Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenues
Net earned premiums	$ 758,505	$ 774,328	$ 771,078
Net investment income	46,725	44,135	41,045
Earnings from partnership investments	12,484	19,829	6,901
Net realized gains on investments	9,190	14,885	957
Change in unrealized gains on equity securities	(44,386)	16,130	10,449
Credit loss benefit (expense)	14	363	(1,054)
Commission income	566
Finance and other service income	14,461	15,241	16,872
Total revenue	797,559	884,911	846,248
Expenses
Losses and loss adjustment expenses	491,979	461,727	404,556
Underwriting, operating and related expenses	245,145	258,392	266,482
Other expense	330
Interest expense	524	522	440
Total expenses	737,978	720,641	671,478
Income before income taxes	59,581	164,270	174,770
Income tax expense	13,020	33,560	36,559
Net income	$ 46,561	$ 130,710	$ 138,211
Earnings per weighted average common share:
Basic (in dollars per share)	$ 3.17	$ 8.85	$ 9.25
Diluted (in dollars per share)	3.15	8.80	9.18
Cash dividends paid per common share (in dollars per share)	$ 3.60	$ 3.60	$ 3.60
Number of shares used in computing earnings per share:
Basic (in shares)	14,607,483	14,828,736	15,002,755
Diluted (in shares)	14,710,611	14,925,726	15,119,027