Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Abstract]
Corporate income tax rate	21.00%			35.00%
Deferred tax liabilities [Abstract]
Unrealized gain on fixed income and equity security investments	$ 8,159	$ 5,327
Deferred acquisition costs	2,538	2,821
Loss and loss expense reserves	2,222	2,701
Limited partnership investments	0	2,587
Accelerated depreciation	669	687
Other	1,495	1,361
Total deferred tax liabilities	15,083	15,484
Deferred tax assets [Abstract]
Loss and loss expense reserves	12,923	11,460
Limited partnership investments	822	0
Unearned premiums discount	2,339	2,529
Impairment related investment declines	435	39
Deferred compensation	1,999	1,181
Deferred ceding commission	492	1,037
Allowance for credit losses	3,580	0
Other	1,473	1,273
Total deferred tax assets	24,063	17,519
Net deferred tax assets	8,980	2,035
Difference between federal income tax expense (benefit) computed at statutory rate [Abstract]
Statutory federal income rate applied to pre-tax income (loss)	1,336	1,821	$ (9,213)
Tax effect of (deduction) [Abstract]
Tax-exempt investment income	(239)	(402)	(253)
Valuation allowance	1,264	0	0
Other	(461)	(93)	(331)
Federal income tax expense (benefit)	1,900	1,326	(9,797)
Tax expense (benefit) on pre-tax income (loss) [Abstract]
Current	7,144	1,377	8,997
Deferred	(5,244)	(51)	(18,794)
Federal income tax expense (benefit)	1,900	1,326	(9,797)
Provisions for deferred federal income taxes [Abstract]
Limited partnerships	(3,409)	1,143	(2,383)
Discounts of loss and loss expense reserves	(1,944)	(2,269)	(2,704)
Reserves - salvage and subrogation and other	1	(74)	427
Unearned premium discount	190	(208)	(484)
Deferred compensation	(818)	(600)	305
Impairment related investment declines	(1,400)	(411)	695
Deferred acquisitions costs and ceding commission	262	405	201
Unrealized gains / losses	(59)	1,837	(13,876)
Valuation allowance	1,264	0	0
Other	669	126	(975)
Provision for deferred federal income taxes	(5,244)	(51)	(18,794)
Deferred tax assets, valuation allowance	0	0
Valuation allowance recorded in statement of operations	1,264
Uncertain tax positions	0	0
Accrued interest	$ 0	$ 0	$ 0