Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Statement of Cash Flows [Abstract]
Net cash provided by operating activities	$ 42,829	$ 103,514
Purchase of:
Fixed income securities, available-for-sale	(195,814)	(153,952)
Equity securities	(13,500)	(41,503)
Property and equipment	(1,062)	(1,053)
Other	(3,815)	(2,710)
Proceeds from sale of:
Fixed income securities, available-for-sale	62,748	10,207
Equity securities	18,205	26,679
Other	747	953
Proceeds from call or maturity of:
Fixed income securities, available-for-sale	118,529	99,651
Net proceeds from sale (purchase) of short-term investments	(265,657)	(41,686)
Net cash used in investing activities	(279,619)	(103,414)
Cash Flows from Financing Activities
Proceeds from issuance of debt	297,223
Payment of debt	(50,000)
Cash dividends paid	(14,707)	(13,761)
Proceeds from stock option exercises	1,830	929
Net cash used in financing activities	234,346	(12,832)
Net increase in cash	(2,444)	(12,732)
Cash at the beginning of the period	51,565	39,790
Cash at March 31,	$ 49,121	$ 27,058