Loans and Allowance for Loan And Lease Losses - Summary of Loan Portfolio (Details) - USD ($)	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Loans And Leases Receivable Disclosure [Line Items]
Total loans	$ 1,004,218,000	$ 936,218,000
Less net unearned income	(784,000)	(967,000)
Loans and leases , net of unearned income	1,003,433,910	935,250,703
Less allowance for loan and lease losses	(13,996,869)	(11,633,531)	$ (10,299,000)	$ (10,132,000)
Loans and leases, net	989,437,041	923,617,172
Commercial real estate
Loans And Leases Receivable Disclosure [Line Items]
Total loans	360,955,000	302,322,000
Less allowance for loan and lease losses	(3,257,000)	(2,655,000)	(2,970,000)	(2,879,000)
Consumer real estate
Loans And Leases Receivable Disclosure [Line Items]
Total loans	99,952,000	97,015,000
Less allowance for loan and lease losses	(1,048,000)	(1,013,000)	(963,000)	(968,000)
Construction and land development
Loans And Leases Receivable Disclosure [Line Items]
Total loans	74,007,000	94,491,000
Less allowance for loan and lease losses	(1,090,000)	(1,574,000)	(799,000)	(914,000)
Commercial and industrial
Loans And Leases Receivable Disclosure [Line Items]
Total loans	420,825,000	379,620,000
Less allowance for loan and lease losses	(8,013,000)	(5,618,000)	(4,924,000)	(4,693,000)
Consumer
Loans And Leases Receivable Disclosure [Line Items]
Total loans	4,495,000	5,974,000
Less allowance for loan and lease losses	(60,000)	(76,000)	(113,000)	(103,000)
Other
Loans And Leases Receivable Disclosure [Line Items]
Total loans	43,984,000	56,796,000
Less allowance for loan and lease losses	$ (529,000)	$ (698,000)	$ (530,000)	$ (575,000)