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v3.25.3

Fair Value of Financial Instruments - Rollforward of Instruments Measured on Recurring Basis (Details) - Level 3 - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024
Financial Assets |  |  |  |
Beginning balance | $ 519.0 | $ 526.6 | $ 533.0 | $ 518.5
Transfers into Level 3 | 1.2 | 19.8 | 1.2 | 19.8
Transfers out of Level 3 | 0.0 | (7.9) | 0.0 | (12.3)
Total gains or losses |  |  |  |
Net investment gains (losses) included in net income | $ (0.3) | $ (0.4) | $ 4.6 | $ (0.1)
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] | Net investment gains (losses) | Net investment gains (losses) | Net investment gains (losses) | Net investment gains (losses)
Net unrealized gains (losses) included in OCI | $ 11.3 | $ (0.5) | $ 14.4 | $ (0.6)
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Asset, Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration] | Other Comprehensive Income (Loss), Available-for-Sale Securities Adjustment, Net of Tax, Portion Attributable to Parent | Other Comprehensive Income (Loss), Available-for-Sale Securities Adjustment, Net of Tax, Portion Attributable to Parent | Other Comprehensive Income (Loss), Available-for-Sale Securities Adjustment, Net of Tax, Portion Attributable to Parent | Other Comprehensive Income (Loss), Available-for-Sale Securities Adjustment, Net of Tax, Portion Attributable to Parent
Purchases | $ 15.7 | $ 24.3 | $ 37.9 | $ 67.8
Issuances | 0.0 | 0.0 | 0.0 | 0.0
Sales | (28.9) | 0.0 | (56.2) | 0.0
Settlements | 0.0 | 0.0 | 0.0 | 0.0
Paydowns, maturities and distributions | (2.9) | (13.8) | (19.8) | (45.0)
Ending balance | 515.1 | 548.1 | 515.1 | 548.1
Financial Liabilities |  |  |  |
Beginning balance | 74.0 | 77.9 | 75.5 | 82.4
Transfers into Level 3 | 0.0 | 0.0 | 0.0 | 0.0
Transfers out of Level 3 | 0.0 | 0.0 | 0.0 | 0.0
Total gains or losses |  |  |  |
Net investment (gains) losses included in net income related to financial liabilities | (1.2) | 6.6 | 4.4 | 7.6
Net unrealized gains (losses) included in OCI | $ (0.2) | $ 0.2 | $ (0.4) | $ 0.2
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Liability, Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration] | Other Comprehensive Income (Loss), Available-for-Sale Securities Adjustment, Net of Tax, Portion Attributable to Parent | Other Comprehensive Income (Loss), Available-for-Sale Securities Adjustment, Net of Tax, Portion Attributable to Parent | Other Comprehensive Income (Loss), Available-for-Sale Securities Adjustment, Net of Tax, Portion Attributable to Parent | Other Comprehensive Income (Loss), Available-for-Sale Securities Adjustment, Net of Tax, Portion Attributable to Parent
Purchases | $ 0.0 | $ 0.0 | $ 0.0 | $ 0.0
Issuances | 1.0 | 0.8 | 3.1 | 3.6
Sales | 0.0 | 0.0 | 0.0 | 0.0
Settlements | 0.0 | 0.0 | 0.0 | 0.0
Paydowns, maturities and distributions | (3.8) | (4.4) | (12.8) | (12.7)
Ending balance | 69.8 | 81.1 | 69.8 | 81.1
Municipal bonds |  |  |  |
Financial Assets |  |  |  |
Beginning balance | 75.9 | 72.1 | 74.9 | 74.0
Transfers into Level 3 | 1.2 | 0.0 | 1.2 | 0.0
Transfers out of Level 3 | 0.0 | 0.0 | 0.0 | 0.0
Total gains or losses |  |  |  |
Net investment gains (losses) included in net income | 0.0 | 0.0 | 0.0 | 0.0
Net unrealized gains (losses) included in OCI | 1.1 | 1.4 | 2.6 | 0.0
Purchases | 0.0 | 3.2 | 0.0 | 3.2
Issuances | 0.0 | 0.0 | 0.0 | 0.0
Sales | 0.0 | 0.0 | 0.0 | 0.0
Settlements | 0.0 | 0.0 | 0.0 | 0.0
Paydowns, maturities and distributions | (0.1) | (0.1) | (0.6) | (0.6)
Ending balance | 78.1 | 76.6 | 78.1 | 76.6
Corporate bonds |  |  |  |
Financial Assets |  |  |  |
Beginning balance | 342.0 | 366.4 | 351.3 | 342.5
Transfers into Level 3 | 0.0 | 11.8 | 0.0 | 11.8
Transfers out of Level 3 | 0.0 | (3.9) | 0.0 | (8.3)
Total gains or losses |  |  |  |
Net investment gains (losses) included in net income | 0.0 | 0.0 | 0.0 | (0.8)
Net unrealized gains (losses) included in OCI | 9.9 | (3.4) | 11.8 | (3.6)
Purchases | 11.7 | 19.9 | 33.9 | 61.6
Issuances | 0.0 | 0.0 | 0.0 | 0.0
Sales | (23.6) | 0.0 | (49.0) | 0.0
Settlements | 0.0 | 0.0 | 0.0 | 0.0
Paydowns, maturities and distributions | 0.2 | (8.0) | (7.8) | (20.4)
Ending balance | 340.2 | 382.8 | 340.2 | 382.8
Mortgage Backed and Other Asset- Backed Securities |  |  |  |
Financial Assets |  |  |  |
Beginning balance | 63.2 | 85.4 | 73.7 | 97.5
Transfers into Level 3 | 0.0 | 8.0 | 0.0 | 8.0
Transfers out of Level 3 | 0.0 | (4.0) | 0.0 | (4.0)
Total gains or losses |  |  |  |
Net investment gains (losses) included in net income | 0.0 | (0.5) | 0.0 | 0.3
Net unrealized gains (losses) included in OCI | 0.3 | 1.5 | 0.0 | 3.0
Purchases | 4.0 | 0.0 | 4.0 | 1.8
Issuances | 0.0 | 0.0 | 0.0 | 0.0
Sales | (5.3) | 0.0 | (7.2) | 0.0
Settlements | 0.0 | 0.0 | 0.0 | 0.0
Paydowns, maturities and distributions | (3.1) | (5.7) | (11.4) | (21.9)
Ending balance | 59.1 | 84.7 | 59.1 | 84.7
Total Fixed Maturity Securities |  |  |  |
Financial Assets |  |  |  |
Beginning balance | 481.0 | 523.9 | 499.9 | 514.0
Transfers into Level 3 | 1.2 | 19.8 | 1.2 | 19.8
Transfers out of Level 3 | 0.0 | (7.9) | 0.0 | (12.3)
Total gains or losses |  |  |  |
Net investment gains (losses) included in net income | 0.0 | (0.5) | 0.0 | (0.5)
Net unrealized gains (losses) included in OCI | 11.3 | (0.5) | 14.4 | (0.6)
Purchases | 15.7 | 23.1 | 37.9 | 66.6
Issuances | 0.0 | 0.0 | 0.0 | 0.0
Sales | (28.9) | 0.0 | (56.2) | 0.0
Settlements | 0.0 | 0.0 | 0.0 | 0.0
Paydowns, maturities and distributions | (2.9) | (13.8) | (19.8) | (42.9)
Ending balance | 477.4 | 544.1 | 477.4 | 544.1
Equity Securities & Limited Partnership Interests |  |  |  |
Financial Assets |  |  |  |
Beginning balance | 38.0 | 2.7 | 33.1 | 4.5
Transfers into Level 3 | 0.0 | 0.0 | 0.0 | 0.0
Transfers out of Level 3 | 0.0 | 0.0 | 0.0 | 0.0
Total gains or losses |  |  |  |
Net investment gains (losses) included in net income | (0.3) | 0.1 | 4.6 | 0.4
Net unrealized gains (losses) included in OCI |  | 0.0 | 0.0 | 0.0
Purchases | 0.0 | 1.2 | 0.0 | 1.2
Issuances | 0.0 | 0.0 | 0.0 | 0.0
Sales | 0.0 | 0.0 | 0.0 | 0.0
Settlements | 0.0 | 0.0 | 0.0 | 0.0
Paydowns, maturities and distributions | 0.0 | 0.0 | 0.0 | (2.1)
Ending balance | $ 37.7 | $ 4.0 | $ 37.7 | $ 4.0

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