Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues:
Net premiums earned	$ 261,627us-gaap_PremiumsEarnedNet	$ 252,743us-gaap_PremiumsEarnedNet	$ 237,461us-gaap_PremiumsEarnedNet
Net investment income	9,055us-gaap_NetInvestmentIncome	8,770us-gaap_NetInvestmentIncome	9,930us-gaap_NetInvestmentIncome
Commissions and other income	6,430us-gaap_FeesAndCommissions	5,944us-gaap_FeesAndCommissions	5,722us-gaap_FeesAndCommissions
Net realized gains on investments, excluding impairment losses	15,619	24,257	9,899
Total other-than-temporary impairment losses on investments	(689)us-gaap_ImpairmentOfInvestments	(744)us-gaap_ImpairmentOfInvestments	(894)us-gaap_ImpairmentOfInvestments
Portion of other-than-temporary impairment losses recognized in other comprehensive income	0	2	6
Net realized gains on investments	14,930us-gaap_RealizedInvestmentGainsLosses	23,515us-gaap_RealizedInvestmentGainsLosses	9,011us-gaap_RealizedInvestmentGainsLosses
Total revenue	292,042us-gaap_Revenues	290,972us-gaap_Revenues	262,124us-gaap_Revenues
Expenses:
Losses and loss expenses incurred	159,596	150,701	138,088
Other operating expenses	88,048us-gaap_OtherCostAndExpenseOperating	85,361us-gaap_OtherCostAndExpenseOperating	77,430us-gaap_OtherCostAndExpenseOperating
Total expenses	247,644us-gaap_BenefitsLossesAndExpenses	236,062us-gaap_BenefitsLossesAndExpenses	215,518us-gaap_BenefitsLossesAndExpenses
Income before federal income taxes	44,398	54,910	46,606
Federal income taxes	14,681us-gaap_IncomeTaxExpenseBenefit	18,322us-gaap_IncomeTaxExpenseBenefit	14,687us-gaap_IncomeTaxExpenseBenefit
Net income	$ 29,717us-gaap_NetIncomeLoss	$ 36,588us-gaap_NetIncomeLoss	$ 31,919us-gaap_NetIncomeLoss
Per share data:
Basic and diluted earnings (in dollars per share)	$ 1.98us-gaap_EarningsPerShareBasicAndDiluted	$ 2.45us-gaap_EarningsPerShareBasicAndDiluted	$ 2.15us-gaap_EarningsPerShareBasicAndDiluted

The total amount of expense recognized during the period for future policy benefits, claims and claims adjustment costs, and for selling, general and administrative costs.

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Amount, after effects of policies assumed or ceded, of expense related to the provision for policy benefits and costs incurred.

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Amount, after premiums ceded to other entities and premiums assumed by the entity, of premiums earned.

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