Loans and Allowance for Loan Losses Schedule of Past Due Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	$ 3	$ 173
Loans, recorded investment, current	1,457,955	1,400,025
Loans, recorded investment, nonaccrual status	517	1,022
Loans	1,458,475	1,401,220
Commercial loans [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	109
Loans, recorded investment, current	316,716	333,779
Loans, recorded investment, nonaccrual status	0	126
Loans	316,716	334,014
Construction, land and land development [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, recorded investment, current	249,453	205,610
Loans, recorded investment, nonaccrual status	0	0
Loans	249,453	205,610
1-4 family residential first mortgages [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	64
Loans, recorded investment, current	49,275	47,012
Loans, recorded investment, nonaccrual status	94	108
Loans	49,369	47,184
Home equity [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	3	0
Loans, recorded investment, current	14,502	17,740
Loans, recorded investment, nonaccrual status	53	317
Loans	14,558	18,057
Commercial real estate [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, recorded investment, current	819,774	787,529
Loans, recorded investment, nonaccrual status	370	471
Loans	820,144	788,000
Consumer and other loans [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, recorded investment, current	8,235	8,355
Loans, recorded investment, nonaccrual status	0	0
Loans	8,235	8,355
Financing Receivables, 30 to 59 Days Past Due [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	3	173
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial loans [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	109
Financing Receivables, 30 to 59 Days Past Due [Member] | Construction, land and land development [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Financing Receivables, 30 to 59 Days Past Due [Member] | 1-4 family residential first mortgages [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	64
Financing Receivables, 30 to 59 Days Past Due [Member] | Home equity [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	3	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial real estate [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer and other loans [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial loans [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Construction, land and land development [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | 1-4 family residential first mortgages [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Home equity [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial real estate [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer and other loans [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial loans [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Construction, land and land development [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | 1-4 family residential first mortgages [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Home equity [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial real estate [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Consumer and other loans [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	$ 0	$ 0