments of long-term debt	(1)	(7)
Net (repayments of) proceeds from short-term debt	15	0
Other, net	(1)	(1)
Net cash flows from financing activities	180	(108)
Net change in cash and cash equivalents and restricted cash and cash equivalents	23	(204)
Cash and cash equivalents and restricted cash and cash equivalents at beginning of period	642	268
Cash and cash equivalents and restricted cash and cash equivalents at end of period	$ 665	$ 64