v2.4.0.8
Shareholders' Equity (Details 3) (USD $)
In Millions, unless otherwise specified
3 Months Ended 6 Months Ended
Jun. 30, 2014
Jun. 30, 2013
Jun. 30, 2014
Jun. 30, 2013
Significant reclassifications from accumulated other comprehensive income to net income        
Total amortization, before income taxes $ 676 $ 454 $ 1,230 $ 789
Income tax benefit (72) (132) (152) (151)
Total amortization, net of income taxes 587 307 1,043 628
Defined benefit pension plans | Amount Reclassified from Accumulated Other Comprehensive Income
       
Significant reclassifications from accumulated other comprehensive income to net income        
Actuarial losses 6 14 12 28
Prior service costs (1) (1) (1) (1)
Settlements and curtailments (5)   (5)  
Total amortization, before income taxes   13 6 27
Income tax benefit (3) (1) (3) (2)
Total amortization, net of income taxes (3) 12 3 25
Defined benefit pension plans | Amount Reclassified from Accumulated Other Comprehensive Income | Operating and maintenance costs
       
Significant reclassifications from accumulated other comprehensive income to net income        
Total amortization, before income taxes   10 4 21
Defined benefit pension plans | Amount Reclassified from Accumulated Other Comprehensive Income | Operating and maintenance costs | Maximum
       
Significant reclassifications from accumulated other comprehensive income to net income        
Total amortization, before income taxes 1      
Defined benefit pension plans | Amount Reclassified from Accumulated Other Comprehensive Income | General and administrative costs
       
Significant reclassifications from accumulated other comprehensive income to net income        
Total amortization, before income taxes   3 2 6
Defined benefit pension plans | Amount Reclassified from Accumulated Other Comprehensive Income | General and administrative costs | Maximum
       
Significant reclassifications from accumulated other comprehensive income to net income        
Total amortization, before income taxes $ 1