XML 116 R86.htm IDEA: XBRL DOCUMENT v2.4.0.8
Derivative Financial Instruments (Commodity Price Risk) (Details)
12 Months Ended
Dec. 31, 2013
GWh
Dec. 31, 2012
GWh
Dec. 31, 2011
GWh
Exelon Generation Co L L C [Member]
     
Proprietary Trading Volumes [Abstract]      
Proprietary trading activities volume 8,762 12,958 5,742
Exelon Generation Co L L C [Member] | Minimum [Member]
     
Percent Of Expected Generation Being Hedged [Abstract]      
Expected generation hedged in next twelve months 92.00%    
Expected generation hedged in year two 62.00%    
Expected generation hedged in year three 30.00%    
Exelon Generation Co L L C [Member] | Maximum [Member]
     
Percent Of Expected Generation Being Hedged [Abstract]      
Expected generation hedged in next twelve months 95.00%    
Expected generation hedged in year two 65.00%    
Expected generation hedged in year three 33.00%    
PECO Energy Co [Member]
     
Percent Of Gas Purchases Being Hedged [Abstract]      
Estimated percentage of natural gas purchases hedged 30.00%    
Baltimore Gas and Electric Company [Member] | Minimum [Member]
     
Percent Of Gas Purchases Being Hedged [Abstract]      
Estimated percentage of natural gas purchases hedged 10.00%    
Baltimore Gas and Electric Company [Member] | Maximum [Member]
     
Percent Of Gas Purchases Being Hedged [Abstract]      
Estimated percentage of natural gas purchases hedged 20.00%