v3.25.4
Investments (Tables)
12 Months Ended
Dec. 31, 2025
Debt Securities, Available-for-sale [Line Items]  
Schedule of Unrealized Loss on Investments
An aging of unrealized losses on the Company’s Investments in Fixed Maturities at December 31, 2025 is presented below.
(Dollars in Millions)Less Than 12 Months12 Months or LongerTotal
Fair
Value
Unrealized
Losses
Fair
Value
Unrealized
Losses
Fair
Value
Unrealized
Losses
Fixed Maturities:
     U.S. Government and Government Agencies and Authorities$3.1 $— $380.3 $(82.8)$383.4 $(82.8)
States and Political Subdivisions86.2 (2.4)1,063.3 (183.3)1,149.5 (185.7)
Foreign Governments1.0 — 0.5 (0.1)1.5 (0.1)
Corporate Securities:
Bonds and Notes353.0 (5.4)2,759.5 (428.1)3,112.5 (433.5)
Redeemable Preferred Stocks— — 2.0 — 2.0 — 
Collateralized Loan Obligations238.2 (1.2)61.7 (6.6)299.9 (7.8)
Other Mortgage- and Asset-backed24.7 (0.5)249.5 (22.7)274.2 (23.2)
Total Fixed Maturities$706.2 $(9.5)$4,516.8 $(723.6)$5,223.0 $(733.1)
An aging of unrealized losses on the Company’s Investments in Fixed Maturities at December 31, 2024 is presented below.
(Dollars in Millions)Less Than 12 Months12 Months or LongerTotal
Fair
Value
Unrealized
Losses
Fair
Value
Unrealized
Losses
Fair
Value
Unrealized
Losses
Fixed Maturities:
     U.S. Government and Government Agencies and Authorities$41.7 $(0.5)$383.6 $(101.9)$425.3 $(102.4)
     States and Political Subdivisions242.7 (10.3)933.4 (215.1)1,176.1 (225.4)
     Foreign Governments— — 1.4 (0.2)1.4 (0.2)
Corporate Securities:
Bonds and Notes674.3 (40.9)2,605.7 (477.9)3,280.0 (518.8)
Redeemable Preferred Stocks2.0 — 6.6 (1.0)8.6 (1.0)
Collateralized Loan Obligations34.2 (0.1)89.5 (7.1)123.7 (7.2)
Other Mortgage- and Asset-backed12.0 (0.1)261.7 (34.4)273.7 (34.5)
Total Fixed Maturities$1,006.9 $(51.9)$4,281.9 $(837.6)$5,288.8 $(889.5)
Debt Securities, Available-for-Sale, Allowance for Credit Loss
The following table sets forth the change in allowance for credit losses on fixed maturities available-for-sale by major security type for the year ended December 31, 2025. Accrued interest excluded from the amortized cost of fixed maturities total $75.3 million and $70.9 million as of December 31, 2025 and 2024, respectively, and is reported within the Other Receivables line of the Consolidated Balance Sheets. The Company monitors accrued interest and writes off amounts when they are deemed uncollectible.
 States and Political SubdivisionsCorporate Bonds and NotesTotal
(Dollars in Millions)
Balance, Beginning of Year$0.3 $10.4 $10.7 
Additions for Securities for which No Previous Expected Credit Losses were
   Recognized
— 2.4 2.4 
Reductions due to Sales— (1.1)(1.1)
Net (Decrease) Increase in Allowance on Securities for which Expected Credit Losses were Previously Recognized(0.1)9.4 9.3 
Write-Offs Charged Against Allowance
— (1.2)(1.2)
Balance, End of Year$0.2 $19.9 $20.1 
The following table sets forth the change in allowance for credit losses on fixed maturities available-for-sale by major security type for the year ended December 31, 2024.
 States and Political SubdivisionsCorporate Bonds and NotesTotal
(Dollars in Millions)
Balance, Beginning of Year$0.5 $7.7 $8.2 
Additions for Securities for which No Previous Expected Credit Losses were
   Recognized
— 3.4 3.4 
Reduction due to Sales— (0.8)(0.8)
Net (Decrease) Increase in Allowance on Securities for which Expected Credit Losses were Previously Recognized(0.2)0.1 (0.1)
Balance, End of Year$0.3 $10.4 $10.7 
Schedule of Other Investments
The carrying values of the Company’s Other Investments at December 31, 2025 and 2024 were:
(Dollars in Millions)20252024
Equity Securities at Modified Cost$21.7 $22.5 
Real Estate at Depreciated Cost92.7 99.5 
Mortgage Loans149.8 75.3 
Other1
7.1 19.8 
Total Other Investments$271.3 $217.1 
1In 2025, the Company elected to change the presentation of Alternative Energy Partnership Investments by including them within Other Investments. Prior-period amounts have been recast to conform to the current-period presentation.
Investments in Fixed Maturities  
Debt Securities, Available-for-sale [Line Items]  
Schedule of Available-for-sale Securities Reconciliation
The amortized cost and estimated fair values of the Company’s Investments in Fixed Maturities at December 31, 2025 were:
(Dollars in Millions)Amortized
Cost
Gross UnrealizedAllowance for Expected Credit LossesFair Value
GainsLosses
U.S. Government and Government Agencies and Authorities$702.0 $3.2 $(82.8)$— $622.4 
States and Political Subdivisions1,437.3 1.8 (185.7)(0.2)1,253.2 
Foreign Governments10.7 0.4 (0.1)— 11.0 
Corporate Securities:
Bonds and Notes4,089.8 11.4 (433.5)(17.4)3,650.3 
Redeemable Preferred Stocks9.8 0.4 — — 10.2 
Collateralized Loan Obligations850.8 2.5 (7.8)(2.5)843.0 
Other Mortgage- and Asset-backed375.3 1.1 (23.2)— 353.2 
Investments in Fixed Maturities$7,475.7 $20.8 $(733.1)$(20.1)$6,743.3 
The amortized cost and estimated fair values of the Company’s Investments in Fixed Maturities at December 31, 2024 were:
Amortized
Cost
Gross UnrealizedAllowance for Expected Credit LossesFair Value
(Dollars in Millions)
GainsLosses
U.S. Government and Government Agencies and Authorities$588.6 $0.6 $(102.4)$— $486.8 
States and Political Subdivisions1,457.3 1.6 (225.4)(0.3)1,233.2 
Foreign Governments6.5 0.3 (0.2)— 6.6 
Corporate Securities:
Bonds and Notes4,038.3 8.9 (518.8)(8.8)3,519.6 
Redeemable Preferred Stocks9.8 0.1 (1.0)— 8.9 
Collateralized Loan Obligations747.8 2.5 (7.2)(1.6)741.5 
Other Mortgage- and Asset-backed446.7 0.8 (34.5)— 413.0 
Investments in Fixed Maturities$7,295.0 $14.8 $(889.5)$(10.7)$6,409.6 
Investments Classified by Contractual Maturity Date
The amortized cost and estimated fair values of the Company’s Investments in Fixed Maturities at December 31, 2025 by contractual maturity were:
(Dollars in Millions)Amortized CostFair Value
Due in One Year or Less$196.6 $186.1 
Due after One Year to Five Years975.4 946.3 
Due after Five Years to Ten Years942.1 865.9 
Due after Ten Years3,577.4 3,060.3 
Mortgage- and Asset-backed Securities Not Due at a Single Maturity Date1,784.2 1,684.7 
Investments in Fixed Maturities$7,475.7 $6,743.3