Allowance for Loan Losses - Activity in Allowance for Loan Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for Loan Losses:
Beginning Balance	$ 23,400	$ 19,128	$ 17,007
Provision for Loan Losses	5,648	2,411	2,644
Charge-Offs	(4,102)	(1,144)	(3,380)
Recoveries	2,495	3,236	3,012
TDR Allowance Adjustments	(319)	(231)	(218)
Ending Balance	27,122	23,400	19,128
Construction and land developments [Member]
Allowance for Loan Losses:
Beginning Balance	1,219	1,151	722
Provision for Loan Losses	(471)	(150)	1,296
Charge-Offs	0	0	(1,271)
Recoveries	896	226	404
TDR Allowance Adjustments	(2)	(8)	43
Ending Balance	1,642	1,219	1,151
Commercial real estates [Member]
Allowance for Loan Losses:
Beginning Balance	9,273	6,756	4,528
Provision for Loan Losses	(264)	2,599	2,010
Charge-Offs	(407)	(256)	(263)
Recoveries	747	306	700
TDR Allowance Adjustments	(64)	(132)	(69)
Ending Balance	9,285	9,273	6,756
Residential real estates [Member]
Allowance for Loan Losses:
Beginning Balance	7,483	8,057	9,784
Provision for Loan Losses	125	(1,069)	(2,208)
Charge-Offs	(569)	(205)	(779)
Recoveries	336	786	1,260
TDR Allowance Adjustments	(244)	(86)	(150)
Ending Balance	7,131	7,483	8,057
Commercial and financial [Member]
Allowance for Loan Losses:
Beginning Balance	3,636	2,042	1,179
Provision for Loan Losses	5,304	224	1,058
Charge-Offs	(1,869)	(439)	(726)
Recoveries	226	1,809	531
TDR Allowance Adjustments	0	0	(6)
Ending Balance	7,297	3,636	2,042
Consumers [Member]
Allowance for Loan Losses:
Beginning Balance	1,789	1,122	794
Provision for Loan Losses	954	807	552
Charge-Offs	(1,257)	(244)	(341)
Recoveries	290	109	117
TDR Allowance Adjustments	(9)	(5)	(36)
Ending Balance	$ 1,767	$ 1,789	$ 1,122