Segment Information (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Revenues
Net premiums earned/Premiums earned	$ 121,824,349	$ 120,916,960	$ 117,569,122	$ 114,691,791	$ 114,176,695	$ 108,506,809	$ 104,991,401	$ 103,795,279	$ 475,002,222	$ 431,470,184	$ 378,030,129	$ 27,000,000
GAAP adjustments									(5,000)	(3,275,000)	(625,000)
GAAP premiums earned									475,002,000	431,470,000	378,030,000
Net investment income									20,168,919	20,858,179	19,949,714
Realized investment gains									6,859,439	12,281,267	4,395,720
Equity in earnings (loss) of DFSC									4,533,257	2,023,127	(268,341)
Other									8,420,000	8,386,000	6,442,000
Total revenues	131,903,702	130,431,531	127,299,190	125,348,162	127,215,208	119,164,471	117,054,498	111,583,442	514,982,585	475,017,619	408,549,446
Underwriting income (loss):
SAP underwriting loss									(12,985,000)	(47,299,000)	(20,274,000)
GAAP adjustments									5,545,000	1,532,000	2,458,000
GAAP underwriting loss									(7,440,000)	(45,767,000)	(17,816,000)
Net investment income									20,168,919	20,858,179	19,949,714
Realized investment gains									6,859,439	12,281,267	4,395,720
Equity in earnings (loss) of DFSC									4,533,257	2,023,127	(268,341)
Other									3,737,000	3,866,000	3,583,000
Income (loss) before income taxes									27,858,260	(6,739,313)	9,844,149
Commercial Lines [Member]
Revenues
Net premiums earned/Premiums earned									174,735,000	152,247,000	117,755,000
Underwriting income (loss):
GAAP underwriting loss									5,251,000	(6,560,000)	2,252,000
Personal Lines [Member]
Revenues
Net premiums earned/Premiums earned									300,272,000	282,498,000	260,900,000
Underwriting income (loss):
GAAP underwriting loss									$ (18,236,000)	$ (40,739,000)	$ (22,526,000)