Consolidated Statements Of Comprehensive Income (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 3,372,701	$ 1,594,805	$ 4,804,840	$ 2,614,012
Other comprehensive income, before tax:
Amortization related to prior year service cost	2,349	5,097	4,698	10,194
Amortization of unrecognized loss	170	643	340	1,286
Unrealized (losses) gains on investments arising during the period	(461,611)	1,080,784	1,534,815	1,760,987
Reclassification adjustment for sale of securities included in net income	(141,687)	(186,171)	(334,568)	(229,288)
Reclassification adjustment for write-down of securities included in net income	76,539	39,096	76,539	108,372
Other comprehensive (loss) income, before tax	(524,240)	939,449	1,281,824	1,651,551
Income tax expense related to postretirement health benefits	856	1,949	1,713	3,905
Income tax (benefit) expense related to unrealized (losses) gains on investments arising during the year	(155,412)	367,381	536,531	598,747
Income tax (benefit) expense related to reclassification adjustment for sale of securities included in net income	(55,280)	(65,462)	(121,336)	(79,219)
Income tax expense related to reclassification adjustment for write-down of securities included in net income	26,265	15,369	26,265	38,275
Net income tax (benefit) expense on other comprehensive income	(183,571)	319,237	443,173	561,708
Other comprehensive (loss) income	(340,669)	620,212	838,651	1,089,843
Comprehensive income	3,032,032	2,215,017	5,643,491	3,703,855
Less: Comprehensive income attributable to redeemable noncontrolling interest	(23,213)		(23,213)
Comprehensive income attributable to the Company	$ 3,008,819	$ 2,215,017	$ 5,620,278	$ 3,703,855