Revenue from Contracts with Customers (Details) - USD ($) $ in Millions		3 Months Ended				9 Months Ended
		Sep. 30, 2019		Sep. 30, 2018		Sep. 30, 2019		Sep. 30, 2018		Dec. 31, 2018
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		$ 4,315.0		$ 4,333.1		$ 11,945.4		$ 12,394.6
Revenue Not from Contract with Customer, Other		2.9		6.0		(58.5)		(28.8)
Total Revenues		4,315.0		4,333.1		11,945.4		12,394.6
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		908.8				908.8
Revenue Textuals [Abstract]
Revenue from Related Parties		0.0		0.0		0.0		0.0
2019 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		252.7				252.7
2020-2021 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		209.7				209.7
2022-2023 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		160.9				160.9
2023 and Forward [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		285.5				285.5
Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		3,278.2		3,372.0	[1]	9,086.1		9,464.7	[2]
Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		1,648.2		1,660.9		4,406.7		4,618.0
Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		903.4		943.7		2,530.6		2,617.9
Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		666.8		707.6		1,979.9		2,057.6
Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		59.8		59.8		168.9		171.2
Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		931.0		760.5		2,677.5		2,579.1
Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		274.2	[3]	240.8	[4]	838.4	[5]	944.7	[6]
Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		240.9	[7]	120.6	[8]	750.1	[9]	594.2	[10]
Marketing, Competitive Retail and Renewable [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		415.9		399.1		1,089.0		1,040.2
Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		102.9	[11]	194.6	[12]	240.3	[13]	379.6	[14]
Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		4,312.1		4,327.1		12,003.9		12,423.4
Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(11.4)	[11]	(52.6)	[15]	(113.1)	[13]	(107.3)	[16]
Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		67.6		55.5		205.3		212.9
Revenue Not from Contract with Customer, Other		14.3	[11]	58.6	[12]	54.6	[13]	78.5	[14]
AEP Texas Inc. [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		41.1		26.1		122.2		61.0
Total Revenues		489.3		433.4		1,318.0		1,193.3
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		96.8				96.8
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		17.6				17.6				$ 15.0
Revenue Textuals [Abstract]
Revenue from Related Parties		42.7		27.5		125.1		63.3
AEP Texas Inc. [Member] | 2019 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		96.8				96.8
AEP Texas Inc. [Member] | 2020-2021 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
AEP Texas Inc. [Member] | 2022-2023 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
AEP Texas Inc. [Member] | 2023 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		342.3		326.2	[17]	890.9		880.9	[18]
AEP Texas Inc. [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		192.0		178.8		454.9		453.6
AEP Texas Inc. [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		110.6		107.9		314.5		310.8
AEP Texas Inc. [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		32.2		32.1		98.8		94.8
AEP Texas Inc. [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		7.5		7.4		22.7		21.7
AEP Texas Inc. [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		97.7		73.6		282.0		229.6
AEP Texas Inc. [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0	[19]	0.0	[20]	0.0	[21]	0.0	[22]
AEP Texas Inc. [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		97.7	[23]	73.6	[24]	282.0	[25]	229.6	[26]
AEP Texas Inc. [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		8.2	[27]	7.5	[28]	22.9	[29]	21.8	[30]
AEP Texas Inc. [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		448.2		407.3		1,195.8		1,132.3
AEP Texas Inc. [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(0.7)	[31]	(1.0)	[32]	(0.4)	[31]	(1.1)	[33]
AEP Texas Inc. [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		1.2		1.4		2.6		3.0
Revenue Not from Contract with Customer, Other		41.8	[31]	27.1	[34]	122.6	[31]	62.1	[35]
AEP Transmission Co [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(1.2)		(12.4)		(17.8)		(35.4)
Total Revenues		259.7		194.4		770.1		586.2
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		225.8				225.8
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		61.3				61.3				61.0
Revenue Textuals [Abstract]
Revenue from Related Parties		205.7		148.4		608.0		453.8
AEP Transmission Co [Member] | Short-term Contract with Customer [Member]
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		69.9				69.9				58.6
AEP Transmission Co [Member] | 2019 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		225.8				225.8
AEP Transmission Co [Member] | 2020-2021 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
AEP Transmission Co [Member] | 2022-2023 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
AEP Transmission Co [Member] | 2023 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	[17]	0.0		0.0	[18]
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		256.4		206.6		775.3		612.9
AEP Transmission Co [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0	[19]	0.0	[20]	0.0	[21]	0.0	[22]
AEP Transmission Co [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		256.4	[23]	206.6	[24]	775.3	[25]	612.9	[26]
Revenue Textuals [Abstract]
Revenue from Related Parties		194.0		146.0		587.0		448.0
AEP Transmission Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		4.5	[27]	0.2	[28]	12.6	[29]	8.7	[30]
AEP Transmission Co [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		260.9		206.8		787.9		621.6
AEP Transmission Co [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(1.2)	[31]	(12.4)	[32]	(17.8)	[31]	(35.4)	[33]
AEP Transmission Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.1
Revenue Not from Contract with Customer, Other		0.0	[31]	0.0	[34]	0.0	[31]	0.0	[35]
Appalachian Power Co [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		6.6		(2.1)		11.2		(21.6)
Total Revenues		755.5		762.0		2,204.1		2,249.4
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		106.0				106.0
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		56.4				56.4				73.4
Revenue Textuals [Abstract]
Revenue from Related Parties		56.6		42.9		154.6		138.7
Appalachian Power Co [Member] | Short-term Contract with Customer [Member]
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		41.4				41.4				52.5
Appalachian Power Co [Member] | 2019 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		36.4				36.4
Appalachian Power Co [Member] | 2020-2021 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		32.5				32.5
Appalachian Power Co [Member] | 2022-2023 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		25.5				25.5
Appalachian Power Co [Member] | 2023 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		633.6		652.8	[17]	1,867.0		1,974.5	[18]
Appalachian Power Co [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		315.7		320.9		944.7		1,017.3
Appalachian Power Co [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		147.2		155.1		421.5		442.3
Appalachian Power Co [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		152.2		157.6		444.3		457.3
Appalachian Power Co [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		18.5		19.2		56.5		57.6
Appalachian Power Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		96.6		95.4		277.7		254.3
Appalachian Power Co [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		70.4	[19]	74.5	[20]	200.1	[21]	194.1	[22]
Revenue Textuals [Abstract]
Revenue from Related Parties		32.0		30.0		96.0		100.0
Appalachian Power Co [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		26.2	[23]	20.9	[24]	77.6	[25]	60.2	[26]
Appalachian Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		18.7	[27]	15.9	[28]	48.2	[29]	42.2	[30]
Appalachian Power Co [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		748.9		764.1		2,192.9		2,271.0
Appalachian Power Co [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		6.6	[31]	(1.2)	[32]	11.2	[31]	(20.7)	[33]
Appalachian Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		2.2		2.3		8.2		7.6
Revenue Not from Contract with Customer, Other		0.0	[31]	(0.9)	[34]	0.0	[31]	(0.9)	[35]
Indiana Michigan Power Co [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(1.1)		10.2		(1.4)		(4.0)
Total Revenues		611.1		629.7		1,768.5		1,796.2
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		29.3				29.3
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		45.3				45.3				75.0
Revenue Textuals [Abstract]
Revenue from Related Parties		2.7		3.4		7.3		18.9
Indiana Michigan Power Co [Member] | Short-term Contract with Customer [Member]
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		28.0				28.0				35.3
Indiana Michigan Power Co [Member] | 2019 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		7.2				7.2
Indiana Michigan Power Co [Member] | 2020-2021 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		8.9				8.9
Indiana Michigan Power Co [Member] | 2022-2023 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		8.8				8.8
Indiana Michigan Power Co [Member] | 2023 and Forward [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		4.4				4.4
Indiana Michigan Power Co [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		477.1		497.3	[17]	1,347.5		1,362.6	[18]
Indiana Michigan Power Co [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		198.2		207.4		558.8		559.4
Indiana Michigan Power Co [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		138.3		138.0		371.4		369.8
Indiana Michigan Power Co [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		138.7		150.2		411.9		428.0
Indiana Michigan Power Co [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		1.9		1.7		5.4		5.4
Indiana Michigan Power Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		108.5		99.8		346.2		366.6
Indiana Michigan Power Co [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		102.1	[19]	93.6	[20]	327.4	[21]	349.7	[22]
Indiana Michigan Power Co [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		6.4	[23]	6.2	[24]	18.8	[25]	16.9	[26]
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		26.6	[27]	22.4	[28]	76.2	[29]	71.0	[30]
Indiana Michigan Power Co [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		612.2		619.5		1,769.9		1,800.2
Indiana Michigan Power Co [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(1.1)	[31]	1.5	[32]	(1.4)	[31]	(4.0)	[33]
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		3.1		2.7		7.6		10.1
Revenue Not from Contract with Customer, Other		0.0	[31]	8.7	[34]	0.0	[31]	0.0	[35]
Revenue Textuals [Abstract]
Revenue from Related Parties		20.0		17.0		57.0		57.0
Ohio Power Co [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		9.6		37.4		25.8		35.1
Total Revenues		710.6		778.3		2,154.0		2,318.0
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		25.3				25.3
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		56.2				56.2				70.8
Revenue Textuals [Abstract]
Revenue from Related Parties		9.0		3.3		18.2		17.9
Ohio Power Co [Member] | Short-term Contract with Customer [Member]
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		29.2				29.2				46.1
Ohio Power Co [Member] | 2019 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		17.8				17.8
Ohio Power Co [Member] | 2020-2021 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		7.5				7.5
Ohio Power Co [Member] | 2022-2023 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
Ohio Power Co [Member] | 2023 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		646.3		756.0	[17]	1,972.9		2,188.8	[18]
Ohio Power Co [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		395.6		433.5		1,155.5		1,258.4
Ohio Power Co [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		180.5		222.9		573.7		633.2
Ohio Power Co [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		67.1		96.3		233.9		287.4
Ohio Power Co [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		3.1		3.3		9.8		9.8
Ohio Power Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		13.7		14.8		42.0		42.8
Ohio Power Co [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0	[19]	0.0	[20]	0.0	[21]	0.0	[22]
Ohio Power Co [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		13.7	[23]	14.8	[24]	42.0	[25]	42.8	[26]
Ohio Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		41.0	[27]	(29.9)	[28]	113.3	[29]	51.3	[30]
Ohio Power Co [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		701.0		740.9		2,128.2		2,282.9
Ohio Power Co [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		12.4	[31]	(36.9)	[32]	22.0	[31]	(47.2)	[33]
Ohio Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		3.0		2.4		8.4		5.3
Revenue Not from Contract with Customer, Other		(2.8)	[31]	74.3	[34]	3.8	[31]	82.3	[35]
Public Service Co Of Oklahoma [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		7.1		2.3		(25.3)		11.2
Total Revenues		493.0		481.4		1,173.9		1,216.5
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		4.3				4.3
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		27.3				27.3				26.2
Revenue Textuals [Abstract]
Revenue from Related Parties		1.3		1.1		5.0		3.7
Public Service Co Of Oklahoma [Member] | Short-term Contract with Customer [Member]
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		10.3				10.3				12.4
Public Service Co Of Oklahoma [Member] | 2019 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		4.3				4.3
Public Service Co Of Oklahoma [Member] | 2020-2021 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
Public Service Co Of Oklahoma [Member] | 2022-2023 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
Public Service Co Of Oklahoma [Member] | 2023 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		463.1		447.6	[17]	1,125.1		1,134.6	[18]
Public Service Co Of Oklahoma [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		231.9		220.8		519.6		531.4
Public Service Co Of Oklahoma [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		122.2		119.9		304.3		309.3
Public Service Co Of Oklahoma [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		84.1		82.4		238.1		228.7
Public Service Co Of Oklahoma [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		24.9		24.5		63.1		65.2
Public Service Co Of Oklahoma [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		17.7		26.0		57.4		56.1
Public Service Co Of Oklahoma [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		21.1	[19]	12.5	[20]	35.5	[21]	26.7	[22]
Public Service Co Of Oklahoma [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(3.4)	[23]	13.5	[24]	21.9	[25]	29.4	[26]
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		5.1	[27]	5.5	[28]	16.7	[29]	14.6	[30]
Public Service Co Of Oklahoma [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		485.9		479.1		1,199.2		1,205.3
Public Service Co Of Oklahoma [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		7.1	[31]	2.3	[32]	(25.3)	[31]	11.2	[33]
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		1.2		1.2		4.6		3.3
Revenue Not from Contract with Customer, Other		0.0	[31]	0.0	[34]	0.0	[31]	0.0	[35]
Southwestern Electric Power Co [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(4.0)		(0.3)		(47.4)		2.3
Total Revenues		545.5		535.3		1,342.1		1,411.8
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		9.8				9.8
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		56.8				56.8				28.8
Revenue Textuals [Abstract]
Revenue from Related Parties		8.8		8.7		21.6		20.2
Southwestern Electric Power Co [Member] | Short-term Contract with Customer [Member]
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		17.8				17.8				$ 16.3
Southwestern Electric Power Co [Member] | 2019 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		9.8				9.8
Southwestern Electric Power Co [Member] | 2020-2021 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
Southwestern Electric Power Co [Member] | 2022-2023 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0.0				0.0
Southwestern Electric Power Co [Member] | 2023 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		461.8		446.3	[17]	1,138.7		1,145.4	[18]
Southwestern Electric Power Co [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		222.9		214.1		503.7		512.4
Southwestern Electric Power Co [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		144.3		140.4		371.1		372.6
Southwestern Electric Power Co [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		92.3		89.6		257.2		254.0
Southwestern Electric Power Co [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		2.3		2.2		6.7		6.4
Southwestern Electric Power Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		80.7		82.7		230.7		246.1
Southwestern Electric Power Co [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		50.7	[19]	53.2	[20]	152.7	[21]	168.8	[22]
Southwestern Electric Power Co [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		30.0	[23]	29.5	[24]	78.0	[25]	77.3	[26]
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		7.0	[27]	6.6	[28]	20.1	[29]	18.0	[30]
Southwestern Electric Power Co [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		549.5		535.6		1,389.5		1,409.5
Southwestern Electric Power Co [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(4.0)	[31]	(0.3)	[32]	(47.4)	[31]	2.3	[33]
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.3		0.6		1.0		1.2
Revenue Not from Contract with Customer, Other		0.0	[31]	0.0	[34]	0.0	[31]	0.0	[35]
Consolidation Eliminations [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
Revenue Not from Contract with Customer, Other		(56.6)		43.0		(169.5)		0.0
Total Revenues		(348.2)		(247.6)		(991.7)		(674.1)
Revenue Textuals [Abstract]
Revenue from Related Parties		(348.2)		(247.6)		(991.7)		(674.1)
Consolidation Eliminations [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		1.5		0.0	[1]	0.0		0.0	[2]
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		1.5		0.0		0.0		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		(250.9)		(340.1)		(708.6)		(675.9)
Consolidation Eliminations [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(34.2)	[3]	(98.5)	[4]	(105.5)	[5]	(155.2)	[6]
Consolidation Eliminations [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(217.2)	[7]	(241.6)	[8]	(603.6)	[9]	(520.7)	[10]
Consolidation Eliminations [Member] | Marketing, Competitive Retail and Renewable [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.5		0.0		0.5		0.0
Consolidation Eliminations [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(42.2)	[11]	49.5	[12]	(113.6)	[13]	1.8	[14]
Consolidation Eliminations [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(291.6)		(290.6)		(822.2)		(674.1)
Consolidation Eliminations [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(16.8)	[11]	0.0	[15]	(60.3)	[13]	0.0	[16]
Consolidation Eliminations [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(39.8)	[11]	43.0	[12]	(109.2)	[13]	0.0	[14]
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		0.0		0.0		0.0
Vertically Integrated Utilities [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		1.2		10.0		(55.7)		(18.1)
Total Revenues		2,645.5		2,636.7		7,172.6		7,393.7
Revenue Textuals [Abstract]
Revenue from Related Parties		46.6		26.5		85.0		61.3
Vertically Integrated Utilities [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		2,287.9		2,289.4	[1]	6,222.2		6,395.1	[2]
Vertically Integrated Utilities [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		1,060.2		1,048.7		2,797.6		2,906.9
Vertically Integrated Utilities [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		612.5		612.8		1,641.2		1,672.7
Vertically Integrated Utilities [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		566.0		578.8		1,647.3		1,676.1
Vertically Integrated Utilities [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		49.2		49.1		136.1		139.4
Vertically Integrated Utilities [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		309.1		297.0		877.3		894.9
Vertically Integrated Utilities [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		231.3	[3]	224.2	[4]	661.9	[5]	686.5	[6]
Vertically Integrated Utilities [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		77.8	[7]	72.8	[8]	215.4	[9]	208.4	[10]
Vertically Integrated Utilities [Member] | Marketing, Competitive Retail and Renewable [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
Vertically Integrated Utilities [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		47.3	[11]	40.3	[12]	128.8	[13]	121.8	[14]
Vertically Integrated Utilities [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		2,644.3		2,626.7		7,228.3		7,411.8
Vertically Integrated Utilities [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		1.2	[11]	0.2	[15]	(55.7)	[13]	(19.2)	[16]
Vertically Integrated Utilities [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		0.0	[11]	9.8	[12]	0.0	[13]	1.1	[14]
Transmission And Distribution Utilities [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		44.0		(29.0)		138.8		3.6
Total Revenues		1,186.6		1,211.5		3,454.3		3,510.9
Revenue Textuals [Abstract]
Revenue from Related Parties		39.3		30.6		125.6		60.9
Transmission And Distribution Utilities [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		988.8		1,082.6	[1]	2,863.9		3,069.6	[2]
Transmission And Distribution Utilities [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		588.0		612.2		1,609.1		1,711.1
Transmission And Distribution Utilities [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		290.9		330.9		889.4		945.2
Transmission And Distribution Utilities [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		99.3		128.8		332.6		381.5
Transmission And Distribution Utilities [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		10.6		10.7		32.8		31.8
Transmission And Distribution Utilities [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		110.9		88.0		324.0		272.6
Transmission And Distribution Utilities [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0	[3]	0.0	[4]	0.0	[5]	0.0	[6]
Transmission And Distribution Utilities [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		110.9	[7]	88.0	[8]	324.0	[9]	272.6	[10]
Transmission And Distribution Utilities [Member] | Marketing, Competitive Retail and Renewable [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
Transmission And Distribution Utilities [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		42.9	[11]	69.9	[12]	127.6	[13]	165.1	[14]
Transmission And Distribution Utilities [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		1,142.6		1,240.5		3,315.5		3,507.3
Transmission And Distribution Utilities [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		5.1	[11]	(37.9)	[15]	21.5	[13]	(48.3)	[16]
Transmission And Distribution Utilities [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		38.9	[11]	8.9	[12]	117.3	[13]	51.9	[14]
AEP Transmission Holdco [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(0.9)		(14.9)		(18.6)		(39.8)
Total Revenues		273.0		187.2		808.3		605.2
AEP Transmission Holdco [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0	[1]	0.0		0.0	[2]
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		269.4		201.4		814.3		633.9
AEP Transmission Holdco [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0	[3]	0.0	[4]	0.0	[5]	0.0	[6]
AEP Transmission Holdco [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		269.4	[7]	201.4	[8]	814.3	[9]	633.9	[10]
Revenue Textuals [Abstract]
Revenue from Related Parties		197.0		147.0		596.0		444.0
AEP Transmission Holdco [Member] | Marketing, Competitive Retail and Renewable [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
AEP Transmission Holdco [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		4.5	[11]	0.7	[12]	12.6	[13]	11.1	[14]
AEP Transmission Holdco [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		273.9		202.1		826.9		645.0
AEP Transmission Holdco [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(0.9)	[11]	(14.9)	[15]	(18.6)	[13]	(39.8)	[16]
AEP Transmission Holdco [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		0.0	[11]	0.0	[12]	0.0	[13]	0.0	[14]
Generation And Marketing [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		26.4		(5.3)		53.2		18.8
Total Revenues		533.7		521.6		1,428.2		1,487.4
Revenue Textuals [Abstract]
Revenue from Related Parties		32.5		35.1		104.4		88.1
Generation And Marketing [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0	[1]	0.0		0.0	[2]
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		492.5		514.2		1,370.5		1,453.6
Generation And Marketing [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		77.1	[3]	115.1	[4]	282.0	[5]	413.4	[6]
Revenue Textuals [Abstract]
Revenue from Related Parties		34.0		35.0		105.0		87.0
Generation And Marketing [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0	[7]	0.0	[8]	0.0	[9]	0.0	[10]
Generation And Marketing [Member] | Marketing, Competitive Retail and Renewable [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		415.4		399.1		1,088.5		1,040.2
Generation And Marketing [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		14.8	[11]	12.7	[12]	4.5	[13]	15.0	[14]
Generation And Marketing [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		507.3		526.9		1,375.0		1,468.6
Generation And Marketing [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		0.0	[11]	0.0	[15]	0.0	[13]	0.0	[16]
Generation And Marketing [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		26.4	[11]	(5.3)	[12]	53.2	[13]	18.8	[14]
Other Segments [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(11.2)		2.2		(6.7)		6.7
Total Revenues	[36]	24.4		23.7		73.7		71.5
Revenue Textuals [Abstract]
Revenue from Related Parties	[36]	22.3		20.1		64.9		55.1
Other Segments [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0	[1]	0.0		0.0	[2]
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		0.0		0.0		0.0		0.0
Other Segments [Member] | Generation [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] | Transmission [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] | Marketing, Competitive Retail and Renewable [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.0		0.0		0.0		0.0
Other Segments [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		35.6	[11]	21.5	[12]	80.4	[13]	64.8	[14]
Other Segments [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		35.6		21.5		80.4		64.8
Other Segments [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		0.0	[11]	0.0	[15]	0.0	[13]	0.0	[16]
Other Segments [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers	[36]	2.1		3.6		8.8		16.4
Revenue Not from Contract with Customer, Other		$ (11.2)	[11]	$ 2.2	[12]	$ (6.7)	[13]	$ 6.7	[14]

[1] 2018 amounts have been revised to reflect the reclassification of certain customer accounts between Retail classes. This reclassification did not impact previously reported Total Retail Revenues. Management concluded that these prior period disclosure only errors were immaterial individually and in the aggregate.

[2] 2018 amounts have been revised to reflect the reclassification of certain customer accounts between Retail classes. This reclassification did not impact previously reported Total Retail Revenues. Management concluded that these prior period disclosure only errors were immaterial individually and in the aggregate.

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

[4] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $35 million. The remaining affiliated amounts were immaterial.

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

[6] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $87 million. The remaining affiliated amounts were immaterial

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

[8] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $147 million. The remaining affiliated amounts were immaterial.

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

[10] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $444 million. The remaining affiliated amounts were immaterial.

[11] Amounts include affiliated and nonaffiliated revenues.

[12] Amounts include affiliated and nonaffiliated revenues.

[13] Amounts include affiliated and nonaffiliated revenues.

[14] Amounts include affiliated and nonaffiliated revenues.

[15] The alternative revenue for Transmission and Distribution Utilities was primarily the $48 million reduction in revenue relating to the Ohio Tax Reform settlement.

[16] The alternative revenue for Transmission and Distribution Utilities was primarily the $48 million reduction in revenue relating to the Ohio Tax Reform settlement.

[17] 2018 amounts have been revised to reflect the reclassification of certain customer accounts between Retail classes. This reclassification did not impact previously reported Total Retail Revenues. Management concluded that these prior period disclosure only errors were immaterial individually and in the aggregate.

[18] 2018 amounts have been revised to reflect the reclassification of certain customer accounts between Retail classes. This reclassification did not impact previously reported Total Retail Revenues. Management concluded that these prior period disclosure only errors were immaterial individually and in the aggregate.

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

[20] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $30 million primarily relating to the PPA with Kingsport. The remaining affiliated amounts were immaterial.

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

[22] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $100 million primarily relating to the PPA with Kingsport. The remaining affiliated amounts were immaterial.

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

[24] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEPTCo was $146 million. The remaining affiliated amounts were immaterial.

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

[26] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEPTCo was $448 million. The remaining affiliated amounts were immaterial.

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

[28] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $17 million primarily relating to the barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial.

[29] 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.

[30] 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.

[31] Amounts include affiliated and nonaffiliated revenues.

[32] The alternative revenue for OPCo was primarily the $48 million reduction in revenue relating to the Ohio Tax Reform settlement.

[33] The alternative revenue for OPCo was primarily the $48 million reduction in revenue relating to the Ohio Tax Reform settlement.

[34] Amounts include affiliated and nonaffiliated revenues.

[35] Amounts include affiliated and nonaffiliated revenues.

[36] 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.