Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2019		Jun. 30, 2018		Jun. 30, 2019		Jun. 30, 2018
Revenues
Revenue from Contracts with Customers	$ 3,573.6		$ 4,013.2		$ 7,630.4		$ 8,061.5
Sales to AEP Affiliates	0.0		0.0		0.0		0.0
TOTAL REVENUES	3,573.6		4,013.2		7,630.4		8,061.5
Expenses
Other Operation	607.4		780.3		1,273.4		1,506.7
Maintenance	348.7		295.9		623.2		594.4
Depreciation and Amortization	622.6		553.2		1,228.4		1,092.9
Taxes Other Than Income Taxes	302.3		283.2		612.2		568.8
TOTAL EXPENSES	3,022.6		3,256.2		6,291.0		6,598.5
OPERATING INCOME (LOSS)	551.0		757.0		1,339.4		1,463.0
Other Income (Expense):
Other Income	6.6		6.7		15.2		12.2
Allowance for Equity Funds Used During Construction	50.4		30.8		79.3		61.5
Non-Service Cost Components of Net Periodic Benefit Cost	30.0		31.4		60.0		63.4
Interest Expense	(250.7)		(242.3)		(506.5)		(476.3)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	387.3		583.6		987.4		1,123.8
Income Tax Expense (Benefit)	(54.4)		72.2		(9.9)		174.2
Equity Earnings (Loss) of Unconsolidated Subsidiaries	17.4		18.7		35.9		37.2
Net Income (Loss)	459.1		530.1		1,033.2		986.8
Net Income (Loss) Attributable to Noncontrolling Interests	(2.2)		1.7		(0.9)		4.0
Earnings Attributable to Common Shareholders	$ 461.3		$ 528.4		$ 1,034.1		$ 982.8
Earnings Per Share
Weighted Average Number of Basic AEP Common Shares Outstanding	493,584,347		492,688,342		493,447,477		492,479,035
Total Basic Earnings Per Share Attributable to AEP Common Shareholders	$ 0.93		$ 1.07		$ 2.10		$ 2.00
Weighted Average Number of Diluted AEP Common Shares Outstanding	495,382,966		493,505,085		494,934,320		493,317,355
Total Diluted Earnings Per Share Attributable to AEP Common Shareholders	$ 0.93		$ 1.07		$ 2.09		$ 1.99
Common Stock, Dividends Per Share, Declared	$ 0.67		$ 0.62
Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	$ 2,116.4		$ 2,340.7		$ 4,488.7		$ 4,722.2
Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	1,001.6		1,127.9		2,181.4		2,269.1
Generation and Marketing [Member]
Revenues
Revenue from Contracts with Customers	382.9		435.3		822.6		912.8
Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	72.7		109.3		137.7		157.4
TOTAL REVENUES	(9.4)	[1]	(8.6)	[2]	40.3	[3]	19.9	[4]
Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	512.8	[5]	344.8	[6]	767.8	[7]	703.9	[8]
Expenses
Cost of Goods and Services Sold	480.9		566.9		1,031.3		1,068.7
Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	660.7		776.7		1,522.5		1,767.0
AEP Texas Inc. [Member]
Revenues
Sales to AEP Affiliates	42.2		17.6		82.4		35.8
TOTAL REVENUES	438.0		388.3		828.7		759.9
Expenses
Other Operation	111.2		118.0		221.0		235.0
Maintenance	89.9		23.1		115.2		44.6
Depreciation and Amortization	155.7		121.6		294.6		231.6
Taxes Other Than Income Taxes	34.0		33.6		70.5		66.0
TOTAL EXPENSES	399.3		302.1		719.2		591.9
OPERATING INCOME (LOSS)	38.7		86.2		109.5		168.0
Other Income (Expense):
Other Income	2.1		2.9		4.3		8.9
Allowance for Equity Funds Used During Construction					3.2		9.4
Non-Service Cost Components of Net Periodic Benefit Cost	2.8		3.0		5.6		6.1
Interest Expense	(19.5)		(36.6)		(56.9)		(71.6)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	24.1		55.5		62.5		111.4
Income Tax Expense (Benefit)	(56.5)		9.0		(52.5)		18.1
Net Income (Loss)	80.6		46.5		115.0		93.3
AEP Texas Inc. [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	395.1		370.1		744.9		722.5
AEP Texas Inc. [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.7		0.6		1.4		1.6
TOTAL REVENUES	41.0	[9]	17.2	[10]	80.8	[11]	35.0	[12]
AEP Texas Inc. [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	0.0	[13]	0.0	[14]	0.0	[15]	0.0	[16]
Expenses
Cost of Goods and Services Sold	8.5		5.8		17.9		14.7
AEP Transmission Co [Member]
Revenues
Sales to AEP Affiliates	209.1		144.7		402.3		305.4
TOTAL REVENUES	266.9		200.1	[17]	510.4		391.8	[18]
Expenses
Other Operation	18.7		18.5		35.7		35.1
Maintenance	2.5		2.2		5.7		4.8
Depreciation and Amortization	42.8		32.3		83.1		62.6
Taxes Other Than Income Taxes	41.9		36.6		83.3		67.7
TOTAL EXPENSES	105.9		89.6		207.8		170.2
OPERATING INCOME (LOSS)	161.0		110.5		302.6		221.6
Other Income (Expense):
Interest Income	0.6		0.4		1.3		0.8
Allowance for Equity Funds Used During Construction	28.8		15.8		40.1		30.7
Interest Expense	(21.4)		(20.6)		(43.1)		(40.9)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	169.0		106.1		300.9		212.2
Income Tax Expense (Benefit)	33.0		24.1		60.6		46.1
Net Income (Loss)	136.0		82.0		240.3		166.1
AEP Transmission Co [Member] | Transmission [Member]
Revenues
Revenue from Contracts with Customers	57.8		55.4		108.1		86.3
AEP Transmission Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.0		0.0		0.0		0.1
TOTAL REVENUES	0.0	[9]	0.0	[10],[17]	0.0	[11]	0.0	[12],[18]
AEP Transmission Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	0.0	[13]	0.0	[14],[17]	0.0	[15]	0.0	[16],[18]
Appalachian Power Co [Member]
Revenues
Sales to AEP Affiliates	46.3		46.4		98.0		95.8
TOTAL REVENUES	655.8		667.0		1,448.6		1,487.4
Expenses
Other Operation	138.9		109.9		275.8		248.1
Maintenance	61.3		65.7		122.8		137.7
Depreciation and Amortization	117.1		105.3		229.6		213.8
Taxes Other Than Income Taxes	35.9		33.7		71.8		67.5
TOTAL EXPENSES	578.9		534.4		1,219.6		1,161.8
OPERATING INCOME (LOSS)	76.9		132.6		229.0		325.6
Other Income (Expense):
Interest Income	1.0		0.6		1.8		0.9
Carrying Costs Income	0.0		0.5		0.0		1.0
Allowance for Equity Funds Used During Construction	6.0		2.9		7.7		5.5
Non-Service Cost Components of Net Periodic Benefit Cost	4.2		4.4		8.5		8.9
Interest Expense	(51.6)		(47.8)		(100.9)		(95.2)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	36.5		93.2		146.1		246.7
Income Tax Expense (Benefit)	(19.0)		15.8		(43.1)		43.8
Net Income (Loss)	55.5		77.4		189.2		202.9
Appalachian Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	605.9		618.8		1,344.6		1,386.3
Appalachian Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	3.6		1.8		6.0		5.3
TOTAL REVENUES	0.0	[9]	0.0	[10]	0.0	[11]	0.0	[12]
Appalachian Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	62.2	[13]	56.8	[14]	129.7	[15]	119.6	[16]
Sales to AEP Affiliates	30.0		29.0		64.0		69.0
Expenses
Cost of Goods and Services Sold	161.2		155.3		344.5		224.3
Appalachian Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	64.5		64.5		175.1		270.4
Indiana Michigan Power Co [Member]
Revenues
Sales to AEP Affiliates	2.3		10.8		4.6		15.5
Other Revenues - Affiliated	20.9		16.4		34.2		29.6
TOTAL REVENUES	543.1		589.7		1,157.4		1,166.5
Expenses
Purchased Electricity from AEP Affiliates	51.3		60.4		111.1		121.8
Other Operation	154.5		130.4		295.0		276.5
Maintenance	54.6		57.4		112.9		111.9
Depreciation and Amortization	87.3		62.6		173.5		121.9
Taxes Other Than Income Taxes	26.2		24.9		53.5		49.9
TOTAL EXPENSES	465.2		472.3		964.5		951.7
OPERATING INCOME (LOSS)	77.9		117.4		192.9		214.8
Other Income (Expense):
Carrying Costs Income					(1.4)		4.0
Other Income	6.1		4.9		11.8		9.3
Allowance for Equity Funds Used During Construction					12.5		4.1
Non-Service Cost Components of Net Periodic Benefit Cost	4.4		4.5		8.8		9.0
Interest Expense	(28.2)		(31.4)		(57.1)		(61.1)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	60.2		95.4		156.4		172.0
Income Tax Expense (Benefit)	(0.1)		0.7		(2.8)		13.1
Net Income (Loss)	60.3		94.7		159.2		158.9
Indiana Michigan Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	517.4		560.1		1,114.1		1,114.0
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	2.5		2.4		4.5		7.4
Sales to AEP Affiliates	23.0		26.0		38.0		41.0
TOTAL REVENUES	0.0	[9]	(14.2)	[10]	0.0	[11]	(8.7)	[12]
Indiana Michigan Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	113.4	[13]	142.1	[14]	225.3	[15]	256.1	[16]
Expenses
Cost of Goods and Services Sold	42.4		73.4		100.0		150.9
Indiana Michigan Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	48.9		63.2		118.5		118.8
Ohio Power Co [Member]
Revenues
Sales to AEP Affiliates	1.7		11.5		9.2		14.6
TOTAL REVENUES	606.6		748.8		1,443.4		1,539.7
Expenses
Purchased Electricity from AEP Affiliates	33.7		27.9		79.8		58.1
Amortization of Generation Deferrals	24.1		56.4		56.5		115.0
Other Operation	153.9		199.0		370.8		371.2
Maintenance	34.2		34.1		66.7		71.3
Depreciation and Amortization	56.1		65.1		119.4		129.9
Taxes Other Than Income Taxes	106.0		99.0		214.9		204.1
TOTAL EXPENSES	529.5		644.4		1,203.8		1,318.0
OPERATING INCOME (LOSS)	77.1		104.4		239.6		221.7
Other Income (Expense):
Interest Income	1.1		0.9		1.9		1.8
Carrying Costs Income	0.2		0.6		0.4		1.3
Allowance for Equity Funds Used During Construction	4.1		3.3		9.3		5.8
Non-Service Cost Components of Net Periodic Benefit Cost	3.6		3.9		7.3		7.8
Interest Expense	(25.6)		(25.3)		(50.2)		(50.5)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	60.5		87.8		208.3		187.9
Income Tax Expense (Benefit)	9.9		19.0		29.7		39.5
Net Income (Loss)	50.6		68.8		178.6		148.4
Ohio Power Co [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	602.3		735.9		1,428.8		1,522.2
Ohio Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	2.6		1.4		5.4		2.9
TOTAL REVENUES	1.5	[9]	4.1	[10]	6.6	[11]	8.0	[12]
Ohio Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	0.0	[13]	0.0	[14]	0.0	[15]	0.0	[16]
Ohio Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	121.5		162.9		295.7		368.4
Public Service Co Of Oklahoma [Member]
Revenues
Sales to AEP Affiliates	2.1		1.5		3.7		2.6
TOTAL REVENUES	348.1		398.3		680.9		735.1
Expenses
Other Operation	64.8		93.7		138.4		180.5
Maintenance	26.1		24.0		48.6		50.9
Depreciation and Amortization	42.8		41.4		86.3		78.2
Taxes Other Than Income Taxes	10.5		10.2		21.9		21.8
TOTAL EXPENSES	291.5		341.1		603.4		674.0
OPERATING INCOME (LOSS)	56.6		57.2		77.5		61.1
Other Income (Expense):
Other Income	0.8		(0.1)		0.9		(0.1)
Allowance for Equity Funds Used During Construction					0.7		(0.1)
Non-Service Cost Components of Net Periodic Benefit Cost	2.1		2.2		4.2		4.4
Interest Expense	(17.3)		(16.3)		(34.2)		(31.0)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	42.2		43.0		48.4		34.4
Income Tax Expense (Benefit)	0.3		6.4		0.3		5.0
Net Income (Loss)	41.9		36.6		48.1		29.4
Public Service Co Of Oklahoma [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	344.6		395.3		673.8		730.4
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	1.4		1.5		3.4		2.1
TOTAL REVENUES	0.0	[9]	0.0	[10]	0.0	[11]	0.0	[12]
Public Service Co Of Oklahoma [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	5.8	[13]	8.3	[14]	14.4	[15]	14.2	[16]
Expenses
Cost of Goods and Services Sold	44.8		58.7		82.8		107.1
Public Service Co Of Oklahoma [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	102.5		113.1		225.4		235.5
Southwestern Electric Power Co [Member]
Revenues
Sales to AEP Affiliates	6.4		5.4		12.8		11.5
Provision for Refund	(25.2)		0.0		(25.2)		0.0
TOTAL REVENUES	375.5		457.1		796.6		876.5
Expenses
Other Operation	65.9		98.0		150.5		192.9
Maintenance	39.3		37.6		68.2		68.6
Depreciation and Amortization	61.8		58.6		123.9		116.0
Taxes Other Than Income Taxes	24.5		24.5		49.8		49.5
TOTAL EXPENSES	342.5		386.6		709.5		764.4
OPERATING INCOME (LOSS)	33.0		70.5		87.1		112.1
Other Income (Expense):
Interest Income	0.7		0.6		1.4		2.4
Allowance for Equity Funds Used During Construction	1.1		0.9		2.9		3.2
Non-Service Cost Components of Net Periodic Benefit Cost	2.2		2.3		4.3		4.6
Interest Expense	(30.5)		(30.9)		(60.2)		(63.1)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	6.5		43.4		35.5		59.2
Income Tax Expense (Benefit)	0.0		5.4		0.7		8.3
Equity Earnings (Loss) of Unconsolidated Subsidiaries	0.8		0.7		1.5		1.2
Net Income (Loss)	7.3		38.7		36.3		52.1
Net Income (Loss) Attributable to Noncontrolling Interests	1.1		1.1		2.3		2.7
Earnings Attributable to Common Shareholders	6.2		37.6		34.0		49.4
Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	394.0		451.4		808.3		864.4
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.3		0.3		0.7		0.6
TOTAL REVENUES	0.0	[9]	0.0	[10]	0.0	[11]	0.0	[12]
Southwestern Electric Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	44.8	[13]	55.7	[14]	102.0	[15]	115.6	[16]
Expenses
Cost of Goods and Services Sold	117.9		114.5		251.4		241.3
Southwestern Electric Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	$ 33.1		$ 53.4		$ 65.7		$ 96.1

[1] Amounts include affiliated and nonaffiliated revenues.

[2] Amounts include affiliated and nonaffiliated revenues.

[3] Amounts include affiliated and nonaffiliated revenues.

[4] Amounts include affiliated and nonaffiliated revenues.

[5] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing is $34 million. The remaining affiliated amounts are immaterial.

[6] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing is $25 million. The remaining affiliated amounts are immaterial.

[7] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing is $71 million. The remaining affiliated amounts are immaterial.

[8] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing is $52 million. The remaining affiliated amounts are immaterial

[9] Amounts include affiliated and nonaffiliated revenues.

[10] Amounts include affiliated and nonaffiliated revenues.

[11] Amounts include affiliated and nonaffiliated revenues.

[12] Amounts include affiliated and nonaffiliated revenues.

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

[14] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo is $29 million primarily relating to the PPA with Kingsport. The remaining affiliated amounts are immaterial.

[15] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo is $64 million primarily relating to the PPA with Kingsport. The remaining affiliated amounts are immaterial.

[16] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo is $69 million primarily relating to the PPA with Kingsport. The remaining affiliated amounts are immaterial.

[17] These amounts presented reflect the revisions made to AEPTCo’s previously issued financial statement. See the “revisions to Previously Issued Financial Statements” section of Note 1 for additional information.

[18] The amounts presented reflect the revisions made to AEPTCo’s previously issued financial statements. For additional details on revisions made to AEPTCo’s financial statements, see Note 1- Significant Accounting Matters.