Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Basic
Net income	$ 3,481,463	$ 2,727,817	$ 10,488,765	$ 7,336,572
Undistributed earnings allocated to participating securities	(106,918)	(98,721)	(320,191)	(306,484)
Net income allocated to common shares	$ 3,374,545	$ 2,629,096	$ 10,168,574	$ 7,030,088
Weighted average common shares outstanding	15,714,226	13,132,237	14,870,232	13,023,145
Basic earnings per common share	$ 0.22	$ 0.20	$ 0.68	$ 0.54
Diluted
Net income allocated to common shares	$ 3,374,545	$ 2,629,096	$ 10,168,574	$ 7,030,088
Weighted average common shares outstanding	15,714,226	13,132,237	14,870,232	13,023,145
Add: Dilutive effects of assumed exercises of stock options	520,700	427,903	506,750	409,601
Average shares and dilutive potential common shares	16,234,926	13,560,140	15,376,982	13,432,746
Diluted earnings per common share	$ 0.21	$ 0.19	$ 0.66	$ 0.52