Consolidated Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Statement Of Financial Position [Abstract]
Securities held to maturity, fair value	$ 49,731,169	$ 46,458,841
Preferred stock, par value	$ 1	$ 1
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	878,049	1,609,756
Preferred stock, shares outstanding	878,049	1,609,756
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	20,000,000	20,000,000
Common stock, shares issued	11,204,515	8,577,051
Common stock, shares outstanding	11,204,515	8,577,051