Loans and Allowance for Loan Losses - Summary of Changes in Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period	$ 15,723	$ 15,297	$ 15,557	$ 15,151
Provision for loan losses	225	450	425	600
Gross loan charge-offs	(56)	(293)	(192)	(401)
Recoveries	260	201	362	305
Net loan charge-offs	204	(92)	170	(96)
Balance at end of period	16,152	15,655	16,152	15,655
Real Estate Term
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period	6,692	5,564	6,783	5,181
Provision for loan losses	172	(443)	77	(65)
Gross loan charge-offs		(1)		(1)
Recoveries	5	64	9	69
Net loan charge-offs	5	63	9	68
Balance at end of period	6,869	5,184	6,869	5,184
Construction and Land Development
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period	4,344	4,125	3,984	4,425
Provision for loan losses	351	(61)	695	(364)
Gross loan charge-offs		(245)		(245)
Recoveries	30	33	46	36
Net loan charge-offs	30	(212)	46	(209)
Balance at end of period	4,725	3,852	4,725	3,852
Residential and Home Equity
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period	595	670	603	671
Provision for loan losses	(44)	(20)	(56)	(26)
Recoveries	77	42	81	47
Net loan charge-offs	77	42	81	47
Balance at end of period	628	692	628	692
Consumer and Other
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period	171	256	246	266
Provision for loan losses	(30)	(12)	(82)	51
Gross loan charge-offs	(56)	(28)	(120)	(121)
Recoveries	77	17	118	37
Net loan charge-offs	21	(11)	(2)	(84)
Balance at end of period	162	233	162	233
Commercial and Industrial
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period	3,921	4,682	3,941	4,608
Provision for loan losses	(224)	986	(209)	1,004
Gross loan charge-offs		(19)	(72)	(34)
Recoveries	71	45	108	116
Net loan charge-offs	71	26	36	82
Balance at end of period	$ 3,768	$ 5,694	$ 3,768	$ 5,694