Regulatory Matters - Schedule of Nuclear Construction Cost and Schedule (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Commitments [Line Items] | |||
| Total AFUDC and interest capitalized | $ 210 | $ 249 | $ 327 |
| Georgia Power | |||
| Commitments [Line Items] | |||
| Total AFUDC and interest capitalized | 94 | $ 63 | $ 68 |
| Maximum guarantee | 30 | ||
| Customer refund | 40 | ||
| Georgia Power | Plant Vogtle Units 3 And 4 | |||
| Commitments [Line Items] | |||
| Base project capital cost forecast | 8,000 | ||
| Construction contingency estimate | 400 | ||
| Total project capital cost forecast | 8,400 | ||
| Net investment | (4,600) | ||
| Remaining estimate to complete | 3,800 | ||
| Total AFUDC and interest capitalized | 315 | ||
| Maximum guarantee | 1,700 | ||
| Customer refund | $ 188 | ||