Schedule II [Disclosure] - Condensed Statement of Cash Flows (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Activities
Net income	$ 19,515,452	$ 12,549,053	$ 9,672,498
Depreciation	1,306,643	1,105,839	833,104
Amortization of investments, net	772,100	728,510	630,782
Net (gain) loss on disposals of property	(12,439)	(24,867)	24,608
Net (earnings) loss from other investments	(1,750,485)	(2,002,276)	(1,450,980)
(Benefit) provision for deferred income taxes	2,790,000	1,015,000	611,000
Decrease (increase) in receivables	(261,464)	217,594	206,041
Decrease (increase) in income taxes recoverable	0	0	366,772
Decrease (increase) in other assets	2,631,205	(4,879,418)	(393,359)
(Decrease) increase in accounts payable and accrued liabilities	(581,518)	6,689,204	(2,080,492)
Net cash provided by (used in) operating activities	22,534,969	16,889,631	9,683,980
Investing Activities
Purchases of available-for-sale securities	(19,424,849)	(20,164,353)	(30,899,452)
Purchases of short-term securities	(1,775,239)	(4,593,240)	(911,188)
Purchases of and net earnings from other investments	(2,743,413)	(3,717,978)	(1,689,950)
Proceeds from sales and maturities of available-for-sale securities	20,258,089	22,151,408	12,472,817
Proceeds from sales and maturities of short-term securities	2,081,805	304,827	6,260,568
Proceeds from sales and distributions of other investments	3,437,999	3,911,286	1,584,337
Proceeds from sales of other assets	17,601	149,128	38,052
Purchases of property	(2,456,951)	(2,742,619)	(2,017,379)
Proceeds from disposals of property	91,656	75,060	24,400
Net cash provided by (used in) investing activities	(8,838,598)	(4,699,081)	(15,653,070)
Financing Activities
Repurchases of common stock	(6,219,670)	(5,483,953)	(1,055,765)
Exercise of stock appreciation rights and options	(200)	54,988	27,100
Proceeds from note payable	6,000,000	0	0
Payments on note payable	(6,000,000)	0	0
Excess tax benefit	32,293	26,875	15,999
Dividends paid	(1,370,390)	(789,907)	(650,433)
Net cash provided by (used in) financing activities	(7,557,967)	(6,226,997)	(1,831,156)
Net Increase in Cash and Cash Equivalents	6,138,404	5,963,553	(7,800,246)
Cash and Cash Equivalents, Beginning of Period	21,790,068	15,826,515	23,626,761
Cash and Cash Equivalents, End of Period	27,928,472	21,790,068	15,826,515
Parent Company
Operating Activities
Net income	19,515,452	12,549,053	9,672,498
Equity in net earnings of subsidiaries	(19,665,205)	(12,640,260)	(9,777,925)
Depreciation	93,086	112,690	136,369
Amortization of investments, net	163,989	192,654	210,768
Share-based compensation expense related to stock appreciation rights and options	132,098	137,759	164,730
Net (gain) loss on disposals of property	0	1,683	2,722
Net realized loss (gain) on investments	(77,895)	152,026	(19,231)
Net (earnings) loss from other investments	(13,135)	(237,686)	322
(Benefit) provision for deferred income taxes	(18,000)	13,000	(40,000)
Decrease (increase) in receivables	1,037,423	(847,177)	(685,052)
Decrease (increase) in income taxes recoverable	(829,275)	142,928	1,354,735
Decrease (increase) in other assets	33,888	7,852	(24,650)
(Decrease) increase in accounts payable and accrued liabilities	(896,311)	1,192,927	516,252
Net cash provided by (used in) operating activities	(523,885)	777,449	1,511,538
Investing Activities
Purchase of subsidiary	(10,918,003)	0	0
Dividends received from subsidiaries	17,330,948	7,630,835	5,051,664
Purchases of available-for-sale securities	(1,783,223)	(260,044)	(6,883,612)
Purchases of short-term securities	(3,162,283)	(2,721,578)	(104,207)
Purchases of and net earnings from other investments	(1,552,769)	(2,007,798)	(964,197)
Proceeds from sales and maturities of available-for-sale securities	6,815,907	2,475,557	1,631,987
Proceeds from sales and maturities of short-term securities	3,005,647	0	2,033,634
Proceeds from sales and distributions of other investments	321,758	734,170	123,017
Purchases of property	(144,915)	(32,071)	(5,200)
Net cash provided by (used in) investing activities	9,913,067	5,819,071	883,086
Financing Activities
Repurchases of common stock	(6,219,670)	(5,483,953)	(1,055,765)
Exercise of stock appreciation rights and options	(200)	54,988	27,100
Proceeds from note payable	6,000,000	0	0
Payments on note payable	(6,000,000)	0	0
Excess tax benefit	32,293	26,875	15,999
Dividends paid	(1,370,390)	(789,907)	(650,433)
Net cash provided by (used in) financing activities	(7,557,967)	(6,191,997)	(1,663,099)
Net Increase in Cash and Cash Equivalents	1,831,215	404,523	731,525
Cash and Cash Equivalents, Beginning of Period	8,347,004	7,942,481	7,210,956
Cash and Cash Equivalents, End of Period	10,178,219	8,347,004	7,942,481
Supplemental Disclosures:
Income tax payments, net	$ 4,964,000	$ 4,598,000	$ 2,699,000