Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash flows from operating activities
Net income (loss)	$ 1,012	$ 1,063
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	1,727	1,854
Gain on sales of assets and businesses	0	(8)
Deferred income taxes and amortization of investment tax credits	94	143
Net fair value changes related to derivatives	4	(59)
Net realized and unrealized (gains) losses on NDT funds	0	205
Net unrealized (gains) losses on equity investments	0	16
Other non-cash operating activities	(222)	276
Changes in assets and liabilities:
Accounts receivable	387	(795)
Inventories	44	12
Accounts payable and accrued expenses	(734)	544
Option premiums paid, net	0	(39)
Collateral received (posted), net	(187)	1,689
Income taxes	97	23
Regulatory assets and liabilities, net	(516)	(376)
Pension and non-pension postretirement benefit contributions	(85)	(585)
Other assets and liabilities	140	(723)
Net Cash Provided by (Used in) Operating Activities, Total	1,761	3,240
Cash flows from investing activities
Capital expenditures	(3,685)	(3,507)
Proceeds from NDT fund sales	0	488
Investment in NDT funds	0	(516)
Collection of deferred purchase price	0	169
Proceeds from Sale of Property Held-for-sale	0	16
Other investing activities	10	4
Net Cash Provided by (Used in) Investing Activities, Total	(3,675)	(3,346)
Cash flows from financing activities
Changes in short-term borrowings	(1,600)	(597)
Proceeds from short-term borrowings with maturities greater than 90 days	400	1,150
Repayments on short-term borrowings with maturities greater than 90 days	(150)	(350)
Issuance of long-term debt	5,200	5,151
Retirement of long-term debt	(1,209)	(1,707)
Dividends paid on common stock	(717)	(663)
Proceeds from employee stock plans	19	17
Transfer of cash, restricted cash, and cash equivalents to Constellation	0	(2,594)
Other financing activities	(84)	(84)
Net cash flows provided by financing activities	1,859	323
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	(55)	217
Cash, restricted cash, and cash equivalents at beginning of period	1,090	1,619
Cash, restricted cash, and cash equivalents at end of period	1,035	1,836
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	(164)	(276)
Increase in deferred purchase price	0	348
Increase in PPE related to ARO update	0	(335)
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	0	207
Gain on sales of assets and businesses	0	9
Deferred income taxes and amortization of investment tax credits	0	(143)
Net fair value changes related to derivatives	0	(59)
Net realized and unrealized (gains) losses on NDT funds	0	205
Net unrealized (gains) losses on equity investments	0	16
Other non-cash operating activities	0	(36)
Cash flows from investing activities
Capital expenditures	0	(227)
Collection of deferred purchase price	0	169
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	0	(128)
Increase in deferred purchase price	0	348
Increase in PPE related to ARO update	0	335
Commonwealth Edison Co [Member]
Cash flows from operating activities
Net income (loss)	489	415
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	688	649
Deferred income taxes and amortization of investment tax credits	106	122
Other non-cash operating activities	(260)	(18)
Changes in assets and liabilities:
Accounts receivable	(30)	(163)
Receivables from payables to affiliates, net	(3)	(43)
Inventories	(43)	(2)
Accounts payable and accrued expenses	(311)	123
Collateral received (posted), net	25	60
Income taxes	16	(19)
Regulatory assets and liabilities, net	(459)	(267)
Pension and non-pension postretirement benefit contributions	(24)	(178)
Other assets and liabilities	110	(91)
Net Cash Provided by (Used in) Operating Activities, Total	304	588
Cash flows from investing activities
Capital expenditures	(1,262)	(1,208)
Other investing activities	3	15
Net Cash Provided by (Used in) Investing Activities, Total	(1,259)	(1,193)
Cash flows from financing activities
Changes in short-term borrowings	(130)	0
Proceeds from short-term borrowings with maturities greater than 90 days	400	0
Repayments on short-term borrowings with maturities greater than 90 days	(150)	0
Issuance of long-term debt	975	750
Dividends paid on common stock	(374)	(289)
Contributions from parent	372	335
Other financing activities	(13)	(12)
Net cash flows provided by financing activities	1,080	784
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	125	179
Cash, restricted cash, and cash equivalents at beginning of period	511	384
Cash, restricted cash, and cash equivalents at end of period	636	563
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	(7)	(44)
PECO Energy Co [Member]
Cash flows from operating activities
Net income (loss)	263	339
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	197	185
Deferred income taxes and amortization of investment tax credits	(26)	14
Other non-cash operating activities	12	4
Changes in assets and liabilities:
Accounts receivable	182	(29)
Receivables from payables to affiliates, net	(3)	(40)
Inventories	52	(8)
Accounts payable and accrued expenses	(167)	5
Income taxes	56	49
Regulatory assets and liabilities, net	14	(24)
Pension and non-pension postretirement benefit contributions	(1)	(13)
Other assets and liabilities	(34)	(70)
Net Cash Provided by (Used in) Operating Activities, Total	545	412
Cash flows from investing activities
Capital expenditures	(707)	(658)
Changes in Exelon/PHI intercompany money pool	(225)	0
Other investing activities	0	5
Net Cash Provided by (Used in) Investing Activities, Total	(932)	(653)
Cash flows from financing activities
Changes in short-term borrowings	(239)	210
Issuance of long-term debt	575	350
Retirement of long-term debt	(50)	(350)
Dividends paid on common stock	(202)	(200)
Contributions from parent	330	227
Other financing activities	(4)	(8)
Net cash flows provided by financing activities	410	229
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	23	(12)
Cash, restricted cash, and cash equivalents at beginning of period	68	44
Cash, restricted cash, and cash equivalents at end of period	91	32
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	3	(11)
Baltimore Gas and Electric Company [Member]
Cash flows from operating activities
Net income (loss)	241	234
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	325	322
Deferred income taxes and amortization of investment tax credits	38	13
Other non-cash operating activities	(36)	79
Changes in assets and liabilities:
Accounts receivable	185	(14)
Receivables from payables to affiliates, net	(8)	(11)
Inventories	51	(27)
Accounts payable and accrued expenses	(114)	(12)
Collateral received (posted), net	(22)	190
Income taxes	8	(27)
Regulatory assets and liabilities, net	(83)	(36)
Pension and non-pension postretirement benefit contributions	(11)	(59)
Other assets and liabilities	37	24
Net Cash Provided by (Used in) Operating Activities, Total	611	676
Cash flows from investing activities
Capital expenditures	(656)	(578)
Other investing activities	4	7
Net Cash Provided by (Used in) Investing Activities, Total	(652)	(571)
Cash flows from financing activities
Changes in short-term borrowings	(408)	(130)
Issuance of long-term debt	700	500
Retirement of long-term debt	(300)	0
Dividends paid on common stock	(158)	(150)
Contributions from parent	237	186
Other financing activities	(7)	(7)
Net cash flows provided by financing activities	64	399
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	23	504
Cash, restricted cash, and cash equivalents at beginning of period	67	55
Cash, restricted cash, and cash equivalents at end of period	90	559
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	(60)	(21)
Pepco Holdings LLC [Member]
Cash flows from operating activities
Net income (loss)	258	230
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	484	459
Deferred income taxes and amortization of investment tax credits	26	(7)
Other non-cash operating activities	20	76
Changes in assets and liabilities:
Accounts receivable	55	(92)
Receivables from payables to affiliates, net	(8)	(53)
Inventories	(14)	(7)
Accounts payable and accrued expenses	(25)	10
Collateral received (posted), net	(191)	403
Income taxes	6	(2)
Regulatory assets and liabilities, net	8	(71)
Pension and non-pension postretirement benefit contributions	(11)	(70)
Other assets and liabilities	(80)	(86)
Net Cash Provided by (Used in) Operating Activities, Total	528	790
Cash flows from investing activities
Capital expenditures	(1,022)	(776)
Other investing activities	8	3
Net Cash Provided by (Used in) Investing Activities, Total	(1,014)	(773)
Cash flows from financing activities
Changes in short-term borrowings	(377)	(425)
Issuance of long-term debt	450	700
Retirement of long-term debt	0	(200)
Increase (Decrease) in Due to Affiliates, Current	8	17
Payments of Distributions to Affiliates	(212)	(395)
Proceeds from Contributions from Affiliates	405	704
Other financing activities	(25)	(12)
Net cash flows provided by financing activities	249	389
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	(237)	406
Cash, restricted cash, and cash equivalents at beginning of period	373	213
Cash, restricted cash, and cash equivalents at end of period	136	619
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	(91)	(48)
Potomac Electric Power Company [Member]
Cash flows from operating activities
Net income (loss)	130	116
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	216	213
Deferred income taxes and amortization of investment tax credits	12	(7)
Other non-cash operating activities	3	17
Changes in assets and liabilities:
Accounts receivable	12	(62)
Receivables from payables to affiliates, net	(2)	(39)
Inventories	(10)	(6)
Accounts payable and accrued expenses	(21)	6
Collateral received (posted), net	(26)	85
Income taxes	(1)	(24)
Regulatory assets and liabilities, net	(6)	(36)
Pension and non-pension postretirement benefit contributions	(8)	(7)
Other assets and liabilities	7	(15)
Net Cash Provided by (Used in) Operating Activities, Total	306	241
Cash flows from investing activities
Capital expenditures	(483)	(402)
Other investing activities	8	2
Net Cash Provided by (Used in) Investing Activities, Total	(475)	(400)
Cash flows from financing activities
Changes in short-term borrowings	(299)	(132)
Issuance of long-term debt	250	400
Retirement of long-term debt	0	(200)
Increase (Decrease) in Due to Affiliates, Current	52	73
Dividends paid on common stock	(115)	(300)
Contributions from parent	243	387
Other financing activities	(19)	(6)
Net cash flows provided by financing activities	112	222
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	(57)	63
Cash, restricted cash, and cash equivalents at beginning of period	99	68
Cash, restricted cash, and cash equivalents at end of period	42	131
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	(43)	(24)
Delmarva Power and Light Company [Member]
Cash flows from operating activities
Net income (loss)	85	77
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	121	113
Deferred income taxes and amortization of investment tax credits	3	3
Other non-cash operating activities	2	13
Changes in assets and liabilities:
Accounts receivable	48	(8)
Receivables from payables to affiliates, net	1	(3)
Inventories	5	1
Accounts payable and accrued expenses	(9)	12
Collateral received (posted), net	(121)	180
Income taxes	11	6
Regulatory assets and liabilities, net	25	(11)
Pension and non-pension postretirement benefit contributions	0	(1)
Other assets and liabilities	10	1
Net Cash Provided by (Used in) Operating Activities, Total	181	383
Cash flows from investing activities
Capital expenditures	(258)	(194)
Changes in Exelon/PHI intercompany money pool	(102)	(73)
Other investing activities	0	2
Net Cash Provided by (Used in) Investing Activities, Total	(360)	(265)
Cash flows from financing activities
Changes in short-term borrowings	(115)	(149)
Issuance of long-term debt	125	125
Dividends paid on common stock	(60)	(56)
Contributions from parent	99	144
Other financing activities	(4)	(4)
Net cash flows provided by financing activities	45	60
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	(134)	178
Cash, restricted cash, and cash equivalents at beginning of period	152	71
Cash, restricted cash, and cash equivalents at end of period	18	249
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	(3)	(5)
Atlantic City Electric Company [Member]
Cash flows from operating activities
Net income (loss)	51	37
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	135	118
Deferred income taxes and amortization of investment tax credits	12	0
Other non-cash operating activities	(3)	25
Changes in assets and liabilities:
Accounts receivable	(5)	(20)
Receivables from payables to affiliates, net	(5)	(10)
Inventories	(9)	(2)
Accounts payable and accrued expenses	15	9
Collateral received (posted), net	(45)	137
Income taxes	(4)	8
Regulatory assets and liabilities, net	(12)	(11)
Pension and non-pension postretirement benefit contributions	0	(7)
Other assets and liabilities	(89)	(63)
Net Cash Provided by (Used in) Operating Activities, Total	41	221
Cash flows from investing activities
Capital expenditures	(275)	(179)
Net Cash Provided by (Used in) Investing Activities, Total	(275)	(179)
Cash flows from financing activities
Changes in short-term borrowings	37	(144)
Issuance of long-term debt	75	175
Increase (Decrease) in Due to Affiliates, Current	50	0
Dividends paid on common stock	(36)	(38)
Contributions from parent	63	173
Other financing activities	(3)	(4)
Net cash flows provided by financing activities	186	162
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	(48)	204
Cash, restricted cash, and cash equivalents at beginning of period	72	29
Cash, restricted cash, and cash equivalents at end of period	24	233
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	$ (44)	$ (19)