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Other Commitments And Contingencies (Narrative) (Details) $ in Millions | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | ---
Dec. 31, 2023 USD ($) Rate MW | Jan. 31, 2024 | Jan. 04, 2024 USD ($) | Jun. 17, 2023 Rate | Dec. 31, 2022 USD ($)
Other Commitments And Contingencies [Line Items] |  |  |  |  |
Wind power purchase agreement capacity | MW | 700 |  |  |  |
Major Rail Operators | 3 |  |  |  |
Line of Credit Facility, Amount Outstanding | $ 0.0 |  |  |  | $ 0.0
Guarantor Obligations, Current Carrying Value | $ 646.1 |  |  |  | 841.6
Wind Power Purchase Agreement, Purchase Percentage | Rate | 100.00% |  |  |  |
Accrual for Environmental Loss Contingencies, Gross | $ 80.0 |  |  |  | 86.5
Other Commitment | $ 250.0 |  |  |  |
Linde Inc. |  |  |  |  |
Other Commitments And Contingencies [Line Items] |  |  |  |  |
Estimated Maximum Disgorgement Exposure |  |  | $ 48.5 |  |
NIPSCO Holdings II |  |  |  |  |
Other Commitments And Contingencies [Line Items] |  |  |  |  |
Subsidiary, Ownership Percentage, Noncontrolling Owner |  | 4.50% |  |  |
Subsidiary, Ownership Percentage, Parent | Rate |  |  |  | 19.90% |
NIPSCO Holdings II | Director |  |  |  |  |
Other Commitments And Contingencies [Line Items] |  |  |  |  |
Subsidiary, Ownership Percentage, Parent | Rate | 17.50% |  |  |  |
MGP Sites |  |  |  |  |
Other Commitments And Contingencies [Line Items] |  |  |  |  |
Number of waste disposal sites identified by program | 53 |  |  |  |
Liability for estimated remediation costs | $ 73.7 |  |  |  | 81.0
Reasonably possible remediation costs variance from reserve | $ 15.1 |  |  |  |
NIPSCO |  |  |  |  |
Other Commitments And Contingencies [Line Items] |  |  |  |  |
Estimated Maximum Disgorgement Exposure |  |  | $ 7.7 |  |
Coal Transportation | Maximum |  |  |  |  |
Other Commitments And Contingencies [Line Items] |  |  |  |  |
Long Term Purchase Commitment Expiration Year | 2025 |  |  |  |
Pipeline Service Agreements [Member] | Maximum |  |  |  |  |
Other Commitments And Contingencies [Line Items] |  |  |  |  |
Long Term Purchase Commitment Expiration Year | 2038 |  |  |  |
Pipeline Service Agreements [Member] | Minimum |  |  |  |  |
Other Commitments And Contingencies [Line Items] |  |  |  |  |
Long Term Purchase Commitment Expiration Year | 2024 |  |  |  |
IT Service Agreements [Member] | Maximum |  |  |  |  |
Other Commitments And Contingencies [Line Items] |  |  |  |  |
Long Term Purchase Commitment Expiration Year | 2028 |  |  |  |
Standby Letters of Credit |  |  |  |  |
Other Commitments And Contingencies [Line Items] |  |  |  |  |
Line of Credit Facility, Amount Outstanding | $ 9.9 |  |  |  | $ 10.2

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- Definition Minimum amount of other commitment not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in the taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions. + References No definition available. + Details
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