Significant Accounting Matters (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Amounts Attributable to AEP Common Shareholders
Earnings Attributable to Common Shareholders		$ 714,700	$ 575,000
Total Basic Earnings Per Share Attributable to AEP Common Shareholders		$ 1.41	$ 1.16
Weighted Average Dilutive Effect of:
Total Diluted Earnings Per Share Attributable to AEP Common Shareholders		$ 1.41	$ 1.15
Organization and Summary of Significant Accounting Policies (Textuals)
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		0	0
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents		$ 675,600		$ 403,400
Restricted Cash		49,900		48,000
Total Cash, Cash Equivalents and Restricted Cash		725,500	$ 324,000	451,400	$ 438,300
Proceeds from Issuance of Debt	[1]	501,000
Securities Received as Collateral		655,000		263,000
Obligation to Return Securities Received as Collateral		$ 0		3,000
Weighted Average Number of Diluted AEP Common Shares Outstanding		507,658,522	498,164,219
Weighted Average Number of Basic AEP Common Shares Outstanding		506,050,147	497,058,635
AEP Texas Inc. [Member]
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents		$ 100		100
Restricted Cash		39,900		30,400
Total Cash, Cash Equivalents and Restricted Cash		40,000	$ 39,400	30,500	28,800
AEP Transmission Co [Member]
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents		0	0	0	0
Appalachian Power Co [Member]
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents		6,000		2,500
Restricted Cash		10,000		17,600
Total Cash, Cash Equivalents and Restricted Cash		16,000	16,400	20,100	22,700
Indiana Michigan Power Co [Member]
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents		3,300	2,800	1,300	3,300
Ohio Power Co [Member]
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents		7,400		3,000
Total Cash, Cash Equivalents and Restricted Cash		7,400	6,100	3,000	7,400
Public Service Co Of Oklahoma [Member]
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents		2,900	2,400	1,300	2,600
Southwestern Electric Power Co [Member]
Amounts Attributable to AEP Common Shareholders
Earnings Attributable to Common Shareholders		44,100	62,400
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents		$ 58,100	$ 18,200	$ 51,200	$ 13,200
Restricted Stock Units and Performance Share Units [Member]
Weighted Average Dilutive Effect of:
Weighted Average Dilutive Effect of Shares		1,600,000	1,100,000
Dilutive Securities, Effect on Basic Earnings Per Share		$ 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.