Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Abstract]
Corporate income tax rate	21.00%		35.00%
Tax benefit related to remeasurement of deferred tax assets and liabilities			$ 9,572
Tax Cuts and Jobs Act of 2017, change in methodology, provisional income tax impact			1,696
Tax Cuts and Jobs Act of 2017, offsetting deferred tax liability		$ 2,262
Deferred tax liabilities amortized amount into income	$ 281	228
Deferred tax liabilities amortized amount into income, before revision		323
Deferred tax liabilities [Abstract]
Unrealized gain on fixed income and equity security investments	5,327	4,572
Deferred acquisition costs	2,821	2,552
Loss and loss expense reserves	2,701	3,583
Limited partnership investments	2,587	0
Accelerated depreciation	687	690
Other	1,361	1,509
Total deferred tax liabilities	15,484	12,906
Deferred tax assets [Abstract]
Loss and loss expense reserves	11,460	9,999
Limited partnership investments	0	3,498
Unearned premiums discount	2,529	2,321
Other-than-temporary investment declines	39	625
Deferred compensation	1,181	580
Deferred ceding commission	1,037	1,173
Other	1,273	972
Total deferred tax assets	17,519	19,168
Net deferred tax assets	(2,035)	(6,262)
Difference between federal income tax expense (benefit) computed at statutory rate [Abstract]
Statutory federal income rate applied to pre-tax income (loss)	1,821	(9,213)	3,543
Tax effect of (deduction) [Abstract]
Tax-exempt investment income	(402)	(253)	(968)
Change in enacted tax rates	0	0	(9,572)
Other	(93)	(331)	(1,204)
Federal income tax expense (benefit)	1,326	(9,797)	(8,201)
Tax expense (benefit) on pre-tax income (loss) [Abstract]
Current	1,377	8,997	(4,335)
Deferred	(51)	(18,794)	(3,866)
Federal income tax expense (benefit)	1,326	(9,797)	(8,201)
Provisions for deferred federal income taxes [Abstract]
Limited partnerships	1,143	(2,383)	4,099
Discounts of loss and loss expense reserves	(2,269)	(2,704)	1,315
Reserves - salvage and subrogation and other	(74)	427	56
Unearned premium discount	(208)	(484)	(1,767)
Deferred compensation	(600)	305	(168)
Other-than-temporary investment declines	(411)	695	(127)
Deferred acquisitions costs and ceding commission	405	201	1,553
Change in enacted tax rates	0	0	(9,572)
Unrealized gains / losses	1,837	(13,876)	0
Other	126	(975)	745
Provision for deferred federal income taxes	(51)	(18,794)	(3,866)
Deferred tax assets, valuation allowance	0	0
Uncertain tax positions	0	0
Accrued interest	$ 0	$ 0	$ 0