Loans and Allowance for Loan Losses Schedule of Past Due Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	$ 279	$ 135
Loans, recorded investment, current	1,600,849	1,511,508
Loans, recorded investment, nonaccrual status	1,846	622
Loans	1,602,974	1,512,265
Commercial [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	75	60
Loans, recorded investment, current	315,462	347,422
Loans, recorded investment, nonaccrual status	930	0
Loans	316,467	347,482
Construction, land and land development [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, recorded investment, current	204,891	207,451
Loans, recorded investment, nonaccrual status	0	0
Loans	204,891	207,451
1-4 family residential first mortgages [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	174	75
Loans, recorded investment, current	49,127	50,878
Loans, recorded investment, nonaccrual status	110	91
Loans	49,411	51,044
Home equity [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	30	0
Loans, recorded investment, current	14,059	13,618
Loans, recorded investment, nonaccrual status	14	193
Loans	14,103	13,811
Commercial real estate [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, recorded investment, current	1,011,017	885,776
Loans, recorded investment, nonaccrual status	792	338
Loans	1,011,809	886,114
Consumer and other [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, recorded investment, current	6,293	6,363
Loans, recorded investment, nonaccrual status	0	0
Loans	6,293	6,363
Loans, 30 to 59 Days Past Due [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	279	40
Loans, 30 to 59 Days Past Due [Member] | Commercial [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	75	40
Loans, 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
Loans, 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	174	0
Loans, 30 to 59 Days Past Due [Member] | Home equity [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	30	0
Loans, 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
Loans, 30 to 59 Days Past Due [Member] | Consumer and other [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, 60 to 89 Days Past Due [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	95
Loans, 60 to 89 Days Past Due [Member] | Commercial [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	20
Loans, 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
Loans, 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	75
Loans, 60 to 89 Days Past Due [Member] | Home equity [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, 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
Loans, 60 to 89 Days Past Due [Member] | Consumer and other [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, Equal to Greater than 90 Days Past Due [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, Equal to Greater than 90 Days Past Due [Member] | Commercial [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, 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
Loans, 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
Loans, 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
Loans, 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
Loans, Equal to Greater than 90 Days Past Due [Member] | Consumer and other [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	$ 0	$ 0