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Derivatives and Hedging (Details) (USD $)
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2012
gal
MMBTU
MWh
T
Sep. 30, 2011
Sep. 30, 2012
gal
MMBTU
MWh
T
Sep. 30, 2011
Dec. 31, 2011
MWh
MMBTU
gal
T
Commodity:          
Power (In MWHs) 617,000,000   617,000,000   609,000,000
Coal (In Tons) 15,000,000   15,000,000   21,000,000
Natural Gas (In MMBtus) 123,000,000   123,000,000   100,000,000
Heating Oil and Gasoline (In Gallons) 5,000,000   5,000,000   6,000,000
Interest Rate $ 258,000,000   $ 258,000,000   $ 226,000,000
Interest Rate and Foreign Currency 703,000,000   703,000,000   907,000,000
Cash Collateral Netting          
Cash Collateral Received Netted Against Risk Management Assets 18,000,000   18,000,000   26,000,000
Cash Collateral Paid Netted Against Risk Management Liabilities 48,000,000   48,000,000   133,000,000
Fair Value of Derivative Instruments          
Current Risk Management Assets 175,000,000   175,000,000   193,000,000
Long-term Risk Management Assets 390,000,000   390,000,000   403,000,000
Total Assets 565,000,000   565,000,000   596,000,000
Current Risk Management Liabilities 150,000,000   150,000,000   150,000,000
Long-term Risk Management Liabilities 224,000,000   224,000,000   195,000,000
Total Liabilities 374,000,000   374,000,000   345,000,000
Total MTM Derivative Contract Net Assets (Liabilities) 191,000,000   191,000,000   251,000,000
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 13,000,000 9,000,000 24,000,000 72,000,000  
Total Accumulated Other Comprehensive Income (Loss) Activity for Cash Flow Hedges          
Beginning Balance in AOCI (44,000,000) 17,000,000 (23,000,000) 11,000,000 11,000,000
Changes in Fair Value Recognized in AOCI 13,000,000 (19,000,000) (22,000,000) (15,000,000)  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Ending Balance in AOCI (31,000,000) (3,000,000) (31,000,000) (3,000,000) (23,000,000)
Impact of Cash Flow Hedges on the Condensed Balance Sheet          
Hedging Assets 33,000,000 [1]   33,000,000 [1]   20,000,000 [1]
Hedging Liabilities 71,000,000 [1]   71,000,000 [1]   67,000,000 [1]
AOCI Gain (Loss) Net of Tax (31,000,000) (3,000,000) (31,000,000) (3,000,000) (23,000,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months     (4,000,000)   (5,000,000)
Maximum Term for Exposure to Variability of Future Cash Flows     36 months    
Collateral Triggering Events [Abstract]          
Liabilities for Derivative Contracts with Credit Downgrade Triggers 7,000,000   7,000,000   32,000,000
Amount of Collateral AEP Subsidiaries Would Have Been Required to Post 44,000,000   44,000,000   39,000,000
Amount Attributable to RTO and ISO Activities 42,000,000   42,000,000   38,000,000
Liabilities for Contracts with Cross Default Provisions Prior to Contractural Netting Arrangements 519,000,000   519,000,000   515,000,000
Amount of Cash Collateral Posted 3,000,000   3,000,000   56,000,000
Additional Settlement Liability if Cross Default Provision is Triggered 329,000,000   329,000,000   291,000,000
Derivatives and Hedging (Textuals) [Abstract]          
Cash Collateral Received Netted Against Risk Management Assets 18,000,000   18,000,000   26,000,000
Cash Collateral Paid Netted Against Risk Management Liabilities 48,000,000   48,000,000   133,000,000
Maximum Term for Exposure to Variability of Future Cash Flows     36 months    
Gain on Fair Value Hedging Instrument 1,000,000 1,000,000 3,000,000 3,000,000  
Loss on Fair Value Portion of Long Term Debt 1,000,000 3,000,000 3,000,000 6,000,000  
Appalachian Power Co [Member]
          
Commodity:          
Power (In MWHs) 142,425,000   142,425,000   169,459,000
Coal (In Tons) 2,498,000   2,498,000   3,714,000
Natural Gas (In MMBtus) 11,127,000   11,127,000   7,923,000
Heating Oil and Gasoline (In Gallons) 858,000   858,000   1,057,000
Interest Rate 29,011,000   29,011,000   31,029,000
Interest Rate and Foreign Currency 0   0   0
Cash Collateral Netting          
Cash Collateral Received Netted Against Risk Management Assets 2,375,000   2,375,000   4,291,000
Cash Collateral Paid Netted Against Risk Management Liabilities 10,408,000   10,408,000   28,964,000
Fair Value of Derivative Instruments          
Current Risk Management Assets 31,227,000   31,227,000   39,645,000
Long-term Risk Management Assets 38,371,000   38,371,000   39,226,000
Total Assets 69,598,000   69,598,000   78,871,000
Current Risk Management Liabilities 18,326,000   18,326,000   26,606,000
Long-term Risk Management Liabilities 20,805,000   20,805,000   12,923,000
Total Liabilities 39,131,000   39,131,000   39,529,000
Total MTM Derivative Contract Net Assets (Liabilities) 30,467,000   30,467,000   39,342,000
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts (1,432,000) 144,000 1,485,000 13,995,000  
Total Accumulated Other Comprehensive Income (Loss) Activity for Cash Flow Hedges          
Beginning Balance in AOCI (258,000) 1,155,000 (285,000) (56,000) (56,000)
Changes in Fair Value Recognized in AOCI 1,302,000 (646,000) (946,000) (896,000)  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Ending Balance in AOCI 1,461,000 711,000 1,461,000 711,000  
Impact of Cash Flow Hedges on the Condensed Balance Sheet          
AOCI Gain (Loss) Net of Tax 1,461,000 711,000 1,461,000 711,000  
Maximum Term for Exposure to Variability of Future Cash Flows     20 months    
Collateral Triggering Events [Abstract]          
Liabilities for Derivative Contracts with Credit Downgrade Triggers 2,155,000   2,155,000   10,007,000
Amount of Collateral AEP Subsidiaries Would Have Been Required to Post 4,301,000   4,301,000   6,211,000
Amount Attributable to RTO and ISO Activities 4,301,000   4,301,000   6,211,000
Liabilities for Contracts with Cross Default Provisions Prior to Contractural Netting Arrangements 64,466,000   64,466,000   76,868,000
Amount of Cash Collateral Posted 76,000   76,000   8,107,000
Additional Settlement Liability if Cross Default Provision is Triggered 33,019,000   33,019,000   27,603,000
Derivatives and Hedging (Textuals) [Abstract]          
Cash Collateral Received Netted Against Risk Management Assets 2,375,000   2,375,000   4,291,000
Cash Collateral Paid Netted Against Risk Management Liabilities 10,408,000   10,408,000   28,964,000
Maximum Term for Exposure to Variability of Future Cash Flows     20 months    
Indiana Michigan Power Co [Member]
          
Commodity:          
Power (In MWHs) 98,176,000   98,176,000   109,326,000
Coal (In Tons) 2,944,000   2,944,000   1,920,000
Natural Gas (In MMBtus) 7,647,000   7,647,000   5,081,000
Heating Oil and Gasoline (In Gallons) 440,000   440,000   525,000
Interest Rate 19,936,000   19,936,000   19,890,000
Interest Rate and Foreign Currency 200,000,000   200,000,000   200,000,000
Cash Collateral Netting          
Cash Collateral Received Netted Against Risk Management Assets 1,632,000   1,632,000   2,752,000
Cash Collateral Paid Netted Against Risk Management Liabilities 7,151,000   7,151,000   18,547,000
Fair Value of Derivative Instruments          
Current Risk Management Assets 28,502,000   28,502,000   32,152,000
Long-term Risk Management Assets 26,304,000   26,304,000   29,362,000
Total Assets 54,806,000   54,806,000   61,514,000
Current Risk Management Liabilities 33,188,000   33,188,000   16,980,000
Long-term Risk Management Liabilities 14,829,000   14,829,000   18,871,000
Total Liabilities 48,017,000   48,017,000   35,851,000
Total MTM Derivative Contract Net Assets (Liabilities) 6,789,000   6,789,000   25,663,000
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts (2,666,000) 657,000 3,829,000 8,248,000  
Total Accumulated Other Comprehensive Income (Loss) Activity for Cash Flow Hedges          
Beginning Balance in AOCI (20,261,000) (7,626,000) (15,284,000) (8,685,000) (8,685,000)
Changes in Fair Value Recognized in AOCI (655,000) (5,096,000) (7,131,000) (5,043,000)  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Ending Balance in AOCI (20,665,000) (12,517,000) (20,665,000) (12,517,000)  
Impact of Cash Flow Hedges on the Condensed Balance Sheet          
AOCI Gain (Loss) Net of Tax (20,665,000) (12,517,000) (20,665,000) (12,517,000)  
Maximum Term for Exposure to Variability of Future Cash Flows     20 months    
Collateral Triggering Events [Abstract]          
Liabilities for Derivative Contracts with Credit Downgrade Triggers 1,481,000   1,481,000   6,418,000
Amount of Collateral AEP Subsidiaries Would Have Been Required to Post 2,956,000   2,956,000   3,983,000
Amount Attributable to RTO and ISO Activities 2,956,000   2,956,000   3,983,000
Liabilities for Contracts with Cross Default Provisions Prior to Contractural Netting Arrangements 64,767,000   64,767,000   59,936,000
Amount of Cash Collateral Posted 52,000   52,000   5,200,000
Additional Settlement Liability if Cross Default Provision is Triggered 43,156,000   43,156,000   28,339,000
Derivatives and Hedging (Textuals) [Abstract]          
Cash Collateral Received Netted Against Risk Management Assets 1,632,000   1,632,000   2,752,000
Cash Collateral Paid Netted Against Risk Management Liabilities 7,151,000   7,151,000   18,547,000
Maximum Term for Exposure to Variability of Future Cash Flows     20 months    
Ohio Power Co [Member]
          
Commodity:          
Power (In MWHs) 200,993,000   200,993,000   229,468,000
Coal (In Tons) 5,052,000   5,052,000   8,337,000
Natural Gas (In MMBtus) 15,703,000   15,703,000   10,728,000
Heating Oil and Gasoline (In Gallons) 1,041,000   1,041,000   1,254,000
Interest Rate 40,940,000   40,940,000   42,093,000
Interest Rate and Foreign Currency 0   0   0
Cash Collateral Netting          
Cash Collateral Received Netted Against Risk Management Assets 3,352,000   3,352,000   5,810,000
Cash Collateral Paid Netted Against Risk Management Liabilities 14,687,000   14,687,000   39,183,000
Fair Value of Derivative Instruments          
Current Risk Management Assets 44,704,000   44,704,000   54,293,000
Long-term Risk Management Assets 54,327,000   54,327,000   53,614,000
Total Assets 99,031,000   99,031,000   107,907,000
Current Risk Management Liabilities 26,658,000   26,658,000   36,561,000
Long-term Risk Management Liabilities 29,513,000   29,513,000   17,890,000
Total Liabilities 56,171,000   56,171,000   54,451,000
Total MTM Derivative Contract Net Assets (Liabilities) 42,860,000   42,860,000   53,456,000
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts (3,701,000) 1,956,000 2,482,000 19,842,000  
Total Accumulated Other Comprehensive Income (Loss) Activity for Cash Flow Hedges          
Beginning Balance in AOCI 6,135,000 10,970,000 7,706,000 10,449,000 10,449,000
Changes in Fair Value Recognized in AOCI 1,916,000 (765,000) (1,486,000) (622,000)  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Ending Balance in AOCI 7,911,000 9,766,000 7,911,000 9,766,000  
Impact of Cash Flow Hedges on the Condensed Balance Sheet          
AOCI Gain (Loss) Net of Tax 7,911,000 9,766,000 7,911,000 9,766,000  
Maximum Term for Exposure to Variability of Future Cash Flows     20 months    
Collateral Triggering Events [Abstract]          
Liabilities for Derivative Contracts with Credit Downgrade Triggers 3,042,000   3,042,000   13,550,000
Amount of Collateral AEP Subsidiaries Would Have Been Required to Post 6,070,000   6,070,000   8,410,000
Amount Attributable to RTO and ISO Activities 6,070,000   6,070,000   8,410,000
Liabilities for Contracts with Cross Default Provisions Prior to Contractural Netting Arrangements 90,977,000   90,977,000   104,091,000
Amount of Cash Collateral Posted 107,000   107,000   10,978,000
Additional Settlement Liability if Cross Default Provision is Triggered 46,597,000   46,597,000   37,380,000
Derivatives and Hedging (Textuals) [Abstract]          
Cash Collateral Received Netted Against Risk Management Assets 3,352,000   3,352,000   5,810,000
Cash Collateral Paid Netted Against Risk Management Liabilities 14,687,000   14,687,000   39,183,000
Maximum Term for Exposure to Variability of Future Cash Flows     20 months    
Public Service Co Of Oklahoma [Member]
          
Commodity:          
Power (In MWHs) 14,000   14,000   39,000
Coal (In Tons) 2,416,000   2,416,000   3,574,000
Natural Gas (In MMBtus) 13,000   13,000   115,000
Heating Oil and Gasoline (In Gallons) 494,000   494,000   618,000
Interest Rate 0   0   175,000
Interest Rate and Foreign Currency 0   0   0
Cash Collateral Netting          
Cash Collateral Received Netted Against Risk Management Assets 5,000   5,000   53,000
Cash Collateral Paid Netted Against Risk Management Liabilities 9,000   9,000   130,000
Fair Value of Derivative Instruments          
Current Risk Management Assets 545,000   545,000   565,000
Long-term Risk Management Assets 124,000   124,000   314,000
Total Assets 669,000   669,000   879,000
Current Risk Management Liabilities 5,071,000   5,071,000   1,280,000
Long-term Risk Management Liabilities 1,051,000   1,051,000   1,330,000
Total Liabilities 6,122,000   6,122,000   2,610,000
Total MTM Derivative Contract Net Assets (Liabilities) (5,453,000)   (5,453,000)   (1,731,000)
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 671,000 1,138,000 (5,126,000) 2,924,000  
Total Accumulated Other Comprehensive Income (Loss) Activity for Cash Flow Hedges          
Beginning Balance in AOCI 6,737,000 7,738,000 7,149,000 8,494,000 8,494,000
Changes in Fair Value Recognized in AOCI 127,000 (162,000) 111,000 (458,000)  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Ending Balance in AOCI 6,684,000 7,306,000 6,684,000 7,306,000  
Impact of Cash Flow Hedges on the Condensed Balance Sheet          
AOCI Gain (Loss) Net of Tax 6,684,000 7,306,000 6,684,000 7,306,000  
Maximum Term for Exposure to Variability of Future Cash Flows     15 months    
Collateral Triggering Events [Abstract]          
Liabilities for Derivative Contracts with Credit Downgrade Triggers 0   0   0
Amount of Collateral AEP Subsidiaries Would Have Been Required to Post 1,288,000   1,288,000   856,000
Amount Attributable to RTO and ISO Activities 885,000   885,000   414,000
Liabilities for Contracts with Cross Default Provisions Prior to Contractural Netting Arrangements 26,000   26,000   142,000
Amount of Cash Collateral Posted 0   0   0
Additional Settlement Liability if Cross Default Provision is Triggered 16,000   16,000   61,000
Derivatives and Hedging (Textuals) [Abstract]          
Cash Collateral Received Netted Against Risk Management Assets 5,000   5,000   53,000
Cash Collateral Paid Netted Against Risk Management Liabilities 9,000   9,000   130,000
Maximum Term for Exposure to Variability of Future Cash Flows     15 months    
Southwestern Electric Power Co [Member]
          
Commodity:          
Power (In MWHs) 16,000   16,000   49,000
Coal (In Tons) 2,241,000   2,241,000   2,974,000
Natural Gas (In MMBtus) 15,000   15,000   145,000
Heating Oil and Gasoline (In Gallons) 471,000   471,000   569,000
Interest Rate 0   0   203,000
Interest Rate and Foreign Currency 0   0   200,069,000
Cash Collateral Netting          
Cash Collateral Received Netted Against Risk Management Assets 6,000   6,000   66,000
Cash Collateral Paid Netted Against Risk Management Liabilities 9,000   9,000   124,000
Fair Value of Derivative Instruments          
Current Risk Management Assets 705,000   705,000   445,000
Long-term Risk Management Assets 178,000   178,000   282,000
Total Assets 883,000   883,000   727,000
Current Risk Management Liabilities 4,148,000   4,148,000   24,359,000
Long-term Risk Management Liabilities 134,000   134,000   221,000
Total Liabilities 4,282,000   4,282,000   24,580,000
Total MTM Derivative Contract Net Assets (Liabilities) (3,399,000)   (3,399,000)   (23,853,000)
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 300,000 (229,000) (6,545,000) 3,375,000  
Total Accumulated Other Comprehensive Income (Loss) Activity for Cash Flow Hedges          
Beginning Balance in AOCI (16,903,000) (2,925,000) (15,524,000) (4,190,000) (4,190,000)
Changes in Fair Value Recognized in AOCI 122,000 (11,044,000) (2,672,000) (10,075,000)  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Ending Balance in AOCI (16,206,000) (13,838,000) (16,206,000) (13,838,000)  
Impact of Cash Flow Hedges on the Condensed Balance Sheet          
AOCI Gain (Loss) Net of Tax (16,206,000) (13,838,000) (16,206,000) (13,838,000)  
Maximum Term for Exposure to Variability of Future Cash Flows     15 months    
Collateral Triggering Events [Abstract]          
Liabilities for Derivative Contracts with Credit Downgrade Triggers 0   0   0
Amount of Collateral AEP Subsidiaries Would Have Been Required to Post 1,517,000   1,517,000   1,128,000
Amount Attributable to RTO and ISO Activities 1,042,000   1,042,000   522,000
Liabilities for Contracts with Cross Default Provisions Prior to Contractural Netting Arrangements 30,000   30,000   19,322,000
Amount of Cash Collateral Posted 0   0   0
Additional Settlement Liability if Cross Default Provision is Triggered 19,000   19,000   19,220,000
Derivatives and Hedging (Textuals) [Abstract]          
Cash Collateral Received Netted Against Risk Management Assets 6,000   6,000   66,000
Cash Collateral Paid Netted Against Risk Management Liabilities 9,000   9,000   124,000
Maximum Term for Exposure to Variability of Future Cash Flows     15 months    
Risk Management Contracts [Member]
          
Fair Value of Derivative Instruments          
Total Assets 511,000,000 [2],[3]   511,000,000 [2],[3]   548,000,000 [2],[4]
Total Liabilities 303,000,000 [2],[3]   303,000,000 [2],[3]   278,000,000 [2],[4]
Risk Management Contracts [Member] | Appalachian Power Co [Member]
          
Fair Value of Derivative Instruments          
Total Assets 68,083,000 [2],[5]   68,083,000 [2],[5]   76,907,000 [2],[5]
Total Liabilities 37,628,000 [2],[5]   37,628,000 [2],[5]   37,111,000 [2],[5]
Risk Management Contracts [Member] | Indiana Michigan Power Co [Member]
          
Fair Value of Derivative Instruments          
Total Assets 53,778,000 [2],[5]   53,778,000 [2],[5]   60,254,000 [2],[5]
Total Liabilities 26,520,000 [2],[5]   26,520,000 [2],[5]   23,691,000 [2],[5]
Risk Management Contracts [Member] | Ohio Power Co [Member]
          
Fair Value of Derivative Instruments          
Total Assets 96,909,000 [2],[5]   96,909,000 [2],[5]   105,247,000 [2],[5]
Total Liabilities 54,051,000 [2],[5]   54,051,000 [2],[5]   51,212,000 [2],[5]
Risk Management Contracts [Member] | Public Service Co Of Oklahoma [Member]
          
Fair Value of Derivative Instruments          
Total Assets 623,000 [2],[5]   623,000 [2],[5]   879,000 [2],[5]
Total Liabilities 6,116,000 [2],[5]   6,116,000 [2],[5]   2,503,000 [2],[5]
Risk Management Contracts [Member] | Southwestern Electric Power Co [Member]
          
Fair Value of Derivative Instruments          
Total Assets 840,000 [2],[5]   840,000 [2],[5]   724,000 [2],[5]
Total Liabilities 4,276,000 [2],[5]   4,276,000 [2],[5]   5,340,000 [2],[5]
Fair Value Hedges [Member]
          
Fair Value of Derivative Instruments          
Total Assets 2,000,000   2,000,000    
Other [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets (561,000,000) [6]   (561,000,000) [6]   (683,000,000) [6]
Long-term Risk Management Assets (229,000,000) [6]   (229,000,000) [6]   (253,000,000) [6]
Total Assets (790,000,000) [6]   (790,000,000) [6]   (936,000,000) [6]
Current Risk Management Liabilities (578,000,000) [6]   (578,000,000) [6]   (746,000,000) [6]
Long-term Risk Management Liabilities (250,000,000) [6]   (250,000,000) [6]   (325,000,000) [6]
Total Liabilities (828,000,000) [6]   (828,000,000) [6]   (1,071,000,000) [6]
Total MTM Derivative Contract Net Assets (Liabilities) 38,000,000 [6]   38,000,000 [6]   135,000,000 [6]
Other [Member] | Appalachian Power Co [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets (135,893,000) [6]   (135,893,000) [6]   (194,179,000) [6]
Long-term Risk Management Assets (44,658,000) [6]   (44,658,000) [6]   (60,615,000) [6]
Total Assets (180,551,000) [6]   (180,551,000) [6]   (254,794,000) [6]
Current Risk Management Liabilities (141,267,000) [6]   (141,267,000) [6]   (211,515,000) [6]
Long-term Risk Management Liabilities (47,907,000) [6]   (47,907,000) [6]   (69,485,000) [6]
Total Liabilities (189,174,000) [6]   (189,174,000) [6]   (281,000,000) [6]
Total MTM Derivative Contract Net Assets (Liabilities) 8,623,000 [6]   8,623,000 [6]   26,206,000 [6]
Other [Member] | Indiana Michigan Power Co [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets (90,582,000) [6]   (90,582,000) [6]   (123,143,000) [6]
Long-term Risk Management Assets (30,606,000) [6]   (30,606,000) [6]   (38,743,000) [6]
Total Assets (121,188,000) [6]   (121,188,000) [6]   (161,886,000) [6]
Current Risk Management Liabilities (94,275,000) [6]   (94,275,000) [6]   (134,233,000) [6]
Long-term Risk Management Liabilities (32,838,000) [6]   (32,838,000) [6]   (44,431,000) [6]
Total Liabilities (127,113,000) [6]   (127,113,000) [6]   (178,664,000) [6]
Total MTM Derivative Contract Net Assets (Liabilities) 5,925,000 [6]   5,925,000 [6]   16,778,000 [6]
Other [Member] | Ohio Power Co [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets (200,027,000) [6]   (200,027,000) [6]   (273,020,000) [6]
Long-term Risk Management Assets (63,355,000) [6]   (63,355,000) [6]   (83,027,000) [6]
Total Assets (263,382,000) [6]   (263,382,000) [6]   (356,047,000) [6]
Current Risk Management Liabilities (207,611,000) [6]   (207,611,000) [6]   (296,458,000) [6]
Long-term Risk Management Liabilities (67,939,000) [6]   (67,939,000) [6]   (95,038,000) [6]
Total Liabilities (275,550,000) [6]   (275,550,000) [6]   (391,496,000) [6]
Total MTM Derivative Contract Net Assets (Liabilities) 12,168,000 [6]   12,168,000 [6]   35,449,000 [6]
Other [Member] | Public Service Co Of Oklahoma [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets (4,377,000) [6]   (4,377,000) [6]   (6,415,000) [6]
Long-term Risk Management Assets (180,000) [6]   (180,000) [6]   (600,000) [6]
Total Assets (4,557,000) [6]   (4,557,000) [6]   (7,015,000) [6]
Current Risk Management Liabilities (4,377,000) [6]   (4,377,000) [6]   (6,492,000) [6]
Long-term Risk Management Liabilities (184,000) [6]   (184,000) [6]   (600,000) [6]
Total Liabilities (4,561,000) [6]   (4,561,000) [6]   (7,092,000) [6]
Total MTM Derivative Contract Net Assets (Liabilities) 4,000 [6]   4,000 [6]   77,000 [6]
Other [Member] | Southwestern Electric Power Co [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets (7,234,000) [6]   (7,234,000) [6]   (5,885,000) [6]
Long-term Risk Management Assets (293,000) [6]   (293,000) [6]   (536,000) [6]
Total Assets (7,527,000) [6]   (7,527,000) [6]   (6,421,000) [6]
Current Risk Management Liabilities (7,233,000) [6]   (7,233,000) [6]   (5,943,000) [6]
Long-term Risk Management Liabilities (297,000) [6]   (297,000) [6]   (536,000) [6]
Total Liabilities (7,530,000) [6]   (7,530,000) [6]   (6,479,000) [6]
Total MTM Derivative Contract Net Assets (Liabilities) 3,000 [6]   3,000 [6]   58,000 [6]
Interest Rate and Foreign Currency [Member]
          
Total Accumulated Other Comprehensive Income (Loss) Activity for Cash Flow Hedges          
Beginning Balance in AOCI (30,000,000) 5,000,000 (20,000,000) 4,000,000 4,000,000
Changes in Fair Value Recognized in AOCI (3,000,000) (21,000,000) (15,000,000) (22,000,000)  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Ending Balance in AOCI (32,000,000) (15,000,000) (32,000,000) (15,000,000) (20,000,000)
Impact of Cash Flow Hedges on the Condensed Balance Sheet          
Hedging Assets 0 [1]   0 [1]   0 [1]
Hedging Liabilities 39,000,000 [1]   39,000,000 [1]   42,000,000 [1]
AOCI Gain (Loss) Net of Tax (32,000,000) (15,000,000) (32,000,000) (15,000,000) (20,000,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months     (4,000,000)   (2,000,000)
Interest Rate and Foreign Currency [Member] | Appalachian Power Co [Member]
          
Total Accumulated Other Comprehensive Income (Loss) Activity for Cash Flow Hedges          
Beginning Balance in AOCI 1,562,000 486,000 1,024,000 217,000 217,000
Changes in Fair Value Recognized in AOCI 0 0 0 (373,000)  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Ending Balance in AOCI 1,823,000 755,000 1,823,000 755,000 1,024,000
Impact of Cash Flow Hedges on the Condensed Balance Sheet          
Hedging Assets 0 [1]   0 [1]   0 [1]
Hedging Liabilities 0 [1]   0 [1]   0 [1]
AOCI Gain (Loss) Net of Tax 1,823,000 755,000 1,823,000 755,000 1,024,000
Portion Expected to be Reclassified to Net Income During the Next Twelve Months     (1,013,000)   (1,052,000)
Interest Rate and Foreign Currency [Member] | Indiana Michigan Power Co [Member]
          
Total Accumulated Other Comprehensive Income (Loss) Activity for Cash Flow Hedges          
Beginning Balance in AOCI (19,015,000) (8,004,000) (14,465,000) (8,507,000) (8,507,000)
Changes in Fair Value Recognized in AOCI (1,542,000) (4,764,000) (6,390,000) (4,764,000)  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Ending Balance in AOCI (20,408,000) (12,516,000) (20,408,000) (12,516,000) (14,465,000)
Impact of Cash Flow Hedges on the Condensed Balance Sheet          
Hedging Assets 0 [1]   0 [1]   0 [1]
Hedging Liabilities 20,465,000 [1]   20,465,000 [1]   10,637,000 [1]
AOCI Gain (Loss) Net of Tax (20,408,000) (12,516,000) (20,408,000) (12,516,000) (14,465,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months     (1,316,000)   (595,000)
Interest Rate and Foreign Currency [Member] | Ohio Power Co [Member]
          
Total Accumulated Other Comprehensive Income (Loss) Activity for Cash Flow Hedges          
Beginning Balance in AOCI 8,774,000 10,133,000 9,454,000 10,813,000 10,813,000
Changes in Fair Value Recognized in AOCI 1,000 0 1,000 0  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Ending Balance in AOCI 8,435,000 9,794,000 8,435,000 9,794,000 9,454,000
Impact of Cash Flow Hedges on the Condensed Balance Sheet          
Hedging Assets 0 [1]   0 [1]   0 [1]
Hedging Liabilities 0 [1]   0 [1]   0 [1]
AOCI Gain (Loss) Net of Tax 8,435,000 9,794,000 8,435,000 9,794,000 9,454,000
Portion Expected to be Reclassified to Net Income During the Next Twelve Months     1,359,000   1,359,000
Interest Rate and Foreign Currency [Member] | Public Service Co Of Oklahoma [Member]
          
Total Accumulated Other Comprehensive Income (Loss) Activity for Cash Flow Hedges          
Beginning Balance in AOCI 6,839,000 7,598,000 7,218,000 8,406,000 8,406,000
Changes in Fair Value Recognized in AOCI 1,000 0 1,000 (476,000)  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Ending Balance in AOCI 6,650,000 7,408,000 6,650,000 7,408,000 7,218,000
Impact of Cash Flow Hedges on the Condensed Balance Sheet          
Hedging Assets 0 [1]   0 [1]   0 [1]
Hedging Liabilities 0 [1]   0 [1]   0 [1]
AOCI Gain (Loss) Net of Tax 6,650,000 7,408,000 6,650,000 7,408,000 7,218,000
Portion Expected to be Reclassified to Net Income During the Next Twelve Months     759,000   759,000
Interest Rate and Foreign Currency [Member] | Southwestern Electric Power Co [Member]
          
Total Accumulated Other Comprehensive Income (Loss) Activity for Cash Flow Hedges          
Beginning Balance in AOCI (16,806,000) (3,057,000) (15,462,000) (4,272,000) (4,272,000)
Changes in Fair Value Recognized in AOCI (1,000) (10,896,000) (2,778,000) (10,095,000)  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Ending Balance in AOCI (16,240,000) (13,746,000) (16,240,000) (13,746,000) (15,462,000)
Impact of Cash Flow Hedges on the Condensed Balance Sheet          
Hedging Assets 0 [1]   0 [1]   3,000 [1]
Hedging Liabilities 0 [1]   0 [1]   19,143,000 [1]
AOCI Gain (Loss) Net of Tax (16,240,000) (13,746,000) (16,240,000) (13,746,000) (15,462,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months     (2,369,000)   (1,864,000)
Interest Rate and Foreign Currency [Member] | Hedging Contracts [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets 1,000,000 [7]   1,000,000 [7]   0 [7]
Long-term Risk Management Assets 1,000,000 [7]   1,000,000 [7]   0 [7]
Total Assets 2,000,000 [7]   2,000,000 [7]   0 [7]
Current Risk Management Liabilities 37,000,000 [7]   37,000,000 [7]   20,000,000 [7]
Long-term Risk Management Liabilities 2,000,000 [7]   2,000,000 [7]   22,000,000 [7]
Total Liabilities 39,000,000 [7]   39,000,000 [7]   42,000,000 [7]
Total MTM Derivative Contract Net Assets (Liabilities) (37,000,000) [7]   (37,000,000) [7]   (42,000,000) [7]
Interest Rate and Foreign Currency [Member] | Hedging Contracts [Member] | Appalachian Power Co [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets 0 [7]   0 [7]   0 [7]
Long-term Risk Management Assets 0 [7]   0 [7]   0 [7]
Total Assets 0 [7]   0 [7]   0 [7]
Current Risk Management Liabilities 0 [7]   0 [7]   0 [7]
Long-term Risk Management Liabilities 0 [7]   0 [7]   0 [7]
Total Liabilities 0 [7]   0 [7]   0 [7]
Total MTM Derivative Contract Net Assets (Liabilities) 0 [7]   0 [7]   0 [7]
Interest Rate and Foreign Currency [Member] | Hedging Contracts [Member] | Indiana Michigan Power Co [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets 0 [7]   0 [7]   0 [7]
Long-term Risk Management Assets 0 [7]   0 [7]   0 [7]
Total Assets 0 [7]   0 [7]   0 [7]
Current Risk Management Liabilities 20,465,000 [7]   20,465,000 [7]   0 [7]
Long-term Risk Management Liabilities 0 [7]   0 [7]   10,637,000 [7]
Total Liabilities 20,465,000 [7]   20,465,000 [7]   10,637,000 [7]
Total MTM Derivative Contract Net Assets (Liabilities) (20,465,000) [7]   (20,465,000) [7]   (10,637,000) [7]
Interest Rate and Foreign Currency [Member] | Hedging Contracts [Member] | Ohio Power Co [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets 0 [7]   0 [7]   0 [7]
Long-term Risk Management Assets 0 [7]   0 [7]   0 [7]
Total Assets 0 [7]   0 [7]   0 [7]
Current Risk Management Liabilities 0 [7]   0 [7]   0 [7]
Long-term Risk Management Liabilities 0 [7]   0 [7]   0 [7]
Total Liabilities 0 [7]   0 [7]   0 [7]
Total MTM Derivative Contract Net Assets (Liabilities) 0 [7]   0 [7]   0 [7]
Interest Rate and Foreign Currency [Member] | Hedging Contracts [Member] | Public Service Co Of Oklahoma [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets 0 [7]   0 [7]   0 [7]
Long-term Risk Management Assets 0 [7]   0 [7]   0 [7]
Total Assets 0 [7]   0 [7]   0 [7]
Current Risk Management Liabilities 0 [7]   0 [7]   0 [7]
Long-term Risk Management Liabilities 0 [7]   0 [7]   0 [7]
Total Liabilities 0 [7]   0 [7]   0 [7]
Total MTM Derivative Contract Net Assets (Liabilities) 0 [7]   0 [7]   0 [7]
Interest Rate and Foreign Currency [Member] | Hedging Contracts [Member] | Southwestern Electric Power Co [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets 0 [7]   0 [7]   3,000 [7]
Long-term Risk Management Assets 0 [7]   0 [7]   0 [7]
Total Assets 0 [7]   0 [7]   3,000 [7]
Current Risk Management Liabilities 0 [7]   0 [7]   19,143,000 [7]
Long-term Risk Management Liabilities 0 [7]   0 [7]   0 [7]
Total Liabilities 0 [7]   0 [7]   19,143,000 [7]
Total MTM Derivative Contract Net Assets (Liabilities) 0 [7]   0 [7]   (19,140,000) [7]
Commodity [Member]
          
Total Accumulated Other Comprehensive Income (Loss) Activity for Cash Flow Hedges          
Beginning Balance in AOCI (14,000,000) 12,000,000 (3,000,000) 7,000,000 7,000,000
Changes in Fair Value Recognized in AOCI 16,000,000 2,000,000 (7,000,000) 7,000,000  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Ending Balance in AOCI 1,000,000 12,000,000 1,000,000 12,000,000 (3,000,000)
Impact of Cash Flow Hedges on the Condensed Balance Sheet          
Hedging Assets 33,000,000 [1]   33,000,000 [1]   20,000,000 [1]
Hedging Liabilities 32,000,000 [1]   32,000,000 [1]   25,000,000 [1]
AOCI Gain (Loss) Net of Tax 1,000,000 12,000,000 1,000,000 12,000,000 (3,000,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months     0   (3,000,000)
Commodity [Member] | Appalachian Power Co [Member]
          
Total Accumulated Other Comprehensive Income (Loss) Activity for Cash Flow Hedges          
Beginning Balance in AOCI (1,820,000) 669,000 (1,309,000) (273,000) (273,000)
Changes in Fair Value Recognized in AOCI 1,302,000 (646,000) (946,000) (523,000)  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Ending Balance in AOCI (362,000) (44,000) (362,000) (44,000) (1,309,000)
Impact of Cash Flow Hedges on the Condensed Balance Sheet          
Hedging Assets 925,000 [1]   925,000 [1]   431,000 [1]
Hedging Liabilities 1,503,000 [1]   1,503,000 [1]   2,418,000 [1]
AOCI Gain (Loss) Net of Tax (362,000) (44,000) (362,000) (44,000) (1,309,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months     (278,000)   (1,140,000)
Commodity [Member] | Indiana Michigan Power Co [Member]
          
Total Accumulated Other Comprehensive Income (Loss) Activity for Cash Flow Hedges          
Beginning Balance in AOCI (1,246,000) 378,000 (819,000) (178,000) (178,000)
Changes in Fair Value Recognized in AOCI 887,000 (332,000) (741,000) (279,000)  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Ending Balance in AOCI (257,000) (1,000) (257,000) (1,000) (819,000)
Impact of Cash Flow Hedges on the Condensed Balance Sheet          
Hedging Assets 622,000 [1]   622,000 [1]   277,000 [1]
Hedging Liabilities 1,032,000 [1]   1,032,000 [1]   1,523,000 [1]
AOCI Gain (Loss) Net of Tax (257,000) (1,000) (257,000) (1,000) (819,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months     (202,000)   (712,000)
Commodity [Member] | Ohio Power Co [Member]
          
Total Accumulated Other Comprehensive Income (Loss) Activity for Cash Flow Hedges          
Beginning Balance in AOCI (2,639,000) 837,000 (1,748,000) (364,000) (364,000)
Changes in Fair Value Recognized in AOCI 1,915,000 (765,000) (1,487,000) (622,000)  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Ending Balance in AOCI (524,000) (28,000) (524,000) (28,000) (1,748,000)
Impact of Cash Flow Hedges on the Condensed Balance Sheet          
Hedging Assets 1,289,000 [1]   1,289,000 [1]   584,000 [1]
Hedging Liabilities 2,120,000 [1]   2,120,000 [1]   3,239,000 [1]
AOCI Gain (Loss) Net of Tax (524,000) (28,000) (524,000) (28,000) (1,748,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months     (405,000)   (1,518,000)
Commodity [Member] | Public Service Co Of Oklahoma [Member]
          
Total Accumulated Other Comprehensive Income (Loss) Activity for Cash Flow Hedges          
Beginning Balance in AOCI (102,000) 140,000 (69,000) 88,000 88,000
Changes in Fair Value Recognized in AOCI 126,000 (162,000) 110,000 18,000  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Ending Balance in AOCI 34,000 (102,000) 34,000 (102,000) (69,000)
Impact of Cash Flow Hedges on the Condensed Balance Sheet          
Hedging Assets 46,000 [1]   46,000 [1]   0 [1]
Hedging Liabilities 6,000 [1]   6,000 [1]   107,000 [1]
AOCI Gain (Loss) Net of Tax 34,000 (102,000) 34,000 (102,000) (69,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months     36,000   (70,000)
Commodity [Member] | Southwestern Electric Power Co [Member]
          
Total Accumulated Other Comprehensive Income (Loss) Activity for Cash Flow Hedges          
Beginning Balance in AOCI (97,000) 132,000 (62,000) 82,000 82,000
Changes in Fair Value Recognized in AOCI 123,000 (148,000) 106,000 20,000  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Ending Balance in AOCI 34,000 (92,000) 34,000 (92,000) (62,000)
Impact of Cash Flow Hedges on the Condensed Balance Sheet          
Hedging Assets 43,000 [1]   43,000 [1]   0 [1]
Hedging Liabilities 6,000 [1]   6,000 [1]   97,000 [1]
AOCI Gain (Loss) Net of Tax 34,000 (92,000) 34,000 (92,000) (62,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months     34,000   (63,000)
Commodity [Member] | Risk Management Contracts [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets 699,000,000 [7]   699,000,000 [7]   852,000,000 [7]
Long-term Risk Management Assets 606,000,000 [7]   606,000,000 [7]   641,000,000 [7]
Total Assets 1,305,000,000 [7]   1,305,000,000 [7]   1,493,000,000 [7]
Current Risk Management Liabilities 656,000,000 [7]   656,000,000 [7]   847,000,000 [7]
Long-term Risk Management Liabilities 460,000,000 [7]   460,000,000 [7]   483,000,000 [7]
Total Liabilities 1,116,000,000 [7]   1,116,000,000 [7]   1,330,000,000 [7]
Total MTM Derivative Contract Net Assets (Liabilities) 189,000,000 [7]   189,000,000 [7]   163,000,000 [7]
Commodity [Member] | Risk Management Contracts [Member] | Appalachian Power Co [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets 165,813,000 [7]   165,813,000 [7]   232,784,000 [7]
Long-term Risk Management Assets 82,738,000 [7]   82,738,000 [7]   99,751,000 [7]
Total Assets 248,551,000 [7]   248,551,000 [7]   332,535,000 [7]
Current Risk Management Liabilities 157,836,000 [7]   157,836,000 [7]   235,354,000 [7]
Long-term Risk Management Liabilities 68,293,000 [7]   68,293,000 [7]   82,058,000 [7]
Total Liabilities 226,129,000 [7]   226,129,000 [7]   317,412,000 [7]
Total MTM Derivative Contract Net Assets (Liabilities) 22,422,000 [7]   22,422,000 [7]   15,123,000 [7]
Commodity [Member] | Risk Management Contracts [Member] | Indiana Michigan Power Co [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets 118,202,000 [7]   118,202,000 [7]   154,628,000 [7]
Long-term Risk Management Assets 56,711,000 [7]   56,711,000 [7]   68,047,000 [7]
Total Assets 174,913,000 [7]   174,913,000 [7]   222,675,000 [7]
Current Risk Management Liabilities 105,794,000 [7]   105,794,000 [7]   149,466,000 [7]
Long-term Risk Management Liabilities 47,380,000 [7]   47,380,000 [7]   52,441,000 [7]
Total Liabilities 153,174,000 [7]   153,174,000 [7]   201,907,000 [7]
Total MTM Derivative Contract Net Assets (Liabilities) 21,739,000 [7]   21,739,000 [7]   20,768,000 [7]
Commodity [Member] | Risk Management Contracts [Member] | Ohio Power Co [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets 242,904,000 [7]   242,904,000 [7]   325,904,000 [7]
Long-term Risk Management Assets 117,272,000 [7]   117,272,000 [7]   136,519,000 [7]
Total Assets 360,176,000 [7]   360,176,000 [7]   462,423,000 [7]
Current Risk Management Liabilities 231,792,000 [7]   231,792,000 [7]   329,307,000 [7]
Long-term Risk Management Liabilities 96,861,000 [7]   96,861,000 [7]   112,454,000 [7]
Total Liabilities 328,653,000 [7]   328,653,000 [7]   441,761,000 [7]
Total MTM Derivative Contract Net Assets (Liabilities) 31,523,000 [7]   31,523,000 [7]   20,662,000 [7]
Commodity [Member] | Risk Management Contracts [Member] | Public Service Co Of Oklahoma [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets 4,868,000 [7]   4,868,000 [7]   6,980,000 [7]
Long-term Risk Management Assets 300,000 [7]   300,000 [7]   914,000 [7]
Total Assets 5,168,000 [7]   5,168,000 [7]   7,894,000 [7]
Current Risk Management Liabilities 9,435,000 [7]   9,435,000 [7]   7,665,000 [7]
Long-term Risk Management Liabilities 1,230,000 [7]   1,230,000 [7]   1,930,000 [7]
Total Liabilities 10,665,000 [7]   10,665,000 [7]   9,595,000 [7]
Total MTM Derivative Contract Net Assets (Liabilities) (5,497,000) [7]   (5,497,000) [7]   (1,701,000) [7]
Commodity [Member] | Risk Management Contracts [Member] | Southwestern Electric Power Co [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets 7,888,000 [7]   7,888,000 [7]   6,327,000 [7]
Long-term Risk Management Assets 467,000 [7]   467,000 [7]   818,000 [7]
Total Assets 8,355,000 [7]   8,355,000 [7]   7,145,000 [7]
Current Risk Management Liabilities 11,369,000 [7]   11,369,000 [7]   11,062,000 [7]
Long-term Risk Management Liabilities 425,000 [7]   425,000 [7]   757,000 [7]
Total Liabilities 11,794,000 [7]   11,794,000 [7]   11,819,000 [7]
Total MTM Derivative Contract Net Assets (Liabilities) (3,439,000) [7]   (3,439,000) [7]   (4,674,000) [7]
Commodity [Member] | Hedging Contracts [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets 36,000,000 [7]   36,000,000 [7]   24,000,000 [7]
Long-term Risk Management Assets 12,000,000 [7]   12,000,000 [7]   15,000,000 [7]
Total Assets 48,000,000 [7]   48,000,000 [7]   39,000,000 [7]
Current Risk Management Liabilities 35,000,000 [7]   35,000,000 [7]   29,000,000 [7]
Long-term Risk Management Liabilities 12,000,000 [7]   12,000,000 [7]   15,000,000 [7]
Total Liabilities 47,000,000 [7]   47,000,000 [7]   44,000,000 [7]
Total MTM Derivative Contract Net Assets (Liabilities) 1,000,000 [7]   1,000,000 [7]   (5,000,000) [7]
Commodity [Member] | Hedging Contracts [Member] | Appalachian Power Co [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets 1,307,000 [7]   1,307,000 [7]   1,040,000 [7]
Long-term Risk Management Assets 291,000 [7]   291,000 [7]   90,000 [7]
Total Assets 1,598,000 [7]   1,598,000 [7]   1,130,000 [7]
Current Risk Management Liabilities 1,757,000 [7]   1,757,000 [7]   2,767,000 [7]
Long-term Risk Management Liabilities 419,000 [7]   419,000 [7]   350,000 [7]
Total Liabilities 2,176,000 [7]   2,176,000 [7]   3,117,000 [7]
Total MTM Derivative Contract Net Assets (Liabilities) (578,000) [7]   (578,000) [7]   (1,987,000) [7]
Commodity [Member] | Hedging Contracts [Member] | Indiana Michigan Power Co [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets 882,000 [7]   882,000 [7]   667,000 [7]
Long-term Risk Management Assets 199,000 [7]   199,000 [7]   58,000 [7]
Total Assets 1,081,000 [7]   1,081,000 [7]   725,000 [7]
Current Risk Management Liabilities 1,204,000 [7]   1,204,000 [7]   1,747,000 [7]
Long-term Risk Management Liabilities 287,000 [7]   287,000 [7]   224,000 [7]
Total Liabilities 1,491,000 [7]   1,491,000 [7]   1,971,000 [7]
Total MTM Derivative Contract Net Assets (Liabilities) (410,000) [7]   (410,000) [7]   (1,246,000) [7]
Commodity [Member] | Hedging Contracts [Member] | Ohio Power Co [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets 1,827,000 [7]   1,827,000 [7]   1,409,000 [7]
Long-term Risk Management Assets 410,000 [7]   410,000 [7]   122,000 [7]
Total Assets 2,237,000 [7]   2,237,000 [7]   1,531,000 [7]
Current Risk Management Liabilities 2,477,000 [7]   2,477,000 [7]   3,712,000 [7]
Long-term Risk Management Liabilities 591,000 [7]   591,000 [7]   474,000 [7]
Total Liabilities 3,068,000 [7]   3,068,000 [7]   4,186,000 [7]
Total MTM Derivative Contract Net Assets (Liabilities) (831,000) [7]   (831,000) [7]   (2,655,000) [7]
Commodity [Member] | Hedging Contracts [Member] | Public Service Co Of Oklahoma [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets 54,000 [7]   54,000 [7]   0 [7]
Long-term Risk Management Assets 4,000 [7]   4,000 [7]   0 [7]
Total Assets 58,000 [7]   58,000 [7]   0 [7]
Current Risk Management Liabilities 13,000 [7]   13,000 [7]   107,000 [7]
Long-term Risk Management Liabilities 5,000 [7]   5,000 [7]   0 [7]
Total Liabilities 18,000 [7]   18,000 [7]   107,000 [7]
Total MTM Derivative Contract Net Assets (Liabilities) 40,000 [7]   40,000 [7]   (107,000) [7]
Commodity [Member] | Hedging Contracts [Member] | Southwestern Electric Power Co [Member]
          
Fair Value of Derivative Instruments          
Current Risk Management Assets 51,000 [7]   51,000 [7]   0 [7]
Long-term Risk Management Assets 4,000 [7]   4,000 [7]   0 [7]
Total Assets 55,000 [7]   55,000 [7]   0 [7]
Current Risk Management Liabilities 12,000 [7]   12,000 [7]   97,000 [7]
Long-term Risk Management Liabilities 6,000 [7]   6,000 [7]   0 [7]
Total Liabilities 18,000 [7]   18,000 [7]   97,000 [7]
Total MTM Derivative Contract Net Assets (Liabilities) 37,000 [7]   37,000 [7]   (97,000) [7]
Utility Operations Revenues [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 5,000,000 8,000,000 19,000,000 46,000,000  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 1,000,000 0 3,000,000  
Utility Operations Revenues [Member] | Interest Rate and Foreign Currency [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Utility Operations Revenues [Member] | Commodity [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 1,000,000 0 3,000,000  
Electric Generation, Transmission and Distribution Revenues [Member] | Appalachian Power Co [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 378,000 960,000 (548,000) 3,659,000  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income (4,000) 84,000 (7,000) 255,000  
Electric Generation, Transmission and Distribution Revenues [Member] | Indiana Michigan Power Co [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 3,814,000 3,094,000 9,206,000 12,211,000  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income (10,000) 167,000 (19,000) 553,000  
Electric Generation, Transmission and Distribution Revenues [Member] | Ohio Power Co [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 87,000 4,652,000 11,118,000 26,806,000  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income (23,000) 461,000 (47,000) 1,495,000  
Electric Generation, Transmission and Distribution Revenues [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 71,000 (530,000) 231,000 128,000  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Electric Generation, Transmission and Distribution Revenues [Member] | Southwestern Electric Power Co [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 174,000 (186,000) 426,000 340,000  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Electric Generation, Transmission and Distribution Revenues [Member] | Commodity [Member] | Appalachian Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income (4,000) 84,000 (7,000) 255,000  
Electric Generation, Transmission and Distribution Revenues [Member] | Commodity [Member] | Indiana Michigan Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income (10,000) 167,000 (19,000) 553,000  
Electric Generation, Transmission and Distribution Revenues [Member] | Commodity [Member] | Ohio Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income (23,000) 461,000 (47,000) 1,495,000  
Electric Generation, Transmission and Distribution Revenues [Member] | Commodity [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Electric Generation, Transmission and Distribution Revenues [Member] | Commodity [Member] | Southwestern Electric Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Sales to AEP Affiliates [Member] | Appalachian Power Co [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 0 103,000 0 136,000  
Sales to AEP Affiliates [Member] | Indiana Michigan Power Co [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 0 58,000 0 81,000  
Sales to AEP Affiliates [Member] | Ohio Power Co [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 0 126,000 0 171,000  
Sales to AEP Affiliates [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 0 2,000 0 2,000  
Sales to AEP Affiliates [Member] | Southwestern Electric Power Co [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 0 2,000 0 2,000  
Other Revenues [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 20,000,000 6,000,000 28,000,000 21,000,000  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income (1,000,000) (1,000,000) (4,000,000) (3,000,000)  
Other Revenues [Member] | Interest Rate and Foreign Currency [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Other Revenues [Member] | Commodity [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income (1,000,000) (1,000,000) (4,000,000) (3,000,000)  
Fuel and Other Consumables Used for Electric Generation [Member] | Appalachian Power Co [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 0 0 0 0  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Fuel and Other Consumables Used for Electric Generation [Member] | Indiana Michigan Power Co [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 0 0 0 0  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Fuel and Other Consumables Used for Electric Generation [Member] | Ohio Power Co [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 0 (2,000) 0 (2,000)  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Fuel and Other Consumables Used for Electric Generation [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 0 0 0 0  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Fuel and Other Consumables Used for Electric Generation [Member] | Southwestern Electric Power Co [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 0 0 0 0  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Fuel and Other Consumables Used for Electric Generation [Member] | Commodity [Member] | Appalachian Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Fuel and Other Consumables Used for Electric Generation [Member] | Commodity [Member] | Indiana Michigan Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Fuel and Other Consumables Used for Electric Generation [Member] | Commodity [Member] | Ohio Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Fuel and Other Consumables Used for Electric Generation [Member] | Commodity [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Fuel and Other Consumables Used for Electric Generation [Member] | Commodity [Member] | Southwestern Electric Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Purchased Electricity for Resale [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 (2,000,000) 13,000,000 (3,000,000)  
Purchased Electricity for Resale [Member] | Appalachian Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 35,000 (70,000) 411,000 (24,000)  
Purchased Electricity for Resale [Member] | Indiana Michigan Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 88,000 (148,000) 1,074,000 (46,000)  
Purchased Electricity for Resale [Member] | Ohio Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 221,000 (402,000) 2,806,000 (127,000)  
Purchased Electricity for Resale [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Purchased Electricity for Resale [Member] | Southwestern Electric Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Purchased Electricity for Resale [Member] | Interest Rate and Foreign Currency [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Purchased Electricity for Resale [Member] | Commodity [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 (2,000,000) 13,000,000 (3,000,000)  
Purchased Electricity for Resale [Member] | Commodity [Member] | Appalachian Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 35,000 (70,000) 411,000 (24,000)  
Purchased Electricity for Resale [Member] | Commodity [Member] | Indiana Michigan Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 88,000 (148,000) 1,074,000 (46,000)  
Purchased Electricity for Resale [Member] | Commodity [Member] | Ohio Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 221,000 (402,000) 2,806,000 (127,000)  
Purchased Electricity for Resale [Member] | Commodity [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Purchased Electricity for Resale [Member] | Commodity [Member] | Southwestern Electric Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Other Operation Expense [Member] | Appalachian Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income (4,000) (32,000) (20,000) (76,000)  
Other Operation Expense [Member] | Indiana Michigan Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income (1,000) (22,000) (11,000) (59,000)  
Other Operation Expense [Member] | Ohio Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income (6,000) (50,000) (30,000) (133,000)  
Other Operation Expense [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 (28,000) (11,000) (75,000)  
Other Operation Expense [Member] | Southwestern Electric Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 1,000 (28,000) (8,000) (74,000)  
Other Operation Expense [Member] | Interest Rate and Foreign Currency [Member] | Appalachian Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Other Operation Expense [Member] | Interest Rate and Foreign Currency [Member] | Indiana Michigan Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Other Operation Expense [Member] | Interest Rate and Foreign Currency [Member] | Ohio Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Other Operation Expense [Member] | Interest Rate and Foreign Currency [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Other Operation Expense [Member] | Interest Rate and Foreign Currency [Member] | Southwestern Electric Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Other Operation Expense [Member] | Commodity [Member] | Appalachian Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income (4,000) (32,000) (20,000) (76,000)  
Other Operation Expense [Member] | Commodity [Member] | Indiana Michigan Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income (1,000) (22,000) (11,000) (59,000)  
Other Operation Expense [Member] | Commodity [Member] | Ohio Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income (6,000) (50,000) (30,000) (133,000)  
Other Operation Expense [Member] | Commodity [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 (28,000) (11,000) (75,000)  
Other Operation Expense [Member] | Commodity [Member] | Southwestern Electric Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 1,000 (28,000) (8,000) (74,000)  
Maintenance Expense [Member] | Appalachian Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 12,000 (51,000) 3,000 (141,000)  
Maintenance Expense [Member] | Indiana Michigan Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 4,000 (21,000) 0 (53,000)  
Maintenance Expense [Member] | Ohio Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 7,000 (46,000) (3,000) (116,000)  
Maintenance Expense [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 5,000 (20,000) 3,000 (49,000)  
Maintenance Expense [Member] | Southwestern Electric Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 4,000 (21,000) 1,000 (53,000)  
Maintenance Expense [Member] | Commodity [Member] | Appalachian Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 12,000 (51,000) 3,000 (141,000)  
Maintenance Expense [Member] | Commodity [Member] | Indiana Michigan Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 4,000 (21,000) 0 (53,000)  
Maintenance Expense [Member] | Commodity [Member] | Ohio Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 7,000 (46,000) (3,000) (116,000)  
Maintenance Expense [Member] | Commodity [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 5,000 (20,000) 3,000 (49,000)  
Maintenance Expense [Member] | Commodity [Member] | Southwestern Electric Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 4,000 (21,000) 1,000 (53,000)  
Depreciation and Amortization Expense [Member] | Appalachian Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Depreciation and Amortization Expense [Member] | Indiana Michigan Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Depreciation and Amortization Expense [Member] | Ohio Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 1,000 1,000 3,000 3,000  
Depreciation and Amortization Expense [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Depreciation and Amortization Expense [Member] | Southwestern Electric Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Depreciation and Amortization Expense [Member] | Interest Rate and Foreign Currency [Member] | Appalachian Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Depreciation and Amortization Expense [Member] | Interest Rate and Foreign Currency [Member] | Indiana Michigan Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Depreciation and Amortization Expense [Member] | Interest Rate and Foreign Currency [Member] | Ohio Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 1,000 1,000 3,000 3,000  
Depreciation and Amortization Expense [Member] | Interest Rate and Foreign Currency [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Depreciation and Amortization Expense [Member] | Interest Rate and Foreign Currency [Member] | Southwestern Electric Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Interest Expense [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 1,000,000 1,000,000 3,000,000 3,000,000  
Interest Expense [Member] | Appalachian Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 261,000 269,000 799,000 911,000  
Interest Expense [Member] | Indiana Michigan Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 149,000 252,000 447,000 755,000  
Interest Expense [Member] | Ohio Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income (341,000) (340,000) (1,023,000) (1,022,000)  
Interest Expense [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income (190,000) (190,000) (569,000) (522,000)  
Interest Expense [Member] | Southwestern Electric Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 567,000 207,000 2,000,000 621,000  
Interest Expense [Member] | Interest Rate and Foreign Currency [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 1,000,000 1,000,000 3,000,000 3,000,000  
Interest Expense [Member] | Interest Rate and Foreign Currency [Member] | Appalachian Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 261,000 269,000 799,000 911,000  
Interest Expense [Member] | Interest Rate and Foreign Currency [Member] | Indiana Michigan Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 149,000 252,000 447,000 755,000  
Interest Expense [Member] | Interest Rate and Foreign Currency [Member] | Ohio Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income (341,000) (340,000) (1,023,000) (1,022,000)  
Interest Expense [Member] | Interest Rate and Foreign Currency [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income (190,000) (190,000) (569,000) (522,000)  
Interest Expense [Member] | Interest Rate and Foreign Currency [Member] | Southwestern Electric Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 567,000 207,000 2,000,000 621,000  
Interest Expense [Member] | Commodity [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income 0 0 0 0  
Property, Plant and Equipment [Member] | Appalachian Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 3,000 (51,000) (9,000) (131,000)  
Property, Plant and Equipment [Member] | Indiana Michigan Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 1,000 (28,000) (6,000) (67,000)  
Property, Plant and Equipment [Member] | Ohio Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 1,000 (63,000) (15,000) (161,000)  
Property, Plant and Equipment [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 5,000 (32,000) 1,000 (84,000)  
Property, Plant and Equipment [Member] | Southwestern Electric Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 3,000 (27,000) (3,000) (67,000)  
Property, Plant and Equipment [Member] | Commodity [Member] | Appalachian Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 3,000 (51,000) (9,000) (131,000)  
Property, Plant and Equipment [Member] | Commodity [Member] | Indiana Michigan Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 1,000 (28,000) (6,000) (67,000)  
Property, Plant and Equipment [Member] | Commodity [Member] | Ohio Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 1,000 (63,000) (15,000) (161,000)  
Property, Plant and Equipment [Member] | Commodity [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 5,000 (32,000) 1,000 (84,000)  
Property, Plant and Equipment [Member] | Commodity [Member] | Southwestern Electric Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 3,000 (27,000) (3,000) (67,000)  
Regulatory Assets [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 2,000,000 [8] (3,000,000) [8] (35,000,000) [8] (3,000,000) [8]  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 0 [8] 0 [8] 2,000,000 [8] 1,000,000 [8]  
Regulatory Assets [Member] | Appalachian Power Co [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts (138,000) [8] 139,000 [8] (6,133,000) [8] 373,000 [8]  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 114,000 [8] 53,000 [8] 1,515,000 [8] 869,000 [8]  
Regulatory Assets [Member] | Indiana Michigan Power Co [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts (1,213,000) [8] 71,000 [8] (7,228,000) [8] 186,000 [8]  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 20,000 [8] 5,000 [8] 265,000 [8] 128,000 [8]  
Regulatory Assets [Member] | Ohio Power Co [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 3,000,000 [8] (2,846,000) [8] (9,026,000) [8] (7,028,000) [8]  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 0 [8] 0 [8] 0 [8] 0 [8]  
Regulatory Assets [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 598,000 [8] (264,000) [8] (5,360,000) [8] 285,000 [8]  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 0 [8] 0 [8] 0 [8] 0 [8]  
Regulatory Assets [Member] | Southwestern Electric Power Co [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 115,000 [8] (219,000) [8] (6,977,000) [8] 2,975,000 [8]  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 0 [8] 0 [8] 0 [8] 0 [8]  
Regulatory Assets [Member] | Interest Rate and Foreign Currency [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 0 [8] 0 [8] 0 [8] 0 [8]  
Regulatory Assets [Member] | Commodity [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 0 [8] 0 [8] 2,000,000 [8] 1,000,000 [8]  
Regulatory Assets [Member] | Commodity [Member] | Appalachian Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 114,000 [8] 53,000 [8] 1,515,000 [8] 869,000 [8]  
Regulatory Assets [Member] | Commodity [Member] | Indiana Michigan Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 20,000 [8] 5,000 [8] 265,000 [8] 128,000 [8]  
Regulatory Assets [Member] | Commodity [Member] | Ohio Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 0 [8] 0 [8] 0 [8] 0 [8]  
Regulatory Assets [Member] | Commodity [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 0 [8] 0 [8] 0 [8] 0 [8]  
Regulatory Assets [Member] | Commodity [Member] | Southwestern Electric Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 0 [8] 0 [8] 0 [8] 0 [8]  
Regulatory Liabilities [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts (14,000,000) [8] (2,000,000) [8] 12,000,000 [8] 8,000,000 [8]  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 0 [8] 0 [8] 0 [8] 0 [8]  
Regulatory Liabilities [Member] | Appalachian Power Co [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts (1,672,000) [8] (1,058,000) [8] 8,166,000 [8] 9,827,000 [8]  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 0 [8] 0 [8] 0 [8] 0 [8]  
Regulatory Liabilities [Member] | Indiana Michigan Power Co [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts (5,267,000) [8] (2,566,000) [8] 1,851,000 [8] (4,230,000) [8]  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 0 [8] 0 [8] 0 [8] 0 [8]  
Regulatory Liabilities [Member] | Ohio Power Co [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts (6,788,000) [8] 26,000 [8] 390,000 [8] (105,000) [8]  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 0 [8] 0 [8] 0 [8] 0 [8]  
Regulatory Liabilities [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 2,000 [8] 1,930,000 [8] 3,000 [8] 2,509,000 [8]  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 0 [8] 0 [8] 0 [8] 0 [8]  
Regulatory Liabilities [Member] | Southwestern Electric Power Co [Member]
          
Amount of Gain (Loss) Recognized on Risk Management Contracts          
Amount of Gain (Loss) Recognized on Risk Management Contracts 11,000 [8] 174,000 [8] 6,000 [8] 58,000 [8]  
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 0 [8] 0 [8] 0 [8] 0 [8]  
Regulatory Liabilities [Member] | Interest Rate and Foreign Currency [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 0 [8] 0 [8] 0 [8] 0 [8]  
Regulatory Liabilities [Member] | Commodity [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 0 [8] 0 [8] 0 [8] 0 [8]  
Regulatory Liabilities [Member] | Commodity [Member] | Appalachian Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 0 [8] 0 [8] 0 [8] 0 [8]  
Regulatory Liabilities [Member] | Commodity [Member] | Indiana Michigan Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 0 [8] 0 [8] 0 [8] 0 [8]  
Regulatory Liabilities [Member] | Commodity [Member] | Ohio Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 0 [8] 0 [8] 0 [8] 0 [8]  
Regulatory Liabilities [Member] | Commodity [Member] | Public Service Co Of Oklahoma [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet 0 [8] 0 [8] 0 [8] 0 [8]  
Regulatory Liabilities [Member] | Commodity [Member] | Southwestern Electric Power Co [Member]
          
Amount of (Gain) or Loss Reclassified from AOCI to Statement of Income/within Balance Sheet:          
Amount of (Gain) or Loss Reclassified from AOCI within Balance Sheet $ 0 [8] $ 0 [8] $ 0 [8] $ 0 [8]  
[1] Hedging Assets and Hedging Liabilities are included in Risk Management Assets and Liabilities on the condensed balance sheets.
[2] Amounts in ''Other'' column primarily represent counterparty netting of risk management and hedging contracts and associated cash collateral under the accounting guidance for ''Derivatives and Hedging.''
[3] The September 30, 2012 maturity of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), is as follows: Level 1 matures $12 million in periods 2013-2015 and ($7) million in periods 2016-2018; Level 2 matures $59 million in periods 2013-2015, $14 million in periods 2016-2017 and $9 million in periods 2018-2030; Level 3 matures $7 million in 2012, $35 million in periods 2013-2015, $31 million in periods 2016-2017 and $29 million in periods 2018-2030. Risk management commodity contracts are substantially comprised of power contracts.
[4] The December 31, 2011 maturity of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), is as follows: Level 1 matures $3 million in 2012, $7 million in periods 2013-2015 and ($6) million in periods 2016-2018; Level 2 matures $21 million in 2012, $50 million in periods 2013-2015, $11 million in periods 2016-2017 and $8 million in periods 2018-2030; Level 3 matures ($19) million in 2012, $44 million in periods 2013-2015, $18 million in periods 2016-2017 and $26 million in periods 2018-2030. Risk management commodity contracts are substantially comprised of power contracts.
[5] Substantially comprised of power contracts for APCo, I&M and OPCo and coal contracts for PSO and SWEPCo.
[6] Amounts include counterparty netting of risk management and hedging contracts and associated cash collateral in accordance with the accounting guidance for "Derivatives and Hedging." Amounts also include de-designated risk management contracts.
[7] Derivative instruments within these categories are reported gross. These instruments are subject to master netting agreements and are presented on the condensed balance sheets on a net basis in accordance with the accounting guidance for "Derivatives and Hedging."
[8] Represents realized and unrealized gains and losses subject to regulatory accounting treatment recorded as either current or noncurrent on the condensed balance sheets.