Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues
Net premiums earned	$ 350,326	$ 346,156	$ 368,704
Net investment income	30,452	29,281	28,106
Net realized losses on investments	(1,536)	(647)	(494)
Net unrealized losses on equity securities	(2,088)
Fee and other income	599	418	346
Total revenues	377,753	375,208	396,662
Expenses
Loss and loss adjustment expenses incurred	204,891	209,324	199,031
Underwriting and certain other operating costs	28,981	28,333	29,470
Commissions	26,160	24,812	26,243
Salaries and benefits	25,992	25,631	24,881
Policyholder dividends	4,148	4,868	4,216
Total expenses	290,172	292,968	283,841
Income before income taxes	87,581	82,240	112,821
Income tax expense	15,949	36,009	34,956
Net income	$ 71,632	$ 46,231	$ 77,865
Earnings per share
Basic	$ 3.73	$ 2.41	$ 4.08
Diluted	$ 3.71	$ 2.40	$ 4.05
Shares used in computing earnings per share
Basic	19,208,978	19,165,489	19,105,806
Diluted	19,293,082	19,245,866	19,203,650
Extraordinary cash dividends declared per common share	$ 3.50	$ 3.50	$ 3.25
Cash dividends declared per common share	$ 0.88	$ 0.80	$ 0.72