Schedule I - Condensed Financial Information of Parent (Exelon Corporate) - Debt and Credit Agreements - Schedule of Outstanding Long-term Debt (Details) - USD ($)		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Jun. 30, 2014
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 25,113,000,000	$ 20,864,000,000
Unamortized debt discount and premium, net		(63,000,000)	(37,000,000)
Long-term debt		$ 23,645,000,000	19,212,000,000
Maximum interest rate on long-term debt		3.95%
Unamortized Debt Issuance Expense	[1]	$ (180,000,000)	(150,000,000)
Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 1,150,000,000	1,150,000,000	$ 1,150,000,000.00
Maximum interest rate on long-term debt		6.50%
Senior Notes [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 9,803,000,000	7,071,000,000
Minimum interest rate on long-term debt		1.55%
Maximum interest rate on long-term debt		7.60%
contract Payments Junior Subordinate Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 64,000,000	108,000,000
Maximum interest rate on long-term debt		2.50%
Exelon Corporate [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 5,853,000,000	3,916,000,000
Unamortized debt discount and premium, net		(4,000,000)	1,000,000
Fair value adjustment of consolidated subsidiary		275,000,000	333,000,000
Long-term debt due within one year		(60,000,000)	(1,409,000,000)
Long-term debt		6,017,000,000	2,818,000,000
Unamortized Debt Issuance Expense		(47,000,000)	(23,000,000)
Exelon Corporate [Member] | Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 1,150,000,000	1,150,000,000
Maximum interest rate on long-term debt		6.50%
Exelon Corporate [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Unsecured Long Term Debt	[2]	$ 4,639,000,000	2,658,000,000
Minimum interest rate on long-term debt	[2]	1.55%
Maximum interest rate on long-term debt	[2]	7.60%
Exelon Corporate [Member] | contract Payments Junior Subordinate Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 64,000,000	$ 108,000,000
Maximum interest rate on long-term debt		2.50%

[1] Certain December 31, 2014 balances have been adjusted for the adoption of accounting guidance related to simplifying the presentation of debt costs. See Note 1 - Significant Accounting Policies for additional information.

[2] {F|ahBzfndlYmZpbGluZ3MtaHJkcmoLEgZYTUxEb2MiXlhCUkxEb2NHZW5JbmZvOmJiZTkxZGVlYTU0NDQzYzU5MmI5ODA2YTIzODFjMGRkfFRleHRTZWxlY3Rpb246QUM1QzUxNjBCNkEwMjA1MjMyMzgxMjI1RThCRDgwNEUM}