Consolidated Statements of Cash Flows - ComEd - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities
Net income	$ 2,328	$ 2,171	$ 1,829
Adjustments to reconcile net income to net cash flows used in operating activities:
Depreciation and amortization	3,506	3,533	7,573
Deferred income taxes and amortization of investment tax credits	319	255	18
Net fair value changes related to derivatives	(22)	53	568
Other non-cash operating activities	(335)	370	(200)
Changes in assets and liabilities:
Accounts receivable	(37)	(1,222)	(703)
Inventories	(45)	(121)	(141)
Accounts payable and accrued expenses	(191)	1,318	440
Collateral (paid) received, net	(146)	1,248	(74)
Income taxes	48	(4)	327
Regulatory assets and liabilities, net	439	1,326	634
Pension and non-pension postretirement benefit contributions	(129)	(616)	(665)
Other assets and liabilities	(188)	(905)	(3,777)
Net cash flows provided by operating activities	4,703	4,870	3,012
Cash flows from investing activities
Capital expenditures	(7,408)	(7,147)	(7,981)
Other investing activities	8	0	26
Net cash flows used in investing activities	(7,375)	(6,990)	(3,317)
Cash flows from financing activities
Changes in short-term borrowings	(313)	986	269
Proceeds from short-term borrowings with maturities greater than 90 days	400	1,300	1,380
Repayments on short-term borrowings with maturities greater than 90 days	(150)	(1,500)	(350)
Issuance of long-term debt	5,825	6,309	3,481
Retirement of long-term debt	(1,713)	(2,073)	(1,640)
Dividends paid on common stock	(1,433)	(1,334)	(1,497)
Other financing activities	(114)	(102)	(80)
Net cash flows provided by financing activities	2,683	1,591	758
(Decrease) increase in cash, restricted cash, and cash equivalents	11	(529)	453
Cash, restricted cash, and cash equivalents at beginning of period	1,090	1,619	1,166
Cash, restricted cash, and cash equivalents at end of period	1,101	1,090	1,619
Commonwealth Edison Co
Cash flows from operating activities
Net income	1,090	917	742
Adjustments to reconcile net income to net cash flows used in operating activities:
Depreciation and amortization	1,403	1,323	1,205
Deferred income taxes and amortization of investment tax credits	196	241	244
Other non-cash operating activities	(536)	(165)	126
Changes in assets and liabilities:
Accounts receivable	(138)	(163)	(25)
Inventories	(82)	(28)	(2)
Accounts payable and accrued expenses	(87)	406	0
Collateral (paid) received, net	69	51	0
Income taxes	106	0	0
Regulatory assets and liabilities, net	(60)	(1,033)	(388)
Pension and non-pension postretirement benefit contributions	(41)	(184)	(196)
Other assets and liabilities	(70)	(134)	(143)
Net cash flows provided by operating activities	1,848	1,197	1,595
Cash flows from investing activities
Capital expenditures	(2,576)	(2,506)	(2,387)
Other investing activities	8	28	26
Net cash flows used in investing activities	(2,568)	(2,478)	(2,361)
Cash flows from financing activities
Changes in short-term borrowings	(225)	427	(323)
Proceeds from short-term borrowings with maturities greater than 90 days	400	150	0
Repayments on short-term borrowings with maturities greater than 90 days	(150)	0	0
Issuance of long-term debt	975	750	1,150
Retirement of long-term debt	0	0	(350)
Dividends paid on common stock	(746)	(578)	(507)
Contributions from parent	655	670	791
Other financing activities	(14)	(11)	(16)
Net cash flows provided by financing activities	895	1,408	745
(Decrease) increase in cash, restricted cash, and cash equivalents	175	127	(21)
Cash, restricted cash, and cash equivalents at beginning of period	511	384	405
Cash, restricted cash, and cash equivalents at end of period	686	511	384
Commonwealth Edison Co | Related Party
Changes in assets and liabilities:
Receivables from and payables to affiliates, net	$ (2)	$ (34)	$ 32