v3.26.1
Investments (Tables)
 6 Months Ended
Jun. 30, 2026
Investments [Abstract]  
Amortized Cost and Estimated Fair Values Of Fixed Income Securities
The amortized cost and fair values by type and contractual maturity of fixed income securities are shown in the following tables. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.
Amortized
Cost		Gross
Unrealized
Gains		Gross
Unrealized
Losses
Fair
Value
Fixed Income Securities by Type:
June 30, 2026:
Government & Agency$1,695.8 $2.5 $33.2 $1,665.0 
Corporate10,420.7 120.7 45.2 10,496.2 
$12,116.5 $123.2 $78.5 $12,161.2 
December 31, 2025:
Government & Agency$1,795.3 $13.2 $21.1 $1,787.4 
Corporate10,683.5 255.8 16.9 10,922.3 
$12,478.8 $269.1 $38.1 $12,709.8 
Amortized Cost and Estimated Fair Values Of Fixed Income Securities By Contractual Maturities
Amortized
Cost
Fair
Value
Fixed Income Securities Stratified by Contractual Maturity at June 30, 2026:
Due in one year or less$1,291.6 $1,291.4 
Due after one year through five years5,821.8 5,845.2 
Due after five years through ten years4,709.1 4,730.8 
Due after ten years293.9 293.7 
$12,116.5 $12,161.2 
Gross Unrealized Losses and Fair Value, Aggregated
The following table reflects the Company's gross unrealized losses and fair value of fixed income securities, aggregated by category and length of time that individual securities have been in an unrealized loss position.
Less than 12 Months12 Months or GreaterTotal
Fair
Value		Unrealized LossesFair
Value		Unrealized LossesFair
Value		Unrealized Losses
June 30, 2026:
Fixed Income Securities:
Government & Agency$747.2 $9.0 $518.7 $24.2 $1,266.0 $33.2 
Corporate3,174.6 34.5 472.5 10.6 3,647.2 45.2 
$3,921.9 $43.6 $991.2 $34.9 $4,913.2 $78.5 
December 31, 2025:
Fixed Income Securities:
Government & Agency$179.9 $1.0 $594.7 $20.1 $774.7 $21.1 
Corporate895.2 4.3 767.9 12.6 1,663.1 16.9 
$1,075.1 $5.4 $1,362.7 $32.7 $2,437.8 $38.1 
Equity Securities Reflecting Reported Cost
The following table shows cost and fair value information for equity securities:

Equity Securities

Cost		Gross
Unrealized
Gains		Gross
Unrealized
Losses
Fair
Value
June 30, 2026$1,318.2 $1,380.6 $19.8 $2,679.0 
December 31, 2025$1,377.7 $1,134.4 $24.3 $2,487.7 
Fair Value, Assets Measured on Recurring Basis
The following tables show a summary of the fair value of financial assets segregated among the various input levels described above:
Fair Value Measurements
As of June 30, 2026:Level 1Level 2Level 3Total
Fixed income securities:
Government & Agency$1,502.5 $162.4 $— $1,665.0 
Corporate— 10,486.6 9.6 10,496.2 
Equity securities2,676.8 — 2.2 2,679.0 
Short-term investments$2,233.1 $— $— $2,233.1 
As of December 31, 2025:
Fixed income securities:
Government & Agency$1,591.8 $195.6 $— $1,787.4 
Corporate— 10,912.7 9.5 10,922.3 
Equity securities2,485.5 — 2.2 2,487.7 
Short-term investments$1,613.6 $— $— $1,613.6 
Investment Income
The following table reflects the composition of net investment income, net realized gains or losses, and the net change in unrealized investment gains or losses for each of the periods shown.
Quarters EndedSix Months Ended
June 30,June 30,
2026202520262025
Net investment income:
Fixed income securities$149.1 $141.2 $298.4 $279.8 
Equity securities18.9 20.9 38.0 41.7 
Short-term investments12.7 11.8 23.7 23.8 
Other investments (a)
6.5 2.8 10.2 7.6 
Gross investment income187.4 176.9 370.5 353.1 
Investment expenses (a)
5.4 5.4 10.4 10.8 
Net investment income$182.0 $171.5 $360.1 $342.2 
Net investment gains (losses):
Realized from actual transactions:
Fixed income securities:
Gains$3.1 $1.5 $6.0 $2.1 
Losses(7.5)(4.1)(7.8)(5.8)
Net(4.3)(2.6)(1.8)(3.6)
Equity securities:
Gains46.0 11.4 138.9 51.4 
Losses— (11.3)— (12.4)
Net46.0 0.1 138.8 38.9 
Other investments, net0.3 — 0.3 (0.3)
Total realized from actual transactions42.0 (2.4)137.3 34.9 
From impairments
(3.8)— (13.8)— 
From unrealized changes in fair value of equity securities134.2 (4.9)250.7 12.7 
Total realized and unrealized investment gains
172.4 (7.3)374.3 47.7 
Current and deferred income taxes
36.2 (2.6)78.6 9.1 
Net of tax realized and unrealized investment gains
$136.2 $(4.7)$295.7 $38.5 
Changes in unrealized investment gains (losses)
reflected directly in shareholders' equity:
Fixed income securities$(42.9)$90.6 $(186.0)$230.6 
Less: Deferred income taxes (credits)
(8.9)19.0 (39.0)48.6 
(33.9)71.6 (146.9)182.0 
Other investments(0.1)— (0.2)1.6 
Less: Deferred income taxes
— — — 0.3 
— — (0.2)1.3 
Net changes in unrealized investment gains,
net of tax (credits)
$(34.0)$71.6 $(147.2)$183.3 
_________

(a) Includes interest on funds held.