XML 37 R27.htm IDEA: XBRL DOCUMENT v3.24.3
Investments (Tables)
 9 Months Ended 12 Months Ended
Sep. 30, 2024
Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]    
Available-For-Sale Investments The following tables summarize the Company's available-for-sale investments. Agency mortgage-backed securities include securities issued by U.S. government-sponsored enterprises and U.S. government agencies. The net unrealized holding gains (losses) in the tables below are presented before taxes.
 September 30, 2024
(dollars in thousands)Amortized
Cost		Gross
Unrealized
Holding
Gains		Gross
Unrealized
Holding
Losses		Estimated
Fair
Value
Fixed maturity securities:
U.S. Treasury securities$4,946,495 $79,659 $(31,894)$4,994,260 
U.S. government-sponsored enterprises1,420,858 19,757 (65,452)1,375,163 
Obligations of states, municipalities and political subdivisions4,003,008 36,672 (129,328)3,910,352 
Foreign governments, agencies and supranationals
2,783,826 77,781 (103,644)2,757,963 
Agency mortgage-backed securities
2,738,131 25,754 (86,205)2,677,680 
Non-agency mortgage-backed securities
122,640 — (3,416)119,224 
Corporate and university bonds
250,785 230 (17,809)233,206 
Total fixed maturity securities16,265,743 239,853 (437,748)16,067,848 
Short-term investments2,351,758 4,070 (90)2,355,738 
Investments, available-for-sale$18,617,501 $243,923 $(437,838)$18,423,586 
 December 31, 2023
(dollars in thousands)Amortized
Cost		Gross
Unrealized
Holding
Gains		Gross
Unrealized
Holding
Losses		Estimated
Fair
Value
Fixed maturity securities:
U.S. Treasury securities$3,811,293 $35,824 $(62,404)$3,784,713 
U.S. government-sponsored enterprises1,225,426 7,292 (89,904)1,142,814 
Obligations of states, municipalities and political subdivisions4,196,096 14,787 (181,578)4,029,305 
Foreign governments, agencies and supranationals
2,554,874 34,352 (142,008)2,447,218 
Agency mortgage-backed securities
2,507,682 8,939 (135,611)2,381,010 
Non-agency mortgage-backed securities
355,673 — (22,603)333,070 
Corporate and university bonds
281,242 141 (26,781)254,602 
Total fixed maturity securities14,932,286 101,335 (660,889)14,372,732 
Short-term investments2,564,620 7,155 (393)2,571,382 
Investments, available-for-sale$17,496,906 $108,490 $(661,282)$16,944,114 
Summary Of Gross Unrealized Investment Losses By Length Of Time That Securities Have Continuously Been In An Unrealized Loss Position The following tables summarize gross unrealized investment losses on available-for-sale investments by the length of time that securities have continuously been in an unrealized loss position.
September 30, 2024
Less than 12 months12 months or longerTotal
(dollars in thousands)Estimated
Fair
Value		Gross
Unrealized
Holding Losses		Estimated
Fair
Value		Gross
Unrealized
Holding Losses		Estimated
Fair
Value
Gross
Unrealized
Holding
Losses
Fixed maturity securities:
U.S. Treasury securities$52,587 $(85)$1,420,909 $(31,809)$1,473,496 $(31,894)
U.S. government-sponsored enterprises18,881 (584)723,075 (64,868)741,956 (65,452)
Obligations of states, municipalities and political subdivisions153,371 (518)2,249,754 (128,810)2,403,125 (129,328)
Foreign governments, agencies and supranationals
16,767 (57)1,316,288 (103,587)1,333,055 (103,644)
Agency mortgage-backed securities
53,196 (412)1,818,419 (85,793)1,871,615 (86,205)
Non-agency mortgage-backed securities
— — 119,224 (3,416)119,224 (3,416)
Corporate and university bonds
2,203 (48)227,773 (17,761)229,976 (17,809)
Total fixed maturity securities297,005 (1,704)7,875,442 (436,044)8,172,447 (437,748)
Short-term investments327,973 (90)— — 327,973 (90)
Total$624,978 $(1,794)$7,875,442 $(436,044)$8,500,420 $(437,838)
December 31, 2023
Less than 12 months12 months or longerTotal
(dollars in thousands)Estimated
Fair
Value
Gross
Unrealized
Holding
Losses
Estimated
Fair
Value
Gross
Unrealized
Holding 
Losses
Estimated
Fair
Value
Gross
Unrealized
Holding 
Losses
Fixed maturity securities:
U.S. Treasury securities$317,027 $(2,147)$1,507,784 $(60,257)$1,824,811 $(62,404)
U.S. government-sponsored enterprises145,143 (2,134)723,537 (87,770)868,680 (89,904)
Obligations of states, municipalities and political subdivisions679,124 (3,881)2,332,281 (177,697)3,011,405 (181,578)
Foreign governments, agencies and supranationals
83,396 (395)1,492,912 (141,613)1,576,308 (142,008)
Agency mortgage-backed securities
189,977 (1,871)1,889,272 (133,740)2,079,249 (135,611)
Non-agency mortgage-backed securities
— — 333,070 (22,603)333,070 (22,603)
Corporate and university bonds
— — 236,205 (26,781)236,205 (26,781)
Total fixed maturity securities1,414,667 (10,428)8,515,061 (650,461)9,929,728 (660,889)
Short-term investments52,601 (393)— — 52,601 (393)
Total$1,467,268 $(10,821)$8,515,061 $(650,461)$9,982,329 $(661,282)
Schedule Of Amortized Cost And Estimated Fair Value Of Fixed Maturity Securities By Contractual Maturity Date The amortized cost and estimated fair value of fixed maturity securities at September 30, 2024 are shown below by contractual maturity.
(dollars in thousands)Amortized
Cost		Estimated
Fair Value
Due in one year or less$1,486,434 $1,478,425 
Due after one year through five years5,577,381 5,559,647 
Due after five years through ten years4,992,655 4,971,587 
Due after ten years1,348,502 1,261,285 
13,404,972 13,270,944 
Agency mortgage-backed securities
2,738,131 2,677,680 
Non-agency mortgage-backed securities
122,640 119,224 
Total fixed maturity securities$16,265,743 $16,067,848 
  
Components Of Net Investment Income The following table presents the components of net investment income.
Quarter Ended September 30, Nine Months Ended September 30,
(dollars in thousands)2024202320242023
Interest:
Fixed maturity securities$131,424 $98,891 $372,089 $269,438 
Short-term investments30,971 26,768 94,809 77,099 
Cash and cash equivalents and restricted cash and cash equivalents
41,220 39,473 122,840 102,565 
Dividends on equity securities36,739 31,134 101,263 84,968 
240,354 196,266 691,001 534,070 
Investment expenses(4,877)(4,059)(14,194)(12,835)
Net investment income
$235,477 $192,207 $676,807 $521,235 
  
Summary Of Net Investment Gains (Losses) And The Change In Net Unrealized Gains On Available-For-Sale Investments The following table presents the components of net investment gains (losses) included in net income and the change in net unrealized losses included in other comprehensive income (loss). Gross realized investment gains and losses on fixed maturity securities, short-term investments and other investments were not material to the consolidated financial statements and are presented on a net basis in the following table.
Quarter Ended September 30, Nine Months Ended September 30,
(dollars in thousands)2024202320242023
Fixed maturity securities, short-term investments and other investments:
Net realized investment gains (losses)$13,891 $(36,093)$(4,604)$(38,159)
Equity securities:
Change in fair value of securities sold during the period(6,652)2,683 (11,263)16,706 
Change in fair value of securities held at the end of the period910,291 (232,507)1,705,661 612,626 
Total change in fair value903,639 (229,824)1,694,398 629,332 
Net investment gains (losses)$917,530 $(265,917)$1,689,794 $591,173 
Change in net unrealized losses on available-for-sale investments included in other comprehensive income (loss):
Fixed maturity securities$546,386 $(208,598)$361,659 $(167,411)
Short-term investments4,858 193 (2,782)(3,195)
Net increase (decrease)$551,244 $(208,405)$358,877 $(170,606)