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Intervenor recommended return on common equity.

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Maximum ownership percentage of solar and wind projects as proposed in stipulation agreement.

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PUCO-approved amount of reduced customer credits.

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Percentage of output to be received from solar and wind projects as proposed in stipulation agreement.

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Projected capital costs of property, plant and equipment.

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Requested annual increase.

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Amount of annual increase in environmental surcharge.

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Requested return on equity.

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Solar energy projects to be developed and implemented by 2021 as proposed in stipulation agreement (in MWs).

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Amount of structure or a modification to a structure under construction. Includes recently completed structures or modifications to structures that have not been placed into service.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

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Rate Matters - East Companies (Details) $ in Millions	1 Months Ended	6 Months Ended
Rate Matters - East Companies (Details) $ in Millions	Jul. 27, 2017 USD ($)	Jun. 30, 2017 USD ($) MW	Dec. 31, 2016 USD ($)
Public Utilities, General Disclosures [Line Items]
Construction Work in Progress		$ 3,336.8	$ 3,183.9
Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Construction Work in Progress		397.8	390.3
Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Construction Work in Progress		592.4	654.2
Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Construction Work in Progress		$ 285.1	$ 221.5
FERC Transmission Complaint - AEP PJM Participants [Member]
Public Utilities, General Disclosures [Line Items]
Approved Return on Common Equity		10.99%
Intervenor Recommended Return on Common Equity		8.32%
Kentucky Base Rate Case - 2017 [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase		$ 66.0
Requested Return on Common Equity		10.31%
Requested Annual Increase in Environmental Surcharge		$ 4.0
Michigan Base Rate Case - 2017 [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase		$ 52.0
Requested Return on Common Equity		10.60%
Amount of Increase Related to Annual Depreciation Rates		$ 23.0
Amount of Increase Related to Amortization of Regulatory Assets		4.0
Michigan Base Rate Case - 2017 [Member] \| Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase		$ 52.0
Requested Return on Common Equity		10.60%
Amount of Increase Related to Annual Depreciation Rates		$ 23.0
Amount of Increase Related to Amortization of Regulatory Assets		$ 4.0
Ohio Electric Security Plan Filing [Member]
Public Utilities, General Disclosures [Line Items]
Approved Return on Common Equity		10.20%
PUCO Approved Reduced Customer Credits		$ 15.0
Solar Energy Projects To Be Developed And Implemented By 2021 As Proposed In Stipulation Agreement \| MW		400
Wind Energy Projects To Be Developed And Implemented By 2021 As Proposed In Stipulation Agreement \| MW		500
Percentage of Output to be Received from Solar and Wind Projects as Proposed in Stipulation Agreement		100.00%
Maximum Ownership Percentage of Solar and Wind Projects as Proposed in Stipulation Agreement		50.00%
Return on Common Equity Proposed in the Amended ESP Filing		10.41%
Ohio Electric Security Plan Filing [Member] \| Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Approved Return on Common Equity		10.20%
PUCO Approved Reduced Customer Credits		$ 15.0
Solar Energy Projects To Be Developed And Implemented By 2021 As Proposed In Stipulation Agreement \| MW		400
Wind Energy Projects To Be Developed And Implemented By 2021 As Proposed In Stipulation Agreement \| MW		500
Percentage of Output to be Received from Solar and Wind Projects as Proposed in Stipulation Agreement		100.00%
Maximum Ownership Percentage of Solar and Wind Projects as Proposed in Stipulation Agreement		50.00%
Return on Common Equity Proposed in the Amended ESP Filing		10.41%
Rockport Plant, Unit 2 Selective Catalytic Reduction [Member]
Public Utilities, General Disclosures [Line Items]
Projected Capital Costs		$ 274.0
Construction Work in Progress		9.0
Rockport Plant, Unit 2 Selective Catalytic Reduction [Member] \| Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Projected Capital Costs		274.0
Construction Work in Progress		9.0
2016 SEET Filing [Member]
Public Utilities, General Disclosures [Line Items]
Provision for Refund		58.0
2016 SEET Filing [Member] \| Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Provision for Refund		$ 58.0
Subsequent Event [Member] \| Indiana Base Rate Case - 2017 [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase	$ 263.0
Requested Return on Common Equity	10.60%
Amount Of Annual Reduction To Customer Bills Through Credit Adjustment Rider	$ 23.0
Amount of Increase Related to Annual Depreciation Rates	78.0
Amount of Increase Related to Amortization of Regulatory Assets	11.0
Subsequent Event [Member] \| Indiana Base Rate Case - 2017 [Member] \| Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase	$ 263.0
Requested Return on Common Equity	10.60%
Amount Of Annual Reduction To Customer Bills Through Credit Adjustment Rider	$ 23.0
Amount of Increase Related to Annual Depreciation Rates	78.0
Amount of Increase Related to Amortization of Regulatory Assets	$ 11.0