Consolidated Statements Of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Other Comprehensive Income [Abstract]
Net income	$ 5,543,523	$ 3,238,915	$ 12,953,991	$ 8,043,755
Other comprehensive income, before tax:
(Accretion) amortization related to prior year service cost	(380)	2,349	(1,139)	7,047
Amortization of unrecognized loss	1,573	171	4,720	511
Unrealized gains on investments arising during the period	1,115,120	2,142,925	1,864,591	3,677,740
Reclassification adjustment for sale of securities included in net income	(261,938)	(99,790)	(367,624)	(434,358)
Reclassification adjustment for write-down of securities included in net income	0	0	34,070	76,539
Other comprehensive income, before tax	854,375	2,045,655	1,534,618	3,327,479
Income tax expense related to postretirement health benefits	415	858	1,228	2,571
Income tax expense related to unrealized gains on investments arising during the year	385,115	737,122	645,438	1,273,653
Income tax benefit related to reclassification adjustment for sale of securities included in net income	(89,575)	(34,576)	(126,173)	(155,912)
Income tax expense related to reclassification adjustment for write-down of securities included in net income	0	0	13,134	26,265
Net income tax expense on other comprehensive income	295,955	703,404	533,627	1,146,577
Other comprehensive income	558,420	1,342,251	1,000,991	2,180,902
Comprehensive Income	6,101,943	4,581,166	13,954,982	10,224,657
Less: Comprehensive income attributable to redeemable noncontrolling interest	(27,725)	(80,730)	(55,788)	(103,943)
Comprehensive Income Attributable to the Company	$ 6,074,218	$ 4,500,436	$ 13,899,194	$ 10,120,714