Loans and Allowance for Credit Losses - Summary of Credit Exposure by Portfolio Segment and Class of Receivable (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Financing Receivable Recorded Investment [Line Items]
Recorded investment	$ 278,509	$ 249,133
Special Mention
Financing Receivable Recorded Investment [Line Items]
Recorded investment	128,961	111,625
Special Mention | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	2,471	1,722
Substandard
Financing Receivable Recorded Investment [Line Items]
Recorded investment	131,756	123,022
Substandard | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	66,410	8,970
Doubtful
Financing Receivable Recorded Investment [Line Items]
Recorded investment	17,792	14,486
Doubtful | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	979	39
Commercial and Industrial
Financing Receivable Recorded Investment [Line Items]
Recorded investment	261,381	242,048
Commercial and Industrial | General C&I
Financing Receivable Recorded Investment [Line Items]
Recorded investment	161,609	154,407
Commercial and Industrial | Restaurant Industry
Financing Receivable Recorded Investment [Line Items]
Recorded investment	62,102	50,620
Commercial and Industrial | Energy Sector
Financing Receivable Recorded Investment [Line Items]
Recorded investment	30,048	32,525
Commercial and Industrial | Healthcare
Financing Receivable Recorded Investment [Line Items]
Recorded investment	7,622	4,496
Commercial and Industrial | Special Mention
Financing Receivable Recorded Investment [Line Items]
Recorded investment	117,459	110,853
Commercial and Industrial | Special Mention | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	497	426
Commercial and Industrial | Special Mention | General C&I
Financing Receivable Recorded Investment [Line Items]
Recorded investment	78,070	74,592
Commercial and Industrial | Special Mention | General C&I | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	497	426
Commercial and Industrial | Special Mention | Restaurant Industry
Financing Receivable Recorded Investment [Line Items]
Recorded investment	36,216	24,449
Commercial and Industrial | Special Mention | Energy Sector
Financing Receivable Recorded Investment [Line Items]
Recorded investment		11,812
Commercial and Industrial | Special Mention | Healthcare
Financing Receivable Recorded Investment [Line Items]
Recorded investment	3,173
Commercial and Industrial | Substandard
Financing Receivable Recorded Investment [Line Items]
Recorded investment	126,130	116,709
Commercial and Industrial | Substandard | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	23,923	1,445
Commercial and Industrial | Substandard | General C&I
Financing Receivable Recorded Investment [Line Items]
Recorded investment	73,623	79,815
Commercial and Industrial | Substandard | General C&I | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	22,394	1,445
Commercial and Industrial | Substandard | Restaurant Industry
Financing Receivable Recorded Investment [Line Items]
Recorded investment	25,886	26,171
Commercial and Industrial | Substandard | Restaurant Industry | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	1,529
Commercial and Industrial | Substandard | Energy Sector
Financing Receivable Recorded Investment [Line Items]
Recorded investment	22,172	6,227
Commercial and Industrial | Substandard | Healthcare
Financing Receivable Recorded Investment [Line Items]
Recorded investment	4,449	4,496
Commercial and Industrial | Doubtful
Financing Receivable Recorded Investment [Line Items]
Recorded investment	17,792	14,486
Commercial and Industrial | Doubtful | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	979	39
Commercial and Industrial | Doubtful | General C&I
Financing Receivable Recorded Investment [Line Items]
Recorded investment	9,916
Commercial and Industrial | Doubtful | General C&I | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	979	39
Commercial and Industrial | Doubtful | Energy Sector
Financing Receivable Recorded Investment [Line Items]
Recorded investment	7,876	14,486
Commercial Real Estate
Financing Receivable Recorded Investment [Line Items]
Recorded investment	8,139	985
Commercial Real Estate | Income Producing
Financing Receivable Recorded Investment [Line Items]
Recorded investment	1,752
Commercial Real Estate | Land and Development
Financing Receivable Recorded Investment [Line Items]
Recorded investment	6,387	985
Commercial Real Estate | Special Mention
Financing Receivable Recorded Investment [Line Items]
Recorded investment	8,043
Commercial Real Estate | Special Mention | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	1,420	1,207
Commercial Real Estate | Special Mention | Income Producing
Financing Receivable Recorded Investment [Line Items]
Recorded investment	1,752
Commercial Real Estate | Special Mention | Income Producing | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	1,254	1,207
Commercial Real Estate | Special Mention | Land and Development
Financing Receivable Recorded Investment [Line Items]
Recorded investment	6,291
Commercial Real Estate | Special Mention | Land and Development | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	166
Commercial Real Estate | Substandard
Financing Receivable Recorded Investment [Line Items]
Recorded investment	96	985
Commercial Real Estate | Substandard | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	18,598	3,080
Commercial Real Estate | Substandard | Income Producing | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	15,778	3,080
Commercial Real Estate | Substandard | Land and Development
Financing Receivable Recorded Investment [Line Items]
Recorded investment	96	985
Commercial Real Estate | Substandard | Land and Development | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	2,820
Consumer
Financing Receivable Recorded Investment [Line Items]
Recorded investment	4,187	3,315
Consumer | Other
Financing Receivable Recorded Investment [Line Items]
Recorded investment	6
Consumer | Residential Real Estate
Financing Receivable Recorded Investment [Line Items]
Recorded investment	4,181	3,315
Consumer | Special Mention | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	84	89
Consumer | Special Mention | Residential Real Estate | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	84	89
Consumer | Substandard
Financing Receivable Recorded Investment [Line Items]
Recorded investment	4,187	3,315
Consumer | Substandard | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	4,999	4,445
Consumer | Substandard | Other
Financing Receivable Recorded Investment [Line Items]
Recorded investment	6
Consumer | Substandard | Other | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	49	3
Consumer | Substandard | Residential Real Estate
Financing Receivable Recorded Investment [Line Items]
Recorded investment	4,181	3,315
Consumer | Substandard | Residential Real Estate | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	4,950	4,442
Small Business Lending
Financing Receivable Recorded Investment [Line Items]
Recorded investment	4,802	2,785
Small Business Lending | Special Mention
Financing Receivable Recorded Investment [Line Items]
Recorded investment	3,459	772
Small Business Lending | Special Mention | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	470
Small Business Lending | Substandard
Financing Receivable Recorded Investment [Line Items]
Recorded investment	1,343	$ 2,013
Small Business Lending | Substandard | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	$ 18,890