Vogtle Units No. 3 and No. 4 Construction Project - Project Budget and Actual Costs (Details) - Vogtle Units No. 3 & No. 4 $ in Millions	6 Months Ended
	Jun. 30, 2020 USD ($)
Project Budget
Project-Level Contingency	$ 75
Oglethorpe-Level Contingency	325
Remaining Project Budget
Proceeds from guarantee agreement	1,100
Jointly Owned Nuclear Power Plant
Project Budget
Construction Costs	5,524
Financing Costs	1,576
Total Costs	7,100
Project-Level Contingency	75
Oglethorpe-Level Contingency	325
Total Contingency	400
Total Contingency	7,500
Actual Costs
Construction Costs	4,303
Financing Costs	1,151
Total Costs	5,454
Project-Level Contingency	0
Oglethorpe-Level Contingency	0
Total Contingency	0
Totals	5,454
Remaining Project Budget
Construction Costs	1,221
Financing Costs	425
Total Costs	1,646
Project-Level Contingency	75
Oglethorpe-Level Contingency	325
Total Contingency	400
Totals	$ 2,046