Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019		Mar. 31, 2018
Revenues
Revenue from Contracts with Customers	$ 4,056.8		$ 4,048.3
Sales to AEP Affiliates	0.0		0.0
TOTAL REVENUES	4,056.8		4,048.3
Expenses
Other Operation	666.0		726.4
Maintenance	274.5		298.5
Depreciation and Amortization	605.8		539.7
Taxes Other Than Income Taxes	309.9		285.6
TOTAL EXPENSES	3,268.4		3,342.3
OPERATING INCOME (LOSS)	788.4		706.0
Other Income (Expense):
Other Income	8.6		5.5
Allowance for Equity Funds Used During Construction	28.9		30.7
Non-Service Cost Components of Net Periodic Benefit Cost	30.0		32.0
Interest Expense	(255.8)		(234.0)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	600.1		540.2
Income Tax Expense (Benefit)	44.5		102.0
Equity Earnings (Loss) of Unconsolidated Subsidiaries	18.5		18.5
NET INCOME (LOSS)	574.1		456.7
Net Income Attributable to Noncontrolling Interests	1.3		2.3
EARNINGS ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ 572.8		$ 454.4
Earnings Per Share
Weighted Average Number of Basic AEP Common Shares Outstanding	493,309,076		492,267,402
Total Basic Earnings Per Share Attributable to AEP Common Shareholders	$ 1.16		$ 0.92
Weighted Average Number of Diluted AEP Common Shares Outstanding	494,484,144		493,127,300
Total Diluted Earnings Per Share Attributable to AEP Common Shareholders	$ 1.16		$ 0.92
Common Stock, Dividends, Per Share, Declared	$ 0.67		$ 0.62
Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	$ 2,372.3		$ 2,381.5
Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	1,179.8		1,141.2
Generation & Marketing [Member]
Revenues
Revenue from Contracts with Customers	439.7		477.5
Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	65.0		48.1
TOTAL REVENUES	50.8	[1]	28.5	[2]
Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	550.4		501.8
Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	861.8		990.3
AEP Texas Inc. [Member]
Revenues
Revenue from Contracts with Customers	351.8		354.1
Sales to AEP Affiliates	40.2		18.2
TOTAL REVENUES	390.7		371.6
Expenses
Other Operation	109.8		117.0
Maintenance	25.3		21.5
Depreciation and Amortization	138.9		110.0
Taxes Other Than Income Taxes	36.5		32.4
TOTAL EXPENSES	319.9		289.8
OPERATING INCOME (LOSS)	70.8		81.8
Other Income (Expense):
Interest Income	0.4		0.5
Allowance for Equity Funds Used During Construction	1.8		5.5
Non-Service Cost Components of Net Periodic Benefit Cost	2.8		3.1
Interest Expense	(37.4)		(35.0)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	38.4		55.9
Income Tax Expense (Benefit)	4.0		9.1
NET INCOME (LOSS)	34.4		46.8
AEP Texas Inc. [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	349.8		352.4
AEP Texas Inc. [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.7		1.0
TOTAL REVENUES	39.8	[3]	17.8	[4]
AEP Texas Inc. [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	9.4		8.9
AEP Transmission Co [Member]
Revenues
Revenue from Contracts with Customers	245.2		187.0	[5]
Sales to AEP Affiliates	193.2		160.7	[6]
TOTAL REVENUES	243.5		191.7	[5],[6]
Expenses
Other Operation	17.0		16.6
Maintenance	3.2		2.6
Depreciation and Amortization	40.3		30.3
Taxes Other Than Income Taxes	41.4		31.1
TOTAL EXPENSES	101.9		80.6
OPERATING INCOME (LOSS)	141.6		111.1
Other Income (Expense):
Interest Income	0.7		0.4	[6]
Allowance for Equity Funds Used During Construction	11.3		14.9
Interest Expense	(21.7)		(20.3)	[6]
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	131.9		106.1
Income Tax Expense (Benefit)	27.6		22.0	[6]
NET INCOME (LOSS)	104.3		84.1	[6]
AEP Transmission Co [Member] | Transmission Revenues [Member]
Revenues
Revenue from Contracts with Customers	50.3		30.9	[6]
AEP Transmission Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.0		0.1	[6]
TOTAL REVENUES	0.0	[3]	0.0	[4],[5]
Appalachian Power Co [Member]
Revenues
Revenue from Contracts with Customers	788.4		826.3
Sales to AEP Affiliates	51.7		49.4
TOTAL REVENUES	792.8		820.4
Expenses
Other Operation	136.9		138.2
Maintenance	61.5		72.0
Depreciation and Amortization	112.5		108.5
Taxes Other Than Income Taxes	35.9		33.8
TOTAL EXPENSES	640.7		627.4
OPERATING INCOME (LOSS)	152.1		193.0
Other Income (Expense):
Interest Income	0.8		0.3
Carrying Costs Income	0.0		0.5
Allowance for Equity Funds Used During Construction	1.7		2.6
Non-Service Cost Components of Net Periodic Benefit Cost	4.3		4.5
Interest Expense	(49.3)		(47.4)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	109.6		153.5
Income Tax Expense (Benefit)	(24.1)		28.0
NET INCOME (LOSS)	133.7		125.5
Appalachian Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	738.7		767.5
Appalachian Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	2.4		3.5
TOTAL REVENUES	0.0	[3]	0.0	[4]
Appalachian Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	183.3		69.0
Appalachian Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	110.6		205.9
Indiana Michigan Power Co [Member]
Revenues
Revenue from Contracts with Customers	619.1		576.3
Sales to AEP Affiliates	2.3		4.7
Other Revenues - Affiliated	13.3		13.2
TOTAL REVENUES	614.3		576.8
Expenses
Purchased Electricity from AEP Affiliates	59.8		61.4
Other Operation	140.5		146.1
Maintenance	58.3		54.5
Depreciation and Amortization	86.2		59.3
Taxes Other Than Income Taxes	27.3		25.0
TOTAL EXPENSES	499.3		479.4
OPERATING INCOME (LOSS)	115.0		97.4
Other Income (Expense):
Carrying Costs Income	(0.7)		2.4
Other Income	5.7		4.4
Allowance for Equity Funds Used During Construction	6.2		1.8
Non-Service Cost Components of Net Periodic Benefit Cost	4.4		4.5
Interest Expense	(28.9)		(29.7)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	96.2		76.6
Income Tax Expense (Benefit)	(2.7)		12.4
NET INCOME (LOSS)	98.9		64.2
Indiana Michigan Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	596.7		553.9
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	2.0		5.0
Sales to AEP Affiliates	15.0		15.0
TOTAL REVENUES	0.0	[3]	5.5	[4]
Indiana Michigan Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	57.6		77.5
Indiana Michigan Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	69.6		55.6
Ohio Power Co [Member]
Revenues
Revenue from Contracts with Customers	828.1		780.7
Sales to AEP Affiliates	7.5		3.1
TOTAL REVENUES	836.8		790.9
Expenses
Purchased Electricity from AEP Affiliates	46.1		30.2
Amortization Of Generation Deferrals	32.4		58.6
Other Operation	216.9		172.2
Maintenance	32.5		37.2
Depreciation and Amortization	63.3		64.8
Taxes Other Than Income Taxes	108.9		105.1
TOTAL EXPENSES	674.3		673.6
OPERATING INCOME (LOSS)	162.5		117.3
Other Income (Expense):
Interest Income	0.8		0.9
Carrying Costs Income	0.2		0.7
Allowance for Equity Funds Used During Construction	5.2		2.5
Non-Service Cost Components of Net Periodic Benefit Cost	3.7		3.9
Interest Expense	(24.6)		(25.2)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	147.8		100.1
Income Tax Expense (Benefit)	19.8		20.5
NET INCOME (LOSS)	128.0		79.6
Ohio Power Co [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	826.5		786.3
Ohio Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	2.8		1.5
TOTAL REVENUES	5.1	[3]	3.9	[4]
Ohio Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	174.2		205.5
Public Service Co Of Oklahoma [Member]
Revenues
Revenue from Contracts with Customers	334.0		333.5
Sales to AEP Affiliates	1.6		1.1
TOTAL REVENUES	332.8		336.8
Expenses
Other Operation	73.6		86.8
Maintenance	22.5		26.9
Depreciation and Amortization	43.5		36.8
Taxes Other Than Income Taxes	11.4		11.6
TOTAL EXPENSES	311.9		332.9
OPERATING INCOME (LOSS)	20.9		3.9
Other Income (Expense):
Other Income	0.1		0.0
Allowance for Equity Funds Used During Construction	0.1		(0.1)
Non-Service Cost Components of Net Periodic Benefit Cost	2.1		2.2
Interest Expense	(16.9)		(14.7)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	6.2		(8.6)
Income Tax Expense (Benefit)	0.0		(1.4)
NET INCOME (LOSS)	6.2		(7.2)
Public Service Co Of Oklahoma [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	329.2		335.1
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	2.0		0.6
TOTAL REVENUES	0.0	[3]	0.0	[4]
Public Service Co Of Oklahoma [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	38.0		48.4
Public Service Co Of Oklahoma [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	122.9		122.4
Southwestern Electric Power Co [Member]
Revenues
Revenue from Contracts with Customers	426.4		419.7
Sales to AEP Affiliates	6.4		6.1
TOTAL REVENUES	421.1		419.4
Expenses
Other Operation	84.6		94.9
Maintenance	28.9		31.0
Depreciation and Amortization	62.1		57.4
Taxes Other Than Income Taxes	25.3		25.0
TOTAL EXPENSES	367.0		377.8
OPERATING INCOME (LOSS)	54.1		41.6
Other Income (Expense):
Interest Income	0.7		1.8
Allowance for Equity Funds Used During Construction	1.8		2.3
Non-Service Cost Components of Net Periodic Benefit Cost	2.1		2.3
Interest Expense	(29.7)		(32.2)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	29.0		15.8
Income Tax Expense (Benefit)	0.7		2.9
Equity Earnings (Loss) of Unconsolidated Subsidiaries	0.7		0.5
NET INCOME (LOSS)	29.0		13.4
Net Income Attributable to Noncontrolling Interests	1.2		1.6
EARNINGS ATTRIBUTABLE TO COMMON SHAREHOLDERS	27.8		11.8
Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	414.3		413.0
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.4		0.3
TOTAL REVENUES	0.0	[3]	0.0	[4]
Southwestern Electric Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	133.5		126.8
Southwestern Electric Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	$ 32.6		$ 42.7

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

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