Significant Accounting Matters (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Amounts Attributable to AEP Common Shareholders
Earnings Attributable to Common Shareholders		$ 578,200	$ 520,800	$ 1,153,200	$ 1,016,000
Total Basic Earnings Per Share Attributable to AEP Common Shareholders		$ 1.16	$ 1.05	$ 2.31	$ 2.05
Weighted Average Dilutive Effect of:
Total Diluted Earnings Per Share Attributable to AEP Common Shareholders		$ 1.15	$ 1.05	$ 2.31	$ 2.04
Organization and Summary of Significant Accounting Policies (Textuals)
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount				0	156,000
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents		$ 312,700		$ 312,700		$ 392,700
Restricted Cash		47,000		47,000		45,600
Total Cash, Cash Equivalents and Restricted Cash		359,700	$ 504,700	359,700	$ 504,700	438,300	$ 432,600
Proceeds from Issuance of Debt	[1]			3,082,700
Securities Received as Collateral		105,400		105,400		3,400
Obligation to Return Securities Received as Collateral		$ 12,400		$ 12,400		6,800
Weighted Average Number of Diluted AEP Common Shares Outstanding		500,983,778	497,337,980	499,581,893	496,973,449
Weighted Average Number of Basic AEP Common Shares Outstanding		499,916,640	495,655,053	498,495,532	495,125,961
AEP Texas Inc. [Member]
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents		$ 100		$ 100		100
Restricted Cash		27,900		27,900		28,700
Total Cash, Cash Equivalents and Restricted Cash		28,000	$ 136,700	28,000	$ 136,700	28,800	157,800
AEP Transmission Co [Member]
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents		0	0	0	0	0	0
Appalachian Power Co [Member]
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents		3,900		3,900		5,800
Restricted Cash		19,100		19,100		16,900
Total Cash, Cash Equivalents and Restricted Cash		23,000	21,800	23,000	21,800	22,700	26,800
Securities Received as Collateral		700		700		400
Obligation to Return Securities Received as Collateral		5,300		5,300		0
Indiana Michigan Power Co [Member]
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents		2,500	2,000	2,500	2,000	3,300	2,000
Securities Received as Collateral		300		300		1,700
Obligation to Return Securities Received as Collateral		4,500		4,500		0
Ohio Power Co [Member]
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents		5,800		5,800		7,400
Total Cash, Cash Equivalents and Restricted Cash		5,800	3,300	5,800	3,300	7,400	3,700
Public Service Co Of Oklahoma [Member]
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents		2,600	1,400	2,600	1,400	2,600	1,500
Southwestern Electric Power Co [Member]
Amounts Attributable to AEP Common Shareholders
Earnings Attributable to Common Shareholders		36,800	58,800	99,200	73,900
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents		$ 28,000	$ 1,800	$ 28,000	$ 1,800	$ 13,200	$ 1,600
Restricted Stock Units and Performance Share Units [Member]
Weighted Average Dilutive Effect of:
Weighted Average Dilutive Effect of Shares		1,100,000	1,600,000	1,100,000	1,900,000
Dilutive Securities, Effect on Basic Earnings Per Share		$ (0.01)	$ 0	$ 0	$ (0.01)

[1] Amounts indicated on the statements of cash flows are net of issuance costs and premium or discount and will not tie to the issuance amounts.