STOCK-BASED COMPENSATION - Performance Shares and Reinvested Dividends (Details) - $ / shares	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awarded (in shares)	440,700	486,700	530,300
Weighted-Average Share Fair Value at Grant Date	$ 99.76	$ 98.63	$ 97.61
Vesting Period (in years)	3 years	3 years	3 years
Performance Shares and AEP Career Shares (Reinvested Dividends Portion)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awarded (in shares)	66,000.0	81,300	63,300
Weighted-Average Share Fair Value at Grant Date	$ 91.75	$ 82.02	$ 98.73