Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net earnings	$ 345,779	$ 304,611	$ 583,411
Adjustments to reconcile net earnings to net cash provided by operating activities:
Net realized gains	(19,966)	(32,518)	(588,515)
Net unrealized (gains) losses on equity securities	(81,734)	(64,787)	121,037
Depreciation	7,664	8,545	7,981
Deferred income tax expense (benefit)	10,052	7,710	(49,639)
Other items, net	13,725	24,947	(20,467)
Change in:
Accrued investment income	(4,257)	(2,803)	(3,754)
Premiums and reinsurance balances receivable (net of direct write-offs and commutations)	(9,328)	(31,705)	(22,222)
Reinsurance balances payable	(26,826)	10,407	18,249
Funds held	(4,066)	302	11,371
Ceded unearned premiums	(12,698)	26,200	(7,541)
Reinsurance balances recoverable on unpaid losses and settlement expenses	1,924	(17,260)	(132,003)
Deferred policy acquisition costs	(19,648)	(18,707)	(24,306)
Accrued expenses	15,362	14,011	(3,405)
Unpaid losses and settlement expenses	247,445	130,388	272,082
Unearned premiums	91,814	107,241	104,641
Current income taxes payable	(3,008)	7,285	(6,619)
Changes in investment in unconsolidated investees:
Undistributed earnings	4,869	(9,610)	(9,853)
Dividends received	3,116
Net cash provided by operating activities	560,219	464,257	250,448
Purchase of:
Fixed income securities, available-for-sale	(811,926)	(662,070)	(2,053,359)
Equity securities	(97,922)	(55,652)	(45,007)
Property and equipment	(4,710)	(5,913)	(5,889)
Equity method investee			(3,819)
Other	(10,956)	(10,786)	(5,704)
Proceeds from sale of:
Fixed income securities - available-for-sale	149,939	50,135	53,300
Equity securities	64,839	51,881	62,212
Equity method investments		14,284	686,666
Property and equipment	13	27	375
Other	5,548	817	2,659
Proceeds from call or maturity of:
Fixed income securities - available-for-sale	326,297	504,168	1,393,674
Net sale (purchase) of short-term investments	60,008	(98,694)	(36,229)
Net cash provided by (used in) investing activities	(318,870)	(211,803)	48,879
Cash Flows from Financing Activities
Proceeds from issuance of debt	73,000	100,000
Repayment of debt	(73,000)	(200,000)
Proceeds from stock option exercises	(2,327)	1,245	(465)
Cash dividends paid	(235,656)	(140,093)	(364,848)
Net cash used in financing activities	(237,983)	(238,848)	(365,313)
Net increase (decrease) in cash	3,366	13,606	(65,986)
Cash at the beginning of year	36,424	22,818	88,804
Cash at end of year	$ 39,790	$ 36,424	$ 22,818