XML 78 R59.htm IDEA: XBRL DOCUMENT v3.10.0.1
Financial and Other Derivative Instruments (Netting Offsets of Derivative Assets and Liabilities) (Details) - USD ($)
$ in Millions
Sep. 30, 2018
Dec. 31, 2017
Derivative assets    
Gross Amounts of Recognized Assets (Liabilities) $ 442 $ 652
Gross Amounts Offset in the Consolidated Statements of Financial Position (314) (498)
Derivative assets, net 128 154
Derivative liabilities    
Gross Amounts of Recognized Assets (Liabilities) (458) (657)
Gross Amounts Offset in the Consolidated Statements of Financial Position 313 511
Derivative liabilities, net (145) (146)
Natural gas    
Derivative assets    
Gross Amounts of Recognized Assets (Liabilities) 200 357
Gross Amounts Offset in the Consolidated Statements of Financial Position (139) (256)
Derivative assets, net 61 101
Derivative liabilities    
Gross Amounts of Recognized Assets (Liabilities) (229) (378)
Gross Amounts Offset in the Consolidated Statements of Financial Position 139 263
Derivative liabilities, net (90) (115)
Electricity    
Derivative assets    
Gross Amounts of Recognized Assets (Liabilities) 234 285
Gross Amounts Offset in the Consolidated Statements of Financial Position (173) (241)
Derivative assets, net 61 44
Derivative liabilities    
Gross Amounts of Recognized Assets (Liabilities) (227) (275)
Gross Amounts Offset in the Consolidated Statements of Financial Position 172 246
Derivative liabilities, net (55) (29)
Other    
Derivative assets    
Gross Amounts of Recognized Assets (Liabilities) 7 9
Gross Amounts Offset in the Consolidated Statements of Financial Position (1) 0
Derivative assets, net 6 9
Derivative liabilities    
Gross Amounts of Recognized Assets (Liabilities) (1) (1)
Gross Amounts Offset in the Consolidated Statements of Financial Position 1 1
Derivative liabilities, net 0 0
Foreign currency exchange contracts    
Derivative assets    
Gross Amounts of Recognized Assets (Liabilities) 1 1
Gross Amounts Offset in the Consolidated Statements of Financial Position (1) (1)
Derivative assets, net 0 0
Derivative liabilities    
Gross Amounts of Recognized Assets (Liabilities) (1) (3)
Gross Amounts Offset in the Consolidated Statements of Financial Position 1 1
Derivative liabilities, net $ 0 $ (2)