| Derivative Instruments, Gain (Loss) [Line Items] | |
| Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion) | |
| Derivative Instruments, Gain (Loss) [Line Items] | |
| Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion) | |
| Derivative Instruments, Gain (Loss) [Line Items] | |
| Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion) | |
| Derivative Instruments, Gain (Loss) [Line Items] | |
| Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion) | |
| Derivative Instruments, Gain (Loss) [Line Items] | |
| Amount of Gain (Loss) Recognized on Regulatory Account on Derivatives (Effective Portion) | |
| Kansas City Power and Light Company [Member] | Cash Flow Hedging [Member] | Income tax benefit (expense) [Member] | |
| Derivative Instruments, Gain (Loss) [Line Items] | |
| Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion) | |
| Kansas City Power and Light Company [Member] | Cash Flow Hedging [Member] | Income tax benefit (expense) [Member] | |
| Derivative Instruments, Gain (Loss) [Line Items] | |
| Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) | |
| Cash Flow Hedging [Member] | Income tax benefit (expense) [Member] | |
| Derivative Instruments, Gain (Loss) [Line Items] | |
| Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion) | |
| Cash Flow Hedging [Member] | Income tax benefit (expense) [Member] | |
| Derivative Instruments, Gain (Loss) [Line Items] | |
| Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) | |
| Derivative Instruments, Gain (Loss) [Line Items] | |
| Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion) | |
| Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) | |
| Derivative Instruments, Gain (Loss) [Line Items] | |
| Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) | |
| Derivative Instruments, Gain (Loss) [Line Items] | |
| Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) | |
| Derivative Instruments, Gain (Loss) [Line Items] | |
| Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion) | |
| Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) | |
| Derivative Instruments, Gain (Loss) [Line Items] | |
| Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) | |
| Derivative Instruments, Gain (Loss) [Line Items] | |
| Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) | |
| Derivative Instruments, Gain (Loss) [Line Items] | |
| Gain(Loss) Reclassified from Regulatory Account into Income (Effective Portion) |