Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenues
Vertically Integrated Utilities	$ 2,269.8	$ 2,218.1
Transmission and Distribution Utilities	1,066.4	1,077.3
Generation & Marketing	558.8	713.9
Other Revenues	38.3	35.6
TOTAL REVENUES	3,933.3	4,044.9
Expenses
Fuel and Other Consumables Used for Electric Generation	635.6	675.6
Purchased Electricity for Resale	769.6	731.4
Other Operation	602.2	715.1
Maintenance	302.4	278.7
Other Asset Impairment Charges	11.2	0.0
Gain on Sale of Merchant Generation Assets	(226.5)	0.0
Depreciation and Amortization	481.9	497.1
Taxes Other Than Income Taxes	259.8	254.1
TOTAL EXPENSES	2,836.2	3,152.0
Operating Income (Loss)	1,097.1	892.9
Other Income (Expense):
Interest and Investment Income	8.0	2.1
Carrying Costs Income	5.9	3.9
Allowance for Equity Funds Used During Construction	21.2	31.7
Interest Expense	(221.8)	(217.0)
INCOME BEFORE INCOME TAX EXPENSE	910.4	713.6
Income Tax Expense (Credit)	343.2	235.5
Equity Earnings (Loss) of Unconsolidated Subsidiaries	27.0	25.0
Net Income (Loss)	594.2	503.1
Net Income Attributable to Noncontrolling Interests	2.0	1.9
Earnings Attributable to Common Shareholders	$ 592.2	$ 501.2
Earnings Per Share
Weighted Average Number of Basic AEP Common Shares Outstanding	491,712,042	491,108,392
Total Basic Earnings Per Share Attributable to AEP Common Shareholders	$ 1.20	$ 1.02
Weighted Average Number of Diluted AEP Common Shares Outstanding	492,031,975	491,332,305
Total Diluted Earnings Per Share Attributable to AEP Common Shareholders	$ 1.20	$ 1.02
Common Stock, Dividends, Per Share, Declared	$ 0.59	$ 0.56
Appalachian Power Co [Member]
Revenues
Vertically Integrated Utilities	$ 745.0	$ 775.5
Sales to AEP Affiliates	42.4	40.4
Other Revenues	5.4	4.1
TOTAL REVENUES	792.8	820.0
Expenses
Fuel and Other Consumables Used for Electric Generation	167.2	150.7
Purchased Electricity for Resale	90.8	108.2
Other Operation	112.6	120.6
Maintenance	71.2	69.3
Depreciation and Amortization	100.6	95.5
Taxes Other Than Income Taxes	30.2	31.3
TOTAL EXPENSES	572.6	575.6
Operating Income (Loss)	220.2	244.4
Other Income (Expense):
Allowance for Equity Funds Used During Construction	1.5	2.3
Other Income	2.1	1.8
Interest Expense	(48.1)	(47.0)
INCOME BEFORE INCOME TAX EXPENSE	174.2	199.2
Income Tax Expense (Credit)	63.6	72.9
Net Income (Loss)	110.6	126.3
Indiana Michigan Power Co [Member]
Revenues
Vertically Integrated Utilities	538.5	500.4
Sales to AEP Affiliates	0.6	11.5
Other Revenues - Affiliated	18.1	15.3
Other Revenues	3.3	5.5
TOTAL REVENUES	560.5	532.7
Expenses
Fuel and Other Consumables Used for Electric Generation	90.7	69.2
Purchased Electricity for Resale	37.3	49.6
Purchased Electricity from AEP Affiliates	53.9	45.4
Other Operation	135.6	141.3
Maintenance	51.4	40.9
Depreciation and Amortization	50.0	47.1
Taxes Other Than Income Taxes	22.9	23.4
TOTAL EXPENSES	441.8	416.9
Operating Income (Loss)	118.7	115.8
Other Income (Expense):
Interest Income	4.5	3.2
Allowance for Equity Funds Used During Construction	2.1	2.3
Interest Expense	(27.7)	(22.5)
INCOME BEFORE INCOME TAX EXPENSE	97.6	98.8
Income Tax Expense (Credit)	29.2	24.1
Net Income (Loss)	68.4	74.7
Ohio Power Co [Member]
Revenues
Transmission and Distribution Utilities	738.4	756.7
Sales to AEP Affiliates	5.7	4.8
Other Revenues	2.0	2.1
TOTAL REVENUES	746.1	763.6
Expenses
Purchased Electricity for Resale	188.3	164.9
Purchased Electricity from AEP Affiliates	32.0	49.1
Amortization Of Generation Deferrals	60.9	55.1
Other Operation	121.2	167.9
Maintenance	37.2	33.7
Depreciation and Amortization	57.3	61.3
Taxes Other Than Income Taxes	98.5	97.6
TOTAL EXPENSES	595.4	629.6
Operating Income (Loss)	150.7	134.0
Other Income (Expense):
Interest Income	2.5	1.5
Carrying Costs Income	1.9	1.9
Allowance for Equity Funds Used During Construction	2.4	1.7
Interest Expense	(25.0)	(31.4)
INCOME BEFORE INCOME TAX EXPENSE	132.5	107.7
Income Tax Expense (Credit)	46.3	37.5
Net Income (Loss)	86.2	70.2
Public Service Co Of Oklahoma [Member]
Revenues
Vertically Integrated Utilities	301.9	271.8
Sales to AEP Affiliates	1.1	1.0
Other Revenues	1.1	1.5
TOTAL REVENUES	304.1	274.3
Expenses
Fuel and Other Consumables Used for Electric Generation	12.3	15.5
Purchased Electricity for Resale	125.3	93.3
Other Operation	67.4	62.9
Maintenance	34.2	21.8
Depreciation and Amortization	33.5	35.3
Taxes Other Than Income Taxes	10.6	9.7
TOTAL EXPENSES	283.3	238.5
Operating Income (Loss)	20.8	35.8
Other Income (Expense):
Interest Income	0.1	0.2
Allowance for Equity Funds Used During Construction	0.4	2.3
Interest Expense	(13.6)	(14.4)
INCOME BEFORE INCOME TAX EXPENSE	7.7	23.9
Income Tax Expense (Credit)	2.9	8.2
Net Income (Loss)	4.8	15.7
Southwestern Electric Power Co [Member]
Revenues
Vertically Integrated Utilities	396.3	375.4
Sales to AEP Affiliates	4.6	3.1
Other Revenues	0.4	0.5
TOTAL REVENUES	401.3	379.0
Expenses
Fuel and Other Consumables Used for Electric Generation	130.9	121.9
Purchased Electricity for Resale	32.4	28.1
Other Operation	78.0	77.1
Maintenance	32.2	31.1
Depreciation and Amortization	50.8	47.5
Taxes Other Than Income Taxes	23.3	21.9
TOTAL EXPENSES	347.6	327.6
Operating Income (Loss)	53.7	51.4
Other Income (Expense):
Interest Income	0.9	0.0
Allowance for Equity Funds Used During Construction	0.8	7.4
Interest Expense	(29.9)	(27.9)
INCOME BEFORE INCOME TAX EXPENSE	25.5	30.9
Income Tax Expense (Credit)	9.5	7.4
Equity Earnings (Loss) of Unconsolidated Subsidiaries	1.3	1.0
Net Income (Loss)	17.3	24.5
Net Income Attributable to Noncontrolling Interests	1.0	1.1
Earnings Attributable to Common Shareholders	$ 16.3	$ 23.4