XML 21 R46.htm IDEA: XBRL DOCUMENT v2.4.0.6
Fair Value (Details 1) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2013
Mar. 31, 2012
Fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis    
Beginning Balance $ (13) $ 44
Transfers into Level 3 0 27
Transfer out of Level 3 (2) (2)
Total gains: [Abstract]    
Included in earnings 0 (7)
Recorded in regulatory assets/liabilities 1 1
Purchases issuances and settlements [Abstract]    
Settlements (27) (26)
Ending Balance (41) 37
The amount of total gains (losses) included in net income attributed to the change in unrealized gains or losses related to assets still held at the end of the period (11) 8
Natural Gas [Member]
   
Fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis    
Beginning Balance (38) 6
Transfers into Level 3 0 0
Transfer out of Level 3 (2) (2)
Total gains: [Abstract]    
Included in earnings (8) 6
Recorded in regulatory assets/liabilities 0 0
Purchases issuances and settlements [Abstract]    
Settlements 14 (4)
Ending Balance (34) 6
The amount of total gains (losses) included in net income attributed to the change in unrealized gains or losses related to assets still held at the end of the period (5) 6
Electricity [Member]
   
Fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis    
Beginning Balance 23 32
Transfers into Level 3 0 27
Transfer out of Level 3 0 0
Total gains: [Abstract]    
Included in earnings 8 (14)
Recorded in regulatory assets/liabilities 0 0
Purchases issuances and settlements [Abstract]    
Settlements (40) (20)
Ending Balance (9) 25
The amount of total gains (losses) included in net income attributed to the change in unrealized gains or losses related to assets still held at the end of the period (6) 1
Other [Member]
   
Fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis    
Beginning Balance 2 6
Transfers into Level 3 0 0
Transfer out of Level 3 0 0
Total gains: [Abstract]    
Included in earnings 0 1
Recorded in regulatory assets/liabilities 1 1
Purchases issuances and settlements [Abstract]    
Settlements (1) (2)
Ending Balance 2 6
The amount of total gains (losses) included in net income attributed to the change in unrealized gains or losses related to assets still held at the end of the period $ 0 $ 1