Quarterly Results of Operations (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Results of Operations (Unaudited) [Abstract]
Net premiums earned	$ 65,995	$ 65,445	$ 65,449	$ 66,446	$ 68,933	$ 65,947	$ 62,905	$ 63,842	$ 263,335	$ 261,627	$ 252,743
Net investment income	3,771	3,014	2,898	2,815	2,599	2,073	2,090	2,294	12,498	9,055	8,770
Net gains on investments	(1,753)	(2,086)	(1,166)	3,743	2,113	658	8,089	4,070
Losses and loss expenses incurred	41,860	35,212	37,031	41,646	41,332	38,693	40,282	39,289	155,750	159,596	150,701
Net income	$ 3,541	$ 7,780	$ 5,718	$ 6,243	$ 8,246	$ 5,770	$ 9,340	$ 6,361	$ 23,283	$ 29,717	$ 36,588
Net income per share - diluted (in dollars per share)	$ 0.24	$ 0.52	$ 0.38	$ 0.42	$ 0.55	$ 0.39	$ 0.62	$ 0.42