v3.25.2
Investments (Tables)
 6 Months Ended
Jun. 30, 2025
Investments, Debt and Equity Securities [Abstract]  
Schedule of Fair Values and Gross Unrealized Gains and Losses
Fair Values and Gross Unrealized Gains and Losses on Investments
Amortized
Cost		Gross UnrealizedFair
Value
GainsLosses
As of June 30, 2025(In Thousands)
U.S. Treasury securities and obligations of U.S. government agencies$113,564 $2,645 $(221)$115,988 
Municipal debt securities669,223 2,145 (36,406)634,962 
Corporate debt securities2,073,047 18,202 (71,916)2,019,333 
Asset-backed securities39,905 — (1,348)38,557 
Total bonds2,895,739 22,992 (109,891)2,808,840 
Short-term investments120,293 — (16)120,277 
Total investments$3,016,032 $22,992 $(109,907)$2,929,117 
Amortized
Cost		Gross UnrealizedFair
Value
GainsLosses
As of December 31, 2024(In Thousands)
U.S. Treasury securities and obligations of U.S. government agencies$115,342 $1,207 $(489)$116,060 
Municipal debt securities684,523 589 (49,867)635,245 
Corporate debt securities1,949,800 3,981 (106,141)1,847,640 
Asset-backed securities44,104 1 (2,125)41,980 
Total bonds2,793,769 5,778 (158,622)2,640,925 
Short-term investments82,574 42 — 82,616 
Total investments$2,876,343 $5,820 $(158,622)$2,723,541 
Schedule of Corporate Debt Securities by Industry Group
The following table presents a breakdown of the fair value of our corporate debt securities by issuer industry group as of June 30, 2025 and December 31, 2024:
June 30, 2025December 31, 2024
Financial39 %40 %
Consumer28 26 
Utilities11 11 
Industrial9 9 
Technology6 7 
Communications6 7 
Basic materials1 — 
Total100 %100 %
Schedule of Investments by Maturity
The amortized cost and fair value of available-for-sale securities as of June 30, 2025 and December 31, 2024, by contractual maturity, are shown below. Expected maturities will differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties. Because most asset-backed securities provide for periodic payments throughout their lives, they are listed below in a separate category.
As of June 30, 2025Amortized
Cost		Fair
Value
(In Thousands)
Due in one year or less$339,885 $338,500 
Due after one through five years1,706,517 1,655,362 
Due after five through ten years922,939 889,975 
Due after ten years6,786 6,723 
Asset-backed securities39,905 38,557 
Total investments$3,016,032 $2,929,117 
As of December 31, 2024Amortized
Cost		Fair
Value
(In Thousands)
Due in one year or less$261,492 $260,132 
Due after one through five years1,549,468 1,479,220 
Due after five through ten years995,717 916,885 
Due after ten years25,562 25,324 
Asset-backed securities44,104 41,980 
Total investments$2,876,343 $2,723,541 
Schedule of Aging Unrealized Losses For those securities in an unrealized loss position, the length of time the securities were in such a position is as follows:
Less Than Twelve MonthsTwelve Months or GreaterTotal
# of SecuritiesFair ValueUnrealized Losses# of SecuritiesFair ValueUnrealized Losses# of SecuritiesFair ValueUnrealized Losses
As of June 30, 2025($ In Thousands)
U.S. Treasury securities and obligations of U.S. government agencies2 $2,859 $(1)7 $10,760 $(220)9 $13,619 $(221)
Municipal debt securities3 12,776 (92)224 475,672 (36,314)227 488,448 (36,406)
Corporate debt securities28 138,522 (1,273)182 919,380 (70,643)210 1,057,902 (71,916)
Asset-backed securities1 233 *16 38,324 (1,348)17 38,557 (1,348)
Short-term investments16 111,046 (16)— — — 16 111,046 (16)
Total 50 $265,436 $(1,382)429 $1,444,136 $(108,525)479 $1,709,572 $(109,907)
Less Than Twelve MonthsTwelve Months or GreaterTotal
# of SecuritiesFair ValueUnrealized Losses# of SecuritiesFair ValueUnrealized Losses# of SecuritiesFair ValueUnrealized Losses
As of December 31, 2024($ In Thousands)
U.S. Treasury securities and obligations of U.S. government agencies4 $8,002 $(98)9 $11,510 $(391)13 $19,512 $(489)
Municipal debt securities25 110,648 (1,928)220 471,770 (47,939)245 582,418 (49,867)
Corporate debt securities68 366,113 (5,822)226 1,053,862 (100,319)294 1,419,975 (106,141)
Asset-backed securities— — — 19 41,559 (2,125)19 41,559 (2,125)
Short-term investments1 1,551 *— — — 1 1,551 *
Total98 $486,314 $(7,848)474 $1,578,701 $(150,774)572 $2,065,015 $(158,622)
*    Amounts not identifiable due to rounding.
Schedule of Net Investment Income
The following table presents the components of net investment income:
For the three months ended June 30,For the six months ended June 30,
2025202420252024
(In Thousands)
Investment income (1)
$25,263 $20,954 $49,298 $40,651 
Investment expenses(314)(266)(663)(527)
Net investment income$24,949 $20,688 $48,635 $40,124 
(1)    Includes interest income recognized on cash and cash equivalents of $1.1 million and $2.0 million during the three and six months ended June 30, 2025, respectively, and $1.8 million and $2.9 million during the three and six months ended June 30, 2024, respectively.
Schedule of Net Realized Investment Gains (Losses)
The following table presents the components of net realized investment gains (losses):
For the three months ended June 30,For the six months ended June 30,
2025202420252024
(In Thousands)
Gross realized investment gains$— $— $24 $— 
Gross realized investment losses(400)— (400)— 
Net realized investment gains (losses)
$(400)$— $(376)$—