Loans and Allowance for Loan Losses - Loan Risk Rating (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 1,374,257	$ 1,323,258
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	663,694	642,988
Consumer Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	299,147	293,457
Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	142,704	135,409
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	256,333	238,087
Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	12,379	13,317
Non PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,344,421	1,290,464
Non PCI Loans [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,335,233	1,270,417
Non PCI Loans [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	6,168	13,668
Non PCI Loans [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	12	3,852
Non PCI Loans [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,963	2,241
Non PCI Loans [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	45	286
Non PCI Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	647,458	625,085
Non PCI Loans [Member] | Commercial Real Estate [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	645,238	616,028
Non PCI Loans [Member] | Commercial Real Estate [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,660	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	560	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	292,162	286,007
Non PCI Loans [Member] | Consumer Real Estate [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	287,350	279,464
Non PCI Loans [Member] | Consumer Real Estate [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,227	2,543
Non PCI Loans [Member] | Consumer Real Estate [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	12	2,627
Non PCI Loans [Member] | Consumer Real Estate [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,573	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	137,701	130,289
Non PCI Loans [Member] | Construction and Land Development [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	137,154	129,359
Non PCI Loans [Member] | Construction and Land Development [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	383
Non PCI Loans [Member] | Construction and Land Development [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	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	255,684	237,229
Non PCI Loans [Member] | Commercial and Industrial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	254,341	233,942
Non PCI Loans [Member] | Commercial and Industrial [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,154	3,007
Non PCI Loans [Member] | Commercial and Industrial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	64
Non PCI Loans [Member] | Commercial and Industrial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	169	157
Non PCI Loans [Member] | Commercial and Industrial [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	20	59
Non PCI Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	11,416	11,854
Non PCI Loans [Member] | Consumer and Other [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	11,150	11,624
Non PCI Loans [Member] | Consumer and Other [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	127	62
Non PCI Loans [Member] | Consumer and Other [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	155
Non PCI Loans [Member] | Consumer and Other [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	114	0
Non PCI Loans [Member] | Consumer and Other [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	25	13
Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	29,836	32,794
Purchased Credit Impaired Loans [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	22,681	23,558
Purchased Credit Impaired Loans [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,546	2,637
Purchased Credit Impaired Loans [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	59	538
Purchased Credit Impaired Loans [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,537	5,308
Purchased Credit Impaired Loans [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	13	753
Purchased Credit Impaired Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	16,236	17,903
Purchased Credit Impaired Loans [Member] | Commercial Real Estate [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	13,474	14,386
Purchased Credit Impaired Loans [Member] | Commercial Real Estate [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,590	261
Purchased Credit Impaired Loans [Member] | Commercial Real Estate [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Purchased Credit Impaired Loans [Member] | Commercial Real Estate [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,172	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	6,985	7,450
Purchased Credit Impaired Loans [Member] | Consumer Real Estate [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,257	4,151
Purchased Credit Impaired Loans [Member] | Consumer Real Estate [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,281	1,345
Purchased Credit Impaired Loans [Member] | Consumer Real Estate [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	456
Purchased Credit Impaired Loans [Member] | Consumer Real Estate [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,447	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	5,003	5,120
Purchased Credit Impaired Loans [Member] | Construction and Land Development [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,008	4,134
Purchased Credit Impaired Loans [Member] | Construction and Land Development [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	651	649
Purchased Credit Impaired Loans [Member] | Construction and Land Development [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Purchased Credit Impaired Loans [Member] | Construction and Land Development [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	344	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	649	858
Purchased Credit Impaired Loans [Member] | Commercial and Industrial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	99	68
Purchased Credit Impaired Loans [Member] | Commercial and Industrial [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3	120
Purchased Credit Impaired Loans [Member] | Commercial and Industrial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	59	58
Purchased Credit Impaired Loans [Member] | Commercial and Industrial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	475	588
Purchased Credit Impaired Loans [Member] | Commercial and Industrial [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	13	24
Purchased Credit Impaired Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	963	1,463
Purchased Credit Impaired Loans [Member] | Consumer and Other [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	843	819
Purchased Credit Impaired Loans [Member] | Consumer and Other [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	21	262
Purchased Credit Impaired Loans [Member] | Consumer and Other [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	24
Purchased Credit Impaired Loans [Member] | Consumer and Other [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	99	107
Purchased Credit Impaired Loans [Member] | Consumer and Other [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 0	$ 251