Derivative Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2024

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Open Gross Derivative Volumes By Commodity Type

The following table presents open gross commodity contract volumes by commodity type for derivative assets and liabilities as of December 31, 2024 and 2023. As of December 31, 2024, these contracts extended through October 2028, October 2029, and May 2032 for fuel oils, natural gas, and power, respectively.

	Quantity (in millions, except as indicated)
	2024			2023
Commodity	Ameren Missouri	Ameren Illinois	Ameren	Ameren Missouri	Ameren Illinois	Ameren
Fuel oils (in gallons)	23	—	23	17	—	17
Natural gas (in mmbtu)	45	213	258	53	218	271
Power (in MWhs)	—	4	4	—	5	5
Uranium (pounds in thousands)	—	—	—	186	—	186

Derivative Instruments Carrying Value

The following table presents the carrying value and balance sheet location of all derivative commodity contracts, none of which were designated as hedging instruments, as of December 31, 2024 and 2023:

		2024						2023
Commodity	Balance Sheet Location	Ameren Missouri		Ameren Illinois		Ameren			Ameren Missouri		Ameren Illinois		Ameren
Fuel oils	Other current assets	$	—	$	—	$	—		$	2	$	—	$	2
	Other assets	—		—		—			—		—		—
Natural gas	Other current assets	2		2		4			—		—		—
	Other assets	2		4		6			3		3		6
Power	Other current assets	6		—		6			5		—		5
	Other assets	—		—		—			—		—		—
Uranium	Other current assets	—		—		—			9		—		9
	Other assets	—		—		—			—		—		—
	Total assets	$	10	$	6	$	16		$	19	$	3	$	22
Fuel oils	Other current liabilities	$	2	$	—	$	2		$	1	$	—	$	1
	Other deferred credits and liabilities	2		—		2			1		—		1
Natural gas	Other current liabilities	5		22		27			12		45		57
	Other deferred credits and liabilities	6		13		19			10		30		40
Power	Other current liabilities	—		10		10			1		12		13
	Other deferred credits and liabilities	—		43		43			—		56		56
	Total liabilities	$	15	$	88	$	103		$	25	$	143	$	168