ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Accounting Policies [Abstract]
Earnings Attributable to AEP Common Shareholders	$ 2,967.1	$ 2,208.1	$ 2,307.2
Earnings Attributable to AEP Common Shareholders	$ 2,967.1	$ 2,208.1	$ 2,307.2
WEIGHTED AVERAGE NUMBER OF BASIC AEP COMMON SHARES OUTSTANDING (in shares)	530,092,672	518,903,682	511,841,946
Weighted-Average Number of Basic AEP Common Shares Outstanding (in USD per share)	$ 5.60	$ 4.26	$ 4.51
Weighted-Average Dilutive Effect of Stock-Based Awards	1,200,000	1,300,000	1,700,000
Weighted-Average Dilutive Effect of Stock-Based Awards (in USD per share)	$ (0.02)	$ (0.02)	$ (0.02)
Weighted-Average Number of Diluted AEP Common Shares Outstanding	531,300,000	520,200,000	513,500,000
Weighted-Average Number of Diluted AEP Common Shares Outstanding (in USD per share)	$ 5.58	$ 4.24	$ 4.49