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INCOME TAX EXPENSE - Reconciliation of Taxes from Federal Statutory Rate to Total Income Tax Expense (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024
Reconciliation of Taxes from Federal Statutory Rate to Total Income Tax Expense [Abstract] |  |  |  |
Income Before Income Taxes | $ 14.9 | $ 35.6 | $ 63.1 | $ 97.7
Statutory Federal Income Tax Rate | 21.00% | 21.00% | 21.00% | 21.00%
Income Taxes Computed at Statutory Federal Rate | $ 3.2 | $ 7.5 | $ 13.3 | $ 20.5
Increase (Decrease) in Income Tax Due to: |  |  |  |
State Income Taxes – Net of Federal Income Tax Benefit | 1.4 | 3.4 | 7.1 | 10.5
Production Tax Credits | (1.7) | (8.3) | (8.1) | (25.0)
Investment Tax Credits | (2.0) | (0.4) | (5.6) | (1.6)
Regulatory Differences – Excess Deferred Tax | (2.5) | (2.0) | (7.0) | (7.7)
Non-Controlling Interest in Subsidiaries | 2.6 | 2.4 | 11.5 | 7.6
AFUDC – Equity | (0.4) | (0.4) | (1.1) | (1.3)
Nondeductible Portion of Transaction Costs | 0.6 | 0.7 | 1.4 | 4.0
Other | 0.4 | 0.0 | (3.0) | 1.3
Total Income Tax Expense | $ 1.6 | $ 2.9 | $ 8.5 | $ 8.3

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