Schedule I - Condensed Financial Information of Parent (Exelon Corporate) - Condensed Balance Sheet (Details) - USD ($) $ in Millions		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current assets
Cash and cash equivalents		$ 635	$ 6,502	$ 1,878	$ 1,609
Prepaid Taxes		1,250	0
Accounts receivable, net
Other		1,201	912
Regulatory assets		1,342	759
Other		930	752
Total current assets		12,412	15,334
Property, plant and equipment, net		71,555	57,439
Deferred debits and other assets
Regulatory assets		10,046	6,065
Other		1,472	1,445
Total assets (a)	[1]	114,904	95,384
Current liabilities
Short-term Debt		1,267	533
Due to Affiliate, Current		706	0
Long-term debt due within one year		2,430	1,500
Accounts payable		3,441	2,883
Unamortized energy contract liabilities		407	100
Accrued expenses		3,460	2,376
Regulatory liabilities		602	369
Other		981	842
Total current liabilities		13,457	9,118
Long-term debt		31,575	23,645
Deferred credits and other liabilities
Regulatory liabilities		4,187	4,201
Pension obligations		4,248	3,385
Non-pension postretirement benefit obligations		1,848	1,618
Other		1,827	1,491
Total liabilities	[1]	87,292	68,062
Shareholders’ equity
Common stock		18,794	18,676
Treasury stock, at cost (35 shares at December 31, 2016 and 2015, respectively)		(2,327)	(2,327)
Retained earnings		12,030	12,068
Accumulated other comprehensive loss, net		(2,660)	(2,624)
Total shareholders’ equity		25,837	25,793
BGE preference stock not subject to mandatory redemption		0	193
Liabilities and Equity		114,904	95,384
Exelon Corporate [Member]
Current assets
Cash and cash equivalents		18	5,690	$ 879	$ 3
Accounts receivable, net
Other		73	272
Accounts receivable from affiliates		48	20
Receivables from affiliates		88	1,478
Regulatory assets		263	241
Other		1,250	5
Total current assets		1,740	7,706
Property, plant and equipment, net		51	53
Deferred debits and other assets
Regulatory assets		4,033	3,072
Investments in affiliates		34,869	26,119
Deferred income taxes		2,107	2,036
Receivable from affiliates		922	933
Defined Benefit Plan, Assets for Plan Benefits, Noncurrent			108
Other		256	404
Total deferred debits and other assets		42,187	32,672
Total assets (a)		43,978	40,431
Current liabilities
Short-term Debt		0	188
Due to Affiliate, Current		706
Long-term debt due within one year		570	60
Accounts payable		2	5
Accrued expenses		489	440
Regulatory liabilities		16	63
Pension and Other Postretirement Defined Benefit Plans, Current Liabilities		58	52
Other		50	1
Total current liabilities		1,891	809
Long-term debt		7,193	6,017
Deferred credits and other liabilities
Regulatory liabilities		31	31
Pension obligations		8,608	7,520
Non-pension postretirement benefit obligations		7	0
Deferred income taxes		226	134
Other		182	122
Deferred Credits and Other Liabilities, Noncurrent		9,054	7,807
Total liabilities		18,138	14,633
Commitments and Contingencies
Shareholders’ equity
Common stock		18,797	18,678
Treasury stock, at cost (35 shares at December 31, 2016 and 2015, respectively)		(2,327)	(2,327)
Retained earnings		12,030	12,068
Accumulated other comprehensive loss, net		(2,660)	(2,624)
Total shareholders’ equity		25,840	25,795
BGE preference stock not subject to mandatory redemption		0	3
Liabilities and Equity		$ 43,978	$ 40,431

[1] Exelon’s consolidated assets include $8,893 million and $8,268 million at December 31, 2016 and December 31, 2015, respectively, of certain VIEs that can only be used to settle the liabilities of the VIE. Exelon’s consolidated liabilities include $3,356 million and $3,264 million at December 31, 2016 and December 31, 2015, respectively, of certain VIEs for which the VIE creditors do not have recourse to Exelon. See Note 2–Variable Interest Entities.