Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash flows from operating activities
Net income (loss)	$ 1,739	$ 1,441
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	2,679	6,204
Asset impairments	46	541
Gain on sales of assets and businesses	(8)	(147)
Deferred income taxes and amortization of investment tax credits	256	(45)
Net fair value changes related to derivatives	(59)	(1,244)
Net realized and unrealized (gains) losses on NDT funds	205	(383)
Net unrealized (gains) losses on equity investments	16	83
Other non-cash operating activities	265	(293)
Changes in assets and liabilities:
Accounts receivable	(1,049)	(254)
Inventories	(121)	(101)
Accounts payable and accrued expenses	823	354
Option premiums paid, net	(39)	(186)
Collateral received (posted), net	1,456	2,111
Income taxes	3	250
Regulatory assets and liabilities, net	(689)	(367)
Pension and non-pension postretirement benefit contributions	(596)	(602)
Other assets and liabilities	(786)	(3,221)
Net Cash Provided by (Used in) Operating Activities, Total	4,141	4,141
Cash flows from investing activities
Capital expenditures	(5,179)	(5,970)
Proceeds from NDT fund sales	488	5,766
Investment in NDT funds	(516)	(5,900)
Collection of deferred purchase price	169	3,052
Proceeds from Sale of Property Held-for-sale	16	801
Other investing activities	36	40
Net Cash Provided by (Used in) Investing Activities, Total	(4,986)	(2,211)
Cash flows from financing activities
Changes in short-term borrowings	(335)	(744)
Proceeds from short-term borrowings with maturities greater than 90 days	1,150	1,380
Repayments on short-term borrowings with maturities greater than 90 days	(925)	0
Issuance of long-term debt	5,801	3,406
Retirement of long-term debt	(2,067)	(1,618)
Proceeds from Issuance of Common Stock	563	0
Dividends paid on common stock	(999)	(1,121)
Payments to Acquire Additional Interest in Subsidiaries	0	(885)
Proceeds from employee stock plans	26	63
Transfer of cash, restricted cash, and cash equivalents to Constellation	(2,594)	0
Other financing activities	(121)	(93)
Net cash flows provided by financing activities	499	388
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	(346)	2,318
Cash, restricted cash, and cash equivalents at beginning of period	1,619	1,166
Cash, restricted cash, and cash equivalents at end of period	1,273	3,484
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	(147)	(334)
Increase in deferred purchase price	348	2,933
Increase in PPE related to ARO update	331	574
Exelon Generation Co L L C [Member]
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	207	3,951
Gain on sales of assets and businesses	9	(144)
Deferred income taxes and amortization of investment tax credits	(143)	(242)
Net fair value changes related to derivatives	(59)	(1,244)
Net realized and unrealized (gains) losses on NDT funds	205	(383)
Net unrealized (gains) losses on equity investments	16	83
Other non-cash operating activities	(36)	810
Cash flows from investing activities
Capital expenditures	(227)	(1,098)
Collection of deferred purchase price	169	3,052
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	(128)	(77)
Increase in deferred purchase price	348	2,933
Increase in PPE related to ARO update	335	550
Commonwealth Edison Co [Member]
Cash flows from operating activities
Net income (loss)	706	609
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	982	893
Deferred income taxes and amortization of investment tax credits	192	211
Other non-cash operating activities	(89)	95
Changes in assets and liabilities:
Accounts receivable	(351)	(72)
Receivables from payables to affiliates, net	(54)	(16)
Inventories	(9)	(6)
Accounts payable and accrued expenses	226	(36)
Collateral received (posted), net	69	68
Income taxes	0	(9)
Regulatory assets and liabilities, net	(499)	(250)
Pension and non-pension postretirement benefit contributions	(179)	(176)
Other assets and liabilities	(152)	(126)
Net Cash Provided by (Used in) Operating Activities, Total	842	1,185
Cash flows from investing activities
Capital expenditures	(1,801)	(1,723)
Other investing activities	21	20
Net Cash Provided by (Used in) Investing Activities, Total	(1,780)	(1,703)
Cash flows from financing activities
Changes in short-term borrowings	233	(323)
Issuance of long-term debt	750	1,150
Retirement of long-term debt	0	(350)
Dividends paid on common stock	(434)	(380)
Contributions from parent	503	593
Other financing activities	(10)	(16)
Net cash flows provided by financing activities	1,042	674
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	104	156
Cash, restricted cash, and cash equivalents at beginning of period	384	405
Cash, restricted cash, and cash equivalents at end of period	488	561
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	(30)	(118)
PECO Energy Co [Member]
Cash flows from operating activities
Net income (loss)	474	383
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	277	259
Deferred income taxes and amortization of investment tax credits	49	19
Other non-cash operating activities	14	4
Changes in assets and liabilities:
Accounts receivable	(49)	47
Receivables from payables to affiliates, net	(34)	16
Inventories	(59)	(21)
Accounts payable and accrued expenses	25	(23)
Income taxes	30	55
Regulatory assets and liabilities, net	(27)	(16)
Pension and non-pension postretirement benefit contributions	(13)	(15)
Other assets and liabilities	(31)	(71)
Net Cash Provided by (Used in) Operating Activities, Total	656	637
Cash flows from investing activities
Capital expenditures	(991)	(878)
Other investing activities	8	5
Net Cash Provided by (Used in) Investing Activities, Total	(983)	(873)
Cash flows from financing activities
Issuance of long-term debt	775	750
Retirement of long-term debt	(350)	(300)
Increase (Decrease) in Due to Affiliates, Current	0	(40)
Dividends paid on common stock	(299)	(254)
Contributions from parent	274	414
Other financing activities	(14)	(8)
Net cash flows provided by financing activities	386	562
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	59	326
Cash, restricted cash, and cash equivalents at beginning of period	44	26
Cash, restricted cash, and cash equivalents at end of period	103	352
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	7	25
Baltimore Gas and Electric Company [Member]
Cash flows from operating activities
Net income (loss)	267	290
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	470	434
Asset impairments	46	0
Deferred income taxes and amortization of investment tax credits	1	7
Other non-cash operating activities	101	77
Changes in assets and liabilities:
Accounts receivable	18	92
Receivables from payables to affiliates, net	(9)	(13)
Inventories	(74)	(30)
Accounts payable and accrued expenses	15	14
Collateral received (posted), net	125	20
Income taxes	(20)	3
Regulatory assets and liabilities, net	(113)	(106)
Pension and non-pension postretirement benefit contributions	(64)	(76)
Other assets and liabilities	14	(43)
Net Cash Provided by (Used in) Operating Activities, Total	777	669
Cash flows from investing activities
Capital expenditures	(918)	(907)
Other investing activities	7	13
Net Cash Provided by (Used in) Investing Activities, Total	(911)	(894)
Cash flows from financing activities
Changes in short-term borrowings	26	0
Issuance of long-term debt	500	600
Retirement of long-term debt	(250)	(300)
Dividends paid on common stock	(225)	(219)
Contributions from parent	186	257
Other financing activities	(8)	(6)
Net cash flows provided by financing activities	229	332
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	95	107
Cash, restricted cash, and cash equivalents at beginning of period	55	145
Cash, restricted cash, and cash equivalents at end of period	150	252
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	12	(70)
Pepco Holdings LLC [Member]
Cash flows from operating activities
Net income (loss)	518	535
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	697	614
Deferred income taxes and amortization of investment tax credits	(2)	0
Other non-cash operating activities	112	(35)
Changes in assets and liabilities:
Accounts receivable	(143)	(112)
Receivables from payables to affiliates, net	(49)	(19)
Inventories	(35)	(13)
Accounts payable and accrued expenses	(15)	19
Collateral received (posted), net	230	25
Income taxes	(3)	17
Regulatory assets and liabilities, net	(82)	(45)
Pension and non-pension postretirement benefit contributions	(75)	(43)
Other assets and liabilities	(71)	(100)
Net Cash Provided by (Used in) Operating Activities, Total	1,082	843
Cash flows from investing activities
Capital expenditures	(1,174)	(1,299)
Other investing activities	5	(1)
Net Cash Provided by (Used in) Investing Activities, Total	(1,169)	(1,300)
Cash flows from financing activities
Changes in short-term borrowings	(468)	(81)
Issuance of long-term debt	925	750
Retirement of long-term debt	(310)	(255)
Increase (Decrease) in Due to Affiliates, Current	36	(5)
Payments of Distributions to Affiliates	(625)	(605)
Proceeds from Contributions from Affiliates	787	667
Other financing activities	(18)	(12)
Net cash flows provided by financing activities	327	459
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	240	2
Cash, restricted cash, and cash equivalents at beginning of period	213	160
Cash, restricted cash, and cash equivalents at end of period	453	162
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	(8)	(74)
Potomac Electric Power Company [Member]
Cash flows from operating activities
Net income (loss)	261	264
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	312	302
Deferred income taxes and amortization of investment tax credits	(5)	12
Other non-cash operating activities	20	(54)
Changes in assets and liabilities:
Accounts receivable	(87)	(57)
Receivables from payables to affiliates, net	(31)	(2)
Inventories	(19)	(6)
Accounts payable and accrued expenses	11	14
Collateral received (posted), net	46	0
Income taxes	(25)	(10)
Regulatory assets and liabilities, net	(44)	(55)
Pension and non-pension postretirement benefit contributions	(9)	(9)
Other assets and liabilities	(29)	(59)
Net Cash Provided by (Used in) Operating Activities, Total	401	340
Cash flows from investing activities
Capital expenditures	(595)	(641)
Other investing activities	2	(2)
Net Cash Provided by (Used in) Investing Activities, Total	(593)	(643)
Cash flows from financing activities
Changes in short-term borrowings	(175)	5
Issuance of long-term debt	625	275
Retirement of long-term debt	(310)	(1)
Increase (Decrease) in Due to Affiliates, Current	25	0
Dividends paid on common stock	(400)	(221)
Contributions from parent	465	244
Other financing activities	(8)	(4)
Net cash flows provided by financing activities	222	298
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	30	(5)
Cash, restricted cash, and cash equivalents at beginning of period	68	65
Cash, restricted cash, and cash equivalents at end of period	98	60
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	2	(16)
Delmarva Power and Light Company [Member]
Cash flows from operating activities
Net income (loss)	130	135
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	172	157
Deferred income taxes and amortization of investment tax credits	9	5
Other non-cash operating activities	22	(2)
Changes in assets and liabilities:
Accounts receivable	(3)	26
Receivables from payables to affiliates, net	(8)	(12)
Inventories	(11)	(5)
Accounts payable and accrued expenses	0	17
Collateral received (posted), net	114	25
Income taxes	4	19
Regulatory assets and liabilities, net	(23)	(20)
Pension and non-pension postretirement benefit contributions	(1)	(1)
Other assets and liabilities	23	(12)
Net Cash Provided by (Used in) Operating Activities, Total	428	332
Cash flows from investing activities
Capital expenditures	(294)	(320)
Changes in Exelon/PHI intercompany money pool	(25)	0
Other investing activities	2	1
Net Cash Provided by (Used in) Investing Activities, Total	(317)	(319)
Cash flows from financing activities
Changes in short-term borrowings	(149)	(124)
Issuance of long-term debt	125	125
Dividends paid on common stock	(95)	(106)
Contributions from parent	147	120
Other financing activities	(4)	(4)
Net cash flows provided by financing activities	24	11
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	135	24
Cash, restricted cash, and cash equivalents at beginning of period	71	15
Cash, restricted cash, and cash equivalents at end of period	206	39
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	2	(24)
Atlantic City Electric Company [Member]
Cash flows from operating activities
Net income (loss)	131	141
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	192	133
Deferred income taxes and amortization of investment tax credits	2	(20)
Other non-cash operating activities	36	(8)
Changes in assets and liabilities:
Accounts receivable	(53)	(81)
Receivables from payables to affiliates, net	(10)	0
Inventories	(6)	(1)
Accounts payable and accrued expenses	(10)	(3)
Collateral received (posted), net	70	0
Income taxes	7	10
Regulatory assets and liabilities, net	(6)	29
Pension and non-pension postretirement benefit contributions	(7)	(3)
Other assets and liabilities	(54)	(14)
Net Cash Provided by (Used in) Operating Activities, Total	292	183
Cash flows from investing activities
Capital expenditures	(284)	(336)
Other investing activities	1	1
Net Cash Provided by (Used in) Investing Activities, Total	(283)	(335)
Cash flows from financing activities
Changes in short-term borrowings	(144)	38
Issuance of long-term debt	175	350
Retirement of long-term debt	0	(254)
Dividends paid on common stock	(128)	(280)
Contributions from parent	175	303
Other financing activities	(4)	(5)
Net cash flows provided by financing activities	74	152
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	83	0
Cash, restricted cash, and cash equivalents at beginning of period	29	30
Cash, restricted cash, and cash equivalents at end of period	112	30
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	$ (12)	$ (34)