Subsequent Event (Details) (PECO Energy Co [Member])	Dec. 31, 2013 Customers
PECO Energy Co [Member]
Storm Damage Impact [Abstract]
Customers impacted from storm damage	715,000

The total number of customers impacted by damage from large individual storm.

No definition available.

Name:	exc_CustomersImpactedFromStormDamage
Namespace Prefix:	exc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant