Loans and Allowance for Credit Losses - Summary of Aging of Past Due Originated and ANCI Loans by Portfolio Segment and Class of Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	$ 1,913	$ 4,768
Accruing Loans | 60-89 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	513	1,361
Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	760	827
Non-Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	356	474
Non-Accruing Loans | 60-89 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	99	293
Non-Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	1,479	13,206
Non-Accruing Loans | 0-29 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	72,305	33,495
Commercial and Industrial | Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	120	59
Commercial and Industrial | Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due		476
Commercial and Industrial | Non-Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	176	263
Commercial and Industrial | Non-Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due		10,507
Commercial and Industrial | Non-Accruing Loans | 0-29 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	71,179	32,315
Commercial and Industrial | General C&I | Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	120	59
Commercial and Industrial | General C&I | Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due		476
Commercial and Industrial | General C&I | Non-Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	176	192
Commercial and Industrial | General C&I | Non-Accruing Loans | 0-29 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	23,928
Commercial and Industrial | Restaurant Industry | Non-Accruing Loans | 0-29 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	22,043
Commercial and Industrial | Energy Sector | Non-Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due		10,507
Commercial and Industrial | Energy Sector | Non-Accruing Loans | 0-29 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	20,712	32,315
Commercial and Industrial | Healthcare | Non-Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due		71
Commercial and Industrial | Healthcare | Non-Accruing Loans | 0-29 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	4,496
Commercial Real Estate | Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due		55
Commercial Real Estate | Accruing Loans | 60-89 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	61
Commercial Real Estate | Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due		26
Commercial Real Estate | Accruing Loans | Income Producing | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due		26
Commercial Real Estate | Accruing Loans | Land and Development | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due		55
Commercial Real Estate | Accruing Loans | Land and Development | 60-89 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	61
Consumer | Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	1,302	3,723
Consumer | Accruing Loans | 30-59 DPD | Residential Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	1,275	3,191
Consumer | Accruing Loans | 30-59 DPD | Other
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	27	532
Consumer | Accruing Loans | 60-89 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	427	1,033
Consumer | Accruing Loans | 60-89 DPD | Residential Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	315	1,030
Consumer | Accruing Loans | 60-89 DPD | Other
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	112	3
Consumer | Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	760	325
Consumer | Accruing Loans | 90+DPD | Residential Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	760	325
Consumer | Non-Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	151	173
Consumer | Non-Accruing Loans | 30-59 DPD | Residential Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	151	173
Consumer | Non-Accruing Loans | 60-89 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	95	293
Consumer | Non-Accruing Loans | 60-89 DPD | Residential Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	95	293
Consumer | Non-Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	1,429	2,205
Consumer | Non-Accruing Loans | 90+DPD | Residential Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	1,429	2,205
Consumer | Non-Accruing Loans | 0-29 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	876	1,070
Consumer | Non-Accruing Loans | 0-29 DPD | Residential Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	876	1,070
Small Business Lending | Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	491	931
Small Business Lending | Accruing Loans | 60-89 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	25	328
Small Business Lending | Non-Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	29	38
Small Business Lending | Non-Accruing Loans | 60-89 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	4
Small Business Lending | Non-Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	50	494
Small Business Lending | Non-Accruing Loans | 0-29 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	$ 250	$ 110