Investments - Security Holdings in an Unrealized Loss Position (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Debt Securities, Available-for-Sale [Line Items]
Less than 12 months, Estimated fair value	$ 295,384	$ 71,429
Less than 12 months, Gross unrealized losses	(3,108)	(164)
12 months or longer, Estimated fair value	3,271	47,179
12 months or longer, Gross unrealized losses	(76)	(502)
Estimated fair value	298,655	118,608
Gross unrealized losses	(3,184)	(666)
Corporate
Debt Securities, Available-for-Sale [Line Items]
Less than 12 months, Estimated fair value	110,584	6,307
Less than 12 months, Gross unrealized losses	(1,377)	(7)
12 months or longer, Estimated fair value	328	9,461
12 months or longer, Gross unrealized losses	(10)	(108)
Estimated fair value	110,912	15,768
Gross unrealized losses	(1,387)	(115)
U.S. Treasury
Debt Securities, Available-for-Sale [Line Items]
Less than 12 months, Estimated fair value	81,022	35,150
Less than 12 months, Gross unrealized losses	(644)	(83)
12 months or longer, Estimated fair value	2,943	14,948
12 months or longer, Gross unrealized losses	(66)	(78)
Estimated fair value	83,965	50,098
Gross unrealized losses	(710)	(161)
States and municipalities
Debt Securities, Available-for-Sale [Line Items]
Less than 12 months, Estimated fair value	9,423	880
Less than 12 months, Gross unrealized losses	(126)	(3)
12 months or longer, Estimated fair value	0	0
12 months or longer, Gross unrealized losses	0	0
Estimated fair value	9,423	880
Gross unrealized losses	(126)	(3)
Foreign
Debt Securities, Available-for-Sale [Line Items]
Less than 12 months, Estimated fair value	22,573	17,009
Less than 12 months, Gross unrealized losses	(146)	(62)
12 months or longer, Estimated fair value	0	0
12 months or longer, Gross unrealized losses	0	0
Estimated fair value	22,573	17,009
Gross unrealized losses	(146)	(62)
Asset-backed securities
Debt Securities, Available-for-Sale [Line Items]
Less than 12 months, Estimated fair value	10,557	1,771
Less than 12 months, Gross unrealized losses	(47)	(5)
12 months or longer, Estimated fair value	0	1,881
12 months or longer, Gross unrealized losses	0	(37)
Estimated fair value	10,557	3,652
Gross unrealized losses	(47)	(42)
Mortgage-backed securities
Debt Securities, Available-for-Sale [Line Items]
Less than 12 months, Estimated fair value	61,225	10,312
Less than 12 months, Gross unrealized losses	(768)	(4)
12 months or longer, Estimated fair value	0	20,889
12 months or longer, Gross unrealized losses	0	(279)
Estimated fair value	61,225	31,201
Gross unrealized losses	$ (768)	$ (283)