Consolidated Statement of Changes in Shareholders Equity (Unaudited) (Parenthetical) (USD $) In Millions, unless otherwise specified	6 Months Ended
Jun. 30, 2013
Accumulated Other Comprehensive (Loss) Income, Net
Other comprehensive income, income taxes	$ 67
Exelon Generation Co L L C [Member]
Other comprehensive income, income taxes	$ 152

Tax effect of other comprehensive income (loss) attributable to both parent entity and noncontrolling interest.

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+ Details