Consolidated Balance Sheet - UE (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Accounts receivable - trade, allowance for doubtful accounts	$ 30	$ 30
Regulatory Asset, Noncurrent	2,397	1,810
Long-Term Debt, Current Maturities	317	849
Long-Term Debt, Excluding Current Maturities	$ 17,262	$ 15,121
Common Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	400,000,000.0	400,000,000.0
Common Stock, Shares, Outstanding	269,900,000	266,300,000
Variable Interest Entity, Primary Beneficiary
Regulatory Asset, Noncurrent	$ 465
Long-Term Debt, Current Maturities	17
Long-Term Debt, Excluding Current Maturities	448
Ameren Missouri
Accounts receivable - trade, allowance for doubtful accounts	12	$ 12
Regulatory Asset, Noncurrent	1,366	755
Long-Term Debt, Current Maturities	17	350
Long-Term Debt, Excluding Current Maturities	$ 7,671	5,991
Common Stock, No Par Value (in dollars per share)	$ 5
Common stock, shares authorized	150,000,000.0
Common Stock, Shares, Outstanding	102,100,000
Ameren Missouri | Variable Interest Entity, Primary Beneficiary
Regulatory Asset, Noncurrent	$ 465	0
Long-Term Debt, Current Maturities	17	0
Long-Term Debt, Excluding Current Maturities	$ 448	$ 0