Revenue from Contracts with Customers (Details) - USD ($) $ in Millions		3 Months Ended				9 Months Ended
		Sep. 30, 2020		Sep. 30, 2019		Sep. 30, 2020		Sep. 30, 2019		Dec. 31, 2019
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		$ 4,066.4		$ 4,315.0		$ 11,307.9		$ 11,945.4
Total Revenues		4,066.4		4,315.0		11,307.9		11,945.4
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		839.7				839.7
Revenue Textuals [Abstract]
Revenue from Related Parties		0.0		0.0		0.0		0.0
2020 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		263.8				263.8
2021-2022 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		188.3				188.3
2023-2024 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		164.2				164.2
2024 and Forward [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		223.4				223.4
Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		3,116.7		3,278.2		8,664.6		9,086.1
Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		1,648.1		1,648.2		4,399.7		4,406.7
Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		818.9		903.4		2,316.0		2,530.6
Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		598.3		666.8		1,798.6		1,979.9
Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		51.4		59.8		150.3		168.9
Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		872.3		931.0		2,436.4		2,677.5
Wholesale Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		188.9		274.2	[1]	553.5		838.4	[2]
Wholesale Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		244.3	[3]	240.9	[4]	786.0	[5]	750.1	[6]
Renewable Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		15.5	[7]	20.1	[8]	49.5	[9]	39.5	[10]
Retail, Trading and Marketing Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		423.6	[11]	395.8	[8]	1,047.4	[12]	1,049.5	[10]
Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		70.2	[7]	102.9	[8]	224.3	[9]	240.3	[10]
Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		4,059.2		4,312.1		11,325.3		12,003.9
Alternative and Other [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		7.2		2.9		(17.4)		(58.5)
Alternative [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		12.7	[7]	(11.4)	[8]	(30.7)	[9]	(113.1)	[10]
Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		77.4		67.6		220.4		205.3
Total Revenues		(5.5)	[7]	14.3	[8]	13.3	[9]	54.6	[10]
AEP Texas Inc. [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		432.0		489.3		1,257.1		1,318.0
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		108.2				108.2
Revenue Textuals [Abstract]
Revenue from Related Parties		41.4		42.7		89.4		125.1
Affiliated Companies		22.0				22.0				$ 10.1
AEP Texas Inc. [Member] | 2020 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		108.2				108.2
AEP Texas Inc. [Member] | 2021-2022 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
AEP Texas Inc. [Member] | 2023-2024 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
AEP Texas Inc. [Member] | 2024 and Forward [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
AEP Texas Inc. [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		275.1		342.3		846.7		890.9
AEP Texas Inc. [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		165.3		192.0		447.8		454.9
AEP Texas Inc. [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		78.0		110.6		285.2		314.5
AEP Texas Inc. [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		24.9		32.2		91.4		98.8
AEP Texas Inc. [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		6.9		7.5		22.3		22.7
AEP Texas Inc. [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		101.8		97.7		290.4		282.0
AEP Texas Inc. [Member] | Wholesale Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0	[13]	0.0	[14]	0.0	[15]	0.0	[16]
AEP Texas Inc. [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		101.8	[17]	97.7	[18]	290.4	[19]	282.0	[20]
AEP Texas Inc. [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		15.2	[21]	8.2	[22]	33.4	[23]	22.9	[24]
AEP Texas Inc. [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		392.1		448.2		1,170.5		1,195.8
AEP Texas Inc. [Member] | Alternative and Other [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		39.9		41.1		86.6		122.2
AEP Texas Inc. [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		(0.7)	[25]	(0.7)	[26]	(0.3)	[27]	(0.4)	[28]
AEP Texas Inc. [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.5		1.2		2.5		2.6
Total Revenues		40.6	[25]	41.8	[26]	86.9	[27]	122.6	[28]
AEP Transmission Co [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		304.1		259.7		837.8		770.1
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		274.8				274.8
Revenue Textuals [Abstract]
Revenue from Related Parties		241.2		205.7		652.6		608.0
Affiliated Companies		81.1				81.1				66.1
AEP Transmission Co [Member] | Short-term Contract with Customer [Member]
Revenue Textuals [Abstract]
Affiliated Companies		79.9				79.9				65.9
AEP Transmission Co [Member] | 2020 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		274.8				274.8
AEP Transmission Co [Member] | 2021-2022 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
AEP Transmission Co [Member] | 2023-2024 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
AEP Transmission Co [Member] | 2024 and Forward [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
AEP Transmission Co [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
AEP Transmission Co [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
AEP Transmission Co [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
AEP Transmission Co [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
AEP Transmission Co [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
AEP Transmission Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		305.7		256.4		902.6		775.3
AEP Transmission Co [Member] | Wholesale Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0	[13]	0.0	[14]	0.0	[15]	0.0	[16]
AEP Transmission Co [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		305.7	[17]	256.4	[18]	902.6	[19]	775.3	[20]
Revenue Textuals [Abstract]
Revenue from Related Parties		243.0		194.0		715.0		587.0
AEP Transmission Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		3.0	[21]	4.5	[22]	17.5	[23]	12.6	[24]
AEP Transmission Co [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		308.7		260.9		920.1		787.9
AEP Transmission Co [Member] | Alternative and Other [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		(4.6)		(1.2)		(82.3)		(17.8)
AEP Transmission Co [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		(4.6)	[25]	(1.2)	[26]	(82.3)	[27]	(17.8)	[28]
AEP Transmission Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.6		0.0
Total Revenues		0.0	[25]	0.0	[26]	0.0	[27]	0.0	[28]
Appalachian Power Co [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		735.7		755.5		2,122.6		2,204.1
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		111.4				111.4
Revenue Textuals [Abstract]
Revenue from Related Parties		44.4		56.6		124.9		154.6
Affiliated Companies		60.2				60.2				64.3
Appalachian Power Co [Member] | Short-term Contract with Customer [Member]
Revenue Textuals [Abstract]
Affiliated Companies		49.3				49.3				47.3
Appalachian Power Co [Member] | 2020 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		40.1				40.1
Appalachian Power Co [Member] | 2021-2022 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		33.1				33.1
Appalachian Power Co [Member] | 2023-2024 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		26.6				26.6
Appalachian Power Co [Member] | 2024 and Forward [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		11.6				11.6
Appalachian Power Co [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		619.6		633.6		1,810.9		1,867.0
Appalachian Power Co [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		324.2		315.7		954.4		944.7
Appalachian Power Co [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		138.4		147.2		390.6		421.5
Appalachian Power Co [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		139.4		152.2		415.0		444.3
Appalachian Power Co [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		17.6		18.5		50.9		56.5
Appalachian Power Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		101.1		96.6		276.8		277.7
Appalachian Power Co [Member] | Wholesale Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		70.3	[13]	70.4	[14]	185.3	[15]	200.1	[16]
Appalachian Power Co [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		30.8	[17]	26.2	[18]	91.5	[19]	77.6	[20]
Appalachian Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		16.1	[21]	18.7	[22]	46.8	[23]	48.2	[24]
Appalachian Power Co [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		736.8		748.9		2,134.5		2,192.9
Appalachian Power Co [Member] | Alternative and Other [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		(1.1)		6.6		(11.9)		11.2
Appalachian Power Co [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		(1.1)	[25]	6.6	[26]	(11.9)	[27]	11.2	[28]
Appalachian Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		2.4		2.2		7.8		8.2
Total Revenues		0.0	[25]	0.0	[26]	0.0	[27]	0.0	[28]
Appalachian Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenue Textuals [Abstract]
Revenue from Related Parties		28.0		32.0		85.0		96.0
Indiana Michigan Power Co [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		586.7		611.1		1,703.6		1,768.5
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		32.8				32.8
Revenue Textuals [Abstract]
Revenue from Related Parties		1.3		2.7		9.1		7.3
Affiliated Companies		43.5				43.5				53.7
Indiana Michigan Power Co [Member] | Short-term Contract with Customer [Member]
Revenue Textuals [Abstract]
Affiliated Companies		30.5				30.5				37.1
Indiana Michigan Power Co [Member] | 2020 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		8.6				8.6
Indiana Michigan Power Co [Member] | 2021-2022 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		10.9				10.9
Indiana Michigan Power Co [Member] | 2023-2024 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		8.8				8.8
Indiana Michigan Power Co [Member] | 2024 and Forward [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		4.5				4.5
Indiana Michigan Power Co [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		499.7		477.1		1,400.0		1,347.5
Indiana Michigan Power Co [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		222.6		198.2		610.8		558.8
Indiana Michigan Power Co [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		135.8		138.3		376.0		371.4
Indiana Michigan Power Co [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		139.7		138.7		408.2		411.9
Indiana Michigan Power Co [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		1.6		1.9		5.0		5.4
Indiana Michigan Power Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		68.9		108.5		237.6		346.2
Indiana Michigan Power Co [Member] | Wholesale Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		61.5	[13]	102.1	[14]	215.5	[15]	327.4	[16]
Indiana Michigan Power Co [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		7.4	[17]	6.4	[18]	22.1	[19]	18.8	[20]
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		17.7	[21]	26.6	[22]	60.6	[23]	76.2	[24]
Indiana Michigan Power Co [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		586.3		612.2		1,698.2		1,769.9
Indiana Michigan Power Co [Member] | Alternative and Other [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		0.4		(1.1)		5.4		(1.4)
Indiana Michigan Power Co [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		0.4	[25]	(1.1)	[26]	5.4	[27]	(1.4)	[28]
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		1.2		3.1		3.7		7.6
Total Revenues		0.0	[25]	0.0	[26]	0.0	[27]	0.0	[28]
Revenue Textuals [Abstract]
Revenue from Related Parties		15.0		20.0		49.0		57.0
Ohio Power Co [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		741.0		710.6		2,071.7		2,154.0
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		21.8				21.8
Revenue Textuals [Abstract]
Revenue from Related Parties		8.3		9.0		33.0		18.2
Affiliated Companies		61.0				61.0				59.3
Ohio Power Co [Member] | Short-term Contract with Customer [Member]
Revenue Textuals [Abstract]
Affiliated Companies		36.5				36.5				33.9
Ohio Power Co [Member] | 2020 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		16.5				16.5
Ohio Power Co [Member] | 2021-2022 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		5.3				5.3
Ohio Power Co [Member] | 2023-2024 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
Ohio Power Co [Member] | 2024 and Forward [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
Ohio Power Co [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		682.8		646.3		1,878.8		1,972.9
Ohio Power Co [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		429.4		395.6		1,162.6		1,155.5
Ohio Power Co [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		181.2		180.5		507.3		573.7
Ohio Power Co [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		69.1		67.1		199.1		233.9
Ohio Power Co [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		3.1		3.1		9.8		9.8
Ohio Power Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		17.2		13.7		51.1		42.0
Ohio Power Co [Member] | Wholesale Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0	[13]	0.0	[14]	0.0	[15]	0.0	[16]
Ohio Power Co [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		17.2	[17]	13.7	[18]	51.1	[19]	42.0	[20]
Ohio Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		27.6	[21]	41.0	[22]	78.9	[23]	113.3	[24]
Ohio Power Co [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		727.6		701.0		2,008.8		2,128.2
Ohio Power Co [Member] | Alternative and Other [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		13.4		9.6		62.9		25.8
Ohio Power Co [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		10.0	[25]	12.4	[26]	49.6	[27]	22.0	[28]
Ohio Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		2.3		3.0		7.3		8.4
Total Revenues		3.4	[25]	(2.8)	[26]	13.3	[27]	3.8	[28]
Public Service Co Of Oklahoma [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		382.2		493.0		988.1		1,173.9
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		3.8				3.8
Revenue Textuals [Abstract]
Revenue from Related Parties		1.4		1.3		3.8		5.0
Affiliated Companies		27.1				27.1				20.6
Public Service Co Of Oklahoma [Member] | Short-term Contract with Customer [Member]
Revenue Textuals [Abstract]
Affiliated Companies		11.0				11.0				9.7
Public Service Co Of Oklahoma [Member] | 2020 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		3.8				3.8
Public Service Co Of Oklahoma [Member] | 2021-2022 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
Public Service Co Of Oklahoma [Member] | 2023-2024 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
Public Service Co Of Oklahoma [Member] | 2024 and Forward [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
Public Service Co Of Oklahoma [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		363.6		463.1		933.3		1,125.1
Public Service Co Of Oklahoma [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		195.8		231.9		463.5		519.6
Public Service Co Of Oklahoma [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		94.4		122.2		247.8		304.3
Public Service Co Of Oklahoma [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		55.0		84.1		170.8		238.1
Public Service Co Of Oklahoma [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		18.4		24.9		51.2		63.1
Public Service Co Of Oklahoma [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		14.3		17.7		30.1		57.4
Public Service Co Of Oklahoma [Member] | Wholesale Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		5.8	[13]	21.1	[14]	9.9	[15]	35.5	[16]
Public Service Co Of Oklahoma [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		8.5	[17]	(3.4)	[18]	20.2	[19]	21.9	[20]
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		4.8	[21]	5.1	[22]	23.2	[23]	16.7	[24]
Public Service Co Of Oklahoma [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		382.7		485.9		986.6		1,199.2
Public Service Co Of Oklahoma [Member] | Alternative and Other [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		(0.5)		7.1		1.5		(25.3)
Public Service Co Of Oklahoma [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		(0.5)	[25]	7.1	[26]	1.5	[27]	(25.3)	[28]
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		1.0		1.2		8.0		4.6
Total Revenues		0.0	[25]	0.0	[26]	0.0	[27]	0.0	[28]
Southwestern Electric Power Co [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		517.3		545.5		1,318.2		1,342.1
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		10.3				10.3
Revenue Textuals [Abstract]
Revenue from Related Parties		8.5		8.8		33.5		21.6
Affiliated Companies		28.3				28.3				34.5
Southwestern Electric Power Co [Member] | Short-term Contract with Customer [Member]
Revenue Textuals [Abstract]
Affiliated Companies		18.4				18.4				$ 17.6
Southwestern Electric Power Co [Member] | 2020 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		10.3				10.3
Southwestern Electric Power Co [Member] | 2021-2022 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
Southwestern Electric Power Co [Member] | 2023-2024 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
Southwestern Electric Power Co [Member] | 2024 and Forward [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
Southwestern Electric Power Co [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		440.5		461.8		1,102.4		1,138.7
Southwestern Electric Power Co [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		219.4		222.9		498.7		503.7
Southwestern Electric Power Co [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		135.0		144.3		351.2		371.1
Southwestern Electric Power Co [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		83.8		92.3		245.9		257.2
Southwestern Electric Power Co [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		2.3		2.3		6.6		6.7
Southwestern Electric Power Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		71.0		80.7		194.2		230.7
Southwestern Electric Power Co [Member] | Wholesale Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		42.3	[13]	50.7	[14]	106.7	[15]	152.7	[16]
Southwestern Electric Power Co [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		28.7	[17]	30.0	[18]	87.5	[19]	78.0	[20]
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		5.6	[21]	7.0	[22]	21.1	[23]	20.1	[24]
Southwestern Electric Power Co [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		517.1		549.5		1,317.7		1,389.5
Southwestern Electric Power Co [Member] | Alternative and Other [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		0.2		(4.0)		0.5		(47.4)
Southwestern Electric Power Co [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		0.2	[25]	(4.0)	[26]	0.5	[27]	(47.4)	[28]
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.7		0.3		2.4		1.0
Total Revenues		0.0	[25]	0.0	[26]	0.0	[27]	0.0	[28]
Consolidation Eliminations [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
Total Revenues		(374.2)		(348.2)		(1,007.6)		(991.7)
Revenue Textuals [Abstract]
Revenue from Related Parties		(374.2)		(348.2)		(1,007.6)		(991.7)
Consolidation Eliminations [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(0.1)		1.5		(0.5)		0.0
Consolidation Eliminations [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
Consolidation Eliminations [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
Consolidation Eliminations [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(0.1)		1.5		(0.5)		0.0
Consolidation Eliminations [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
Consolidation Eliminations [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(302.0)		(250.9)		(823.6)		(708.6)
Consolidation Eliminations [Member] | Wholesale Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		(34.2)	[1]	0.0		(105.5)	[2]
Consolidation Eliminations [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(276.9)	[3]	(217.2)	[4]	(741.7)	[5]	(603.6)	[6]
Consolidation Eliminations [Member] | Renewable Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(0.3)	[7]	0.0	[8]	(1.2)	[9]	0.5	[10]
Consolidation Eliminations [Member] | Retail, Trading and Marketing Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(24.8)	[11]	0.5	[8]	(80.7)	[12]	0.0	[10]
Consolidation Eliminations [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(43.7)	[7]	(42.2)	[8]	(115.7)	[9]	(113.6)	[10]
Consolidation Eliminations [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(345.8)		(291.6)		(939.8)		(822.2)
Consolidation Eliminations [Member] | Alternative and Other [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		(28.4)		(56.6)		(67.8)		(169.5)
Consolidation Eliminations [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		6.6	[7]	(16.8)	[8]	3.5	[9]	(60.3)	[10]
Consolidation Eliminations [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		(35.0)	[7]	(39.8)	[8]	(71.3)	[9]	(109.2)	[10]
Consolidation Eliminations [Member] | AEP Transmission Co [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
Total Revenues		0.0		0.0		0.0		0.0
Revenue Textuals [Abstract]
Revenue from Related Parties		0.0		0.0		0.0		0.0
Consolidation Eliminations [Member] | AEP Transmission Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers						0.0
Vertically Integrated Utilities [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		2,434.8		2,645.5		6,753.5		7,172.6
Revenue Textuals [Abstract]
Revenue from Related Parties		34.7		46.6		98.1		85.0
Vertically Integrated Utilities [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		2,158.9		2,287.9		5,939.6		6,222.2
Vertically Integrated Utilities [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		1,053.3		1,060.2		2,789.1		2,797.6
Vertically Integrated Utilities [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		559.7		612.5		1,523.6		1,641.2
Vertically Integrated Utilities [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		504.5		566.0		1,508.7		1,647.3
Vertically Integrated Utilities [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		41.4		49.2		118.2		136.1
Vertically Integrated Utilities [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		242.8		309.1		695.8		877.3
Vertically Integrated Utilities [Member] | Wholesale Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		158.4		231.3	[1]	447.4		661.9	[2]
Vertically Integrated Utilities [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		84.4	[3]	77.8	[4]	248.4	[5]	215.4	[6]
Vertically Integrated Utilities [Member] | Renewable Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0	[7]	0.0	[8]	0.0	[9]	0.0	[10]
Vertically Integrated Utilities [Member] | Retail, Trading and Marketing Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0	[11]	0.0	[8]	0.0	[12]	0.0	[10]
Vertically Integrated Utilities [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		34.1	[7]	47.3	[8]	124.1	[9]	128.8	[10]
Vertically Integrated Utilities [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		2,435.8		2,644.3		6,759.5		7,228.3
Vertically Integrated Utilities [Member] | Alternative and Other [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		(1.0)		1.2		(6.0)		(55.7)
Vertically Integrated Utilities [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		(1.0)	[7]	1.2	[8]	(6.0)	[9]	(55.7)	[10]
Vertically Integrated Utilities [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		0.0	[7]	0.0	[8]	0.0	[9]	0.0	[10]
Transmission And Distribution Utilities [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		1,165.3		1,186.6		3,306.7		3,454.3
Revenue Textuals [Abstract]
Revenue from Related Parties		41.2		39.3		98.0		125.6
Transmission And Distribution Utilities [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		957.9		988.8		2,725.5		2,863.9
Transmission And Distribution Utilities [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		594.8		588.0		1,610.6		1,609.1
Transmission And Distribution Utilities [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		259.2		290.9		792.4		889.4
Transmission And Distribution Utilities [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		93.9		99.3		290.4		332.6
Transmission And Distribution Utilities [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		10.0		10.6		32.1		32.8
Transmission And Distribution Utilities [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		119.1		110.9		341.6		324.0
Transmission And Distribution Utilities [Member] | Wholesale Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0	[1]	0.0		0.0	[2]
Transmission And Distribution Utilities [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		119.1	[3]	110.9	[4]	341.6	[5]	324.0	[6]
Transmission And Distribution Utilities [Member] | Renewable Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0	[7]	0.0	[8]	0.0	[9]	0.0	[10]
Transmission And Distribution Utilities [Member] | Retail, Trading and Marketing Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0	[11]	0.0	[8]	0.0	[12]	0.0	[10]
Transmission And Distribution Utilities [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		42.8	[7]	42.9	[8]	112.3	[9]	127.6	[10]
Transmission And Distribution Utilities [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		1,119.8		1,142.6		3,179.4		3,315.5
Transmission And Distribution Utilities [Member] | Alternative and Other [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		45.5		44.0		127.3		138.8
Transmission And Distribution Utilities [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		9.3	[7]	5.1	[8]	49.2	[9]	21.5	[10]
Transmission And Distribution Utilities [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		36.2	[7]	38.9	[8]	78.1	[9]	117.3	[10]
AEP Transmission Holdco [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		317.9		273.0		877.8		808.3
AEP Transmission Holdco [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
AEP Transmission Holdco [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
AEP Transmission Holdco [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
AEP Transmission Holdco [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
AEP Transmission Holdco [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
AEP Transmission Holdco [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		317.7		269.4		937.7		814.3
AEP Transmission Holdco [Member] | Wholesale Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0	[1]	0.0		0.0	[2]
AEP Transmission Holdco [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		317.7	[3]	269.4	[4]	937.7	[5]	814.3	[6]
Revenue Textuals [Abstract]
Revenue from Related Parties		246.0		197.0		725.0		596.0
AEP Transmission Holdco [Member] | Renewable Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0	[7]	0.0	[8]	0.0	[9]	0.0	[10]
AEP Transmission Holdco [Member] | Retail, Trading and Marketing Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0	[11]	0.0	[8]	0.0	[12]	0.0	[10]
AEP Transmission Holdco [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		2.4	[7]	4.5	[8]	17.5	[9]	12.6	[10]
AEP Transmission Holdco [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		320.1		273.9		955.2		826.9
AEP Transmission Holdco [Member] | Alternative and Other [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		(2.2)		(0.9)		(77.4)		(18.6)
AEP Transmission Holdco [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		(2.2)	[7]	(0.9)	[8]	(77.4)	[9]	(18.6)	[10]
AEP Transmission Holdco [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		0.0	[7]	0.0	[8]	0.0	[9]	0.0	[10]
Generation And Marketing [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		490.0		533.7		1,305.5		1,428.2
Revenue Textuals [Abstract]
Revenue from Related Parties		25.2		32.5		82.1		104.4
Generation And Marketing [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
Generation And Marketing [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
Generation And Marketing [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
Generation And Marketing [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
Generation And Marketing [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
Generation And Marketing [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		493.8		492.5		1,290.6		1,370.5
Generation And Marketing [Member] | Wholesale Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		30.5		77.1	[1]	106.1		282.0	[2]
Revenue Textuals [Abstract]
Revenue from Related Parties		19.0		34.0		81.0		105.0
Generation And Marketing [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0	[3]	0.0	[4]	0.0	[5]	0.0	[6]
Generation And Marketing [Member] | Renewable Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		15.8	[7]	20.1	[8]	50.7	[9]	39.0	[10]
Generation And Marketing [Member] | Retail, Trading and Marketing Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		447.5	[11]	395.3	[8]	1,133.8	[12]	1,049.5	[10]
Generation And Marketing [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.7	[7]	14.8	[8]	1.7	[9]	4.5	[10]
Generation And Marketing [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		494.5		507.3		1,292.3		1,375.0
Generation And Marketing [Member] | Alternative and Other [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		(4.5)		26.4		13.2		53.2
Generation And Marketing [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		0.0	[7]	0.0	[8]	0.0	[9]	0.0	[10]
Generation And Marketing [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		(4.5)	[7]	26.4	[8]	13.2	[9]	53.2	[10]
Other Segments [Member]
Disaggregation of Revenue [Abstract]
Total Revenues	[29]	32.6		24.4		72.0		73.7
Revenue Textuals [Abstract]
Revenue from Related Parties	[29]	28.6		22.3		67.3		64.9
Other Segments [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
Other Segments [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
Other Segments [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
Other Segments [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
Other Segments [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
Other Segments [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.9		0.0		(5.7)		0.0
Other Segments [Member] | Wholesale Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0	[1]	0.0		0.0	[2]
Other Segments [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0	[3]	0.0	[4]	0.0	[5]	0.0	[6]
Other Segments [Member] | Renewable Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0	[7]	0.0	[8]	0.0	[9]	0.0	[10]
Other Segments [Member] | Retail, Trading and Marketing Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.9	[11]	0.0	[8]	(5.7)	[12]	0.0	[10]
Other Segments [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		33.9	[7]	35.6	[8]	84.4	[9]	80.4	[10]
Other Segments [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		34.8		35.6		78.7		80.4
Other Segments [Member] | Alternative and Other [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		(2.2)		(11.2)		(6.7)		(6.7)
Other Segments [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Total Revenues		0.0	[7]	0.0	[8]	0.0	[9]	0.0	[10]
Other Segments [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers	[29]	4.0		2.1		4.7		8.8
Total Revenues		$ (2.2)	[7]	$ (11.2)	[8]	$ (6.7)	[9]	$ (6.7)	[10]

[1] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $34 million. The remaining affiliated amounts were immaterial.

[2] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $105 million. The remaining affiliated amounts were immaterial.

[3] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $246 million. The remaining affiliated amounts were immaterial.(b)Amounts include affiliated and nonaffiliated revenues.

[4] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $197 million. The remaining affiliated amounts were immaterial.

[5] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $725 million. The remaining affiliated amounts were immaterial.(b)Amounts include affiliated and nonaffiliated revenues.

[6] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $596 million. The remaining affiliated amounts were immaterial.

[7] Amounts include affiliated and nonaffiliated revenues.

[8] Amounts include affiliated and nonaffiliated revenues.

[9] Amounts include affiliated and nonaffiliated revenues

[10] Amounts include affiliated and nonaffiliated revenues.

[11] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $19 million. The remaining affiliated amounts were immaterial.

[12] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $81 million. The remaining affiliated amounts were immaterial.

[13] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $28 million primarily relating to the PPA with KGPCo. The remaining affiliated amounts were immaterial

[14] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $32 million primarily relating to the PPA with KGPCo. The remaining affiliated amounts were immaterial.

[15] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $85 million primarily relating to the PPA with KGPCo. The remaining affiliated amounts were immaterial.

[16] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $96 million primarily relating to the PPA with KGPCo. The remaining affiliated amounts were immaterial.

[17] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEPTCo was $243 million. The remaining affiliated amounts were immaterial.

[18] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEPTCo was $194 million. The remaining affiliated amounts were immaterial.

[19] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEPTCo was $715 million. The remaining affiliated amounts were immaterial.

[20] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEPTCo was $587 million. The remaining affiliated amounts were immaterial.

[21] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $15 million primarily relating to barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial.

[22] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $20 million primarily relating to barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial.

[23] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $49 million primarily relating to barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial.

[24] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $57 million primarily relating to barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial.

[25] Amounts include affiliated and nonaffiliated revenues.

[26] Amounts include affiliated and nonaffiliated revenues.

[27] Amounts include affiliated and nonaffiliated revenues.

[28] Amounts include affiliated and nonaffiliated revenues.

[29] Corporate and Other primarily includes the purchasing of receivables from certain AEP utility subsidiaries. This segment also includes Parent’s guarantee revenue received from affiliates, investment income, interest income, interest expense and other nonallocated costs.