- Summarized financial information by segment (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Reconciliation of operating profit loss from segment to consolidated
Premiums earned	$ 132,362,761	$ 121,544,787	$ 380,048,293	$ 341,575,003
Underwriting profit (loss)	(1,094,300)	864,972	3,613,437	(6,090,505)
Net investment income (loss)	10,544,775	10,968,913	32,027,852	33,274,390
Realized investment gains (losses)	1,007,209	(176,368)	3,850,335	7,603,625
Other income	194,732	224,826	592,654	686,575
Interest expense	84,375	225,000	300,000	675,000
Other expenses	1,003,175	906,987	1,761,793	1,662,246
Income before income tax expense	9,564,866	10,750,356	38,022,485	33,136,839
Reconciliation of assets from segment to consolidated
Assets	1,740,383,014		1,740,383,014		1,687,063,626
Eliminations	(396,295,674)		(396,295,674)		(396,288,097)
Reclassifications	(6,342,078)		(6,342,078)		(66,423)
Total assets	1,337,745,262		1,337,745,262		1,290,709,106
Property and casualty insurance [Member]
Reconciliation of operating profit loss from segment to consolidated
Premiums earned	100,085,034	91,059,723	290,606,939	263,916,398
Underwriting profit (loss)	(3,944,842)	1,155,505	(11,752,951)	(12,335,954)
Net investment income (loss)	7,676,989	8,000,165	23,422,804	24,314,494
Realized investment gains (losses)	719,522	(82,254)	3,068,625	7,069,647
Other income	194,732	224,485	592,654	686,234
Interest expense	84,375	225,000	300,000	675,000
Other expenses	161,966	211,601	553,165	609,041
Income before income tax expense	4,400,060	8,861,300	14,477,967	18,450,380
Reconciliation of assets from segment to consolidated
Assets	959,794,148		959,794,148		934,876,596
Eliminations	0		0		0
Reclassifications	(5,291,178)		(5,291,178)		0
Total assets	954,502,970		954,502,970		934,876,596
Reinsurance [Member]
Reconciliation of operating profit loss from segment to consolidated
Premiums earned	32,277,727	30,485,064	89,441,354	77,658,605
Underwriting profit (loss)	2,850,542	(290,533)	15,366,388	6,245,449
Net investment income (loss)	2,869,612	2,970,731	8,612,316	8,965,935
Realized investment gains (losses)	287,687	(94,114)	781,710	533,978
Other income	0	341	0	341
Interest expense	0	0	0	0
Other expenses	557,933	469,379	217,646	96,829
Income before income tax expense	5,449,908	2,117,046	24,542,768	15,648,874
Reconciliation of assets from segment to consolidated
Assets	372,430,306		372,430,306		350,867,500
Eliminations	0		0		0
Reclassifications	(701,513)		(701,513)		0
Total assets	371,728,793		371,728,793		350,867,500
Parent company [Member]
Reconciliation of operating profit loss from segment to consolidated
Premiums earned	0	0	0	0
Underwriting profit (loss)	0	0	0	0
Net investment income (loss)	(1,826)	(1,983)	(7,268)	(6,039)
Realized investment gains (losses)	0	0	0	0
Other income	0	0	0	0
Interest expense	0	0	0	0
Other expenses	283,276	226,007	990,982	956,376
Income before income tax expense	(285,102)	(227,990)	(998,250)	(962,415)
Reconciliation of assets from segment to consolidated
Assets	408,158,560		408,158,560		401,319,530
Eliminations	(396,295,674)		(396,295,674)		(396,288,097)
Reclassifications	(349,387)		(349,387)		(66,423)
Total assets	$ 11,513,499		$ 11,513,499		$ 4,965,010