XML 100 R59.htm IDEA: XBRL DOCUMENT v3.23.2
Income Taxes (Schedule of Effective Income Tax Rate Reconciliation) (Details)
3 Months Ended 6 Months Ended
Jun. 30, 2023
Jun. 30, 2022
Jun. 30, 2023
Jun. 30, 2022
Income Taxes [Line Items]        
Federal statutory corporate income tax rate 21.00% 21.00% 21.00% 21.00%
Increases (decreases) from:        
Amortization of deferred investment tax credit 0.00% 0.00% 0.00% 0.00%
Amortization of excess deferred taxes (7.00%) (8.00%) (8.00%) (8.00%)
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Depreciation, Percent 0.00% 0.00% 0.00% 0.00%
Other 0.00% 1.00%    
Renewable and other tax credits (5.00%) (4.00%) (4.00%) (5.00%)
State tax 5.00% 5.00% 5.00% 5.00%
Other permanent items     (1.00%) 0.00%
Effective income tax rate 14.00% 15.00% 13.00% 13.00%
Union Electric Company        
Income Taxes [Line Items]        
Federal statutory corporate income tax rate 21.00% 21.00% 21.00% 21.00%
Increases (decreases) from:        
Amortization of deferred investment tax credit 0.00% (1.00%) 0.00% (1.00%)
Amortization of excess deferred taxes (15.00%) (15.00%) (15.00%) (16.00%)
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Depreciation, Percent 0.00% 0.00% 0.00% 0.00%
Other 0.00% 0.00%    
Renewable and other tax credits (10.00%) (10.00%) (10.00%) (10.00%)
State tax 3.00% 3.00% 3.00% 3.00%
Other permanent items     0.00% 0.00%
Effective income tax rate (1.00%) (2.00%) (1.00%) (3.00%)
Ameren Illinois Company        
Income Taxes [Line Items]        
Federal statutory corporate income tax rate 21.00% 21.00% 21.00% 21.00%
Increases (decreases) from:        
Amortization of deferred investment tax credit 0.00% 0.00% 0.00% 0.00%
Amortization of excess deferred taxes (2.00%) (2.00%) (2.00%) (2.00%)
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Depreciation, Percent (1.00%) (1.00%) (1.00%) 0.00%
Other 0.00% 0.00%    
Renewable and other tax credits 0.00% 0.00% 0.00% 0.00%
State tax 7.00% 7.00% 7.00% 7.00%
Other permanent items     0.00% 0.00%
Effective income tax rate 25.00% 25.00% 25.00% 26.00%