Consolidated Statements Of Comprehensive Income - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 4,120,497	$ 3,398,044	$ 5,846,621	$ 4,383,559
Other comprehensive income, before tax:
Amortization related to prior year service cost	1,098	555	2,195	1,109
Amortization of unrecognized loss	878	0	1,757	0
Unrealized (losses) gains on investments arising during the period	(2,152,262)	2,208,475	(1,864,497)	2,984,115
Reclassification adjustment for sales of securities included in net income	(923,209)	(68,364)	(932,012)	(833,636)
Reclassification adjustment for write-downs of securities included in net income	11,149	0	11,149	0
Other comprehensive (loss) income, before tax	(3,062,346)	2,140,666	(2,781,408)	2,151,588
Income tax expense related to postretirement health benefits	672	189	1,344	377
Income tax (benefit) expense related to unrealized (losses) gains on investments arising during the year	(739,627)	761,231	(636,089)	1,031,035
Income tax benefit related to reclassification adjustment for sales of securities included in net income	(314,742)	(23,213)	(317,751)	(285,750)
Income tax expense related to reclassification adjustment for write-downs of securities included in net income	3,800	0	3,800	0
Net income tax (benefit) expense on other comprehensive (loss) income	(1,049,897)	738,207	(948,696)	745,662
Other comprehensive (loss) income	(2,012,449)	1,402,459	(1,832,712)	1,405,926
Comprehensive Income	2,108,048	4,800,503	4,013,909	5,789,485
Comprehensive income attributable to redeemable noncontrolling interest	0	(24,446)	0	(23,523)
Comprehensive Income Attributable to the Company	$ 2,108,048	$ 4,776,057	$ 4,013,909	$ 5,765,962