XML 82 R43.htm IDEA: XBRL DOCUMENT v3.22.2.2
Derivative Financial Instruments (Derivative Instruments Carrying Value) (Detail) - Not Designated As Hedging Instrument - USD ($)
$ in Millions
Sep. 30, 2022
Dec. 31, 2021
Derivative [Line Items]    
Derivative assets $ 167 $ 90
Derivative Liability 177 202
Fuel oils | Other current assets    
Derivative [Line Items]    
Derivative assets 12 8
Fuel oils | Other assets    
Derivative [Line Items]    
Derivative assets 3 5
Fuel oils | Other deferred credits and liabilities    
Derivative [Line Items]    
Derivative Liability 1 0
Natural gas | Other current assets    
Derivative [Line Items]    
Derivative assets 71 35
Natural gas | Other assets    
Derivative [Line Items]    
Derivative assets 34 18
Natural gas | Other deferred credits and liabilities    
Derivative [Line Items]    
Derivative Liability 4 3
Natural gas | Other current liabilities    
Derivative [Line Items]    
Derivative Liability 11 8
Power | Other current assets    
Derivative [Line Items]    
Derivative assets 39 23
Power | Other assets    
Derivative [Line Items]    
Derivative assets 5 0
Power | Other deferred credits and liabilities    
Derivative [Line Items]    
Derivative Liability 50 131
Power | Other current liabilities    
Derivative [Line Items]    
Derivative Liability 111 59
Uranium | Other current assets    
Derivative [Line Items]    
Derivative assets 2 0
Uranium | Other assets    
Derivative [Line Items]    
Derivative assets 1 1
Uranium | Other current liabilities    
Derivative [Line Items]    
Derivative Liability 0 1
Union Electric Company    
Derivative [Line Items]    
Derivative assets 73 49
Derivative Liability 129 77
Union Electric Company | Fuel oils | Other current assets    
Derivative [Line Items]    
Derivative assets 12 8
Union Electric Company | Fuel oils | Other assets    
Derivative [Line Items]    
Derivative assets 3 5
Union Electric Company | Fuel oils | Other deferred credits and liabilities    
Derivative [Line Items]    
Derivative Liability 1 0
Union Electric Company | Natural gas | Other current assets    
Derivative [Line Items]    
Derivative assets 14 7
Union Electric Company | Natural gas | Other assets    
Derivative [Line Items]    
Derivative assets 13 5
Union Electric Company | Natural gas | Other deferred credits and liabilities    
Derivative [Line Items]    
Derivative Liability 1 1
Union Electric Company | Natural gas | Mark-to-market derivative liabilities    
Derivative [Line Items]    
Derivative Liability 2 2
Union Electric Company | Natural gas | Other current liabilities    
Derivative [Line Items]    
Derivative Liability 0 0
Union Electric Company | Power | Other current assets    
Derivative [Line Items]    
Derivative assets 28 23
Union Electric Company | Power | Other assets    
Derivative [Line Items]    
Derivative assets 0 0
Union Electric Company | Power | Other deferred credits and liabilities    
Derivative [Line Items]    
Derivative Liability 14 23
Union Electric Company | Power | Mark-to-market derivative liabilities    
Derivative [Line Items]    
Derivative Liability 111 50
Union Electric Company | Power | Other current liabilities    
Derivative [Line Items]    
Derivative Liability 0 0
Union Electric Company | Uranium | Other current assets    
Derivative [Line Items]    
Derivative assets 2 0
Union Electric Company | Uranium | Other assets    
Derivative [Line Items]    
Derivative assets 1 1
Union Electric Company | Uranium | Mark-to-market derivative liabilities    
Derivative [Line Items]    
Derivative Liability 0 1
Union Electric Company | Uranium | Other current liabilities    
Derivative [Line Items]    
Derivative Liability 0 0
Ameren Illinois Company    
Derivative [Line Items]    
Derivative assets 94 41
Derivative Liability 48 125
Ameren Illinois Company | Fuel oils | Other current assets    
Derivative [Line Items]    
Derivative assets 0 0
Ameren Illinois Company | Fuel oils | Other assets    
Derivative [Line Items]    
Derivative assets 0 0
Ameren Illinois Company | Fuel oils | Other deferred credits and liabilities    
Derivative [Line Items]    
Derivative Liability 0 0
Ameren Illinois Company | Natural gas | Other current assets    
Derivative [Line Items]    
Derivative assets 0 0
Ameren Illinois Company | Natural gas | Other assets    
Derivative [Line Items]    
Derivative assets 21 13
Ameren Illinois Company | Natural gas | Mark-to-market derivative assets    
Derivative [Line Items]    
Derivative assets 57 28
Ameren Illinois Company | Natural gas | Other deferred credits and liabilities    
Derivative [Line Items]    
Derivative Liability 3 2
Ameren Illinois Company | Natural gas | Other current liabilities    
Derivative [Line Items]    
Derivative Liability 9 6
Ameren Illinois Company | Power | Other current assets    
Derivative [Line Items]    
Derivative assets 0 0
Ameren Illinois Company | Power | Other assets    
Derivative [Line Items]    
Derivative assets 5 0
Ameren Illinois Company | Power | Mark-to-market derivative assets    
Derivative [Line Items]    
Derivative assets 11 0
Ameren Illinois Company | Power | Other deferred credits and liabilities    
Derivative [Line Items]    
Derivative Liability 36 108
Ameren Illinois Company | Power | Other current liabilities    
Derivative [Line Items]    
Derivative Liability 0 9
Ameren Illinois Company | Uranium | Other current assets    
Derivative [Line Items]    
Derivative assets 0 0
Ameren Illinois Company | Uranium | Other assets    
Derivative [Line Items]    
Derivative assets 0 0
Ameren Illinois Company | Uranium | Other current liabilities    
Derivative [Line Items]    
Derivative Liability $ 0 $ 0