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 (loss)	$ 2,171	$ 1,829	$ 1,954
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion, including nuclear fuel and energy contract amortization	3,533	7,573	6,527
Asset impairments	48	552	591
Gain on sales of assets and businesses	(8)	(201)	(24)
Deferred income taxes and amortization of investment tax credits	255	18	309
Net fair value changes related to derivatives	(53)	(568)	(268)
Net realized and unrealized gains on NDT fund investments	205	(586)	(461)
Net unrealized losses (gains) on equity investments	16	160	(186)
Other non-cash operating activities	370	(200)	592
Changes in assets and liabilities:
Accounts receivable	(1,222)	(703)	697
Inventories	(121)	(141)	(85)
Accounts payable and accrued expenses	1,318	440	(129)
Option premiums paid, net	(39)	(338)	(139)
Collateral received (posted), net	1,248	(74)	494
Income taxes	(4)	327	140
Increase (Decrease) in Regulatory Assets and Liabilities	(1,326)	(634)	(649)
Pension and non-pension postretirement benefit contributions	(616)	(665)	(601)
Other assets and liabilities	(905)	(3,777)	(4,527)
Net cash flows provided by operating activities	4,870	3,012	4,235
Cash flows from investing activities
Capital expenditures	(7,147)	(7,981)	(8,048)
Proceeds from NDT fund sales	488	6,532	3,341
Investment in NDT funds	(516)	(6,673)	(3,464)
Collection of deferred purchase price	169	3,902	3,771
Proceeds from sales of assets and businesses	16	877	46
Other investing activities	0	26	18
Net cash flows used in investing activities	(6,990)	(3,317)	(4,336)
Cash flows from financing activities
Changes in short-term borrowings	986	269	161
Proceeds from short-term borrowings with maturities greater than 90 days	1,300	1,380	500
Repayments on short-term borrowings with maturities greater than 90 days	(1,500)	(350)	0
Issuance of long-term debt	6,309	3,481	7,507
Retirement of long-term debt	(2,073)	(1,640)	(6,440)
Proceeds from Issuance of Common Stock	563	0	0
Dividends paid on common stock	(1,334)	(1,497)	(1,492)
Acquisition of CENG noncontrolling interest	0	(885)	0
Proceeds from employee stock plans	36	80	45
Transfer of cash, restricted cash, and cash equivalents to Constellation	(2,594)	0	0
Other financing activities	(102)	(80)	(136)
Net cash flows provided by (used in) financing activities	1,591	758	145
Increase (decrease) in cash, restricted cash, and cash equivalents	(529)	453	44
Cash, restricted cash, and cash equivalents at beginning of period	1,619	1,166	1,122
Cash, restricted cash, and cash equivalents at end of period	1,090	1,619	1,166
Increase (decrease) in capital expenditures not paid	36	16	194
Increase in Deferred Purchase Price	348	3,652	4,441
Increase (decrease) in PPE related to ARO update	332	642	850
Commonwealth Edison Co [Member]
Cash flows from operating activities
Net income (loss)	917	742	438
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion, including nuclear fuel and energy contract amortization	1,323	1,205	1,133
Deferred income taxes and amortization of investment tax credits	241	244	228
Other non-cash operating activities	(165)	126	202
Changes in assets and liabilities:
Accounts receivable	(163)	(25)	(10)
Receivables from and payables to affiliates, net	(34)	32	(1)
Inventories	(28)	(2)	(13)
Accounts payable and accrued expenses	406	0	63
Collateral received (posted), net	51	0	14
Income taxes	0	0	8
Increase (Decrease) in Regulatory Assets and Liabilities	(1,033)	(388)	(410)
Pension and non-pension postretirement benefit contributions	(184)	(196)	(148)
Other assets and liabilities	(134)	(143)	(180)
Net cash flows provided by operating activities	1,197	1,595	1,324
Cash flows from investing activities
Capital expenditures	(2,506)	(2,387)	(2,217)
Other investing activities	28	26	2
Net cash flows used in investing activities	(2,478)	(2,361)	(2,215)
Cash flows from financing activities
Changes in short-term borrowings	427	(323)	193
Proceeds from short-term borrowings with maturities greater than 90 days	150	0	0
Issuance of long-term debt	750	1,150	1,000
Retirement of long-term debt	0	(350)	(500)
Dividends paid on common stock	(578)	(507)	(499)
Contributions from parent	670	791	712
Other financing activities	(11)	(16)	(13)
Net cash flows provided by (used in) financing activities	1,408	745	893
Increase (decrease) in cash, restricted cash, and cash equivalents	127	(21)	2
Cash, restricted cash, and cash equivalents at beginning of period	384	405	403
Cash, restricted cash, and cash equivalents at end of period	511	384	405
Increase (decrease) in capital expenditures not paid	(20)	(46)	109
PECO Energy Co [Member]
Cash flows from operating activities
Net income (loss)	576	504	447
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion, including nuclear fuel and energy contract amortization	373	348	347
Deferred income taxes and amortization of investment tax credits	70	11	(23)
Other non-cash operating activities	40	0	24
Changes in assets and liabilities:
Accounts receivable	(205)	(35)	(88)
Receivables from and payables to affiliates, net	(31)	21	(6)
Inventories	(56)	(26)	(1)
Accounts payable and accrued expenses	152	15	63
Income taxes	(20)	5	31
Increase (Decrease) in Regulatory Assets and Liabilities	(45)	(21)	1
Pension and non-pension postretirement benefit contributions	(18)	(18)	(18)
Other assets and liabilities	5	(31)	0
Net cash flows provided by operating activities	841	773	777
Cash flows from investing activities
Capital expenditures	(1,349)	(1,240)	(1,147)
Changes in Exelon/PHI intercompany money pool	0	0	68
Other investing activities	8	9	7
Net cash flows used in investing activities	(1,341)	(1,231)	(1,072)
Cash flows from financing activities
Changes in short-term borrowings	239	0	0
Issuance of long-term debt	775	750	350
Retirement of long-term debt	(350)	(300)	0
Changes in Exelon/PHI intercompany money pool	0	(40)	40
Dividends paid on common stock	(399)	(339)	(340)
Contributions from parent	274	414	248
Other financing activities	(15)	(9)	(4)
Net cash flows provided by (used in) financing activities	524	476	294
Increase (decrease) in cash, restricted cash, and cash equivalents	24	18	(1)
Cash, restricted cash, and cash equivalents at beginning of period	44	26	27
Cash, restricted cash, and cash equivalents at end of period	68	44	26
Increase (decrease) in capital expenditures not paid	9	26	55
Baltimore Gas and Electric Company [Member]
Cash flows from operating activities
Net income (loss)	380	408	349
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion, including nuclear fuel and energy contract amortization	630	591	550
Asset impairments	48	0	0
Deferred income taxes and amortization of investment tax credits	9	(17)	37
Other non-cash operating activities	135	75	97
Changes in assets and liabilities:
Accounts receivable	(197)	30	(165)
Receivables from and payables to affiliates, net	(2)	(13)	(8)
Inventories	(61)	(29)	10
Accounts payable and accrued expenses	77	14	102
Collateral received (posted), net	19	3	0
Income taxes	(17)	20	60
Increase (Decrease) in Regulatory Assets and Liabilities	(160)	(152)	(118)
Pension and non-pension postretirement benefit contributions	(68)	(81)	(78)
Other assets and liabilities	(33)	(120)	48
Net cash flows provided by operating activities	760	729	884
Cash flows from investing activities
Capital expenditures	(1,262)	(1,226)	(1,247)
Other investing activities	11	18	2
Net cash flows used in investing activities	(1,251)	(1,208)	(1,245)
Cash flows from financing activities
Changes in short-term borrowings	278	130	(76)
Issuance of long-term debt	500	600	400
Retirement of long-term debt	(250)	(300)	0
Dividends paid on common stock	(300)	(292)	(246)
Contributions from parent	286	257	411
Other financing activities	(11)	(6)	(8)
Net cash flows provided by (used in) financing activities	503	389	481
Increase (decrease) in cash, restricted cash, and cash equivalents	12	(90)	120
Cash, restricted cash, and cash equivalents at beginning of period	55	145	25
Cash, restricted cash, and cash equivalents at end of period	67	55	145
Increase (decrease) in capital expenditures not paid	35	(59)	53
Pepco Holdings LLC [Member]
Cash flows from operating activities
Net income (loss)	608	561	495
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion, including nuclear fuel and energy contract amortization	938	821	782
Deferred income taxes and amortization of investment tax credits	(9)	24	(97)
Other non-cash operating activities	163	(12)	103
Changes in assets and liabilities:
Accounts receivable	(184)	(48)	(159)
Receivables from and payables to affiliates, net	(46)	6	3
Inventories	(34)	(16)	(6)
Accounts payable and accrued expenses	30	34	49
Collateral received (posted), net	148	49	0
Income taxes	(1)	17	(25)
Increase (Decrease) in Regulatory Assets and Liabilities	(136)	(99)	(129)
Pension and non-pension postretirement benefit contributions	(78)	(48)	(39)
Other assets and liabilities	(149)	(132)	25
Net cash flows provided by operating activities	1,250	1,157	1,002
Cash flows from investing activities
Capital expenditures	(1,709)	(1,720)	(1,604)
Other investing activities	6	2	7
Net cash flows used in investing activities	(1,703)	(1,718)	(1,597)
Cash flows from financing activities
Changes in short-term borrowings	(54)	100	160
Issuance of long-term debt	925	825	602
Retirement of long-term debt	(310)	(260)	(128)
Changes in Exelon/PHI intercompany money pool	37	(14)	9
Distributions to member	(750)	(703)	(553)
Contributions from member	787	683	494
Other financing activities	(22)	(17)	(10)
Net cash flows provided by (used in) financing activities	613	614	574
Increase (decrease) in cash, restricted cash, and cash equivalents	160	53	(21)
Cash, restricted cash, and cash equivalents at beginning of period	213	160	181
Cash, restricted cash, and cash equivalents at end of period	373	213	160
Increase (decrease) in capital expenditures not paid	136	(6)	54
Potomac Electric Power Company [Member]
Cash flows from operating activities
Net income (loss)	305	296	266
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion, including nuclear fuel and energy contract amortization	417	403	377
Deferred income taxes and amortization of investment tax credits	(17)	(8)	(46)
Other non-cash operating activities	36	(52)	(23)
Changes in assets and liabilities:
Accounts receivable	(104)	(28)	(67)
Receivables from and payables to affiliates, net	(33)	6	(12)
Inventories	(16)	(8)	1
Accounts payable and accrued expenses	24	16	41
Collateral received (posted), net	24	2	0
Income taxes	(19)	11	(1)
Increase (Decrease) in Regulatory Assets and Liabilities	(69)	(81)	(55)
Pension and non-pension postretirement benefit contributions	(11)	(11)	(11)
Other assets and liabilities	(66)	(84)	31
Net cash flows provided by operating activities	471	462	501
Cash flows from investing activities
Capital expenditures	(874)	(843)	(773)
Other investing activities	3	(1)	0
Net cash flows used in investing activities	(871)	(844)	(773)
Cash flows from financing activities
Changes in short-term borrowings	124	140	(47)
Issuance of long-term debt	625	275	300
Retirement of long-term debt	(310)	0	(3)
Dividends paid on common stock	(463)	(268)	(232)
Contributions from parent	465	244	262
Other financing activities	(10)	(6)	(6)
Net cash flows provided by (used in) financing activities	431	385	274
Increase (decrease) in cash, restricted cash, and cash equivalents	31	3	2
Cash, restricted cash, and cash equivalents at beginning of period	68	65	63
Cash, restricted cash, and cash equivalents at end of period	99	68	65
Increase (decrease) in capital expenditures not paid	65	30	1
Delmarva Power & Light Company [Member]
Cash flows from operating activities
Net income (loss)	169	128	125
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion, including nuclear fuel and energy contract amortization	232	210	191
Deferred income taxes and amortization of investment tax credits	16	39	(13)
Other non-cash operating activities	29	3	51
Changes in assets and liabilities:
Accounts receivable	(59)	15	(34)
Receivables from and payables to affiliates, net	(10)	(3)	8
Inventories	(11)	(8)	(5)
Accounts payable and accrued expenses	19	16	4
Collateral received (posted), net	78	43	0
Income taxes	0	13	(25)
Increase (Decrease) in Regulatory Assets and Liabilities	(34)	(43)	(35)
Pension and non-pension postretirement benefit contributions	(1)	(1)	0
Other assets and liabilities	(10)	(27)	5
Net cash flows provided by operating activities	418	385	272
Cash flows from investing activities
Capital expenditures	(430)	(429)	(424)
Other investing activities	3	4	(3)
Net cash flows used in investing activities	(427)	(425)	(427)
Cash flows from financing activities
Changes in short-term borrowings	(34)	3	90
Issuance of long-term debt	125	125	178
Retirement of long-term debt	0	0	(80)
Dividends paid on common stock	(143)	(147)	(141)
Contributions from parent	147	120	112
Other financing activities	(5)	(5)	(2)
Net cash flows provided by (used in) financing activities	90	96	157
Increase (decrease) in cash, restricted cash, and cash equivalents	81	56	2
Cash, restricted cash, and cash equivalents at beginning of period	71	15	13
Cash, restricted cash, and cash equivalents at end of period	152	71	15
Increase (decrease) in capital expenditures not paid	23	(18)	20
Atlantic City Electric Company [Member]
Cash flows from operating activities
Net income (loss)	148	146	112
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion, including nuclear fuel and energy contract amortization	261	179	180
Deferred income taxes and amortization of investment tax credits	(2)	(15)	(37)
Other non-cash operating activities	46	0	36
Changes in assets and liabilities:
Accounts receivable	(19)	(37)	(55)
Receivables from and payables to affiliates, net	(4)	4	6
Inventories	(7)	1	(3)
Accounts payable and accrued expenses	(9)	3	5
Collateral received (posted), net	46	4	0
Income taxes	11	0	(1)
Increase (Decrease) in Regulatory Assets and Liabilities	(19)	24	(42)
Pension and non-pension postretirement benefit contributions	(7)	(3)	(2)
Other assets and liabilities	(61)	(11)	0
Net cash flows provided by operating activities	384	295	199
Cash flows from investing activities
Capital expenditures	(398)	(445)	(401)
Other investing activities	1	1	6
Net cash flows used in investing activities	(397)	(444)	(395)
Cash flows from financing activities
Changes in short-term borrowings	(144)	(43)	117
Issuance of long-term debt	175	425	123
Retirement of long-term debt	0	(260)	(44)
Dividends paid on common stock	(145)	(288)	(114)
Contributions from parent	175	319	117
Other financing activities	(5)	(5)	(1)
Net cash flows provided by (used in) financing activities	56	148	198
Increase (decrease) in cash, restricted cash, and cash equivalents	43	(1)	2
Cash, restricted cash, and cash equivalents at beginning of period	29	30	28
Cash, restricted cash, and cash equivalents at end of period	72	29	30
Increase (decrease) in capital expenditures not paid	$ 48	$ (18)	$ 33