Organization and Summary of Significant Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Materials and Supplies		$ 680.6	$ 640.7
Supplementary Information
Depreciation and Amortization of Property, Plant and Equipment		2,487.5	2,203.7	$ 1,965.0
Amortization of Certain Securitized Assets		171.3	280.7	287.9
Amortization of Regulatory Assets and Liabilities		24.0	30.1	33.7
Total Depreciation and Amortization		2,682.8	2,514.5	2,286.6
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period		246.8
Restricted Cash		45.6	185.8
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		438.3	432.6	444.1	$ 412.6
Amounts Attributable to AEP Common Shareholders
Net Income (Loss) Attributable to Noncontrolling Interests		(3.4)	(1.3)	7.5
Net Income (Loss)		$ 2,200.1	$ 1,921.1	$ 1,923.8
Weighted Average Number of Basic AEP Common Shares Outstanding		495,718,223	493,694,345	492,774,600
Earnings Per Share, Basic		$ 4.44	$ 3.89	$ 3.90
Weighted Average Dilutive Effect of:
Weighted Average Number of Diluted AEP Common Shares Outstanding		497,226,867	495,306,238	493,758,277
Earnings Per Share, Diluted		$ 4.42	$ 3.88	$ 3.90
Revenues
TOTAL REVENUES		$ 14,918.5	$ 15,561.4	$ 16,195.7
Expenses
Depreciation and Amortization		2,682.8	2,514.5	2,286.6
TOTAL EXPENSES		11,930.8	12,969.1	13,513.0
OPERATING INCOME (LOSS)		2,987.7	2,592.3	2,682.7
Other Income (Expense)
Allowance for Equity Funds Used During Construction		148.1	168.4	132.5
Interest Expense		(1,165.7)	(1,072.5)	(984.4)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)		2,146.1	1,834.8	1,973.5
Income Tax Expense (Benefit)		40.5	(12.9)	115.3
Net Income (Loss)		2,196.7	1,919.8	1,931.3
Accounts Receivable:
Customers		613.6	625.3
Total Accounts Receivable		1,842.7	1,705.1
Accrued Tax Benefits		185.3	85.8
TOTAL CURRENT ASSETS		4,351.5	4,077.8
Property, Plant and Equipment
Transmission		27,886.7	24,808.6
Other Property, Plant and Equipment		5,294.6	4,811.5
Construction Work in Progress		4,025.7	4,319.8
Total Property, Plant and Equipment		84,313.0	79,145.7
Accumulated Depreciation and Amortization		20,411.4	19,007.6
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		63,901.6	60,138.1
Other Noncurrent Assets
TOTAL OTHER NONCURRENT ASSETS		12,504.1	11,676.4
TOTAL ASSETS		80,757.2	75,892.3	68,802.8
Current Liabilities
Accounts Payable		1,709.7	2,085.8
Accrued Taxes		1,476.4	1,357.8
TOTAL CURRENT LIABILITIES		9,926.7	10,299.1
Liabilities, Noncurrent
Deferred Income Taxes		8,240.9	7,588.2
Regulatory Liabilities and Deferred Investment Tax Credits		8,378.7	8,457.6
TOTAL NONCURRENT LIABILITIES		50,010.8	45,571.4
TOTAL LIABILITIES		59,937.5	55,870.5
Equity [Abstract]
Retained Earnings		10,687.8	9,900.9
TOTAL LIABILITIES AND EQUITY		80,757.2	75,892.3
Operating Activites
Net Income (Loss)		2,196.7	1,919.8	1,931.3
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization		2,682.8	2,514.5	2,286.6
Deferred Income Taxes		196.1	(17.8)	104.3
Allowance for Equity Funds Used During Construction		(148.1)	(168.4)	(132.5)
Amortization of Deferred Property Taxes		(43.3)	(73.8)	(59.1)
Change in Other Noncurrent Assets		(142.5)	(112.8)	(172.1)
Increase (Decrease) in Other Noncurrent Liabilities		(54.5)	(116.1)	129.0
Accounts Receivable, Net		(129.3)	247.8	145.9
Accounts Payable		(35.3)	5.8	36.6
Accrued Taxes, Net		20.1	138.9	153.2
Net Cash Flows from Operating Activities		3,832.9	4,270.1	5,223.2
Investing Activities
Net Cash Flows Used for Investing Activities		(6,233.9)	(7,144.5)	(6,353.6)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from Financing Activities		2,406.7	2,862.9	1,161.9
Cash and Cash Equivalents at Beginning of Period		246.8
Cash and Cash Equivalents at End of Period		392.7	246.8
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts		1,029.1	1,022.5	939.3
Income Taxes		(49.1)	6.1	(24.7)
Noncash Investing and Financing Activities:
Noncash Acquisition Under Finance Leases		44.2	87.5	55.6
Construction in Progress Expenditures Incurred but Not yet Paid		975.4	1,341.1	1,120.4
Construction Expenditures Included in Current Liabilities as of December 31,		975.4	1,341.1	1,120.4
Construction Expenditures Included in Noncurrent Liabilities as of December 31,		5.5	0.0	0.0
Acquisition of Nuclear Fuel Included in Current Liabilities as of December 31,		33.4	0.1	4.0
Noncash Contribution of Assets by Noncontrolling Interest		0.0	0.0	84.0
Expected Reimbursement For Spent Nuclear Fuel Dry Cask Storage		2.6	0.3	2.2
Liabilities Assumed with Sempra Renewable LLC and Santa Rita East Acquisition		0.0	32.4	0.0
Forward Equity Purchase Contract included in Current and Noncurrent liabilities		(86.2)	(7.6)	23.1
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt		5,626.1	4,536.6	4,945.7
Repayments of Long-term Debt		1,339.8	1,220.8	2,782.0
Equity Method Investment		1,406.3	1,356.6
Income (Loss) from Equity Method Investment		$ 91.1	$ 72.1	$ 73.1
Antidilutive Shares Outstanding		128,000	0	0
Net Income (Loss)		$ 2,196.7	$ 1,919.8	$ 1,931.3
Retained Earnings		$ 10,687.8	9,900.9
Employees Participating in Voluntary Retirement Incentive Program		200
Percent of Voluntary Retirement Incentive Program Expense Related to AEP Service Corporation		92.00%
Lump Sum Salary Payments and Cash Subsidies
Organization and Summary of Significant Accounting Policies (Textuals)
Voluntary Retirement Incentive Program Expense		$ 13.0
Incremental Long-Term Incentive Plan Grants
Organization and Summary of Significant Accounting Policies (Textuals)
Voluntary Retirement Incentive Program Expense		5.0
Retained Earnings [Member]
Amounts Attributable to AEP Common Shareholders
Net Income (Loss)		2,200.1	1,921.1	1,923.8
Noncash Investing and Financing Activities:
Forward Equity Purchase Contract included in Current and Noncurrent liabilities		$ 110.6	47.3	0.0
Berkshire Hathaway [Member]
Organization and Summary of Significant Accounting Policies (Textuals)
Equity Method Investment, Ownership Percentage		50.00%
AEP Transmission Holdco [Member]
Organization and Summary of Significant Accounting Policies (Textuals)
Equity Method Investment, Ownership Percentage		50.00%
Pension Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		25.00%
Pension Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		59.00%
Pension Plans [Member] | Other Investments [Member]
Target Asset Allocations
Target Asset Allocation		15.00%
Pension Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		1.00%
Other Postretirement Benefit Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Other Postretirement Benefit Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Other Postretirement Benefit Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		2.00%
Pension and Other Postretirement Benefit Plans [Member]
Supplementary Information
Securities Loaned		$ 177.0	246.0
AEP Texas Inc. [Member]
Materials and Supplies		70.0	56.7
Supplementary Information
Depreciation and Amortization of Property, Plant and Equipment		364.2	365.9	262.2
Amortization of Certain Securitized Assets		171.3	258.7	240.0
Amortization of Regulatory Assets and Liabilities		(5.7)	(2.3)	(2.6)
Total Depreciation and Amortization		529.8	622.3	499.6
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period		3.1
Restricted Cash		28.7	154.7
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		$ 28.8	$ 157.8	$ 159.8	157.2
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk		10.00%	10.00%	10.00%
Revenues
TOTAL REVENUES		$ 1,618.9	$ 1,709.3	$ 1,595.3
Expenses
Depreciation and Amortization		529.8	622.3	499.6
TOTAL EXPENSES		1,249.3	1,477.3	1,249.0
OPERATING INCOME (LOSS)		369.6	232.0	346.3
Other Income (Expense)
Allowance for Equity Funds Used During Construction		19.4	15.2	20.0
Interest Expense		(171.8)	(137.2)	(147.3)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)		229.8	124.7	232.1
Income Tax Expense (Benefit)		(11.2)	(53.6)	20.8
Net Income (Loss)		241.0	178.3	211.3
Accounts Receivable:
Customers		112.8	116.0
Total Accounts Receivable		183.6	193.4
Accrued Tax Benefits		16.8	66.1
TOTAL CURRENT ASSETS		310.9	692.9
Property, Plant and Equipment
Transmission		5,279.6	4,466.5
Other Property, Plant and Equipment		868.4	805.9
Construction Work in Progress		614.1	763.9
Total Property, Plant and Equipment		11,342.9	10,603.2
Accumulated Depreciation and Amortization		1,529.3	1,758.1
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		9,813.6	8,845.1
Other Noncurrent Assets
TOTAL OTHER NONCURRENT ASSETS		905.7	1,051.1
TOTAL ASSETS		11,030.2	10,589.1
Current Liabilities
Accounts Payable		231.7	256.8
Affiliated Companies		44.0	35.6
Accrued Taxes		78.3	84.9
TOTAL CURRENT LIABILITIES		676.8	1,027.2
Liabilities, Noncurrent
Deferred Income Taxes		1,016.7	965.4
Regulatory Liabilities and Deferred Investment Tax Credits		1,270.8	1,316.9
TOTAL NONCURRENT LIABILITIES		7,147.4	6,600.8
TOTAL LIABILITIES		7,824.2	7,628.0
Equity [Abstract]
Retained Earnings		1,757.0	1,516.0
TOTAL LIABILITIES AND EQUITY		11,030.2	10,589.1
Operating Activites
Net Income (Loss)		241.0	178.3	211.3
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization		529.8	622.3	499.6
Deferred Income Taxes		(15.2)	(23.5)	(16.5)
Allowance for Equity Funds Used During Construction		(19.4)	(15.2)	(20.0)
Change in Other Noncurrent Assets		(74.0)	9.3	(60.3)
Increase (Decrease) in Other Noncurrent Liabilities		(24.7)	11.3	44.9
Accounts Receivable, Net		9.8	3.5	(2.9)
Accounts Payable		30.2	7.5	(20.3)
Accrued Taxes, Net		42.7	(11.8)	(5.6)
Net Cash Flows from Operating Activities		614.2	823.4	651.9
Investing Activities
Net Cash Flows Used for Investing Activities		(1,065.4)	(1,472.2)	(1,289.7)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from Financing Activities		322.2	646.8	640.4
Cash and Cash Equivalents at Beginning of Period		3.1
Cash and Cash Equivalents at End of Period		0.1	3.1
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts		153.2	148.6	145.9
Income Taxes		(42.9)	(11.0)	7.9
Noncash Investing and Financing Activities:
Construction in Progress Expenditures Incurred but Not yet Paid		177.8	225.5	243.1
Construction Expenditures Included in Current Liabilities as of December 31,		177.8	225.5	243.1
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt		652.7	1,070.4	494.0
Repayments of Long-term Debt		392.1	401.8	266.1
Net Income (Loss)		241.0	178.3	211.3
Retained Earnings		1,757.0	1,516.0
AEP Texas Inc. [Member] | Retained Earnings [Member]
Other Income (Expense)
Net Income (Loss)		241.0	178.3	211.3
Operating Activites
Net Income (Loss)		241.0	178.3	211.3
Organization and Summary of Significant Accounting Policies (Textuals)
Net Income (Loss)		$ 241.0	178.3	211.3
AEP Texas Inc. [Member] | Pension Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		25.00%
AEP Texas Inc. [Member] | Pension Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		59.00%
AEP Texas Inc. [Member] | Pension Plans [Member] | Other Investments [Member]
Target Asset Allocations
Target Asset Allocation		15.00%
AEP Texas Inc. [Member] | Pension Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		1.00%
AEP Texas Inc. [Member] | Other Postretirement Benefit Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
AEP Texas Inc. [Member] | Other Postretirement Benefit Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
AEP Texas Inc. [Member] | Other Postretirement Benefit Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		2.00%
AEP Texas Inc. [Member] | Pension and Other Postretirement Benefit Plans [Member]
Supplementary Information
Securities Loaned		$ 177.0	246.0
AEP Transmission Co [Member]
Materials and Supplies		8.5	13.8
Supplementary Information
Depreciation and Amortization of Property, Plant and Equipment		249.0	176.0	133.9
Amortization of Certain Securitized Assets		0.0	0.0	0.0
Amortization of Regulatory Assets and Liabilities		0.0	0.0	0.0
Total Depreciation and Amortization		249.0	176.0	133.9
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period		$ 0.0	$ 0.0	$ 0.0
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk		10.00%	10.00%	10.00%
Revenues
TOTAL REVENUES		$ 1,145.7	$ 1,021.4	$ 776.1
Expenses
Depreciation and Amortization		249.0	176.0	133.9
TOTAL EXPENSES		564.2	454.2	366.0
OPERATING INCOME (LOSS)		581.5	567.2	410.1
Other Income (Expense)
Allowance for Equity Funds Used During Construction		74.0	84.3	70.6
Interest Expense		(127.8)	(97.4)	(83.2)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)		530.1	557.1	400.0
Income Tax Expense (Benefit)		106.7	117.4	84.1
Net Income (Loss)		423.4	439.7	315.9
Accounts Receivable:
Customers		22.9	19.0
Total Accounts Receivable		104.1	85.1
Accrued Tax Benefits		9.9	9.3
TOTAL CURRENT ASSETS		235.8	197.4
Property, Plant and Equipment
Transmission		9,593.5	8,137.9
Other Property, Plant and Equipment		329.5	269.6
Construction Work in Progress		1,422.6	1,485.7
Total Property, Plant and Equipment		11,345.6	9,893.2
Accumulated Depreciation and Amortization		572.8	402.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		10,772.8	9,490.9
Other Noncurrent Assets
Deferred Property Taxes		220.1	193.5
TOTAL OTHER NONCURRENT ASSETS		237.4	202.5
TOTAL ASSETS		11,246.0	9,890.8	8,394.1
Current Liabilities
Accounts Payable		380.4	493.4
Affiliated Companies		97.3	71.2
Accrued Taxes		418.1	355.6
TOTAL CURRENT LIABILITIES		1,137.5	1,093.1
Liabilities, Noncurrent
Deferred Income Taxes		906.9	817.8
Regulatory Liabilities and Deferred Investment Tax Credits		581.8	540.9
TOTAL NONCURRENT LIABILITIES		5,395.6	4,788.2
TOTAL LIABILITIES		6,533.1	5,881.3
Equity [Abstract]
Retained Earnings		1,947.3	1,528.9
TOTAL MEMBER'S EQUITY		4,712.9	4,009.5	3,569.8	2,589.9
TOTAL LIABILITIES AND EQUITY		11,246.0	9,890.8
Operating Activites
Net Income (Loss)		423.4	439.7	315.9
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization		249.0	176.0	133.9
Deferred Income Taxes		81.6	91.3	98.9
Allowance for Equity Funds Used During Construction		(74.0)	(84.3)	(70.6)
Amortization of Deferred Property Taxes		(26.6)	(35.6)	(32.9)
Change in Other Noncurrent Assets		(8.2)	9.6	14.6
Increase (Decrease) in Other Noncurrent Liabilities		8.3	(8.1)	17.4
Accounts Receivable, Net		(19.0)	(5.4)	36.7
Accounts Payable		77.8	37.6	(7.5)
Accrued Taxes, Net		62.7	90.8	73.4
Net Cash Flows from Operating Activities		771.2	708.6	548.6
Investing Activities
Net Cash Flows Used for Investing Activities		(1,640.4)	(1,403.2)	(1,513.3)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from Financing Activities		869.2	694.6	964.7
Net Increase (Decrease) in Cash and Cash Equivalents		0.0	0.0	0.0
Cash and Cash Equivalents at Beginning of Period		0.0	0.0	0.0
Cash and Cash Equivalents at End of Period		0.0	0.0	0.0
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts		119.7	90.6	80.2
Income Taxes		22.9	1.5	(30.7)
Noncash Investing and Financing Activities:
Construction in Progress Expenditures Incurred but Not yet Paid		311.9	472.7	345.0
Construction Expenditures Included in Current Liabilities as of December 31,		311.9	472.7	345.0
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt		519.5	688.0	321.0
Repayments of Long-term Debt		0.0	85.0	50.0
Net Income (Loss)		423.4	439.7	315.9
Retained Earnings		1,947.3	1,528.9
AEP Transmission Co [Member] | Retained Earnings [Member]
Other Income (Expense)
Net Income (Loss)		423.4	439.7	315.9
Equity [Abstract]
TOTAL MEMBER'S EQUITY		1,947.3	1,528.9	1,089.2	773.3
Operating Activites
Net Income (Loss)		423.4	439.7	315.9
Organization and Summary of Significant Accounting Policies (Textuals)
Net Income (Loss)		423.4	439.7	315.9
Appalachian Power Co [Member]
Materials and Supplies		99.6	105.2
Supplementary Information
Depreciation and Amortization of Property, Plant and Equipment		507.8	466.5	428.1
Amortization of Certain Securitized Assets		0.0	0.0	0.0
Amortization of Regulatory Assets and Liabilities		(0.3)	0.3	0.3
Total Depreciation and Amortization		507.5	466.8	428.4
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period		3.3
Restricted Cash		16.9	23.5
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		$ 22.7	$ 26.8	$ 29.8	19.2
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk		10.00%	10.00%	10.00%
Revenues
TOTAL REVENUES		$ 2,796.2	$ 2,924.7	$ 2,967.5
Expenses
Depreciation and Amortization		507.5	466.8	428.4
TOTAL EXPENSES		2,239.6	2,527.4	2,484.0
OPERATING INCOME (LOSS)		556.6	397.3	483.5
Other Income (Expense)
Allowance for Equity Funds Used During Construction		14.6	16.6	13.2
Interest Expense		(217.6)	(205.0)	(194.8)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)		374.0	228.3	322.9
Income Tax Expense (Benefit)		4.3	(78.0)	(44.9)
Net Income (Loss)		369.7	306.3	367.8
Accounts Receivable:
Customers		142.8	129.0
Total Accounts Receivable		284.4	250.9
TOTAL CURRENT ASSETS		674.1	700.6
Property, Plant and Equipment
Transmission		3,900.5	3,584.1
Other Property, Plant and Equipment		627.2	571.3
Construction Work in Progress		484.6	593.4
Total Property, Plant and Equipment		16,110.3	15,514.2
Accumulated Depreciation and Amortization		4,716.2	4,432.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		11,394.1	11,081.9
Other Noncurrent Assets
TOTAL OTHER NONCURRENT ASSETS		1,247.0	985.8
TOTAL ASSETS		13,315.2	12,768.3
Current Liabilities
Accounts Payable		212.0	307.8
Affiliated Companies		97.1	92.5
Accrued Taxes		109.9	99.6
TOTAL CURRENT LIABILITIES		1,217.7	1,226.0
Liabilities, Noncurrent
Deferred Income Taxes		1,749.9	1,680.8
Regulatory Liabilities and Deferred Investment Tax Credits		1,224.7	1,268.7
TOTAL NONCURRENT LIABILITIES		7,753.2	7,369.9
TOTAL LIABILITIES		8,970.9	8,595.9
Equity [Abstract]
Retained Earnings		2,248.0	2,078.3
TOTAL LIABILITIES AND EQUITY		13,315.2	12,768.3
Operating Activites
Net Income (Loss)		369.7	306.3	367.8
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization		507.5	466.8	428.4
Deferred Income Taxes		(26.2)	(126.2)	(16.8)
Allowance for Equity Funds Used During Construction		(14.6)	(16.6)	(13.2)
Change in Other Noncurrent Assets		(40.4)	(38.2)	58.1
Increase (Decrease) in Other Noncurrent Liabilities		11.2	(40.3)	(4.8)
Accounts Receivable, Net		(30.2)	35.7	33.6
Accounts Payable		(48.1)	37.7	(13.3)
Accrued Taxes, Net		31.3	(10.2)	(13.2)
Net Cash Flows from Operating Activities		712.0	661.4	846.6
Investing Activities
Net Cash Flows Used for Investing Activities		(757.9)	(837.4)	(769.4)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from Financing Activities		41.8	173.0	(66.6)
Cash and Cash Equivalents at Beginning of Period		3.3
Cash and Cash Equivalents at End of Period		5.8	3.3
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts		207.1	190.7	182.0
Income Taxes		0.0	63.0	(13.0)
Noncash Investing and Financing Activities:
Construction in Progress Expenditures Incurred but Not yet Paid		105.6	149.7	134.4
Construction Expenditures Included in Current Liabilities as of December 31,		105.6	149.7	134.4
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt		606.9	478.2	203.2
Repayments of Long-term Debt		140.3	180.5	124.0
Net Income (Loss)		369.7	306.3	367.8
Retained Earnings		2,248.0	2,078.3
Appalachian Power Co [Member] | Retained Earnings [Member]
Other Income (Expense)
Net Income (Loss)		369.7	306.3	367.8
Operating Activites
Net Income (Loss)		369.7	306.3	367.8
Organization and Summary of Significant Accounting Policies (Textuals)
Net Income (Loss)		$ 369.7	306.3	367.8
Appalachian Power Co [Member] | Pension Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		25.00%
Appalachian Power Co [Member] | Pension Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		59.00%
Appalachian Power Co [Member] | Pension Plans [Member] | Other Investments [Member]
Target Asset Allocations
Target Asset Allocation		15.00%
Appalachian Power Co [Member] | Pension Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		1.00%
Appalachian Power Co [Member] | Other Postretirement Benefit Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Appalachian Power Co [Member] | Other Postretirement Benefit Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Appalachian Power Co [Member] | Other Postretirement Benefit Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		2.00%
Appalachian Power Co [Member] | Pension and Other Postretirement Benefit Plans [Member]
Supplementary Information
Securities Loaned		$ 177.0	246.0
Indiana Michigan Power Co [Member]
Materials and Supplies		175.8	171.3
Supplementary Information
Depreciation and Amortization of Property, Plant and Equipment		393.3	330.6	278.9
Amortization of Certain Securitized Assets		0.0	0.0	0.0
Amortization of Regulatory Assets and Liabilities		18.3	20.0	14.2
Total Depreciation and Amortization		411.6	350.6	293.1
Ohio Valley Electric Corporation - Barging and Other Transportation Services (43.47% Owned)		60.8	63.4	63.4
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period		$ 2.0	$ 2.4	$ 1.3
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk		10.00%	10.00%	10.00%
Revenues
TOTAL REVENUES		$ 2,241.8	$ 2,306.7	$ 2,370.7
Expenses
Depreciation and Amortization		411.6	350.6	293.1
TOTAL EXPENSES		1,878.9	1,965.9	1,993.5
OPERATING INCOME (LOSS)		362.9	340.8	377.2
Other Income (Expense)
Allowance for Equity Funds Used During Construction		11.5	19.4	11.9
Interest Expense		(112.3)	(117.9)	(124.1)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)		277.3	258.8	290.4
Income Tax Expense (Benefit)		(7.5)	(10.6)	29.1
Net Income (Loss)		284.8	269.4	261.3
Accounts Receivable:
Customers		44.0	53.6
Total Accounts Receivable		97.0	109.5
Accrued Tax Benefits		10.3	0.0
TOTAL CURRENT ASSETS		418.8	403.0
Property, Plant and Equipment
Transmission		1,696.4	1,641.8
Other Property, Plant and Equipment		686.7	632.6
Construction Work in Progress		362.4	382.3
Total Property, Plant and Equipment		10,604.8	10,194.0
Accumulated Depreciation and Amortization		3,552.5	3,294.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		7,052.3	6,899.7
Other Noncurrent Assets
TOTAL OTHER NONCURRENT ASSETS		4,167.2	3,934.7
TOTAL ASSETS		11,638.3	11,237.4
Current Liabilities
Accounts Payable		153.2	169.4
Affiliated Companies		80.5	68.4
Accrued Taxes		102.5	112.4
TOTAL CURRENT LIABILITIES		1,104.5	883.4
Liabilities, Noncurrent
Deferred Income Taxes		1,064.4	979.7
Regulatory Liabilities and Deferred Investment Tax Credits		2,041.9	1,891.4
TOTAL NONCURRENT LIABILITIES		7,784.6	7,809.6
TOTAL LIABILITIES		8,889.1	8,693.0
Equity [Abstract]
Retained Earnings		1,718.7	1,518.5
TOTAL LIABILITIES AND EQUITY		11,638.3	11,237.4
Operating Activites
Net Income (Loss)		284.8	269.4	261.3
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization		411.6	350.6	293.1
Deferred Income Taxes		(16.2)	(52.7)	(42.9)
Allowance for Equity Funds Used During Construction		(11.5)	(19.4)	(11.9)
Change in Other Noncurrent Assets		6.1	8.3	(36.5)
Increase (Decrease) in Other Noncurrent Liabilities		45.0	33.7	72.1
Accounts Receivable, Net		14.5	35.4	4.8
Accounts Payable		(10.8)	3.6	(14.1)
Accrued Taxes, Net		(20.2)	48.3	41.2
Net Cash Flows from Operating Activities		776.3	685.2	725.7
Investing Activities
Net Cash Flows Used for Investing Activities		(648.9)	(720.1)	(654.8)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from Financing Activities		(126.1)	34.5	(69.8)
Net Increase (Decrease) in Cash and Cash Equivalents		1.3	(0.4)	1.1
Cash and Cash Equivalents at Beginning of Period		2.0	2.4	1.3
Cash and Cash Equivalents at End of Period		3.3	2.0	2.4
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts		107.6	111.9	116.9
Income Taxes		42.1	3.4	32.6
Noncash Investing and Financing Activities:
Construction in Progress Expenditures Incurred but Not yet Paid		62.8	86.0	93.0
Construction Expenditures Included in Current Liabilities as of December 31,		62.8	86.0	93.0
Acquisition of Nuclear Fuel Included in Current Liabilities as of December 31,		33.4	0.1	4.0
Expected Reimbursement For Spent Nuclear Fuel Dry Cask Storage		2.6	0.3	2.2
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt		69.5	123.3	1,168.1
Repayments of Long-term Debt		93.2	117.1	884.9
Net Income (Loss)		284.8	269.4	261.3
Retained Earnings		1,718.7	1,518.5
Indiana Michigan Power Co [Member] | Retained Earnings [Member]
Other Income (Expense)
Net Income (Loss)		284.8	269.4	261.3
Operating Activites
Net Income (Loss)		284.8	269.4	261.3
Organization and Summary of Significant Accounting Policies (Textuals)
Net Income (Loss)		$ 284.8	269.4	261.3
Indiana Michigan Power Co [Member] | Pension Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		25.00%
Indiana Michigan Power Co [Member] | Pension Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		59.00%
Indiana Michigan Power Co [Member] | Pension Plans [Member] | Other Investments [Member]
Target Asset Allocations
Target Asset Allocation		15.00%
Indiana Michigan Power Co [Member] | Pension Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		1.00%
Indiana Michigan Power Co [Member] | Other Postretirement Benefit Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Indiana Michigan Power Co [Member] | Other Postretirement Benefit Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Indiana Michigan Power Co [Member] | Other Postretirement Benefit Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		2.00%
Indiana Michigan Power Co [Member] | Pension and Other Postretirement Benefit Plans [Member]
Supplementary Information
Securities Loaned		$ 177.0	246.0
Ohio Power Co [Member]
Materials and Supplies		66.9	52.3
Supplementary Information
Depreciation and Amortization of Property, Plant and Equipment		275.0	229.4	232.6
Amortization of Certain Securitized Assets		0.0	22.0	47.9
Amortization of Regulatory Assets and Liabilities		1.6	(10.5)	(20.8)
Total Depreciation and Amortization		276.6	240.9	259.7
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period		3.7
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		$ 7.4	$ 3.7	$ 32.5	$ 29.7
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk		10.00%	10.00%	10.00%
Revenues
TOTAL REVENUES		$ 2,749.1	$ 2,797.6	$ 3,063.4
Expenses
Depreciation and Amortization		276.6	240.9	259.7
TOTAL EXPENSES		2,345.4	2,396.4	2,643.6
OPERATING INCOME (LOSS)		403.7	401.2	419.8
Other Income (Expense)
Allowance for Equity Funds Used During Construction		12.5	18.2	9.8
Interest Expense		(117.2)	(106.2)	(100.7)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)		316.6	332.0	349.5
Income Tax Expense (Benefit)		45.2	34.9	24.0
Net Income (Loss)		271.4	297.1	325.5
Accounts Receivable:
Customers		50.0	53.0
Total Accounts Receivable		133.2	132.4
TOTAL CURRENT ASSETS		256.3	238.5
Property, Plant and Equipment
Transmission		2,831.9	2,686.3
Other Property, Plant and Equipment		899.6	765.8
Construction Work in Progress		362.3	394.4
Total Property, Plant and Equipment		9,802.1	9,170.0
Accumulated Depreciation and Amortization		2,350.0	2,263.0
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		7,452.1	6,907.0
Other Noncurrent Assets
TOTAL OTHER NONCURRENT ASSETS		1,002.0	898.1
TOTAL ASSETS		8,710.4	8,043.6
Current Liabilities
Accounts Payable		181.0	233.7
Affiliated Companies		118.4	103.6
Accrued Taxes		631.0	587.9
TOTAL CURRENT LIABILITIES		1,906.2	1,297.9
Liabilities, Noncurrent
Deferred Income Taxes		955.1	849.4
Regulatory Liabilities and Deferred Investment Tax Credits		1,005.2	1,090.9
TOTAL NONCURRENT LIABILITIES		4,111.5	4,237.2
TOTAL LIABILITIES		6,017.7	5,535.1
Equity [Abstract]
Retained Earnings		1,532.7	1,348.5
TOTAL LIABILITIES AND EQUITY		8,710.4	8,043.6
Operating Activites
Net Income (Loss)		271.4	297.1	325.5
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization		276.6	240.9	259.7
Deferred Income Taxes		77.2	43.8	(36.2)
Allowance for Equity Funds Used During Construction		(12.5)	(18.2)	(9.8)
Amortization of Deferred Property Taxes		(16.6)	(33.7)	(12.5)
Change in Other Noncurrent Assets		(49.4)	(35.3)	(11.5)
Increase (Decrease) in Other Noncurrent Liabilities		(66.4)	(93.2)	53.8
Accounts Receivable, Net		4.2	75.0	43.1
Accounts Payable		10.3	0.4	(13.8)
Accrued Taxes, Net		43.3	38.7	26.8
Net Cash Flows from Operating Activities		410.9	421.2	1,028.7
Investing Activities
Net Cash Flows Used for Investing Activities		(791.0)	(744.1)	(707.5)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from Financing Activities		383.8	294.1	(318.4)
Cash and Cash Equivalents at Beginning of Period		3.7
Cash and Cash Equivalents at End of Period		7.4	3.7
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts		111.2	100.6	97.1
Income Taxes		(26.9)	7.3	51.3
Noncash Investing and Financing Activities:
Construction in Progress Expenditures Incurred but Not yet Paid		76.7	125.9	98.2
Construction Expenditures Included in Current Liabilities as of December 31,		76.7	125.9	98.2
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt		347.0	444.3	392.8
Repayments of Long-term Debt		0.1	80.3	397.1
Net Income (Loss)		271.4	297.1	325.5
Retained Earnings		1,532.7	1,348.5
Ohio Power Co [Member] | Retained Earnings [Member]
Other Income (Expense)
Net Income (Loss)		271.4	297.1	325.5
Operating Activites
Net Income (Loss)		271.4	297.1	325.5
Organization and Summary of Significant Accounting Policies (Textuals)
Net Income (Loss)		$ 271.4	297.1	325.5
Ohio Power Co [Member] | Pension Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		25.00%
Ohio Power Co [Member] | Pension Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		59.00%
Ohio Power Co [Member] | Pension Plans [Member] | Other Investments [Member]
Target Asset Allocations
Target Asset Allocation		15.00%
Ohio Power Co [Member] | Pension Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		1.00%
Ohio Power Co [Member] | Other Postretirement Benefit Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Ohio Power Co [Member] | Other Postretirement Benefit Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Ohio Power Co [Member] | Other Postretirement Benefit Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		2.00%
Ohio Power Co [Member] | Pension and Other Postretirement Benefit Plans [Member]
Supplementary Information
Securities Loaned		$ 177.0	246.0
Public Service Co Of Oklahoma [Member]
Materials and Supplies		54.0	46.8
Supplementary Information
Depreciation and Amortization of Property, Plant and Equipment		171.9	162.5	155.5
Amortization of Certain Securitized Assets		0.0	0.0	0.0
Amortization of Regulatory Assets and Liabilities		1.6	7.0	8.5
Total Depreciation and Amortization		173.5	169.5	164.0
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period		$ 1.5	$ 2.0	$ 1.6
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk		10.00%	10.00%	10.00%
Revenues
TOTAL REVENUES		$ 1,266.1	$ 1,481.8	$ 1,547.3
Expenses
Depreciation and Amortization		173.5	169.5	164.0
TOTAL EXPENSES		1,090.2	1,282.5	1,404.8
OPERATING INCOME (LOSS)		175.9	199.3	142.5
Other Income (Expense)
Allowance for Equity Funds Used During Construction		4.0	2.7	0.4
Interest Expense		(60.3)	(66.5)	(63.5)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)		128.2	145.1	88.2
Income Tax Expense (Benefit)		5.2	7.5	5.0
Net Income (Loss)		123.0	137.6	83.2
Accounts Receivable:
Customers		30.8	28.9
Total Accounts Receivable		48.4	49.8
Accrued Tax Benefits		10.9	11.3
TOTAL CURRENT ASSETS		181.3	188.2
Property, Plant and Equipment
Transmission		1,069.9	948.5
Other Property, Plant and Equipment		393.3	342.1
Construction Work in Progress		128.7	133.4
Total Property, Plant and Equipment		5,925.6	5,683.4
Accumulated Depreciation and Amortization		1,605.6	1,580.1
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		4,320.0	4,103.3
Other Noncurrent Assets
TOTAL OTHER NONCURRENT ASSETS		489.4	460.0
TOTAL ASSETS		4,990.7	4,751.5
Current Liabilities
Accounts Payable		107.0	134.3
Affiliated Companies		43.4	59.3
Accrued Taxes		26.8	22.9
TOTAL CURRENT LIABILITIES		478.6	445.8
Liabilities, Noncurrent
Deferred Income Taxes		688.5	628.3
Regulatory Liabilities and Deferred Investment Tax Credits		802.2	837.2
TOTAL NONCURRENT LIABILITIES		2,966.5	2,932.4
TOTAL LIABILITIES		3,445.1	3,378.2
Equity [Abstract]
Retained Earnings		974.3	851.0
TOTAL LIABILITIES AND EQUITY		4,990.7	4,751.5
Operating Activites
Net Income (Loss)		123.0	137.6	83.2
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization		173.5	169.5	164.0
Deferred Income Taxes		17.0	(18.2)	(31.1)
Allowance for Equity Funds Used During Construction		(4.0)	(2.7)	(0.4)
Change in Other Noncurrent Assets		(17.9)	5.7	0.0
Increase (Decrease) in Other Noncurrent Liabilities		1.6	(7.3)	21.4
Accounts Receivable, Net		1.4	15.4	5.1
Accounts Payable		(29.5)	7.0	17.7
Accrued Taxes, Net		3.6	3.9	13.2
Net Cash Flows from Operating Activities		157.0	350.3	330.5
Investing Activities
Net Cash Flows Used for Investing Activities		(295.1)	(328.1)	(233.0)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from Financing Activities		139.2	(22.7)	(97.1)
Net Increase (Decrease) in Cash and Cash Equivalents		1.1	(0.5)	0.4
Cash and Cash Equivalents at Beginning of Period		1.5	2.0	1.6
Cash and Cash Equivalents at End of Period		2.6	1.5	2.0
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts		59.1	61.1	62.0
Income Taxes		(11.8)	22.4	17.9
Noncash Investing and Financing Activities:
Construction in Progress Expenditures Incurred but Not yet Paid		35.5	46.0	33.2
Construction Expenditures Included in Current Liabilities as of December 31,		35.5	46.0	33.2
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt		0.0	349.5	0.0
Repayments of Long-term Debt		13.2	250.5	0.5
Net Income (Loss)		123.0	137.6	83.2
Retained Earnings		974.3	851.0
Public Service Co Of Oklahoma [Member] | Retained Earnings [Member]
Other Income (Expense)
Net Income (Loss)		123.0	137.6	83.2
Operating Activites
Net Income (Loss)		123.0	137.6	83.2
Organization and Summary of Significant Accounting Policies (Textuals)
Net Income (Loss)		$ 123.0	137.6	83.2
Public Service Co Of Oklahoma [Member] | Pension Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		25.00%
Public Service Co Of Oklahoma [Member] | Pension Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		59.00%
Public Service Co Of Oklahoma [Member] | Pension Plans [Member] | Other Investments [Member]
Target Asset Allocations
Target Asset Allocation		15.00%
Public Service Co Of Oklahoma [Member] | Pension Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		1.00%
Public Service Co Of Oklahoma [Member] | Other Postretirement Benefit Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Public Service Co Of Oklahoma [Member] | Other Postretirement Benefit Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Public Service Co Of Oklahoma [Member] | Other Postretirement Benefit Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		2.00%
Public Service Co Of Oklahoma [Member] | Pension and Other Postretirement Benefit Plans [Member]
Supplementary Information
Securities Loaned		$ 177.0	246.0
Southwestern Electric Power Co [Member]
Materials and Supplies		95.8	94.0
Supplementary Information
Depreciation and Amortization of Property, Plant and Equipment		271.2	247.9	237.0
Amortization of Certain Securitized Assets		0.0	0.0	0.0
Amortization of Regulatory Assets and Liabilities		1.5	1.2	2.5
Total Depreciation and Amortization		272.7	249.1	239.5
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period		$ 1.6	$ 24.5	$ 1.6
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk		10.00%	10.00%	10.00%
Amounts Attributable to AEP Common Shareholders
Net Income (Loss) Attributable to Noncontrolling Interests		$ 2.9	$ 3.6	$ 5.0
Net Income (Loss)		180.8	158.6	147.2
Revenues
TOTAL REVENUES		1,738.5	1,750.9	1,821.9
Expenses
Depreciation and Amortization		272.7	249.1	239.5
TOTAL EXPENSES		1,448.0	1,495.2	1,544.2
OPERATING INCOME (LOSS)		290.5	255.7	277.7
Other Income (Expense)
Allowance for Equity Funds Used During Construction		7.7	6.8	6.0
Interest Expense		(118.5)	(119.1)	(127.9)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)		190.2	154.5	169.9
Income Tax Expense (Benefit)		9.4	(4.7)	20.4
Net Income (Loss)		183.7	162.2	152.2
Accounts Receivable:
Customers		27.1	29.0
Total Accounts Receivable		64.9	75.3
Accrued Tax Benefits		29.9	7.6
TOTAL CURRENT ASSETS		428.0	354.1
Property, Plant and Equipment
Transmission		2,165.7	2,056.5
Other Property, Plant and Equipment		788.8	733.4
Construction Work in Progress		228.3	216.9
Total Property, Plant and Equipment		10,246.7	9,968.9
Accumulated Depreciation and Amortization		3,158.5	2,873.7
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		7,088.2	7,095.2
Other Noncurrent Assets
TOTAL OTHER NONCURRENT ASSETS		637.9	382.9
TOTAL ASSETS		8,154.1	7,832.2
Current Liabilities
Accounts Payable		135.9	138.0
Affiliated Companies		43.0	53.6
Accrued Taxes		41.0	41.8
TOTAL CURRENT LIABILITIES		763.6	674.7
Liabilities, Noncurrent
Deferred Income Taxes		1,017.6	940.9
Regulatory Liabilities and Deferred Investment Tax Credits		863.4	892.3
TOTAL NONCURRENT LIABILITIES		4,762.8	4,716.4
TOTAL LIABILITIES		5,526.4	5,391.1
Equity [Abstract]
Retained Earnings		1,811.9	1,629.5
TOTAL LIABILITIES AND EQUITY		8,154.1	7,832.2
Operating Activites
Net Income (Loss)		183.7	162.2	152.2
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization		272.7	249.1	239.5
Deferred Income Taxes		32.4	(11.0)	1.2
Allowance for Equity Funds Used During Construction		(7.7)	(6.8)	(6.0)
Change in Other Noncurrent Assets		16.1	2.7	(18.1)
Increase (Decrease) in Other Noncurrent Liabilities		25.2	2.7	42.8
Accounts Receivable, Net		7.3	0.0	53.5
Accounts Payable		11.1	(28.4)	0.9
Accrued Taxes, Net		(23.1)	(3.2)	2.3
Net Cash Flows from Operating Activities		356.3	339.8	504.8
Investing Activities
Net Cash Flows Used for Investing Activities		(392.6)	(330.2)	(528.9)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from Financing Activities		47.9	(32.5)	47.0
Net Increase (Decrease) in Cash and Cash Equivalents		11.6	(22.9)	22.9
Cash and Cash Equivalents at Beginning of Period		1.6	24.5	1.6
Cash and Cash Equivalents at End of Period		13.2	1.6	24.5
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts		110.7	111.1	125.7
Income Taxes		4.3	8.6	18.8
Noncash Investing and Financing Activities:
Construction in Progress Expenditures Incurred but Not yet Paid		46.0	69.1	42.0
Construction Expenditures Included in Current Liabilities as of December 31,		46.0	69.1	42.0
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt		0.0	0.0	1,065.7
Repayments of Long-term Debt		21.2	59.7	794.5
Income (Loss) from Equity Method Investment		2.9	3.0	2.7
Net Income (Loss)		183.7	162.2	152.2
Retained Earnings		1,811.9	1,629.5
Southwestern Electric Power Co [Member] | Retained Earnings [Member]
Amounts Attributable to AEP Common Shareholders
Net Income (Loss)		$ 180.8	158.6	$ 147.2
Southwestern Electric Power Co [Member] | Pension Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		25.00%
Southwestern Electric Power Co [Member] | Pension Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		59.00%
Southwestern Electric Power Co [Member] | Pension Plans [Member] | Other Investments [Member]
Target Asset Allocations
Target Asset Allocation		15.00%
Southwestern Electric Power Co [Member] | Pension Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		1.00%
Southwestern Electric Power Co [Member] | Other Postretirement Benefit Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Southwestern Electric Power Co [Member] | Other Postretirement Benefit Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Southwestern Electric Power Co [Member] | Other Postretirement Benefit Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		2.00%
Southwestern Electric Power Co [Member] | Pension and Other Postretirement Benefit Plans [Member]
Supplementary Information
Securities Loaned		$ 177.0	$ 246.0
Restricted Stock Units and Performance Share Units [Member]
Weighted Average Dilutive Effect of:
Weighted Average Dilutive Effect of Shares		1,500,000	1,600,000	1,000,000.0
Dilutive Securities, Effect on Basic Earnings Per Share		$ (0.02)	$ (0.01)	$ 0
Revenues [Member] | AEP Texas Inc. [Member]
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk	[1]	46.00%	48.00%	45.00%
Revenues [Member] | AEP Transmission Co [Member]
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk		78.00%	79.00%	77.00%
Accounts Receivable [Member] | AEP Texas Inc. [Member]
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk	[1]	40.00%	43.00%	35.00%
Accounts Receivable [Member] | AEP Transmission Co [Member]
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk		78.00%	78.00%	84.00%
Noncontrolling Interest [Member] | Sempra Renewables LLC and Santa Rita East Acquisition [Member]
Noncash Investing and Financing Activities:
Noncash Contribution of Assets by Noncontrolling Interest		$ 0.0	$ 253.4	$ 0.0
Sabine Mining Co [Member] | Southwestern Electric Power Co [Member]
Materials and Supplies		23.3	23.1
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period		0.0
Property, Plant and Equipment
Other Property, Plant and Equipment		223.7	212.3
Accumulated Depreciation and Amortization		126.5	107.5
Net Cash Provided by (Used in) Financing Activities
Cash and Cash Equivalents at Beginning of Period		0.0
Cash and Cash Equivalents at End of Period		$ 10.1	$ 0.0

[1] In January 2021, NRG Energy, parent company of Reliant Energy, completed a deal to purchase Direct Energy from Centrica.