Segment Information - Information by Reportable Segment (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Gross written premiums	$ 27,440	$ 26,629	$ 26,562	$ 23,737	$ 31,247	$ 29,581	$ 26,981	$ 26,474	$ 104,368	$ 114,284	$ 114,923
Net written premiums	23,800	22,846	22,595	19,845	27,439	18,395	23,082	22,324	89,086	91,240	99,929
Net earned premiums	22,623	23,450	23,938	23,800	25,433	17,659	24,497	24,140	93,811	91,729	89,627
Other income	370	405	450	357	357	477	372	354	1,582	1,560	1,118
Segment revenue									95,393	93,289	90,745
Losses and loss adjustment expenses, net	17,565	16,554	15,068	13,328	15,042	26,468	16,674	15,733	62,515	73,917	59,003
Policy acquisition costs	6,097	6,452	6,472	6,513	6,690	6,655	6,428	6,472	25,534	26,245	25,280
Operating expenses	4,407	4,786	4,303	4,187	3,993	4,474	4,370	4,530	17,683	17,367	17,596
Segment expenses									105,732	117,529	101,879
Segment underwriting gain (loss)									(10,339)	(24,240)	(11,134)
Investment income	911	786	837	802	720	768	663	577	3,336	2,728	2,173
Net realized investment gains	(91)	(21)	12	161	39	39	0	(8)	61	70	1,365
Other gains (losses)					0	0	750	0	0	750	(400)
Change in fair value of equity securities	237	152	29	(297)					121	0	0
Interest expense	(810)	$ (598)	$ (617)	$ (619)	(616)	$ (303)	$ (219)	$ (224)	(2,644)	(1,362)	(647)
Income (loss) before income taxes									(9,465)	(22,054)	(8,643)
Deferred policy acquisition costs	12,011				12,781				12,011	12,781	13,290	$ 12,102
Unearned premiums	52,852				57,672				52,852	57,672	58,126
Loss and loss adjustment expense reserves	92,807				87,896				92,807	87,896	54,651	$ 35,422
Operating Segments | Commercial Lines
Segment Reporting Information [Line Items]
Gross written premiums									97,694	92,112	88,242
Net written premiums									87,038	78,217	78,439
Net earned premiums									83,352	76,786	68,921
Other income									594	628	378
Segment revenue									83,946	77,414	69,299
Losses and loss adjustment expenses, net									53,065	55,701	42,441
Policy acquisition costs									21,474	20,470	18,560
Operating expenses									15,067	11,339	6,767
Segment expenses									89,606	87,510	67,768
Segment underwriting gain (loss)									(5,660)	(10,096)	1,531
Deferred policy acquisition costs	11,257				10,116				11,257	10,116	10,156
Unearned premiums	49,549				45,951				49,549	45,951	44,484
Loss and loss adjustment expense reserves	87,643				76,586				87,643	76,586	46,917
Operating Segments | Personal Lines
Segment Reporting Information [Line Items]
Gross written premiums									6,674	22,172	26,681
Net written premiums									2,048	13,023	21,490
Net earned premiums									10,459	14,943	20,706
Other income									769	780	558
Segment revenue									11,228	15,723	21,264
Losses and loss adjustment expenses, net									9,450	18,216	16,562
Policy acquisition costs									4,060	5,775	6,720
Operating expenses									1,455	2,570	2,911
Segment expenses									14,965	26,561	26,193
Segment underwriting gain (loss)									(3,737)	(10,838)	(4,929)
Deferred policy acquisition costs	754				2,665				754	2,665	3,134
Unearned premiums	3,303				11,721				3,303	11,721	13,642
Loss and loss adjustment expense reserves	5,164				11,310				5,164	11,310	7,734
Corporate & Other
Segment Reporting Information [Line Items]
Gross written premiums									0	0	0
Net written premiums									0	0	0
Net earned premiums									0	0	0
Other income									219	152	182
Segment revenue									219	152	182
Losses and loss adjustment expenses, net									0	0	0
Policy acquisition costs									0	0	0
Operating expenses									1,161	3,458	7,918
Segment expenses									1,161	3,458	7,918
Segment underwriting gain (loss)									(942)	(3,306)	(7,736)
Investment income									3,336	2,728	2,173
Net realized investment gains									61	70	1,365
Other gains (losses)										750	(400)
Change in fair value of equity securities									121
Interest expense									(2,644)	(1,362)	(647)
Income (loss) before income taxes									(68)	(1,120)	(5,245)
Deferred policy acquisition costs	0				0				0	0	0
Unearned premiums	0				0				0	0	0
Loss and loss adjustment expense reserves	$ 0				$ 0				$ 0	$ 0	$ 0