Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) shares in Millions, $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Accumulated depreciation and amortization	$ 24,798	$ 23,979
Common stock, Shares Authorized	2,000	2,000
Common stock, Shares, Outstanding	975	973
Treasury stock, Shares held	2	2
Exelon Generation Co L L C [Member]
Accumulated depreciation and amortization	$ 12,051	$ 12,017
Commonwealth Edison Co [Member]
Accumulated depreciation and amortization	5,424	5,168
PECO Energy Co [Member]
Accumulated depreciation and amortization	3,782	3,718
Baltimore Gas and Electric Company [Member]
Accumulated depreciation and amortization	3,906	3,834
Pepco Holdings LLC [Member]
Accumulated depreciation and amortization	1,591	1,213
Potomac Electric Power Company [Member]
Accumulated depreciation and amortization	3,604	3,517
Delmarva Power and Light Company [Member]
Accumulated depreciation and amortization	1,476	1,425
Atlantic City Electric Company [Member]
Accumulated depreciation and amortization	$ 1,261	$ 1,210

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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