Regulatory Matters (Narrative) (Details) $ in Millions |
3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
|
Sep. 30, 2024
USD ($)
MW
|
Sep. 30, 2023
USD ($)
|
Sep. 30, 2024
USD ($)
MW
|
Sep. 30, 2023
USD ($)
|
Dec. 31, 2023
USD ($)
|
|
| Public Utilities, General Disclosures [Line Items] | |||||
| Depreciation, Nonproduction | $ (24.2) | $ (9.7) | $ (40.8) | $ (19.0) | |
| Deferred Derivative Gain (Loss) | |||||
| Public Utilities, General Disclosures [Line Items] | |||||
| Regulatory Assets | 11.8 | 11.8 | $ 24.4 | ||
| Deferred Derivative Gain (Loss) | NIPSCO | |||||
| Public Utilities, General Disclosures [Line Items] | |||||
| Regulatory Assets | $ 16.9 | $ 16.9 | |||
| Rosewater | |||||
| Public Utilities, General Disclosures [Line Items] | |||||
| Nameplate Capacity | MW | 102 | 102 | |||
| NIPSCO | |||||
| Public Utilities, General Disclosures [Line Items] | |||||
| Nameplate Capacity | MW | 400 | 400 | |||