Fair Value Measurements (Details) (USD $) In Millions	Jun. 30, 2011
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Energy-related derivatives	$ 1
Cash equivalents and restricted cash	41
Fair value assets, total	612
Liabilities:
Energy-related derivatives	25
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets:
Energy-related derivatives	0
Cash equivalents and restricted cash	41
Fair value assets, total	362
Liabilities:
Energy-related derivatives	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Domestic Equity [Member]
Assets:
Nuclear decommissioning trusts	274
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Foreign Equity [Member]
Assets:
Nuclear decommissioning trusts	29
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | US Treasury and Government [Member]
Assets:
Nuclear decommissioning trusts	18
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Corporate Debt Securities [Member]
Assets:
Nuclear decommissioning trusts	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Asset-backed Securities [Member]
Assets:
Nuclear decommissioning trusts	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other [Member]
Assets:
Nuclear decommissioning trusts	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets:
Energy-related derivatives	1
Cash equivalents and restricted cash	0
Fair value assets, total	250
Liabilities:
Energy-related derivatives	25
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Domestic Equity [Member]
Assets:
Nuclear decommissioning trusts	62
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Foreign Equity [Member]
Assets:
Nuclear decommissioning trusts	29
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | US Treasury and Government [Member]
Assets:
Nuclear decommissioning trusts	8
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member]
Assets:
Nuclear decommissioning trusts	114
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Asset-backed Securities [Member]
Assets:
Nuclear decommissioning trusts	29
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other [Member]
Assets:
Nuclear decommissioning trusts	7
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets:
Energy-related derivatives	0
Cash equivalents and restricted cash	0
Fair value assets, total	0
Liabilities:
Energy-related derivatives	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Domestic Equity [Member]
Assets:
Nuclear decommissioning trusts	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Foreign Equity [Member]
Assets:
Nuclear decommissioning trusts	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | US Treasury and Government [Member]
Assets:
Nuclear decommissioning trusts	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Corporate Debt Securities [Member]
Assets:
Nuclear decommissioning trusts	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities [Member]
Assets:
Nuclear decommissioning trusts	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other [Member]
Assets:
Nuclear decommissioning trusts	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Domestic Equity [Member]
Assets:
Nuclear decommissioning trusts	336
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Foreign Equity [Member]
Assets:
Nuclear decommissioning trusts	58
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | US Treasury and Government [Member]
Assets:
Nuclear decommissioning trusts	26
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Corporate Debt Securities [Member]
Assets:
Nuclear decommissioning trusts	114
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Asset-backed Securities [Member]
Assets:
Nuclear decommissioning trusts	29
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Other [Member]
Assets:
Nuclear decommissioning trusts	7
Georgia Power [Member]
Assets:
Nuclear decommissioning trusts	119
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Energy-related derivatives	1
Cash equivalents and restricted cash	8
Fair value assets, total	760
Liabilities:
Energy-related derivatives	68
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets:
Energy-related derivatives	0
Cash equivalents and restricted cash	8
Fair value assets, total	253
Liabilities:
Energy-related derivatives	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Domestic Equity [Member]
Assets:
Nuclear decommissioning trusts	245
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | US Treasury and Government [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Municipal Bonds [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Corporate Debt Securities [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Asset-backed Securities [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets:
Energy-related derivatives	1
Cash equivalents and restricted cash	0
Fair value assets, total	507
Liabilities:
Energy-related derivatives	68
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Domestic Equity [Member]
Assets:
Nuclear decommissioning trusts	1
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | US Treasury and Government [Member]
Assets:
Nuclear decommissioning trusts	106
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal Bonds [Member]
Assets:
Nuclear decommissioning trusts	61
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member]
Assets:
Nuclear decommissioning trusts	180
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Asset-backed Securities [Member]
Assets:
Nuclear decommissioning trusts	118
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other [Member]
Assets:
Nuclear decommissioning trusts	40
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets:
Energy-related derivatives	0
Cash equivalents and restricted cash	0
Fair value assets, total	0
Liabilities:
Energy-related derivatives	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Domestic Equity [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | US Treasury and Government [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Municipal Bonds [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Corporate Debt Securities [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Domestic Equity [Member]
Assets:
Nuclear decommissioning trusts	246
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | US Treasury and Government [Member]
Assets:
Nuclear decommissioning trusts	106
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Municipal Bonds [Member]
Assets:
Nuclear decommissioning trusts	61
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Corporate Debt Securities [Member]
Assets:
Nuclear decommissioning trusts	180
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Asset-backed Securities [Member]
Assets:
Nuclear decommissioning trusts	118
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Other [Member]
Assets:
Nuclear decommissioning trusts	40
Gulf Power [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Energy-related derivatives	1
Cash equivalents and restricted cash	14
Fair value assets, total	15
Liabilities:
Energy-related derivatives	10
Gulf Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets:
Energy-related derivatives	0
Cash equivalents and restricted cash	14
Fair value assets, total	14
Liabilities:
Energy-related derivatives	0
Gulf Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets:
Energy-related derivatives	1
Cash equivalents and restricted cash	0
Fair value assets, total	1
Liabilities:
Energy-related derivatives	10
Gulf Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets:
Energy-related derivatives	0
Cash equivalents and restricted cash	0
Fair value assets, total	0
Liabilities:
Energy-related derivatives	0
Mississippi Power [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Energy-related derivatives	1
Foreign currency derivatives	4
Cash equivalents and restricted cash	48
Fair value assets, total	53
Liabilities:
Energy-related derivatives	34
Mississippi Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets:
Energy-related derivatives	0
Foreign currency derivatives	0
Cash equivalents and restricted cash	48
Fair value assets, total	48
Liabilities:
Energy-related derivatives	0
Mississippi Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets:
Energy-related derivatives	1
Foreign currency derivatives	4
Cash equivalents and restricted cash	0
Fair value assets, total	5
Liabilities:
Energy-related derivatives	34
Mississippi Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets:
Energy-related derivatives	0
Foreign currency derivatives	0
Cash equivalents and restricted cash	0
Fair value assets, total	0
Liabilities:
Energy-related derivatives	0
Southern Power [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Energy-related derivatives	3
Liabilities:
Energy-related derivatives	6
Southern Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets:
Energy-related derivatives	0
Liabilities:
Energy-related derivatives	0
Southern Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets:
Energy-related derivatives	3
Liabilities:
Energy-related derivatives	6
Southern Power [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets:
Energy-related derivatives	0
Liabilities:
Energy-related derivatives	0
Fair Value, Measurements, Recurring [Member]
Assets:
Energy-related derivatives	7
Interest rate derivatives	12
Foreign currency derivatives	4
Nuclear decommissioning trusts	1,321
Cash equivalents and restricted cash	254
Other	77
Fair value assets, total	1,675
Liabilities:
Energy-related derivatives	143
Interest rate derivatives	1
Fair value liabilities, total	144
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets:
Energy-related derivatives	0
Interest rate derivatives	0
Foreign currency derivatives	0
Nuclear decommissioning trusts	566
Cash equivalents and restricted cash	254
Other	11
Fair value assets, total	831
Liabilities:
Energy-related derivatives	0
Interest rate derivatives	0
Fair value liabilities, total	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets:
Energy-related derivatives	7
Interest rate derivatives	12
Foreign currency derivatives	4
Nuclear decommissioning trusts	755
Cash equivalents and restricted cash	0
Other	49
Fair value assets, total	827
Liabilities:
Energy-related derivatives	143
Interest rate derivatives	1
Fair value liabilities, total	144
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets:
Energy-related derivatives	0
Interest rate derivatives	0
Foreign currency derivatives	0
Nuclear decommissioning trusts	0
Cash equivalents and restricted cash	0
Other	17
Fair value assets, total	17
Liabilities:
Energy-related derivatives	0
Interest rate derivatives	0
Fair value liabilities, total	$ 0