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Accumulated Other Comprehensive Loss (Tables) | 12 Months Ended
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Dec. 31, 2023
Components of Accumulated Other Comprehensive Income (Loss) [Abstract] |
Schedule of Accumulated Other Comprehensive Income (Loss) | The following table displays the activity of Accumulated Other Comprehensive Loss, net of tax:
(in millions) | Gains and Losses on Securities(1) |  | Gains and Losses on Cash Flow Hedges(1) |  | Pension and OPEB Items(1) |  | Accumulated Other Comprehensive Loss(1)
Balance as of January 1, 2021 | $ | 6.0 |  |  | $ | (147.9) |  |  | $ | (14.8) |  |  | $ | (156.7) |
Other comprehensive (loss) income before reclassifications | (3.5) |  |  | 25.3 |  |  | 6.6 |  |  | 28.4 |
Amounts reclassified from accumulated other comprehensive loss | (0.4) |  |  | 0.1 |  |  | 1.8 |  |  | 1.5 |
Net current-period other comprehensive (loss) income | (3.9) |  |  | 25.4 |  |  | 8.4 |  |  | 29.9 |
Balance as of December 31, 2021 | $ | 2.1 |  |  | $ | (122.5) |  |  | $ | (6.4) |  |  | $ | (126.8) |
Other comprehensive (loss) income before reclassifications | (13.7) |  |  | 109.7 |  |  | (8.9) |  |  | 87.1 |
Amounts reclassified from accumulated other comprehensive loss | 0.4 |  |  | 0.2 |  |  | 2.0 |  |  | 2.6 |
Net current-period other comprehensive (loss) income | (13.3) |  |  | 109.9 |  |  | (6.9) |  |  | 89.7 |
Balance as of December 31, 2022 | $ | (11.2) |  |  | $ | (12.6) |  |  | $ | (13.3) |  |  | $ | (37.1) |
Other comprehensive income (loss) before reclassifications | 3.1 |  |  | (0.5) |  |  | (1.4) |  |  | 1.2 |
Amounts reclassified from accumulated other comprehensive loss | 0.8 |  |  | 0.3 |  |  | 1.2 |  |  | 2.3 |
Net current-period other comprehensive income (loss) | 3.9 |  |  | (0.2) |  |  | (0.2) |  |  | 3.5 |
Balance as of December 31, 2023 | $ | (7.3) |  |  | $ | (12.8) |  |  | $ | (13.5) |  |  | $ | (33.6) |
(1)All amounts are net of tax. Amounts in parentheses indicate debits.

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