Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues
Vertically Integrated Utilities	$ 2,340.7	$ 2,095.7	$ 4,722.2	$ 4,365.5
Transmission and Distribution Utilities	1,127.9	1,026.6	2,269.1	2,093.0
Generation & Marketing	435.3	386.5	912.8	945.3
Sales to AEP Affiliates	0.0	0.0	0.0	0.0
Other Revenues	109.3	67.7	157.4	106.0
TOTAL REVENUES	4,013.2	3,576.5	8,061.5	7,509.8
Expenses
Fuel and Other Consumables Used for Electric Generation	566.9	522.3	1,068.7	1,157.9
Purchased Electricity for Resale	776.7	669.2	1,767.0	1,438.8
Other Operation	780.3	616.4	1,506.7	1,240.1
Maintenance	295.9	290.1	594.4	593.6
Gain on Sale of Merchant Generation Assets	0.0	0.1	0.0	(226.4)
Depreciation and Amortization	553.2	485.5	1,092.9	967.4
Taxes Other Than Income Taxes	283.2	259.6	568.8	519.4
TOTAL EXPENSES	3,256.2	2,843.2	6,598.5	5,690.8
OPERATING INCOME (LOSS)	757.0	733.3	1,463.0	1,819.0
Other Income (Expense):
Interest and Investment Income	3.8	2.3	5.9	10.3
Carrying Costs Income	2.9	5.7	6.3	11.6
Allowance for Equity Funds Used During Construction	30.8	21.0	61.5	42.2
Non-Service Cost Components of Net Periodic Benefit Cost	31.4	11.4	63.4	22.8
Interest Expense	(242.3)	(222.9)	(476.3)	(444.7)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	583.6	550.8	1,123.8	1,461.2
Income Tax Expense (Credit)	72.2	190.6	174.2	533.8
Equity Earnings (Loss) of Unconsolidated Subsidiaries	18.7	16.0	37.2	43.0
Net Income (Loss)	530.1	376.2	986.8	970.4
Net Income Attributable to Noncontrolling Interests	1.7	1.2	4.0	3.2
Earnings Attributable to Common Shareholders	$ 528.4	$ 375.0	$ 982.8	$ 967.2
Earnings Per Share
Weighted Average Number of Basic AEP Common Shares Outstanding	492,688,342	491,790,752	492,479,035	491,751,614
Basic Earnings Per Share Attributable to AEP Common Shareholders from Continuing Operations	$ 1.07	$ 0.76	$ 2.00	$ 1.97
Total Basic Earnings Per Share Attributable to AEP Common Shareholders	$ 1.07	$ 0.76	$ 2.00	$ 1.97
Weighted Average Number of Diluted AEP Common Shares Outstanding	493,505,085	492,642,100	493,317,355	492,337,255
Diluted Earnings Per Share Attributable to AEP Common Shareholders from Continuing Operations	$ 1.07	$ 0.76	$ 1.99	$ 1.96
Total Diluted Earnings Per Share Attributable to AEP Common Shareholders	1.07	0.76	1.99	1.96
Common Stock, Dividends Per Share, Declared	$ 0.62	$ 0.59	$ 1.24	$ 1.18
AEP Texas Inc. [Member]
Revenues
Transmission and Distribution Utilities	$ 370.1	$ 371.0	$ 722.5	$ 699.9
Sales to AEP Affiliates	17.6	17.8	35.8	31.9
Other Revenues	0.6	0.7	1.6	1.3
TOTAL REVENUES	388.3	389.5	759.9	733.1
Expenses
Fuel and Other Consumables Used for Electric Generation	5.8	5.9	14.7	8.9
Other Operation	118.0	106.5	235.0	215.3
Maintenance	23.1	20.4	44.6	38.8
Depreciation and Amortization	121.6	116.2	231.6	219.0
Taxes Other Than Income Taxes	33.6	31.7	66.0	60.0
TOTAL EXPENSES	302.1	280.7	591.9	542.0
OPERATING INCOME (LOSS)	86.2	108.8	168.0	191.1
Other Income (Expense):
Allowance for Equity Funds Used During Construction			9.4	2.2
Other Income	2.9	0.5	8.9	3.3
Non-Service Cost Components of Net Periodic Benefit Cost	3.0	0.9	6.1	1.8
Interest Expense	(36.6)	(35.3)	(71.6)	(70.3)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	55.5	74.9	111.4	125.9
Income Tax Expense (Credit)	9.0	25.9	18.1	43.6
Net Income (Loss)	46.5	49.0	93.3	82.3
AEP Transmission Co [Member]
Revenues
Electrical Transmission Revenue	51.2	44.0	82.5	63.2
Sales to AEP Affiliates	132.6	185.4	294.7	318.8
Other Revenues	0.0	0.0	0.1	0.1
TOTAL REVENUES	183.8	229.4	377.3	382.1
Expenses
Other Operation	18.5	11.3	35.1	20.4
Maintenance	2.2	2.3	4.8	5.4
Depreciation and Amortization	32.4	22.8	63.0	46.1
Taxes Other Than Income Taxes	36.6	27.6	67.7	54.4
TOTAL EXPENSES	89.7	64.0	170.6	126.3
OPERATING INCOME (LOSS)	94.1	165.4	206.7	255.8
Other Income (Expense):
Interest Income	0.4	0.1	0.8	0.3
Allowance for Equity Funds Used During Construction	16.3	13.4	31.6	24.3
Interest Expense	(20.3)	(15.7)	(40.2)	(31.7)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	90.5	163.2	198.9	248.7
Income Tax Expense (Credit)	20.0	55.8	42.5	84.3
Net Income (Loss)	70.5	107.4	156.4	164.4
Appalachian Power Co [Member]
Revenues
Vertically Integrated Utilities	618.8	625.6	1,386.3	1,370.6
Sales to AEP Affiliates	46.4	46.3	95.8	88.7
Other Revenues	1.8	3.4	5.3	8.8
TOTAL REVENUES	667.0	675.3	1,487.4	1,468.1
Expenses
Fuel and Other Consumables Used for Electric Generation	155.3	152.5	224.3	319.7
Purchased Electricity for Resale	64.5	65.2	270.4	156.0
Other Operation	109.9	139.2	248.1	253.1
Maintenance	65.7	60.8	137.7	132.0
Depreciation and Amortization	105.3	100.7	213.8	201.3
Taxes Other Than Income Taxes	33.7	30.8	67.5	61.0
TOTAL EXPENSES	534.4	549.2	1,161.8	1,123.1
OPERATING INCOME (LOSS)	132.6	126.1	325.6	345.0
Other Income (Expense):
Interest Income	0.6	0.5	0.9	0.8
Carrying Costs Income	0.5	0.3	1.0	0.6
Allowance for Equity Funds Used During Construction	2.9	2.0	5.5	3.5
Non-Service Cost Components of Net Periodic Benefit Cost	4.4	1.3	8.9	2.6
Interest Expense	(47.8)	(48.2)	(95.2)	(96.3)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	93.2	82.0	246.7	256.2
Income Tax Expense (Credit)	15.8	29.9	43.8	93.5
Net Income (Loss)	77.4	52.1	202.9	162.7
Indiana Michigan Power Co [Member]
Revenues
Vertically Integrated Utilities	560.1	451.9	1,114.0	990.4
Other Revenues - Affiliated	27.2	12.4	45.1	31.1
Other Revenues	2.4	3.0	7.4	6.3
TOTAL REVENUES	589.7	467.3	1,166.5	1,027.8
Expenses
Fuel and Other Consumables Used for Electric Generation	73.4	71.1	150.9	161.8
Purchased Electricity for Resale	63.2	31.0	118.8	68.3
Purchased Electricity from AEP Affiliates	60.4	49.9	121.8	103.8
Other Operation	130.4	159.7	276.5	296.8
Maintenance	57.4	50.7	111.9	102.1
Depreciation and Amortization	62.6	49.8	121.9	99.8
Taxes Other Than Income Taxes	24.9	21.5	49.9	44.4
TOTAL EXPENSES	472.3	433.7	951.7	877.0
OPERATING INCOME (LOSS)	117.4	33.6	214.8	150.8
Other Income (Expense):
Interest Income	1.0	0.3	1.2	1.4
Carrying Costs Income	1.6	4.3	4.0	7.7
Allowance for Equity Funds Used During Construction	2.3	2.5	4.1	4.6
Non-Service Cost Components of Net Periodic Benefit Cost	4.5	1.6	9.0	3.1
Interest Expense	(31.4)	(27.8)	(61.1)	(55.5)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	95.4	14.5	172.0	112.1
Income Tax Expense (Credit)	0.7	4.0	13.1	33.2
Net Income (Loss)	94.7	10.5	158.9	78.9
Ohio Power Co [Member]
Revenues
Transmission and Distribution Utilities	735.9	653.4	1,522.2	1,391.8
Sales to AEP Affiliates	11.5	9.1	14.6	14.8
Other Revenues	1.4	1.4	2.9	3.4
TOTAL REVENUES	748.8	663.9	1,539.7	1,410.0
Expenses
Purchased Electricity for Resale	162.9	156.4	368.4	344.7
Purchased Electricity from AEP Affiliates	27.9	24.7	58.1	56.7
Amortization of Generation Deferrals	56.4	53.3	115.0	114.2
Other Operation	199.0	131.7	371.2	254.0
Maintenance	34.1	33.3	71.3	70.5
Depreciation and Amortization	65.1	51.1	129.9	108.4
Taxes Other Than Income Taxes	99.0	94.9	204.1	193.4
TOTAL EXPENSES	644.4	545.4	1,318.0	1,141.9
OPERATING INCOME (LOSS)	104.4	118.5	221.7	268.1
Other Income (Expense):
Interest Income	0.9	0.8	1.8	3.3
Carrying Costs Income	0.6	0.6	1.3	2.5
Allowance for Equity Funds Used During Construction	3.3	0.8	5.8	3.2
Non-Service Cost Components of Net Periodic Benefit Cost	3.9	1.1	7.8	2.2
Interest Expense	(25.3)	(26.1)	(50.5)	(51.1)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	87.8	95.7	187.9	228.2
Income Tax Expense (Credit)	19.0	33.4	39.5	79.7
Net Income (Loss)	68.8	62.3	148.4	148.5
Public Service Co Of Oklahoma [Member]
Revenues
Vertically Integrated Utilities	395.3	342.6	730.4	644.5
Sales to AEP Affiliates	1.5	1.0	2.6	2.1
Other Revenues	1.5	1.1	2.1	2.2
TOTAL REVENUES	398.3	344.7	735.1	648.8
Expenses
Fuel and Other Consumables Used for Electric Generation	58.7	25.6	107.1	37.9
Purchased Electricity for Resale	113.1	126.7	235.5	252.0
Other Operation	93.7	76.1	180.5	144.4
Maintenance	24.0	28.8	50.9	63.0
Depreciation and Amortization	41.4	32.6	78.2	66.1
Taxes Other Than Income Taxes	10.2	9.6	21.8	20.2
TOTAL EXPENSES	341.1	299.4	674.0	583.6
OPERATING INCOME (LOSS)	57.2	45.3	61.1	65.2
Other Income (Expense):
Allowance for Equity Funds Used During Construction			(0.1)	0.4
Other Income	(0.1)	0.0	(0.1)	0.5
Non-Service Cost Components of Net Periodic Benefit Cost	2.2	0.8	4.4	1.7
Interest Expense	(16.3)	(13.4)	(31.0)	(27.0)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	43.0	32.7	34.4	40.4
Income Tax Expense (Credit)	6.4	12.3	5.0	15.2
Net Income (Loss)	36.6	20.4	29.4	25.2
Southwestern Electric Power Co [Member]
Revenues
Vertically Integrated Utilities	451.4	416.0	864.4	812.3
Sales to AEP Affiliates	5.4	8.1	11.5	12.7
Other Revenues	0.3	0.6	0.6	1.0
TOTAL REVENUES	457.1	424.7	876.5	826.0
Expenses
Fuel and Other Consumables Used for Electric Generation	114.5	111.4	241.3	242.3
Purchased Electricity for Resale	53.4	46.3	96.1	78.7
Other Operation	98.0	74.8	192.9	153.7
Maintenance	37.6	41.7	68.6	73.9
Depreciation and Amortization	58.6	52.1	116.0	102.9
Taxes Other Than Income Taxes	24.5	24.3	49.5	47.6
TOTAL EXPENSES	386.6	350.6	764.4	699.1
OPERATING INCOME (LOSS)	70.5	74.1	112.1	126.9
Other Income (Expense):
Interest Income	0.6	0.4	2.4	1.3
Allowance for Equity Funds Used During Construction	0.9	0.0	3.2	0.8
Non-Service Cost Components of Net Periodic Benefit Cost	2.3	0.9	4.6	1.8
Interest Expense	(30.9)	(30.9)	(63.1)	(60.8)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	43.4	44.5	59.2	70.0
Income Tax Expense (Credit)	5.4	13.2	8.3	22.7
Equity Earnings (Loss) of Unconsolidated Subsidiaries	0.7	(6.2)	1.2	(4.9)
Net Income (Loss)	38.7	25.1	52.1	42.4
Net Income Attributable to Noncontrolling Interests	1.1	0.6	2.7	1.6
Earnings Attributable to Common Shareholders	$ 37.6	$ 24.5	$ 49.4	$ 40.8