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Amount of current income tax expense (benefit) pertaining to taxable income (loss) from continuing operations.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
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-Publisher FASB
-Name Accounting Standards Codification
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-Publisher FASB
-Name Accounting Standards Codification
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Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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-Section 45
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=63044130

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
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The amount deducted from an entities' taxes, reflecting a percentage of an amount invested in certain assets spread over the useful life of those assets; includes deferred investment tax credits.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
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Income Taxes - Components of Income Tax Expense (Benefit) from Continuing Operations (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Mar. 23, 2016	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Taxes [Line Items]
Income taxes			$ 761	$ 1,073	$ 666
Exelon Generation Co L L C [Member]
Income Taxes [Line Items]
Income taxes			290	502	207
Commonwealth Edison Co [Member]
Income Taxes [Line Items]
Income taxes			301	280	268
PECO Energy Co [Member]
Income Taxes [Line Items]
Income taxes			149	143	114
Baltimore Gas and Electric Company [Member]
Income Taxes [Line Items]
Income taxes			174	189	140
Potomac Electric Power Company [Member]
Income Taxes [Line Items]
Income taxes			41	102	93
Delmarva Power and Light Company [Member]
Income Taxes [Line Items]
Income taxes			22	49	65
Atlantic City Electric Company [Member]
Income Taxes [Line Items]
Income taxes			(4)	33	30
Pepco Holdings LLC [Member] \| Successor [Member]
Income Taxes [Line Items]
Income taxes		$ 3
Pepco Holdings LLC [Member] \| Predecessor [Member]
Income Taxes [Line Items]
Income taxes	$ 17			163	138
Internal Revenue Service (IRS) [Member]
Income Taxes [Line Items]
Current			60	407	121
Deferred			607	566	576
Investment Tax Credit			(24)	(22)	(20)
Internal Revenue Service (IRS) [Member] \| Exelon Generation Co L L C [Member]
Income Taxes [Line Items]
Current			513	546	360
Deferred			(247)	16	(35)
Investment Tax Credit			(20)	(19)	(16)
Internal Revenue Service (IRS) [Member] \| Commonwealth Edison Co [Member]
Income Taxes [Line Items]
Current			(135)	(80)	(171)
Deferred			379	310	395
Investment Tax Credit			(2)	(2)	(2)
Internal Revenue Service (IRS) [Member] \| PECO Energy Co [Member]
Income Taxes [Line Items]
Current			63	64	28
Deferred			72	69	87
Investment Tax Credit			0	0	0
Internal Revenue Service (IRS) [Member] \| Baltimore Gas and Electric Company [Member]
Income Taxes [Line Items]
Current			51	25	24
Deferred			88	126	90
Investment Tax Credit			(1)	(1)	(1)
Internal Revenue Service (IRS) [Member] \| Potomac Electric Power Company [Member]
Income Taxes [Line Items]
Current			(118)	(54)	(79)
Deferred			136	126	150
Investment Tax Credit			0	0	0
Internal Revenue Service (IRS) [Member] \| Delmarva Power and Light Company [Member]
Income Taxes [Line Items]
Current			(88)	(27)	(45)
Deferred			97	73	98
Investment Tax Credit			0	0	(1)
Internal Revenue Service (IRS) [Member] \| Atlantic City Electric Company [Member]
Income Taxes [Line Items]
Current			(26)	(2)	(6)
Deferred			22	27	31
Investment Tax Credit			0	0	(1)
Internal Revenue Service (IRS) [Member] \| Pepco Holdings LLC [Member] \| Successor [Member]
Income Taxes [Line Items]
Current		(281)
Deferred		283
Investment Tax Credit		(1)
Internal Revenue Service (IRS) [Member] \| Pepco Holdings LLC [Member] \| Predecessor [Member]
Income Taxes [Line Items]
Current	0			12	(153)
Deferred	10			103	261
Investment Tax Credit	0			(1)	(1)
State and Local Jurisdiction [Member]
Income Taxes [Line Items]
Current			39	(86)	42
Deferred			79	208	(53)
State and Local Jurisdiction [Member] \| Exelon Generation Co L L C [Member]
Income Taxes [Line Items]
Current			45	(90)	35
Deferred			(1)	49	(137)
State and Local Jurisdiction [Member] \| Commonwealth Edison Co [Member]
Income Taxes [Line Items]
Current			(4)	7	7
Deferred			63	45	39
State and Local Jurisdiction [Member] \| PECO Energy Co [Member]
Income Taxes [Line Items]
Current			9	(10)	(2)
Deferred			5	20	1
State and Local Jurisdiction [Member] \| Baltimore Gas and Electric Company [Member]
Income Taxes [Line Items]
Current			5	0	0
Deferred			31	39	27
State and Local Jurisdiction [Member] \| Potomac Electric Power Company [Member]
Income Taxes [Line Items]
Current			7	6	(2)
Deferred			16	24	24
State and Local Jurisdiction [Member] \| Delmarva Power and Light Company [Member]
Income Taxes [Line Items]
Current			1	2	0
Deferred			12	1	13
State and Local Jurisdiction [Member] \| Atlantic City Electric Company [Member]
Income Taxes [Line Items]
Current			0	3	(1)
Deferred			$ 0	5	7
State and Local Jurisdiction [Member] \| Pepco Holdings LLC [Member] \| Successor [Member]
Income Taxes [Line Items]
Current		(11)
Deferred		$ 13
State and Local Jurisdiction [Member] \| Pepco Holdings LLC [Member] \| Predecessor [Member]
Income Taxes [Line Items]
Current	0			17	(10)
Deferred	$ 7			$ 32	$ 41