v3.26.1
Other Income, Net (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Other Nonoperating Income (Expense) [Line Items]        
Allowance for equity funds used during construction $ 38 $ 23 $ 69 $ 39
Other interest income 7 10 16 21
Non-service cost components of net periodic benefit income 49 62 98 128
Miscellaneous income 5 4 10 7
Income (Loss) from Equity Method Investments 22 (6) 24 (10)
Donations (2) (1) (4) (3)
Miscellaneous expense (5) (4) (9) (9)
Total Other Income, Net 118 96 208 181
Gain (Loss) on Extinguishment of Debt 4 8 4 8
Union Electric Company        
Other Nonoperating Income (Expense) [Line Items]        
Allowance for equity funds used during construction 30 15 53 23
Other interest income 2 2 5 4
Non-service cost components of net periodic benefit income 29 32 59 67
Miscellaneous income 2 1 2 2
Donations (1) (1) (2) (2)
Miscellaneous expense (2) (2) (4) (4)
Total Other Income, Net 60 47 113 90
Defined Benefit Plan, Non-service Cost or Income Components - Tracker (20) (16) (40) (32)
Ameren Illinois Company        
Other Nonoperating Income (Expense) [Line Items]        
Allowance for equity funds used during construction 7 8 14 15
Other interest income 5 8 11 17
Non-service cost components of net periodic benefit income 14 20 29 40
Miscellaneous income 3 3 7 5
Donations (1) 0 (2) (1)
Miscellaneous expense (2) (2) (4) (5)
Total Other Income, Net $ 26 $ 37 $ 55 $ 71