Summary of Significant Accounting Policies - Schedule of Concentration of Revenue (Details) - Southern Power - Sales Revenue, Goods, Net - Customer Concentration Risk |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Georgia Power | |||
| Concentration Risk [Line Items] | |||
| Percentage of total revenues for top three customers | 9.80% | 11.30% | 16.50% |
| Duke Energy Corporation | |||
| Concentration Risk [Line Items] | |||
| Percentage of total revenues for top three customers | 6.80% | 6.70% | 7.80% |
| Southern California Edison | |||
| Concentration Risk [Line Items] | |||
| Percentage of total revenues for top three customers | 6.20% | ||
| Morgan Stanley Capital Group | |||
| Concentration Risk [Line Items] | |||
| Percentage of total revenues for top three customers | 4.50% | ||
| San Diego Gas & Electric Company | |||
| Concentration Risk [Line Items] | |||
| Percentage of total revenues for top three customers | 5.70% | ||