Leases (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Dec. 31, 2018
Lease Rental Costs
Operating Lease, Cost		$ 64.6
Finance Lease Right-of-Use Asset Amortization		14.2
Interest Expense on Finance Leases		4.1
Total Lease Rental Costs	[1]	$ 82.9
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases		5 years 5 months 4 days
Weighted Average Remaining Lease Term, Finance Leases		5 years 11 months 8 days
Weighted Average Discount Rate, Operating Leases		3.61%
Weighted Average Discount Rate, Finance Leases		6.19%
Operating Cash Flows from Operating Leases		$ 28.9
Operating Cash Flows from Finance Leases		3.8
Financing Cash Flows from Finance Leases		14.3
Non-cash Acquisitions Under Operating Leases		38.5
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation		21,780.6	$ 21,699.9
Other Property, Plant and Equipment		4,202.7	4,265.0
Total Property, Plant and Equipment		74,151.2	73,085.2
Accumulated Amortization		18,182.6	17,986.1
Net Property, Plant and Equipment Under Finance Leases		294.2
Obligations Under Finance Leases Noncurrent		797.9	782.6
Finance Lease Liability Due Within One Year		888.1	1,190.5
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		298.9
Operating Lease Asset and Related Obligations
Operating Lease Assets		1,045.4	0.0
Operating Lease Assets, Noncurrent		10,838.6	9,589.8
Operating Lease Noncurrent Liability		860.2	0.0
Operating Lease Liability Due Within One Year		228.2	0.0
Total Obligations Under Operating Leases		1,088.4
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Finance Leases, Year 1		74.1
Finance Leases, Year 2		63.6
Finance Leases, Year 3		54.9
Finance Leases, Year 4		46.2
Finance Leases, Year 5		38.8
Finance Leases, Later Years		87.4
Finance Leases, Total Future Minimum Lease Payments		365.0
Imputed Interest on Finance Leases		66.1
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		298.9
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Operating Leases, Year 1		263.3
Operating Leases, Year 2		253.3
Operating Leases, Year 3		235.9
Operating Leases, Year 4		226.8
Operating Leases, Year 5		61.5
Operating Leases, Later Years		180.7
Operating Leases, Total Future Minimum Lease Payments		1,221.5
Imputed Interest on Operating Leases		133.1
Estimated Present Value of Future Minimum Lease Payments on Operating Leases		1,088.4
Finance Lease Future Minimum Lease Payments
Capital Leases, 2019			70.8
Capital Leases, 2020			60.2
Capital Leases, 2021			51.7
Capital Leases, 2022			43.8
Capital Leases, 2023			35.5
Capital Leases, Later Years			90.2
Capital Leases, Total Future Minimum Payments Due			352.2
Estimated Interest Element on Capital Leases			63.2
Estimated Present Value of Future Minimum Lease Payments on Capital Leases			289.0
Operating Lease Future Minimum Lease Payments
Noncancelable Operating Leases, 2019			259.6
Noncancelable Operating Leases, 2020			250.1
Noncancelable Operating Leases, 2021			232.7
Noncancelable Operating Leases, 2022			222.5
Noncancelable Operating Leases, 2023			58.3
Noncancelable Operating Leases, Later Years			165.2
Noncancelable Operating Leases Total Future Minimum Lease Payments			1,188.4
Maximum Potential Loss
Max Potential Loss on Master Lease Agreements		48.8
Rockport Lease [Member]
Future Minimum Rentals, Sale Leaseback Transactions
2019	[2]	147.8
2020	[2]	147.8
2021	[2]	147.8
2022	[2]	147.2
Total Future Minimum Lease Payments	[2]	590.6
Leases (Textuals)
Sale and Leaseback Transaction, Gain (Loss), Net		$ 37.0
Lease Term		33 years
Boat and Barge Leases [Member]
Leases (Textuals)
Maximum Potential Lease Payments, AEPRO Barge and Boat Leases		$ 43.0
Guarantor Obligations, Current Carrying Value		5.0
Guarantee Obligations Current Carrying Value Other Liabilities Current		1.0
Guarantee Obligations Current Carrying Value Other Liabilities Noncurrent		4.0
Finance Lease Assets [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation		166.3
Other Property, Plant and Equipment		277.3
Total Property, Plant and Equipment		443.6
Accumulated Amortization		149.4
Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Obligations Under Finance Leases Noncurrent		237.4
Finance Lease Liability Due Within One Year		61.5
AEP Texas Inc. [Member]
Lease Rental Costs
Operating Lease, Cost		3.8
Finance Lease Right-of-Use Asset Amortization		1.1
Interest Expense on Finance Leases		0.3
Total Lease Rental Costs	[1]	$ 5.2
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases		7 years 3 months 18 days
Weighted Average Remaining Lease Term, Finance Leases		7 years 25 days
Weighted Average Discount Rate, Operating Leases		3.82%
Weighted Average Discount Rate, Finance Leases		4.79%
Operating Cash Flows from Operating Leases		$ 3.8
Operating Cash Flows from Finance Leases		0.3
Financing Cash Flows from Finance Leases		1.2
Non-cash Acquisitions Under Operating Leases		4.6
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation		352.0	352.1
Other Property, Plant and Equipment		734.5	727.9
Total Property, Plant and Equipment		9,906.6	9,643.0
Accumulated Amortization		1,686.6	1,651.2
Net Property, Plant and Equipment Under Finance Leases		29.8
Obligations Under Finance Leases Noncurrent		105.2	104.0
Finance Lease Liability Due Within One Year		82.4	98.3
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		29.8
Operating Lease Asset and Related Obligations
Operating Lease Assets, Noncurrent		1,231.6	1,135.4
Operating Lease Noncurrent Liability		70.2	0.0
Operating Lease Liability Due Within One Year		12.2	0.0
Total Obligations Under Operating Leases		82.4
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Finance Leases, Year 1		6.2
Finance Leases, Year 2		5.8
Finance Leases, Year 3		5.1
Finance Leases, Year 4		4.5
Finance Leases, Year 5		3.9
Finance Leases, Later Years		10.2
Finance Leases, Total Future Minimum Lease Payments		35.7
Imputed Interest on Finance Leases		5.9
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		29.8
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Operating Leases, Year 1		15.2
Operating Leases, Year 2		14.4
Operating Leases, Year 3		13.5
Operating Leases, Year 4		12.5
Operating Leases, Year 5		11.1
Operating Leases, Later Years		29.4
Operating Leases, Total Future Minimum Lease Payments		96.1
Imputed Interest on Operating Leases		13.7
Estimated Present Value of Future Minimum Lease Payments on Operating Leases		82.4
Finance Lease Future Minimum Lease Payments
Capital Leases, 2019			5.8
Capital Leases, 2020			5.3
Capital Leases, 2021			4.7
Capital Leases, 2022			4.2
Capital Leases, 2023			3.7
Capital Leases, Later Years			10.1
Capital Leases, Total Future Minimum Payments Due			33.8
Estimated Interest Element on Capital Leases			5.3
Estimated Present Value of Future Minimum Lease Payments on Capital Leases			28.5
Operating Lease Future Minimum Lease Payments
Noncancelable Operating Leases, 2019			15.1
Noncancelable Operating Leases, 2020			14.1
Noncancelable Operating Leases, 2021			13.2
Noncancelable Operating Leases, 2022			12.2
Noncancelable Operating Leases, 2023			10.8
Noncancelable Operating Leases, Later Years			28.4
Noncancelable Operating Leases Total Future Minimum Lease Payments			93.8
Maximum Potential Loss
Max Potential Loss on Master Lease Agreements		10.9
AEP Texas Inc. [Member] | Finance Lease Assets [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation		0.0
Other Property, Plant and Equipment		39.9
Total Property, Plant and Equipment		39.9
Accumulated Amortization		10.1
AEP Texas Inc. [Member] | Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Obligations Under Finance Leases Noncurrent		24.9
Finance Lease Liability Due Within One Year		4.9
AEP Texas Inc. [Member] | Operating Lease Assets [Member]
Operating Lease Asset and Related Obligations
Operating Lease Assets, Noncurrent		82.4
AEP Transmission Co [Member]
Lease Rental Costs
Operating Lease, Cost		0.6
Finance Lease Right-of-Use Asset Amortization		0.0
Interest Expense on Finance Leases		0.0
Total Lease Rental Costs	[1]	$ 0.6
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases		2 years 8 months 15 days
Weighted Average Remaining Lease Term, Finance Leases		1 year 29 days
Weighted Average Discount Rate, Operating Leases		3.14%
Weighted Average Discount Rate, Finance Leases		9.33%
Operating Cash Flows from Operating Leases		$ 0.7
Operating Cash Flows from Finance Leases		0.0
Financing Cash Flows from Finance Leases		0.0
Non-cash Acquisitions Under Operating Leases		0.0
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Other Property, Plant and Equipment		174.4	174.0
Total Property, Plant and Equipment		8,567.2	8,268.1
Accumulated Amortization		306.7	271.9
Net Property, Plant and Equipment Under Finance Leases		0.1
Obligations Under Finance Leases Noncurrent		17.0	18.4
Finance Lease Liability Due Within One Year		20.3	3.8
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		0.1
Operating Lease Asset and Related Obligations
Operating Lease Assets, Noncurrent		152.5	172.4
Operating Lease Noncurrent Liability		3.2	0.0
Operating Lease Liability Due Within One Year		2.6	0.0
Total Obligations Under Operating Leases		5.8
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Finance Leases, Year 1		0.1
Finance Leases, Year 2		0.0
Finance Leases, Year 3		0.0
Finance Leases, Year 4		0.0
Finance Leases, Year 5		0.0
Finance Leases, Later Years		0.0
Finance Leases, Total Future Minimum Lease Payments		0.1
Imputed Interest on Finance Leases		0.0
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		0.1
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Operating Leases, Year 1		2.7
Operating Leases, Year 2		2.0
Operating Leases, Year 3		0.9
Operating Leases, Year 4		0.6
Operating Leases, Year 5		0.0
Operating Leases, Later Years		0.0
Operating Leases, Total Future Minimum Lease Payments		6.2
Imputed Interest on Operating Leases		0.4
Estimated Present Value of Future Minimum Lease Payments on Operating Leases		5.8
Finance Lease Future Minimum Lease Payments
Capital Leases, 2019			0.1
Capital Leases, 2020			0.0
Capital Leases, 2021			0.0
Capital Leases, 2022			0.0
Capital Leases, 2023			0.0
Capital Leases, Later Years			0.0
Capital Leases, Total Future Minimum Payments Due			0.1
Estimated Interest Element on Capital Leases			0.0
Estimated Present Value of Future Minimum Lease Payments on Capital Leases			0.1
Operating Lease Future Minimum Lease Payments
Noncancelable Operating Leases, 2019			2.3
Noncancelable Operating Leases, 2020			1.8
Noncancelable Operating Leases, 2021			1.0
Noncancelable Operating Leases, 2022			0.5
Noncancelable Operating Leases, 2023			0.1
Noncancelable Operating Leases, Later Years			0.0
Noncancelable Operating Leases Total Future Minimum Lease Payments			5.7
AEP Transmission Co [Member] | Finance Lease Assets [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation		0.0
Other Property, Plant and Equipment		0.2
Total Property, Plant and Equipment		0.2
Accumulated Amortization		0.1
AEP Transmission Co [Member] | Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Obligations Under Finance Leases Noncurrent		0.0
Finance Lease Liability Due Within One Year		0.1
AEP Transmission Co [Member] | Operating Lease Assets [Member]
Operating Lease Asset and Related Obligations
Operating Lease Assets, Noncurrent		5.8
Appalachian Power Co [Member]
Lease Rental Costs
Operating Lease, Cost		4.6
Finance Lease Right-of-Use Asset Amortization		1.5
Interest Expense on Finance Leases		0.7
Total Lease Rental Costs	[1]	$ 6.8
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases		6 years 4 months 2 days
Weighted Average Remaining Lease Term, Finance Leases		6 years 5 months 8 days
Weighted Average Discount Rate, Operating Leases		3.66%
Weighted Average Discount Rate, Finance Leases		8.61%
Operating Cash Flows from Operating Leases		$ 4.2
Operating Cash Flows from Finance Leases		0.7
Financing Cash Flows from Finance Leases		1.6
Non-cash Acquisitions Under Operating Leases		3.5
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation		6,531.5	6,509.6
Other Property, Plant and Equipment		504.5	485.8
Total Property, Plant and Equipment		14,905.6	14,792.7
Accumulated Amortization		4,174.9	4,124.4
Net Property, Plant and Equipment Under Finance Leases		40.3
Obligations Under Finance Leases Noncurrent		58.7	58.6
Finance Lease Liability Due Within One Year		103.7	150.3
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		40.3
Operating Lease Asset and Related Obligations
Operating Lease Assets		79.1	0.0
Operating Lease Assets, Noncurrent		996.6	923.5
Operating Lease Noncurrent Liability		64.8	0.0
Operating Lease Liability Due Within One Year		15.0	0.0
Total Obligations Under Operating Leases		79.8
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Finance Leases, Year 1		9.2
Finance Leases, Year 2		8.4
Finance Leases, Year 3		7.6
Finance Leases, Year 4		7.1
Finance Leases, Year 5		6.6
Finance Leases, Later Years		12.3
Finance Leases, Total Future Minimum Lease Payments		51.2
Imputed Interest on Finance Leases		10.9
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		40.3
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Operating Leases, Year 1		18.0
Operating Leases, Year 2		16.5
Operating Leases, Year 3		14.0
Operating Leases, Year 4		12.8
Operating Leases, Year 5		9.7
Operating Leases, Later Years		20.5
Operating Leases, Total Future Minimum Lease Payments		91.5
Imputed Interest on Operating Leases		11.7
Estimated Present Value of Future Minimum Lease Payments on Operating Leases		79.8
Finance Lease Future Minimum Lease Payments
Capital Leases, 2019			9.0
Capital Leases, 2020			8.0
Capital Leases, 2021			7.3
Capital Leases, 2022			6.8
Capital Leases, 2023			6.3
Capital Leases, Later Years			13.3
Capital Leases, Total Future Minimum Payments Due			50.7
Estimated Interest Element on Capital Leases			10.9
Estimated Present Value of Future Minimum Lease Payments on Capital Leases			39.8
Operating Lease Future Minimum Lease Payments
Noncancelable Operating Leases, 2019			17.6
Noncancelable Operating Leases, 2020			16.5
Noncancelable Operating Leases, 2021			13.9
Noncancelable Operating Leases, 2022			12.8
Noncancelable Operating Leases, 2023			9.9
Noncancelable Operating Leases, Later Years			20.5
Noncancelable Operating Leases Total Future Minimum Lease Payments			91.2
Maximum Potential Loss
Max Potential Loss on Master Lease Agreements		8.9
Appalachian Power Co [Member] | Finance Lease Assets [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation		38.6
Other Property, Plant and Equipment		17.4
Total Property, Plant and Equipment		56.0
Accumulated Amortization		15.7
Appalachian Power Co [Member] | Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Obligations Under Finance Leases Noncurrent		34.0
Finance Lease Liability Due Within One Year		6.3
Indiana Michigan Power Co [Member]
Lease Rental Costs
Operating Lease, Cost		23.0
Finance Lease Right-of-Use Asset Amortization		1.3
Interest Expense on Finance Leases		0.8
Total Lease Rental Costs	[1]	$ 25.1
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases		4 years 3 months 25 days
Weighted Average Remaining Lease Term, Finance Leases		6 years 10 months 28 days
Weighted Average Discount Rate, Operating Leases		3.45%
Weighted Average Discount Rate, Finance Leases		9.03%
Operating Cash Flows from Operating Leases		$ 5.0
Operating Cash Flows from Finance Leases		0.7
Financing Cash Flows from Finance Leases		1.2
Non-cash Acquisitions Under Operating Leases		2.6
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation		4,895.0	4,887.2
Other Property, Plant and Equipment		580.1	583.8
Total Property, Plant and Equipment		9,889.0	9,762.8
Accumulated Amortization		3,208.4	3,151.6
Net Property, Plant and Equipment Under Finance Leases		39.2
Obligations Under Finance Leases Noncurrent		68.9	87.8
Finance Lease Liability Due Within One Year		68.2	103.0
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		39.2
Operating Lease Asset and Related Obligations
Operating Lease Assets		326.3	0.0
Operating Lease Assets, Noncurrent		3,686.1	3,181.0
Operating Lease Noncurrent Liability		266.0	0.0
Operating Lease Liability Due Within One Year		81.8	0.0
Total Obligations Under Operating Leases		347.8
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Finance Leases, Year 1		8.4
Finance Leases, Year 2		7.5
Finance Leases, Year 3		6.9
Finance Leases, Year 4		6.3
Finance Leases, Year 5		5.9
Finance Leases, Later Years		20.9
Finance Leases, Total Future Minimum Lease Payments		55.9
Imputed Interest on Finance Leases		16.7
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		39.2
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Operating Leases, Year 1		92.5
Operating Leases, Year 2		89.5
Operating Leases, Year 3		84.9
Operating Leases, Year 4		85.2
Operating Leases, Year 5		7.0
Operating Leases, Later Years		20.4
Operating Leases, Total Future Minimum Lease Payments		379.5
Imputed Interest on Operating Leases		31.7
Estimated Present Value of Future Minimum Lease Payments on Operating Leases		347.8
Finance Lease Future Minimum Lease Payments
Capital Leases, 2019			8.2
Capital Leases, 2020			7.2
Capital Leases, 2021			6.6
Capital Leases, 2022			6.1
Capital Leases, 2023			5.7
Capital Leases, Later Years			21.7
Capital Leases, Total Future Minimum Payments Due			55.5
Estimated Interest Element on Capital Leases			16.8
Estimated Present Value of Future Minimum Lease Payments on Capital Leases			38.7
Operating Lease Future Minimum Lease Payments
Noncancelable Operating Leases, 2019			92.6
Noncancelable Operating Leases, 2020			89.3
Noncancelable Operating Leases, 2021			84.8
Noncancelable Operating Leases, 2022			83.8
Noncancelable Operating Leases, 2023			6.5
Noncancelable Operating Leases, Later Years			19.5
Noncancelable Operating Leases Total Future Minimum Lease Payments			376.5
Maximum Potential Loss
Max Potential Loss on Master Lease Agreements		3.9
Indiana Michigan Power Co [Member] | Rockport Lease [Member]
Future Minimum Rentals, Sale Leaseback Transactions
2019		73.9
2020		73.9
2021		73.9
2022		73.6
Total Future Minimum Lease Payments		295.3
Leases (Textuals)
Sale and Leaseback Transaction, Gain (Loss), Net		15.0
Indiana Michigan Power Co [Member] | Finance Lease Assets [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation		27.0
Other Property, Plant and Equipment		33.4
Total Property, Plant and Equipment		60.4
Accumulated Amortization		21.2
Indiana Michigan Power Co [Member] | Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Obligations Under Finance Leases Noncurrent		33.7
Finance Lease Liability Due Within One Year		5.5
Ohio Power Co [Member]
Lease Rental Costs
Operating Lease, Cost		3.6
Finance Lease Right-of-Use Asset Amortization		0.7
Interest Expense on Finance Leases		0.2
Total Lease Rental Costs	[1]	$ 4.5
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases		8 years 2 months 15 days
Weighted Average Remaining Lease Term, Finance Leases		6 years 1 month 28 days
Weighted Average Discount Rate, Operating Leases		3.86%
Weighted Average Discount Rate, Finance Leases		4.81%
Operating Cash Flows from Operating Leases		$ 3.6
Operating Cash Flows from Finance Leases		0.2
Financing Cash Flows from Finance Leases		0.7
Non-cash Acquisitions Under Operating Leases		15.8
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Other Property, Plant and Equipment		580.0	574.8
Total Property, Plant and Equipment		8,619.3	8,493.5
Accumulated Amortization		2,224.1	2,218.6
Net Property, Plant and Equipment Under Finance Leases		14.6
Obligations Under Finance Leases Noncurrent		45.0	43.8
Finance Lease Liability Due Within One Year		147.2	214.2
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		14.6
Operating Lease Asset and Related Obligations
Operating Lease Assets, Noncurrent		846.5	841.4
Operating Lease Noncurrent Liability		74.0	0.0
Operating Lease Liability Due Within One Year		13.0	0.0
Total Obligations Under Operating Leases		87.0
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Finance Leases, Year 1		3.8
Finance Leases, Year 2		3.3
Finance Leases, Year 3		2.7
Finance Leases, Year 4		2.0
Finance Leases, Year 5		1.5
Finance Leases, Later Years		4.0
Finance Leases, Total Future Minimum Lease Payments		17.3
Imputed Interest on Finance Leases		2.7
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		14.6
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Operating Leases, Year 1		16.0
Operating Leases, Year 2		14.4
Operating Leases, Year 3		12.4
Operating Leases, Year 4		11.6
Operating Leases, Year 5		10.2
Operating Leases, Later Years		38.6
Operating Leases, Total Future Minimum Lease Payments		103.2
Imputed Interest on Operating Leases		16.2
Estimated Present Value of Future Minimum Lease Payments on Operating Leases		87.0
Finance Lease Future Minimum Lease Payments
Capital Leases, 2019			3.3
Capital Leases, 2020			2.7
Capital Leases, 2021			2.3
Capital Leases, 2022			1.7
Capital Leases, 2023			1.2
Capital Leases, Later Years			2.8
Capital Leases, Total Future Minimum Payments Due			14.0
Estimated Interest Element on Capital Leases			1.9
Estimated Present Value of Future Minimum Lease Payments on Capital Leases			12.1
Operating Lease Future Minimum Lease Payments
Noncancelable Operating Leases, 2019			14.5
Noncancelable Operating Leases, 2020			13.2
Noncancelable Operating Leases, 2021			10.9
Noncancelable Operating Leases, 2022			10.0
Noncancelable Operating Leases, 2023			8.8
Noncancelable Operating Leases, Later Years			31.7
Noncancelable Operating Leases Total Future Minimum Lease Payments			89.1
Maximum Potential Loss
Max Potential Loss on Master Lease Agreements		8.4
Ohio Power Co [Member] | Finance Lease Assets [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation		0.0
Other Property, Plant and Equipment		21.3
Total Property, Plant and Equipment		21.3
Accumulated Amortization		6.7
Ohio Power Co [Member] | Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Obligations Under Finance Leases Noncurrent		11.4
Finance Lease Liability Due Within One Year		3.2
Ohio Power Co [Member] | Operating Lease Assets [Member]
Operating Lease Asset and Related Obligations
Operating Lease Assets, Noncurrent		86.6
Public Service Co Of Oklahoma [Member]
Lease Rental Costs
Operating Lease, Cost		1.5
Finance Lease Right-of-Use Asset Amortization		0.7
Interest Expense on Finance Leases		0.1
Total Lease Rental Costs	[1]	$ 2.3
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases		7 years 1 month 9 days
Weighted Average Remaining Lease Term, Finance Leases		6 years 21 days
Weighted Average Discount Rate, Operating Leases		3.67%
Weighted Average Discount Rate, Finance Leases		4.78%
Operating Cash Flows from Operating Leases		$ 1.5
Operating Cash Flows from Finance Leases		0.1
Financing Cash Flows from Finance Leases		0.7
Non-cash Acquisitions Under Operating Leases		2.3
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation		1,568.6	1,577.0
Other Property, Plant and Equipment		306.0	303.5
Total Property, Plant and Equipment		5,473.1	5,439.6
Accumulated Amortization		1,496.2	1,472.9
Net Property, Plant and Equipment Under Finance Leases		12.8
Obligations Under Finance Leases Noncurrent		34.3	32.5
Finance Lease Liability Due Within One Year		63.5	64.5
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		12.8
Operating Lease Asset and Related Obligations
Operating Lease Assets		34.8	0.0
Operating Lease Assets, Noncurrent		469.8	407.8
Operating Lease Noncurrent Liability		29.1	0.0
Operating Lease Liability Due Within One Year		5.7	0.0
Total Obligations Under Operating Leases		34.8
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Finance Leases, Year 1		3.6
Finance Leases, Year 2		2.9
Finance Leases, Year 3		2.1
Finance Leases, Year 4		1.7
Finance Leases, Year 5		1.4
Finance Leases, Later Years		3.3
Finance Leases, Total Future Minimum Lease Payments		15.0
Imputed Interest on Finance Leases		2.2
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		12.8
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Operating Leases, Year 1		6.8
Operating Leases, Year 2		6.4
Operating Leases, Year 3		5.4
Operating Leases, Year 4		5.1
Operating Leases, Year 5		4.6
Operating Leases, Later Years		12.1
Operating Leases, Total Future Minimum Lease Payments		40.4
Imputed Interest on Operating Leases		5.6
Estimated Present Value of Future Minimum Lease Payments on Operating Leases		34.8
Finance Lease Future Minimum Lease Payments
Capital Leases, 2019			3.4
Capital Leases, 2020			2.6
Capital Leases, 2021			2.0
Capital Leases, 2022			1.6
Capital Leases, 2023			1.4
Capital Leases, Later Years			3.3
Capital Leases, Total Future Minimum Payments Due			14.3
Estimated Interest Element on Capital Leases			2.0
Estimated Present Value of Future Minimum Lease Payments on Capital Leases			12.3
Operating Lease Future Minimum Lease Payments
Noncancelable Operating Leases, 2019			6.5
Noncancelable Operating Leases, 2020			6.0
Noncancelable Operating Leases, 2021			5.0
Noncancelable Operating Leases, 2022			4.6
Noncancelable Operating Leases, 2023			4.1
Noncancelable Operating Leases, Later Years			10.7
Noncancelable Operating Leases Total Future Minimum Lease Payments			36.9
Maximum Potential Loss
Max Potential Loss on Master Lease Agreements		4.0
Public Service Co Of Oklahoma [Member] | Finance Lease Assets [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation		2.6
Other Property, Plant and Equipment		18.3
Total Property, Plant and Equipment		20.9
Accumulated Amortization		8.1
Public Service Co Of Oklahoma [Member] | Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Obligations Under Finance Leases Noncurrent		9.8
Finance Lease Liability Due Within One Year		3.0
Southwestern Electric Power Co [Member]
Lease Rental Costs
Operating Lease, Cost		1.8
Finance Lease Right-of-Use Asset Amortization		2.7
Interest Expense on Finance Leases		0.8
Total Lease Rental Costs	[1]	$ 5.3
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases		6 years 8 months 1 day
Weighted Average Remaining Lease Term, Finance Leases		5 years 7 months 6 days
Weighted Average Discount Rate, Operating Leases		3.89%
Weighted Average Discount Rate, Finance Leases		5.04%
Operating Cash Flows from Operating Leases		$ 1.4
Operating Cash Flows from Finance Leases		0.7
Financing Cash Flows from Finance Leases		2.7
Non-cash Acquisitions Under Operating Leases		2.6
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation		4,711.6	4,672.6
Other Property, Plant and Equipment		658.9	762.7
Total Property, Plant and Equipment		9,676.0	9,680.1
Accumulated Amortization		2,760.6	2,808.3
Net Property, Plant and Equipment Under Finance Leases		59.0
Obligations Under Finance Leases Noncurrent		60.0	51.4
Finance Lease Liability Due Within One Year		87.0	107.3
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		59.9
Operating Lease Asset and Related Obligations
Operating Lease Assets, Noncurrent		420.4	342.0
Operating Lease Noncurrent Liability		32.3	0.0
Operating Lease Liability Due Within One Year		6.1	0.0
Total Obligations Under Operating Leases		38.4
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Finance Leases, Year 1		13.2
Finance Leases, Year 2		11.3
Finance Leases, Year 3		10.5
Finance Leases, Year 4		9.3
Finance Leases, Year 5		9.3
Finance Leases, Later Years		15.7
Finance Leases, Total Future Minimum Lease Payments		69.3
Imputed Interest on Finance Leases		9.4
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		59.9
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Operating Leases, Year 1		7.6
Operating Leases, Year 2		7.4
Operating Leases, Year 3		6.9
Operating Leases, Year 4		6.4
Operating Leases, Year 5		5.2
Operating Leases, Later Years		11.1
Operating Leases, Total Future Minimum Lease Payments		44.6
Imputed Interest on Operating Leases		6.2
Estimated Present Value of Future Minimum Lease Payments on Operating Leases		38.4
Finance Lease Future Minimum Lease Payments
Capital Leases, 2019			13.1
Capital Leases, 2020			11.5
Capital Leases, 2021			10.5
Capital Leases, 2022			9.4
Capital Leases, 2023			8.6
Capital Leases, Later Years			18.7
Capital Leases, Total Future Minimum Payments Due			71.8
Estimated Interest Element on Capital Leases			11.0
Estimated Present Value of Future Minimum Lease Payments on Capital Leases			60.8
Operating Lease Future Minimum Lease Payments
Noncancelable Operating Leases, 2019			7.4
Noncancelable Operating Leases, 2020			7.2
Noncancelable Operating Leases, 2021			6.7
Noncancelable Operating Leases, 2022			6.1
Noncancelable Operating Leases, 2023			5.0
Noncancelable Operating Leases, Later Years			11.7
Noncancelable Operating Leases Total Future Minimum Lease Payments			$ 44.1
Maximum Potential Loss
Max Potential Loss on Master Lease Agreements		4.4
Southwestern Electric Power Co [Member] | Finance Lease Assets [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation		69.4
Other Property, Plant and Equipment		11.7
Total Property, Plant and Equipment		81.1
Accumulated Amortization		22.1
Southwestern Electric Power Co [Member] | Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Obligations Under Finance Leases Noncurrent		49.3
Finance Lease Liability Due Within One Year		10.6
Southwestern Electric Power Co [Member] | Operating Lease Assets [Member]
Operating Lease Asset and Related Obligations
Operating Lease Assets, Noncurrent		$ 38.0

[1] Excludes variable and short-term lease costs, which were immaterial for the three months ended March 31, 2019.

[2] AEP’s future minimum lease payments include equal shares from AEGCo and I&M.