| Component: (Network and Table) | |
|---|---|
| Network | 2414402 - Disclosure - Income Taxes (Schedule Of Effective Income Tax Rate Reconciliation) (Details) (http://www.ameren.com/role/IncomeTaxesScheduleOfEffectiveIncomeTaxRateReconciliationDetails) |
| Table | Income Taxes [Table] |
| Reporting Entity [Axis] | 0001002910 (http://www.sec.gov/CIK) |
| Income Taxes [Line Items] | Period [Axis] | ||||||||
|---|---|---|---|---|---|---|---|---|---|
2016-01-01 - 2016-12-31 | 2015-01-01 - 2015-12-31 | 2014-01-01 - 2014-12-31 | |||||||
| Legal Entity [Axis] | Legal Entity [Axis] | Legal Entity [Axis] | |||||||
| Union Electric Company | Ameren Illinois Company | Entity [Domain] | Union Electric Company | Ameren Illinois Company | Entity [Domain] | Union Electric Company | Ameren Illinois Company | Entity [Domain] | |
Statutory federal income tax rate: | |||||||||
Depreciation differences | ( | ( | |||||||
Amortization of deferred investment tax credit | ( | ( | ( | ( | ( | ||||
State tax | |||||||||
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost, Percent | ( | ||||||||
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent | |||||||||
Effective Income Tax Rate Reconciliation, Other Adjustments, Percent | ( | ( | ( | ||||||
Effective income tax rate | |||||||||