Vogtle Units No. 3 and No. 4 Construction Project - Project Budget and Actual Costs (Details) - Vogtle Units No. 3 & No. 4 - USD ($) $ in Millions	6 Months Ended	9 Months Ended
	Jun. 30, 2020	Sep. 30, 2020
Project Budget
Project-Level Contingency	$ 75
Remaining Project Budget
Proceeds from guarantee agreement		$ 1,100
Jointly Owned Nuclear Power Plant
Project Budget
Construction Costs		5,501
Financing Costs		1,557
Total Costs		7,058
Project-Level Contingency		72
Oglethorpe-Level Contingency		370
Total Contingency		442
Total Contingency		7,500
Actual Costs
Construction Costs		4,536
Financing Costs		1,204
Total Costs		5,740
Project-Level Contingency		0
Oglethorpe-Level Contingency		0
Total Contingency		0
Totals		5,740
Remaining Project Budget
Construction Costs		965
Financing Costs		353
Total Costs		1,318
Project-Level Contingency		72
Oglethorpe-Level Contingency		370
Total Contingency		442
Totals		$ 1,760