v3.19.2
Derivatives - Location and Amount of Gain (Loss) Recognized in Income on Cash Flow and Fair Value Hedging Relationships (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Derivative [Line Items]        
Depreciation and amortization $ 755 $ 783 $ 1,506 $ 1,552
Total interest expense, net of amounts capitalized (429) (470) (859) (928)
Total other income (expense), net 99 78 176 138
Cash Flow Hedging | Gain (loss) on energy-related cash flow hedges | Total depreciation and amortization        
Derivative [Line Items]        
Gain (loss) on hedge (1) 1 (4) 2
Cash Flow Hedging | Interest rate derivatives | Total interest expense, net of amounts capitalized        
Derivative [Line Items]        
Gain (loss) on hedge (5) (6) (9) (11)
Cash Flow Hedging | Foreign currency derivatives | Total interest expense, net of amounts capitalized        
Derivative [Line Items]        
Gain (loss) on hedge (6) (7) (12) (12)
Cash Flow Hedging | Foreign currency derivatives | Total other income (expense), net        
Derivative [Line Items]        
Gain (loss) on hedge 16 (73) (8) (37)
Fair Value Hedging | Interest rate derivatives | Total interest expense, net of amounts capitalized        
Derivative [Line Items]        
Gain (loss) on hedge 19 (7) 33 (31)
SOUTHERN POWER CO        
Derivative [Line Items]        
Depreciation and amortization 119 125 237 240
Total interest expense, net of amounts capitalized (41) (46) (84) (93)
Total other income (expense), net 40 2 41 5
SOUTHERN POWER CO | Cash Flow Hedging | Gain (loss) on energy-related cash flow hedges | Total depreciation and amortization        
Derivative [Line Items]        
Gain (loss) on hedge (1) 1 (4) 2
SOUTHERN POWER CO | Cash Flow Hedging | Foreign currency derivatives | Total interest expense, net of amounts capitalized        
Derivative [Line Items]        
Gain (loss) on hedge (6) (7) (12) (12)
SOUTHERN POWER CO | Cash Flow Hedging | Foreign currency derivatives | Total other income (expense), net        
Derivative [Line Items]        
Gain (loss) on hedge $ 16 $ (73) $ (8) $ (37)