REGULATORY MATTERS - Georgia Power (Details) - GEORGIA POWER CO - USD ($)		4 Months Ended	9 Months Ended
	May 28, 2020	Sep. 30, 2020	Sep. 30, 2020	Oct. 01, 2020	Dec. 31, 2019	Dec. 31, 2013
Public Utilities, General Disclosures [Line Items]
Retail rate of return on common equity						10.95%
Customer refund liability in absence of base rate case					$ 60,000,000
Portion of actual earnings above approved ROE band refunded to customers, value					$ 60,000,000
Incremental COVID-19 costs deferred		$ 38,000,000	$ 38,000,000
Requested decrease in fuel billings	$ 740,000,000	$ 44,000,000
Requested decrease in fuel billings, term	2 years
Adjustment to fuel cost recovery rate if under recovered fuel balance exceeds budget thereafter			$ 200,000,000
Subsequent Event | Traditional Base
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount, due in next fiscal year				$ 120,000,000
Subsequent Event | Environmental Compliance Cost Recovery
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount, due in next fiscal year				2,000,000
Subsequent Event | Demand-Side Management
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount, due in next fiscal year				(15,000,000)
Subsequent Event | Municipal Franchise Fee
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount, due in next fiscal year				$ 4,000,000
Maximum
Public Utilities, General Disclosures [Line Items]
Retail rate of return on common equity					12.00%