Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019		Mar. 31, 2018
Operating Activities
Net Income (Loss)	$ 574.1		$ 456.7
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	605.8		539.7
Deferred Income Taxes	16.8		87.3
Allowance for Equity Funds Used During Construction	(28.9)		(30.7)
Mark-to-Market of Risk Management Contracts	65.5		(0.7)
Amortization of Nuclear Fuel	25.1		27.4
Property Taxes	(75.6)		(63.7)
Deferred Fuel Over/Under-Recovery, Net	32.5		(61.2)
Recovery of Ohio Capacity Costs	14.7		18.0
Provision for Refund - Global Settlement	(4.1)		(5.4)
Change in Other Noncurrent Assets	(47.9)		(59.8)
Change in Other Noncurrent Liabilities	67.3		133.3
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	57.5		39.7
Fuel, Materials and Supplies	(26.4)		28.5
Accounts Payable	(152.6)		(129.3)
Accrued Taxes, Net	(77.0)		(74.3)
Other Current Assets	(18.8)		(40.1)
Other Current Liabilities	(219.7)		(63.2)
Net Cash Flows from (Used for) Operating Activities	808.3		802.2
Investing Activities
Construction Expenditures	(1,565.4)		(1,905.8)
Purchases of Investment Securities	(130.4)		(525.9)
Sales of Investment Securities	111.9		508.6
Acquisitions of Nuclear Fuel	(32.4)		(23.8)
Other Investing Activities	33.5		19.1
Net Cash Flows from (Used for) Investing Activities	(1,582.8)		(1,927.8)
Financing Activities
Issuance of Common Stock, Net	14.5		32.2
Issuance of Long-term Debt	1,285.6		841.0
Commercial Paper and Credit Facility Borrowings	0.0		205.6
Change in Short-term Debt, Net	(52.0)		814.6
Retirement of Long-term Debt	(220.6)		(544.0)
Principal Payments for Finance Lease Obligations	(14.3)		(16.8)
Dividends Paid on Common Stock	(333.6)		(306.1)
Other Financing Activities	13.9		3.0
Net Cash Flows from (Used for) Financing Activities	693.5		1,029.5
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	(81.0)		(96.1)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	444.1		412.6
Cash and Cash Equivalents at Beginning of Period	234.1
Cash, Cash Equivalents and Restricted Cash at End of Period	363.1		316.5
Cash and Cash Equivalents at End of Period	227.7
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	168.9		188.0
Net Cash Paid (Received) for Income Taxes	(0.6)		(0.9)
Noncash Acquisitions Under Finance Leases	23.1		21.4
Construction Expenditures Included in Current Liabilities as of March 31,	846.3		799.9
Noncash Contribution of Assets by Noncontrolling Interest	0.0		84.0
Expected Reimbursement For Spent Nuclear Fuel Dry Cask Storage	1.0		0.1
Forward Equity Purchase Contract Included Current and Noncurrent Liabilities as of March 31,	(55.6)		16.9
AEP Texas Inc. [Member]
Operating Activities
Net Income (Loss)	34.4		46.8
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	138.9		110.0
Deferred Income Taxes	(11.0)		(4.4)
Allowance for Equity Funds Used During Construction	(1.8)		(5.5)
Mark-to-Market of Risk Management Contracts	0.0		0.2
Property Taxes	(73.8)		(56.1)
Change in Other Noncurrent Assets	(3.2)		(12.7)
Change in Other Noncurrent Liabilities	(5.7)		6.5
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(7.8)		1.8
Fuel, Materials and Supplies	(1.0)		(0.2)
Accounts Payable	4.2		(25.9)
Accrued Taxes, Net	57.5		25.2
Other Current Assets	0.5		(1.6)
Other Current Liabilities	(4.4)		(5.1)
Net Cash Flows from (Used for) Operating Activities	126.8		79.0
Investing Activities
Construction Expenditures	(343.1)		(481.6)
Change in Advances to Affiliates, Net	0.3		103.8
Other Investing Activities	6.2		13.4
Net Cash Flows from (Used for) Investing Activities	(336.6)		(364.4)
Financing Activities
Capital Contributions from Parent	200.0		100.0
Change in Advances from Affiliates, Net	55.2		232.7
Retirement of Long-term Debt	(103.5)		(96.5)
Principal Payments for Finance Lease Obligations	(1.2)		(1.1)
Other Financing Activities	0.2		0.3
Net Cash Flows from (Used for) Financing Activities	150.7		235.4
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	(59.1)		(50.0)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	159.8		157.2
Cash and Cash Equivalents at Beginning of Period	3.1
Cash, Cash Equivalents and Restricted Cash at End of Period	100.7		107.2
Cash and Cash Equivalents at End of Period	0.1
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	22.4		27.8
Net Cash Paid (Received) for Income Taxes	(5.6)		0.0
Noncash Acquisitions Under Finance Leases	2.4		4.0
Construction Expenditures Included in Current Liabilities as of March 31,	195.7		169.3
AEP Transmission Co [Member]
Operating Activities
Net Income (Loss)	104.3		84.1	[1]
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	40.3		30.3
Deferred Income Taxes	14.5		15.5
Allowance for Equity Funds Used During Construction	(11.3)		(14.9)
Property Taxes	23.2		17.3
Change in Other Noncurrent Assets	2.7		2.9
Change in Other Noncurrent Liabilities	2.2		23.9
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(8.2)		(9.6)
Fuel, Materials and Supplies	(0.6)		(1.9)
Accounts Payable	11.4		(10.7)
Accrued Taxes, Net	(32.1)		(34.0)
Accrued Interest	19.2		23.3
Other Current Assets	0.4		0.3
Other Current Liabilities	0.2		0.6
Net Cash Flows from (Used for) Operating Activities	166.2		127.1
Investing Activities
Construction Expenditures	(365.0)		(571.8)
Change in Advances to Affiliates, Net	23.4		114.2
Payments to Acquire Property, Plant, and Equipment	(2.5)		(1.8)
Other Investing Activities	0.3		1.0
Net Cash Flows from (Used for) Investing Activities	(343.8)		(458.4)
Financing Activities
Capital Contributions from Parent	0.0		65.0
Change in Advances from Affiliates, Net	177.7		266.4
Other Financing Activities	(0.1)		(0.1)
Net Cash Flows from (Used for) Financing Activities	177.6		331.3
Net Increase (Decrease) in Cash and Cash Equivalents	0.0		0.0
Cash and Cash Equivalents at Beginning of Period	0.0		0.0
Cash and Cash Equivalents at End of Period	0.0		0.0
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	1.6		(3.0)
Net Cash Paid (Received) for Income Taxes	(1.2)		0.0
Construction Expenditures Included in Current Liabilities as of March 31,	261.1		213.8
Appalachian Power Co [Member]
Operating Activities
Net Income (Loss)	133.7		125.5
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	112.5		108.5
Deferred Income Taxes	(45.0)		11.0
Carrying Costs Income	0.0		(0.5)
Allowance for Equity Funds Used During Construction	(1.7)		(2.6)
Mark-to-Market of Risk Management Contracts	50.6		14.9
Deferred Fuel Over/Under-Recovery, Net	20.8		(90.7)
Change in Other Noncurrent Assets	(12.1)		3.9
Change in Other Noncurrent Liabilities	(20.5)		37.9
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	19.5		(14.2)
Fuel, Materials and Supplies	(9.6)		19.3
Accounts Payable	(8.3)		(21.6)
Accrued Taxes, Net	13.7		17.8
Other Current Assets	(0.8)		(15.8)
Other Current Liabilities	(2.3)		5.6
Net Cash Flows from (Used for) Operating Activities	250.5		199.5
Investing Activities
Construction Expenditures	(205.1)		(218.5)
Change in Advances to Affiliates, Net	(193.6)		0.0
Other Investing Activities	15.2		4.4
Net Cash Flows from (Used for) Investing Activities	(383.5)		(214.1)
Financing Activities
Issuance of Long-term Debt	393.3		0.0
Change in Advances from Affiliates, Net	(205.6)		59.9
Retirement of Long-term Debt	(12.0)		(11.7)
Principal Payments for Finance Lease Obligations	(1.6)		(1.7)
Dividends Paid on Common Stock	(50.0)		(40.0)
Other Financing Activities	0.3		0.2
Net Cash Flows from (Used for) Financing Activities	124.4		6.7
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	(8.6)		(7.9)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	29.8		19.2
Cash and Cash Equivalents at Beginning of Period	4.2
Cash, Cash Equivalents and Restricted Cash at End of Period	21.2		11.3
Cash and Cash Equivalents at End of Period	2.9
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	14.5		23.4
Net Cash Paid (Received) for Income Taxes	8.0		0.0
Noncash Acquisitions Under Finance Leases	2.1		1.8
Construction Expenditures Included in Current Liabilities as of March 31,	87.8		94.5
Indiana Michigan Power Co [Member]
Operating Activities
Net Income (Loss)	98.9		64.2
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	86.2		59.3
Deferred Income Taxes	(13.9)		13.7
Deferral of Incremental Nuclear Refueling Outage Expenses, Net	(14.8)		(12.3)
Carrying Costs Income	0.7		(2.4)
Allowance for Equity Funds Used During Construction	(6.2)		(1.8)
Mark-to-Market of Risk Management Contracts	4.7		3.4
Amortization of Nuclear Fuel	25.1		27.4
Deferred Fuel Over/Under-Recovery, Net	(5.2)		3.4
Change in Other Noncurrent Assets	12.8		(11.0)
Change in Other Noncurrent Liabilities	5.2		33.7
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	16.0		3.5
Fuel, Materials and Supplies	6.6		(4.5)
Accounts Payable	(3.1)		1.3
Accrued Taxes, Net	25.6		8.2
Other Current Assets	1.4		(11.1)
Other Current Liabilities	(35.2)		(27.8)
Net Cash Flows from (Used for) Operating Activities	204.8		147.2
Investing Activities
Construction Expenditures	(149.3)		(148.9)
Change in Advances to Affiliates, Net	(0.1)		(0.1)
Purchases of Investment Securities	(130.3)		(525.3)
Sales of Investment Securities	111.9		508.6
Acquisitions of Nuclear Fuel	(32.4)		(23.8)
Other Investing Activities	8.6		4.2
Net Cash Flows from (Used for) Investing Activities	(191.6)		(185.3)
Financing Activities
Change in Advances from Affiliates, Net	33.6		102.5
Retirement of Long-term Debt	(26.5)		(29.4)
Principal Payments for Finance Lease Obligations	(1.2)		(2.7)
Dividends Paid on Common Stock	(20.0)		(33.5)
Other Financing Activities	0.2		0.5
Net Cash Flows from (Used for) Financing Activities	(13.9)		37.4
Net Increase (Decrease) in Cash and Cash Equivalents	(0.7)		(0.7)
Cash and Cash Equivalents at Beginning of Period	2.4		1.3
Cash and Cash Equivalents at End of Period	1.7		0.6
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	43.3		50.6
Net Cash Paid (Received) for Income Taxes	(3.3)		0.0
Noncash Acquisitions Under Finance Leases	1.7		1.7
Construction Expenditures Included in Current Liabilities as of March 31,	80.0		77.2
Acquisition of Nuclear Fuel Included in Current Liabilities as of March 31,	1.0		0.1
Expected Reimbursement For Spent Nuclear Fuel Dry Cask Storage	7.9		0.1
Ohio Power Co [Member]
Operating Activities
Net Income (Loss)	128.0		79.6
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	63.3		64.8
Amortization Of Generation Deferrals	32.4		58.6
Deferred Income Taxes	10.1		(4.9)
Carrying Costs Income	(0.2)		(0.7)
Allowance for Equity Funds Used During Construction	(5.2)		(2.5)
Mark-to-Market of Risk Management Contracts	6.7		(33.7)
Property Taxes	66.0		62.9
Provision for Refund - Global Settlement	(4.1)		(5.4)
Reversal of a Regulatory Provision	(56.2)		0.0
Change in Other Noncurrent Assets	(7.3)		14.3
Change in Other Noncurrent Liabilities	17.6		40.6
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	31.7		38.8
Fuel, Materials and Supplies	(3.4)		(1.9)
Accounts Payable	(23.9)		(22.5)
Accrued Taxes, Net	(114.4)		(92.8)
Other Current Assets	(7.7)		(7.5)
Other Current Liabilities	(16.2)		(2.9)
Net Cash Flows from (Used for) Operating Activities	117.2		184.8
Investing Activities
Construction Expenditures	(198.5)		(168.2)
Change in Advances to Affiliates, Net	0.0		(200.4)
Other Investing Activities	3.7		1.7
Net Cash Flows from (Used for) Investing Activities	(194.8)		(366.9)
Financing Activities
Issuance of Long-term Debt	0.0		393.3
Change in Advances from Affiliates, Net	113.5		(87.8)
Retirement of Long-term Debt	(23.4)		(22.9)
Principal Payments for Finance Lease Obligations	(0.7)		(0.9)
Dividends Paid on Common Stock	(25.0)		(112.5)
Other Financing Activities	0.5		0.5
Net Cash Flows from (Used for) Financing Activities	64.9		169.7
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	(12.7)		(12.4)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	32.5		29.7
Cash and Cash Equivalents at Beginning of Period	4.9
Cash, Cash Equivalents and Restricted Cash at End of Period	19.8		17.3
Cash and Cash Equivalents at End of Period	3.3
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	17.0		17.0
Net Cash Paid (Received) for Income Taxes	(0.2)		0.0
Noncash Acquisitions Under Finance Leases	3.2		1.4
Construction Expenditures Included in Current Liabilities as of March 31,	72.8		52.3
Public Service Co Of Oklahoma [Member]
Operating Activities
Net Income (Loss)	6.2		(7.2)
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	43.5		36.8
Deferred Income Taxes	(5.8)		(4.5)
Allowance for Equity Funds Used During Construction	(0.1)		0.1
Mark-to-Market of Risk Management Contracts	5.1		3.5
Property Taxes	(29.9)		(30.1)
Deferred Fuel Over/Under-Recovery, Net	(2.4)		14.6
Change in Other Noncurrent Assets	8.0		0.0
Change in Other Noncurrent Liabilities	(0.7)		5.7
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	2.0		6.9
Fuel, Materials and Supplies	3.2		(1.7)
Accounts Payable	(23.3)		(10.9)
Accrued Taxes, Net	25.3		22.4
Other Current Assets	(3.8)		0.9
Other Current Liabilities	4.4		(1.3)
Net Cash Flows from (Used for) Operating Activities	31.7		35.2
Investing Activities
Construction Expenditures	(70.7)		(54.4)
Other Investing Activities	0.4		2.0
Net Cash Flows from (Used for) Investing Activities	(70.3)		(52.4)
Financing Activities
Issuance of Long-term Debt	99.9		0.0
Change in Advances from Affiliates, Net	(50.3)		29.5
Retirement of Long-term Debt	(0.1)		(0.1)
Principal Payments for Finance Lease Obligations	(0.7)		(1.0)
Dividends Paid on Common Stock	(11.3)		(12.5)
Other Financing Activities	0.6		0.3
Net Cash Flows from (Used for) Financing Activities	38.1		16.2
Net Increase (Decrease) in Cash and Cash Equivalents	(0.5)		(1.0)
Cash and Cash Equivalents at Beginning of Period	2.0		1.6
Cash and Cash Equivalents at End of Period	1.5		0.6
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	10.9		10.3
Net Cash Paid (Received) for Income Taxes	0.6		0.0
Noncash Acquisitions Under Finance Leases	1.1		0.9
Construction Expenditures Included in Current Liabilities as of March 31,	15.6		25.4
Southwestern Electric Power Co [Member]
Operating Activities
Net Income (Loss)	29.0		13.4
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	62.1		57.4
Deferred Income Taxes	(2.5)		1.0
Allowance for Equity Funds Used During Construction	(1.8)		(2.3)
Mark-to-Market of Risk Management Contracts	2.3		5.1
Property Taxes	(48.9)		(48.8)
Deferred Fuel Over/Under-Recovery, Net	10.3		(4.6)
Change in Other Noncurrent Assets	2.9		1.3
Change in Other Noncurrent Liabilities	7.9		18.8
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	6.3		27.9
Fuel, Materials and Supplies	(16.2)		2.2
Accounts Payable	(55.0)		(24.6)
Accrued Taxes, Net	52.7		55.2
Accrued Interest	(12.7)		(13.0)
Other Current Assets	(10.0)		(0.8)
Other Current Liabilities	(17.0)		(12.5)
Net Cash Flows from (Used for) Operating Activities	9.4		75.7
Investing Activities
Construction Expenditures	(86.6)		(139.7)
Change in Advances to Affiliates, Net	81.4		0.0
Other Investing Activities	(3.1)		(5.4)
Net Cash Flows from (Used for) Investing Activities	(8.3)		(145.1)
Financing Activities
Issuance of Long-term Debt	0.0		444.6
Change in Short-term Debt, Net	0.0		0.6
Change in Advances from Affiliates, Net	74.0		29.9
Retirement of Long-term Debt	(55.1)		(383.4)
Principal Payments for Finance Lease Obligations	(2.7)		(2.8)
Dividends Paid on Common Stock	(18.7)		(20.0)
Dividends Paid on Common Stock	(1.1)		(0.8)
Other Financing Activities	0.1		0.4
Net Cash Flows from (Used for) Financing Activities	(3.5)		68.5
Net Increase (Decrease) in Cash and Cash Equivalents	(2.4)		(0.9)
Cash and Cash Equivalents at Beginning of Period	24.5		1.6
Cash and Cash Equivalents at End of Period	22.1		0.7
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	40.5		43.7
Net Cash Paid (Received) for Income Taxes	0.2		(0.1)
Noncash Acquisitions Under Finance Leases	0.8		1.9
Construction Expenditures Included in Current Liabilities as of March 31,	44.8		50.3
Additional Paid-in Capital [Member]
Supplementary Information
Forward Equity Purchase Contract Included Current and Noncurrent Liabilities as of March 31,	$ 62.1	[2]	$ 0.0

[1] 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.

[2] Includes $(62) million related to a forward equity purchase contract associated with the issuance of Equity Units. See “Equity Units” section of Footnote 13 - Financing Activities.