Investments - Schedule of Gross Unrealized Losses (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Fair Value
Less than 12 Months of Fair value	$ 323,605	$ 112,840
12 Months or Greater of Fair Value	228,758	189,847
Total, Fair Value	552,363	302,687
Gross Unrealized Losses
Less than 12 Months of Gross Unrealized Losses	(1,023)	(989)
12 Months or Greater of Gross Unrealized Losses	(15,619)	(14,800)
Total, Gross Unrealized Losses	(16,642)	(15,789)
U.S. government and government agency
Fair Value
Less than 12 Months of Fair value	212,928	48,598
12 Months or Greater of Fair Value	20,055	10,970
Total, Fair Value	232,983	59,568
Gross Unrealized Losses
Less than 12 Months of Gross Unrealized Losses	(336)	(69)
12 Months or Greater of Gross Unrealized Losses	(159)	(263)
Total, Gross Unrealized Losses	(495)	(332)
State and municipal
Fair Value
Less than 12 Months of Fair value	1,026	2,992
12 Months or Greater of Fair Value	50,480	47,728
Total, Fair Value	51,506	50,720
Gross Unrealized Losses
Less than 12 Months of Gross Unrealized Losses	(4)	(14)
12 Months or Greater of Gross Unrealized Losses	(5,468)	(5,250)
Total, Gross Unrealized Losses	(5,472)	(5,264)
Commercial mortgage-backed securities
Fair Value
Less than 12 Months of Fair value	9,883	2,485
12 Months or Greater of Fair Value	18,364	18,423
Total, Fair Value	28,247	20,908
Gross Unrealized Losses
Less than 12 Months of Gross Unrealized Losses	(98)	(53)
12 Months or Greater of Gross Unrealized Losses	(985)	(1,113)
Total, Gross Unrealized Losses	(1,083)	(1,166)
Residential mortgage-backed securities
Fair Value
Less than 12 Months of Fair value	49,110	17,536
12 Months or Greater of Fair Value	40,197	31,502
Total, Fair Value	89,307	49,038
Gross Unrealized Losses
Less than 12 Months of Gross Unrealized Losses	(284)	(609)
12 Months or Greater of Gross Unrealized Losses	(5,353)	(4,401)
Total, Gross Unrealized Losses	(5,637)	(5,010)
Asset-backed securities
Fair Value
Less than 12 Months of Fair value	15,946	16,253
12 Months or Greater of Fair Value	23,614	18,491
Total, Fair Value	39,560	34,744
Gross Unrealized Losses
Less than 12 Months of Gross Unrealized Losses	(81)	(71)
12 Months or Greater of Gross Unrealized Losses	(777)	(892)
Total, Gross Unrealized Losses	(858)	(963)
Corporate
Fair Value
Less than 12 Months of Fair value	34,712	24,976
12 Months or Greater of Fair Value	76,048	62,733
Total, Fair Value	110,760	87,709
Gross Unrealized Losses
Less than 12 Months of Gross Unrealized Losses	(220)	(173)
12 Months or Greater of Gross Unrealized Losses	(2,877)	(2,881)
Total, Gross Unrealized Losses	$ (3,097)	$ (3,054)