Consolidated Statement of Changes in Shareholders Equity (Unaudited) (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2014	Mar. 31, 2013
Other comprehensive income, income taxes	$ (6)	$ (66)
Accumulated Other Comprehensive (Loss) Income, Net
Other comprehensive income, income taxes	6
Exelon Generation Co L L C [Member]
Other comprehensive income, income taxes	10	68
Exelon Generation Co L L C [Member] \| Accumulated Other Comprehensive (Loss) Income, Net
Other comprehensive income, income taxes	$ 10

Amount of tax expense (benefit) allocated to other comprehensive income (loss).

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 31

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 20

-Section 45

-Paragraph 11

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=18498875&loc=d3e39076-109324

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 12

-URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e640-108580

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Data Type:	xbrli:monetaryItemType
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