Loans and Allowance for Loan Losses - Past Due Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	$ 1,538	$ 1,764
Total Past Due and NonAccrual	6,773	5,269
Current Loans	1,536,004	1,285,195
Total loans	1,575,435	1,323,258
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	6	128
Total Past Due and NonAccrual	2,716	1,373
Current Loans	724,674	623,712
Total loans	745,864	642,988
Consumer Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	463	991
Total Past Due and NonAccrual	1,240	1,987
Current Loans	347,649	284,020
Total loans	355,876	293,457
Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	547	547
Total Past Due and NonAccrual	1,288	938
Current Loans	172,453	129,351
Total loans	179,431	135,409
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	430	85
Total Past Due and NonAccrual	1,190	502
Current Loans	277,760	236,727
Total loans	279,771	238,087
Consumer and Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	92	13
Total Past Due and NonAccrual	339	469
Current Loans	13,468	11,385
Total loans	14,493	13,317
Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	32,658	32,794
Purchased Credit Impaired Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	18,474	17,903
Purchased Credit Impaired Loans [Member] | Consumer Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	6,987	7,450
Purchased Credit Impaired Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	5,690	5,120
Purchased Credit Impaired Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	821	858
Purchased Credit Impaired Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	686	1,463
30-89 Days Past Due and Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, past due	4,568	1,996
30-89 Days Past Due and Accruing [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, past due	2,628	517
30-89 Days Past Due and Accruing [Member] | Consumer Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, past due	701	963
30-89 Days Past Due and Accruing [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, past due	403	65
30-89 Days Past Due and Accruing [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, past due	647	286
30-89 Days Past Due and Accruing [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, past due	189	165
Past Due 90 Days or More and Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, past due	667	1,509
Past Due 90 Days or More and Accruing [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, past due	82	728
Past Due 90 Days or More and Accruing [Member] | Consumer Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, past due	76	33
Past Due 90 Days or More and Accruing [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, past due	338	326
Past Due 90 Days or More and Accruing [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, past due	113	131
Past Due 90 Days or More and Accruing [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, past due	$ 58	$ 291