Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement Of Income And Comprehensive Income [Abstract]
Other Comprehensive Income Pension actuarial net gain (loss), tax	$ 0	$ 147,878	$ 629,200
Other Comprehensive Income Realized Gain on Investment Securities, tax	61,738	0	0
Other Comprehensive Income Unrealized Gain (Loss) on Available-for-Sale Investment Securities, tax	$ 414,962	$ 44,022	$ 0