Loans and Allowance for Loan and Lease Losses - Summary of Breakdown of Allowance for Loan and Lease Losses and Loan Portfolio by Loan Category (Details) - USD ($)	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Allowance for Loan and Lease Losses:
Collectively evaluated for impairment	$ 11,385,000	$ 9,022,000
Individually evaluated for impairment	2,612,000	2,612,000
Allowance for Loan and Lease Losses, Ending Balance	13,996,869	11,633,531	$ 10,299,000	$ 10,132,000
Loans:
Collectively evaluated for impairment	990,594,000	932,599,000
Individually evaluated for impairment	13,624,000	3,619,000
Total	1,004,218,000	936,218,000
Commercial real estate
Allowance for Loan and Lease Losses:
Collectively evaluated for impairment	3,257,000	2,655,000
Individually evaluated for impairment	0
Allowance for Loan and Lease Losses, Ending Balance	3,257,000	2,655,000	2,970,000	2,879,000
Loans:
Collectively evaluated for impairment	359,668,000	301,012,000
Individually evaluated for impairment	1,287,000	1,310,000
Total	360,955,000	302,322,000
Consumer real estate
Allowance for Loan and Lease Losses:
Collectively evaluated for impairment	1,048,000	1,013,000
Individually evaluated for impairment	0
Allowance for Loan and Lease Losses, Ending Balance	1,048,000	1,013,000	963,000	968,000
Loans:
Collectively evaluated for impairment	99,952,000	97,015,000
Individually evaluated for impairment		0
Total	99,952,000	97,015,000
Construction and land development
Allowance for Loan and Lease Losses:
Collectively evaluated for impairment	1,090,000	1,574,000
Individually evaluated for impairment	0
Allowance for Loan and Lease Losses, Ending Balance	1,090,000	1,574,000	799,000	914,000
Loans:
Collectively evaluated for impairment	74,007,000	94,491,000
Individually evaluated for impairment		0
Total	74,007,000	94,491,000
Commercial and industrial
Allowance for Loan and Lease Losses:
Collectively evaluated for impairment	5,401,000	3,006,000
Individually evaluated for impairment	2,612,000	2,612,000
Allowance for Loan and Lease Losses, Ending Balance	8,013,000	5,618,000	4,924,000	4,693,000
Loans:
Collectively evaluated for impairment	408,488,000	377,311,000
Individually evaluated for impairment	12,337,000	2,309,000
Total	420,825,000	379,620,000
Consumer
Allowance for Loan and Lease Losses:
Collectively evaluated for impairment	60,000	76,000
Individually evaluated for impairment	0
Allowance for Loan and Lease Losses, Ending Balance	60,000	76,000	113,000	103,000
Loans:
Collectively evaluated for impairment	4,495,000	5,974,000
Individually evaluated for impairment		0
Total	4,495,000	5,974,000
Other
Allowance for Loan and Lease Losses:
Collectively evaluated for impairment	529,000	698,000
Individually evaluated for impairment	0
Allowance for Loan and Lease Losses, Ending Balance	529,000	698,000	$ 530,000	$ 575,000
Loans:
Collectively evaluated for impairment	43,984,000	56,796,000
Individually evaluated for impairment		0
Total	$ 43,984,000	$ 56,796,000