Consolidated Statements of Comprehensive Income - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 3,807,492	$ 4,033,977	$ 3,373,635
Other comprehensive income (loss), net of tax:
Unrealized gain (loss) on securities available for sale	326,684	(704,188)	116,782
Reclassification adjustment for (gain) loss realized in income on securities available for sale	(186,610)	(144,034)	17,992
Unrealized gain (loss) on pension plan benefits	503,167	(110,306)	(1,032,035)
Federal income tax (expense) benefit	486,869	(325,900)	(305,069)
Other comprehensive income (loss), net of tax	156,372	(632,628)	(592,192)
Total comprehensive income	$ 3,963,864	$ 3,401,349	$ 2,781,443