CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN COMMON SHAREHOLDER’S EQUITY - I&M - USD ($) $ in Millions	Total	Retained Earnings		Accumulated Other Comprehensive Income (Loss)	I&M	I&M Common Stock	I&M Paid-in Capital	I&M Retained Earnings	I&M Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2023					$ 3,140.2	$ 56.6	$ 997.6	$ 2,086.6	$ (0.6)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock Dividends	$ (466.9)	$ (465.5)	[1]		(37.5)			(37.5)
Net Income					145.0			145.0
Other Comprehensive Income	(6.8)			$ (6.8)	0.1				0.1
Ending balance at Mar. 31, 2024					3,247.8	56.6	997.6	2,194.1	(0.5)
Beginning balance at Dec. 31, 2023					3,140.2	56.6	997.6	2,086.6	(0.6)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income					359.3
Other Comprehensive Income	(31.4)			(31.4)	0.2
Ending balance at Sep. 30, 2024					3,390.4	56.6	1,000.8	2,333.4	(0.4)
Beginning balance at Mar. 31, 2024					3,247.8	56.6	997.6	2,194.1	(0.5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital Contribution from Parent					5.0		5.0
Common Stock Dividends	(469.1)	(467.0)	[1]		(37.5)			(37.5)
Net Income					35.2			35.2
Other Comprehensive Income	22.3			22.3
Ending balance at Jun. 30, 2024					3,250.5	56.6	1,002.6	2,191.8	(0.5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Return of Capital to Parent					(1.8)		(1.8)
Common Stock Dividends	(471.4)	(470.2)	[1]		(37.5)			(37.5)
Net Income					179.1			179.1
Other Comprehensive Income	(46.9)			(46.9)	0.1				0.1
Ending balance at Sep. 30, 2024					3,390.4	56.6	1,000.8	2,333.4	(0.4)
Beginning balance at Dec. 31, 2024	26,943.8				3,396.5	56.6	1,011.7	2,328.0	0.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock Dividends	(501.0)	(500.0)	[2]		(50.0)			(50.0)
Net Income					57.5			57.5
Other Comprehensive Income	23.4			23.4	0.1				0.1
Ending balance at Mar. 31, 2025					3,404.1	56.6	1,011.7	2,335.5	0.3
Beginning balance at Dec. 31, 2024	26,943.8				3,396.5	56.6	1,011.7	2,328.0	0.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income					331.3
Other Comprehensive Income	(24.7)			(24.7)	0.5
Ending balance at Sep. 30, 2025	30,389.3				3,687.0	56.6	1,020.4	2,609.3	0.7
Beginning balance at Mar. 31, 2025					3,404.1	56.6	1,011.7	2,335.5	0.3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital Contribution from Parent					7.4		7.4
Common Stock Dividends	(499.5)	(498.5)	[2]
Net Income					124.1			124.1
Other Comprehensive Income	(32.9)			(32.9)	0.2				0.2
Ending balance at Jun. 30, 2025					3,535.8	56.6	1,019.1	2,459.6	0.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital Contribution from Parent					1.3		1.3
Common Stock Dividends	(499.4)	$ (499.4)	[2]
Net Income					149.7			149.7
Other Comprehensive Income	(15.2)			$ (15.2)	0.2				0.2
Ending balance at Sep. 30, 2025	$ 30,389.3				$ 3,687.0	$ 56.6	$ 1,020.4	$ 2,609.3	$ 0.7

[1] Cash dividends declared per AEP common share were $0.88.

[2] Cash dividends declared per AEP common share were $0.93.