Loans and Allowance for Loan Losses - Loan Risk Rating (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 1,575,435	$ 1,323,258
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	745,864	642,988
Consumer Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	355,876	293,457
Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	179,431	135,409
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	279,771	238,087
Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	14,493	13,317
Non PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,542,777	1,290,464
Non PCI Loans [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,531,710	1,270,417
Non PCI Loans [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,992	13,668
Non PCI Loans [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,507	3,852
Non PCI Loans [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,529	2,241
Non PCI Loans [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	39	286
Non PCI Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	727,390	625,085
Non PCI Loans [Member] | Commercial Real Estate [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	724,763	616,028
Non PCI Loans [Member] | Commercial Real Estate [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,604	7,673
Non PCI Loans [Member] | Commercial Real Estate [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	1,006
Non PCI Loans [Member] | Commercial Real Estate [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,023	378
Non PCI Loans [Member] | Commercial Real Estate [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Non PCI Loans [Member] | Consumer Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	348,889	286,007
Non PCI Loans [Member] | Consumer Real Estate [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	343,407	279,464
Non PCI Loans [Member] | Consumer Real Estate [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,168	2,543
Non PCI Loans [Member] | Consumer Real Estate [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	949	2,627
Non PCI Loans [Member] | Consumer Real Estate [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,365	1,159
Non PCI Loans [Member] | Consumer Real Estate [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	214
Non PCI Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	173,741	130,289
Non PCI Loans [Member] | Construction and Land Development [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	172,972	129,359
Non PCI Loans [Member] | Construction and Land Development [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	62	383
Non PCI Loans [Member] | Construction and Land Development [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	160	0
Non PCI Loans [Member] | Construction and Land Development [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	547	547
Non PCI Loans [Member] | Construction and Land Development [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Non PCI Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	278,950	237,229
Non PCI Loans [Member] | Commercial and Industrial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	277,384	233,942
Non PCI Loans [Member] | Commercial and Industrial [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,035	3,007
Non PCI Loans [Member] | Commercial and Industrial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	35	64
Non PCI Loans [Member] | Commercial and Industrial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	483	157
Non PCI Loans [Member] | Commercial and Industrial [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	13	59
Non PCI Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	13,807	11,854
Non PCI Loans [Member] | Consumer and Other [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	13,184	11,624
Non PCI Loans [Member] | Consumer and Other [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	123	62
Non PCI Loans [Member] | Consumer and Other [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	363	155
Non PCI Loans [Member] | Consumer and Other [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	111	0
Non PCI Loans [Member] | Consumer and Other [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	26	13
Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	32,658	32,794
Purchased Credit Impaired Loans [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	23,800	23,558
Purchased Credit Impaired Loans [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,084	2,637
Purchased Credit Impaired Loans [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,854	538
Purchased Credit Impaired Loans [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,920	5,308
Purchased Credit Impaired Loans [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	753
Purchased Credit Impaired Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	18,474	17,903
Purchased Credit Impaired Loans [Member] | Commercial Real Estate [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	14,494	14,386
Purchased Credit Impaired Loans [Member] | Commercial Real Estate [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,513	261
Purchased Credit Impaired Loans [Member] | Commercial Real Estate [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,393	0
Purchased Credit Impaired Loans [Member] | Commercial Real Estate [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,074	3,084
Purchased Credit Impaired Loans [Member] | Commercial Real Estate [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	172
Purchased Credit Impaired Loans [Member] | Consumer Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	6,987	7,450
Purchased Credit Impaired Loans [Member] | Consumer Real Estate [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,558	4,151
Purchased Credit Impaired Loans [Member] | Consumer Real Estate [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	898	1,345
Purchased Credit Impaired Loans [Member] | Consumer Real Estate [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	575	456
Purchased Credit Impaired Loans [Member] | Consumer Real Estate [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	956	1,192
Purchased Credit Impaired Loans [Member] | Consumer Real Estate [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	306
Purchased Credit Impaired Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,690	5,120
Purchased Credit Impaired Loans [Member] | Construction and Land Development [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,973	4,134
Purchased Credit Impaired Loans [Member] | Construction and Land Development [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	653	649
Purchased Credit Impaired Loans [Member] | Construction and Land Development [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	716	0
Purchased Credit Impaired Loans [Member] | Construction and Land Development [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	348	337
Purchased Credit Impaired Loans [Member] | Construction and Land Development [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Purchased Credit Impaired Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	821	858
Purchased Credit Impaired Loans [Member] | Commercial and Industrial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	210	68
Purchased Credit Impaired Loans [Member] | Commercial and Industrial [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2	120
Purchased Credit Impaired Loans [Member] | Commercial and Industrial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	153	58
Purchased Credit Impaired Loans [Member] | Commercial and Industrial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	456	588
Purchased Credit Impaired Loans [Member] | Commercial and Industrial [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	24
Purchased Credit Impaired Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	686	1,463
Purchased Credit Impaired Loans [Member] | Consumer and Other [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	565	819
Purchased Credit Impaired Loans [Member] | Consumer and Other [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	18	262
Purchased Credit Impaired Loans [Member] | Consumer and Other [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	17	24
Purchased Credit Impaired Loans [Member] | Consumer and Other [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	86	107
Purchased Credit Impaired Loans [Member] | Consumer and Other [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 0	$ 251