Consolidated Statements Of Stockholders' Equity - USD ($)	Total	Common Stock	Retained Earnings	Accumulated Other Comprehensive Income	Noncontrolling Interest [Member]
Balance, beginning of year at Dec. 31, 2012	$ 114,638,890	$ 1	$ 105,820,459	$ 8,818,430	$ 0
Balance, beginning of year, shares at Dec. 31, 2012		2,043,359
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to the Company	14,708,210		14,708,210
Dividends	(657,914)		(657,914)
Shares of common stock repurchased and retired (in shares)		(56,223)
Shares of common stock repurchased and retired	(4,262,260)		(4,262,260)
Stock options and stock appreciation rights exercised (in shares)		49,999
Stock options and stock appreciation rights exercised	75,797		75,797
Share-based compensation expense	83,852		83,852
Amortization related to postretirement health benefits	3,140			3,140
Accumulated postretirement benefit obligation adjustment	50,961			50,961
Net unrealized gain (loss) on investments	2,474,873			2,474,873
Subsidiary return of capital	0
Temporary Equity, Interest Resulting From Subsidiary Purchase	0
Income tax benefit from share-based compensation	946,605		946,605
Balance, end of year at Dec. 31, 2013	128,062,154	$ 1	116,714,749	11,347,404	0
Balance, end of year, shares at Dec. 31, 2013		2,037,135
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to the Company	9,648,975		9,648,975
Dividends	(650,433)		(650,433)
Shares of common stock repurchased and retired (in shares)		(15,372)
Shares of common stock repurchased and retired	(1,055,765)		(1,055,765)
Stock options and stock appreciation rights exercised (in shares)		1,507
Stock options and stock appreciation rights exercised	27,100		27,100
Share-based compensation expense	120,891		120,891
Amortization related to postretirement health benefits	1,465			1,465
Accumulated postretirement benefit obligation adjustment	(31,100)			(31,100)
Net unrealized gain (loss) on investments	1,538,740			1,538,740
Subsidiary return of capital	0
Temporary Equity, Interest Resulting From Subsidiary Purchase	(114,320)		(114,320)
Income tax benefit from share-based compensation	15,999		15,999
Balance, end of year at Dec. 31, 2014	137,563,706	$ 1	124,707,196	12,856,509	0
Balance, end of year, shares at Dec. 31, 2014		2,023,270
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to the Company	12,533,905		12,533,905
Dividends	(789,907)		(789,907)
Shares of common stock repurchased and retired (in shares)		(75,665)
Shares of common stock repurchased and retired	(5,483,953)		(5,483,953)
Stock options and stock appreciation rights exercised (in shares)		2,192
Stock options and stock appreciation rights exercised	54,988		54,988
Share-based compensation expense	137,762		137,762
Amortization related to postretirement health benefits	5,216			5,216
Accumulated postretirement benefit obligation adjustment	(41,954)			(41,954)
Net unrealized gain (loss) on investments	(1,336,756)			(1,336,756)
Net effect changes of ownership	127,050				127,050
Subsidiary return of capital	(35,000)				(35,000)
Net Income (Loss) Attributable to Noncontrolling Interest	15,148				15,148
Temporary Equity, Interest Resulting From Subsidiary Purchase	0
Income tax benefit from share-based compensation	26,875		26,875
Balance, end of year at Dec. 31, 2015	$ 142,777,080	$ 1	$ 131,186,866	$ 11,483,015	$ 107,198
Balance, end of year, shares at Dec. 31, 2015		1,949,797