XML 30 R54.htm IDEA: XBRL DOCUMENT v2.4.0.6
Income Taxes (Reconciliation Of Effective Income Tax Rate From Continuing Operations) (Detail) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2013
Mar. 31, 2012
Income Tax Rate Reconciliation [Line Items]    
Income tax at Federal statutory rate $ (103) $ 26
State income taxes, net of Federal effect 5 4
Asset removal costs (3) (3)
Changes in estimates and interest related to uncertain and effectively settled tax positions 67 (13)
Cross-border energy lease investments 64 (1)
Establishment of valuation allowances related to deferred tax assets 101  
Other, net 4 (2)
Consolidated income tax expense related to continuing operations 135 11
Income tax at Federal statutory rate 35.00% 35.00%
State income taxes, net of Federal effect (1.70%) 5.40%
Asset removal costs 1.00% (4.10%)
Changes in estimates and interest related to uncertain and effectively settled tax positions (22.70%) (17.60%)
Cross-border energy lease investments (21.70%) (1.40%)
Establishment of valuation allowances related to deferred tax assets (34.20%)  
Other, net (1.50%) (2.40%)
Consolidated income tax expense related to continuing operations (45.80%) 14.90%
Potomac Electric Power Co [Member]
   
Income Tax Rate Reconciliation [Line Items]    
Income tax at Federal statutory rate 9 7
State income taxes, net of Federal effect 2 1
Asset removal costs (3) (3)
Changes in estimates and interest related to uncertain and effectively settled tax positions (5) (10)
Other, net (1)  
Consolidated income tax expense related to continuing operations 2 (5)
Income tax at Federal statutory rate 35.00% 35.00%
State income taxes, net of Federal effect 8.00% 6.30%
Asset removal costs (12.00%) (15.80%)
Changes in estimates and interest related to uncertain and effectively settled tax positions (20.00%) (50.50%)
Other, net (3.00%) (1.30%)
Consolidated income tax expense related to continuing operations 8.00% (26.30%)
Delmarva Power & Light Co/De [Member]
   
Income Tax Rate Reconciliation [Line Items]    
Income tax at Federal statutory rate 15 12
State income taxes, net of Federal effect 2 2
Changes in estimates and interest related to uncertain and effectively settled tax positions (1)  
Other, net      
Consolidated income tax expense related to continuing operations $ 16 $ 14
Income tax at Federal statutory rate 35.00% 35.00%
State income taxes, net of Federal effect 4.70% 5.70%
Changes in estimates and interest related to uncertain and effectively settled tax positions (2.40%)  
Other, net 0.80% (0.70%)
Consolidated income tax expense related to continuing operations 38.10% 40.00%