Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues
Net premiums earned	$ 332,888	$ 350,326	$ 346,156
Net investment income	32,483	30,452	29,281
Net realized losses on investments	(80)	(1,536)	(647)
Net unrealized gains (losses) on equity securities	4,758	(2,088)
Fee and other income	321	599	418
Total revenues	370,370	377,753	375,208
Expenses
Loss and loss adjustment expenses incurred	176,342	204,891	209,324
Underwriting and certain other operating costs	22,221	28,981	28,333
Commissions	25,010	26,160	24,812
Salaries and benefits	27,120	25,992	25,631
Policyholder dividends	4,160	4,148	4,868
Total expenses	254,853	290,172	292,968
Income before income taxes	115,517	87,581	82,240
Income tax expense	22,827	15,949	36,009
Net income	$ 92,690	$ 71,632	$ 46,231
Earnings per share
Basic	$ 4.82	$ 3.73	$ 2.41
Diluted	$ 4.80	$ 3.71	$ 2.40
Shares used in computing earnings per share
Basic	19,248,657	19,208,978	19,165,489
Diluted	19,329,238	19,293,082	19,245,866
Extraordinary cash dividends declared per common share	$ 3.50	$ 3.50	$ 3.50
Cash dividends declared per common share	$ 1.00	$ 0.88	$ 0.80