REGULATORY MATTERS - GPC Regulatory Matters - Tariffs (Details) - Georgia Power $ in Millions	Dec. 31, 2019 USD ($)
Public Utilities, General Disclosures [Line Items]
Rate increase 2020	$ 342
Rate increase 2021	181
Rate increase 2022	386
Traditional base
Public Utilities, General Disclosures [Line Items]
Rate increase 2020	0
Rate increase 2021	120
Rate increase 2022	192
ECCR
Public Utilities, General Disclosures [Line Items]
Rate increase 2020	318
Rate increase 2021	55
Rate increase 2022	184
DSM
Public Utilities, General Disclosures [Line Items]
Rate increase 2020	12
Rate increase 2021	1
Rate increase 2022	1
Municipal Franchise Fee
Public Utilities, General Disclosures [Line Items]
Rate increase 2020	12
Rate increase 2021	4
Rate increase 2022	$ 9

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