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v3.19.3.a.u2

Commitments And Contingencies (Narrative) (Details) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2019 USD ($) | Dec. 31, 2016 | Dec. 31, 2018 USD ($)
Long-term Purchase Commitment [Line Items] |  |  |
Present value abandonment obligation | $ 39.0 |  |
Other | $ 298.9 |  | $ 287.2
Workforce Subject to Collective Bargaining Arrangements [Member] |  |  |
Long-term Purchase Commitment [Line Items] |  |  |
Employees covered by collective bargaining agreement | 54.00% |  |
Workforce Subject to Collective Bargaining Arrangements Expiring within One Year [Member] |  |  |
Long-term Purchase Commitment [Line Items] |  |  |
Employees covered by collective bargaining agreement | 18.00% |  |
Capital Purchase Commitment [Member] |  |  |
Long-term Purchase Commitment [Line Items] |  |  |
Minimum future commitments | $ 77.0 |  |
IPL [Member] |  |  |
Long-term Purchase Commitment [Line Items] |  |  |
Maximum indemnification limit | 17.0 |  |
Other | $ 253.4 |  | 220.7
IPL [Member] | Workforce Subject to Collective Bargaining Arrangements [Member] |  |  |
Long-term Purchase Commitment [Line Items] |  |  |
Employees covered by collective bargaining agreement | 62.00% |  |
IPL [Member] | Workforce Subject to Collective Bargaining Arrangements Expiring within One Year [Member] |  |  |
Long-term Purchase Commitment [Line Items] |  |  |
Employees covered by collective bargaining agreement | 46.00% |  |
IPL [Member] | Capital Purchase Commitment [Member] |  |  |
Long-term Purchase Commitment [Line Items] |  |  |
Minimum future commitments | $ 60.0 |  |
WPL [Member] |  |  |
Long-term Purchase Commitment [Line Items] |  |  |
Other | $ 168.7 |  | $ 178.2
WPL [Member] | Workforce Subject to Collective Bargaining Arrangements [Member] |  |  |
Long-term Purchase Commitment [Line Items] |  |  |
Employees covered by collective bargaining agreement | 83.00% |  |
WPL [Member] | Capital Purchase Commitment [Member] |  |  |
Long-term Purchase Commitment [Line Items] |  |  |
Minimum future commitments | $ 17.0 |  |
Indemnification Agreement [Member] |  |  |
Long-term Purchase Commitment [Line Items] |  |  |
Maximum indemnification limit | 82.0 |  |
Indemnification Agreement [Member] | Purchased Power [Member] |  |  |
Long-term Purchase Commitment [Line Items] |  |  |
Maximum indemnification limit | $ 17.0 |  |
FERC [Member] |  |  |
Long-term Purchase Commitment [Line Items] |  |  |
Number of FERC complaints (in number of complaints) | 2 |  |
Base return on equity, percentage | 9.88% | 10.32% |
Other | $ 5.8 |  |

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