Allowance for Loan Losses - Activity in Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Allowance for Loan Losses:
Beginning Balance	$ 28,118	$ 24,562	$ 27,122	$ 23,400
Provision for Loan Losses	2,529	1,401	3,614	2,705
Charge- Offs	(2,314)	(604)	(2,819)	(1,108)
Recoveries	624	705	1,128	1,116
TDR Allowance Adjustments	(33)	(64)	(121)	(113)
Ending Balance	28,924	26,000	28,924	26,000
Construction and land development
Allowance for Loan Losses:
Beginning Balance	2,058	1,352	1,642	1,219
Provision for Loan Losses	224	128	635	192
Charge- Offs	0	0	0	0
Recoveries	5	94	10	165
TDR Allowance Adjustments	0	0	0	(2)
Ending Balance	2,287	1,574	2,287	1,574
Commercial real estate
Allowance for Loan Losses:
Beginning Balance	8,842	9,861	9,285	9,273
Provision for Loan Losses	210	(167)	(365)	313
Charge- Offs	(14)	(82)	(14)	(68)
Recoveries	103	331	250	439
TDR Allowance Adjustments	(15)	(20)	(30)	(34)
Ending Balance	9,126	9,923	9,126	9,923
Residential real estate
Allowance for Loan Losses:
Beginning Balance	8,047	7,064	7,131	7,483
Provision for Loan Losses	414	324	1,201	(100)
Charge- Offs	(27)	(21)	(27)	(112)
Recoveries	433	99	634	227
TDR Allowance Adjustments	(17)	(43)	(89)	(75)
Ending Balance	8,850	7,423	8,850	7,423
Commercial and financial
Allowance for Loan Losses:
Beginning Balance	7,393	4,635	7,297	3,636
Provision for Loan Losses	1,630	1,193	1,900	2,314
Charge- Offs	(1,945)	(447)	(2,143)	(616)
Recoveries	24	79	48	126
TDR Allowance Adjustments	0	0	0	0
Ending Balance	7,102	5,460	7,102	5,460
Consumer
Allowance for Loan Losses:
Beginning Balance	1,778	1,650	1,767	1,789
Provision for Loan Losses	51	(77)	243	(14)
Charge- Offs	(328)	(54)	(635)	(312)
Recoveries	59	102	186	159
TDR Allowance Adjustments	(1)	(1)	(2)	(2)
Ending Balance	$ 1,559	$ 1,620	$ 1,559	$ 1,620