Accumulated Other Comprehensive Income Balances Of Each Component Of Accumulated Other Comprehensive Income, Net Of Tax (Details) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 11,761,447	$ 11,483,015
Other comprehensive income before reclassifications	1,097,191	792,939
Amounts reclassified from accumulated other comprehensive income	(57,519)	(91,618)
Other comprehensive income	1,039,672	701,321
Ending balance	12,801,119	12,184,336
Unrealized Gains And Losses On Available-For-Sale Securities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	11,870,647	11,597,741
Other comprehensive income before reclassifications	1,097,191	792,939
Amounts reclassified from accumulated other comprehensive income	(58,941)	(93,093)
Other comprehensive income	1,038,250	699,846
Ending balance	12,908,897	12,297,587
Postretirement Benefits Plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(109,200)	(114,726)
Other comprehensive income before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive income	1,422	1,475
Other comprehensive income	1,422	1,475
Ending balance	$ (107,778)	$ (113,251)