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	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Allowance for loan losses:
Beginning balance	$ 38,233	$ 31,936	$ 31,220	$ 26,364
Provision	1,897	1,510	11,560	7,655
Charge-offs	(5,352)	(1,553)	(8,075)	(2,968)
Recoveries	308	98	381	940
Ending balance	35,086	31,991	35,086	31,991
Loans evaluated for impairment:
Collectively evaluated for impairment					$ 3,153,507	$ 3,104,089	$ 3,032,593
Individually evaluated for impairment					57,884	70,431	70,256
Purchased credit impaired					10,717	15,965	20,506
Total loans held for investment					3,222,108	3,190,485	3,123,355
Allowance for loans losses evaluated:
Collectively evaluated for impairment					24,608	25,478	24,506
Individually evaluated for impairment					10,368	5,667	7,468
Purchased credit impaired					110	75	17
Total allowance for loan losses	38,233	31,936	31,220	26,364	35,086	31,220	31,991
Commercial & industrial
Loans evaluated for impairment:
Total loans held for investment					1,070,420	1,066,266
Owner occupied commercial real estate
Loans evaluated for impairment:
Total loans held for investment					436,153	415,230
Commercial real estate
Loans evaluated for impairment:
Total loans held for investment					1,092,036	1,067,779
Construction, land & land development
Loans evaluated for impairment:
Total loans held for investment					130,533	164,952
Residential mortgage
Loans evaluated for impairment:
Total loans held for investment					235,192	238,580
Consumer and other
Loans evaluated for impairment:
Total loans held for investment					13,733	17,448
Originated
Allowance for loan losses:
Beginning balance	36,535	29,111	29,978	23,855
Provision	2,952	1,816	12,167	7,507
Charge-offs	(5,346)	(434)	(8,055)	(1,577)
Recoveries	11	36	62	744
Ending balance	34,152	30,529	34,152	30,529
Loans evaluated for impairment:
Collectively evaluated for impairment					2,828,512	2,620,375	2,430,570
Individually evaluated for impairment					50,452	56,116	46,184
Purchased credit impaired					0	0	0
Total loans held for investment					2,878,964	2,676,491	2,476,754
Allowance for loans losses evaluated:
Collectively evaluated for impairment					23,940	24,315	23,450
Individually evaluated for impairment					10,212	5,663	7,079
Purchased credit impaired					0	0	0
Total allowance for loan losses	36,535	29,111	29,978	23,855	34,152	29,978	30,529
Originated | Commercial & industrial
Allowance for loan losses:
Beginning balance			16,654
Ending balance	20,527	16,606	20,527	16,606
Loans evaluated for impairment:
Collectively evaluated for impairment					1,237,821	1,173,371	1,010,269
Individually evaluated for impairment					41,041	49,656	42,085
Purchased credit impaired					0	0	0
Total loans held for investment					1,278,862	1,223,027	1,052,354
Allowance for loans losses evaluated:
Collectively evaluated for impairment					10,875	11,245	9,556
Individually evaluated for impairment					9,652	5,409	7,050
Purchased credit impaired					0	0	0
Total allowance for loan losses	20,527	16,606	16,654	16,606	20,527	16,654	16,606
Originated | Commercial & industrial
Allowance for loan losses:
Beginning balance	23,113	15,155	16,654	9,491
Provision	2,713	1,736	11,869	7,970
Charge-offs	(5,300)	(308)	(7,999)	(1,443)
Recoveries	1	23	3	588
Ending balance	20,527	16,606	20,527	16,606
Loans evaluated for impairment:
Total loans held for investment					1,034,821	1,002,797
Allowance for loans losses evaluated:
Total allowance for loan losses	23,113	15,155	16,654	9,491	20,527	16,654	16,606
Originated | Owner occupied commercial real estate
Allowance for loan losses:
Beginning balance	2,871	2,763	2,748	2,609
Provision	480	62	603	216
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Ending balance	3,351	2,825	3,351	2,825
Loans evaluated for impairment:
Collectively evaluated for impairment					368,467	327,906	306,514
Individually evaluated for impairment					5,225	0	0
Purchased credit impaired					0	0	0
Total loans held for investment					373,692	327,906	306,514
Allowance for loans losses evaluated:
Collectively evaluated for impairment					2,820	2,748	2,825
Individually evaluated for impairment					531	0	0
Purchased credit impaired					0	0	0
Total allowance for loan losses	2,871	2,763	2,748	2,609	3,351	2,748	2,825
Originated | Commercial real estate
Allowance for loan losses:
Beginning balance	7,766	8,347	7,738	8,576
Provision	385	(162)	413	(391)
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Ending balance	8,151	8,185	8,151	8,185
Loans evaluated for impairment:
Collectively evaluated for impairment					948,924	823,361	805,362
Individually evaluated for impairment					175	0	1,979
Purchased credit impaired					0	0	0
Total loans held for investment					949,099	823,361	807,341
Allowance for loans losses evaluated:
Collectively evaluated for impairment					8,151	7,738	8,185
Individually evaluated for impairment					0	0	0
Purchased credit impaired					0	0	0
Total allowance for loan losses	7,766	8,347	7,738	8,576	8,151	7,738	8,185
Originated | Construction, land & land development
Allowance for loan losses:
Beginning balance	1,461	1,536	1,481	1,852
Provision	(613)	40	(633)	(276)
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Ending balance	848	1,576	848	1,576
Loans evaluated for impairment:
Collectively evaluated for impairment					105,819	133,711	153,522
Individually evaluated for impairment					107	3,287	0
Purchased credit impaired					0	0	0
Total loans held for investment					105,926	136,998	153,522
Allowance for loans losses evaluated:
Collectively evaluated for impairment					848	1,257	1,576
Individually evaluated for impairment					0	224	0
Purchased credit impaired					0	0	0
Total allowance for loan losses	1,461	1,536	1,481	1,852	848	1,481	1,576
Originated | Residential mortgage
Allowance for loan losses:
Beginning balance	1,159	1,119	1,136	1,134
Provision	(52)	37	(31)	(3)
Charge-offs	0	0	0	0
Recoveries	3	9	5	34
Ending balance	1,110	1,165	1,110	1,165
Loans evaluated for impairment:
Collectively evaluated for impairment					154,672	145,910	135,879
Individually evaluated for impairment					3,859	3,111	2,039
Purchased credit impaired					0	0	0
Total loans held for investment					158,531	149,021	137,918
Allowance for loans losses evaluated:
Collectively evaluated for impairment					1,110	1,136	1,165
Individually evaluated for impairment					0	0	0
Purchased credit impaired					0	0	0
Total allowance for loan losses	1,159	1,119	1,136	1,134	1,110	1,136	1,165
Originated | Consumer and other
Allowance for loan losses:
Beginning balance	165	191	221	193
Provision	39	103	(54)	(9)
Charge-offs	(46)	(126)	(56)	(134)
Recoveries	7	4	54	122
Ending balance	165	172	165	172
Loans evaluated for impairment:
Collectively evaluated for impairment					12,809	16,116	19,024
Individually evaluated for impairment					45	62	81
Purchased credit impaired					0	0	0
Total loans held for investment					12,854	16,178	19,105
Allowance for loans losses evaluated:
Collectively evaluated for impairment					136	191	143
Individually evaluated for impairment					29	30	29
Purchased credit impaired					0	0	0
Total allowance for loan losses	165	191	221	193	165	221	172
Acquired
Allowance for loan losses:
Beginning balance	1,698	2,825	1,242	2,509
Provision	(1,055)	(306)	(607)	148
Charge-offs	(6)	(1,119)	(20)	(1,391)
Recoveries	297	62	319	196
Ending balance	934	1,462	934	1,462
Loans evaluated for impairment:
Collectively evaluated for impairment					324,995	483,714	602,023
Individually evaluated for impairment					7,432	14,315	24,072
Purchased credit impaired					10,717	15,965	20,506
Total loans held for investment					343,144	513,994	646,601
Allowance for loans losses evaluated:
Collectively evaluated for impairment					668	1,163	1,056
Individually evaluated for impairment					156	4	389
Purchased credit impaired					110	75	17
Total allowance for loan losses	1,698	2,825	1,242	2,509	934	1,242	1,462
Acquired | Commercial & industrial
Allowance for loan losses:
Beginning balance	42	586	35	1,260
Provision	(26)	(321)	(25)	(838)
Charge-offs	0	(158)	0	(335)
Recoveries	3	50	9	70
Ending balance	19	157	19	157
Loans evaluated for impairment:
Collectively evaluated for impairment					29,275	49,494	74,661
Individually evaluated for impairment					4,594	10,738	15,029
Purchased credit impaired					1,730	3,237	2,288
Total loans held for investment					35,599	63,469	91,978
Allowance for loans losses evaluated:
Collectively evaluated for impairment					19	35	0
Individually evaluated for impairment					0	0	157
Purchased credit impaired					0	0	0
Total allowance for loan losses	42	586	35	1,260	19	35	157
Acquired | Owner occupied commercial real estate
Allowance for loan losses:
Beginning balance	513	1,064	0	0
Provision	(360)	(103)	153	957
Charge-offs	0	(961)	0	(961)
Recoveries	0	0	0	4
Ending balance	153	0	153	0
Loans evaluated for impairment:
Collectively evaluated for impairment					57,340	81,376	88,714
Individually evaluated for impairment					1,727	1,886	6,958
Purchased credit impaired					3,394	4,062	5,131
Total loans held for investment					62,461	87,324	100,803
Allowance for loans losses evaluated:
Collectively evaluated for impairment					0	0	0
Individually evaluated for impairment					153	0	0
Purchased credit impaired					0	0	0
Total allowance for loan losses	513	1,064	0	0	153	0	0
Acquired | Commercial real estate
Allowance for loan losses:
Beginning balance	574	340	658	437
Provision	(289)	144	(375)	47
Charge-offs	0	0	0	0
Recoveries	5	3	7	3
Ending balance	290	487	290	487
Loans evaluated for impairment:
Collectively evaluated for impairment					139,241	237,669	291,289
Individually evaluated for impairment					105	312	0
Purchased credit impaired					3,591	6,437	10,607
Total loans held for investment					142,937	244,418	301,896
Allowance for loans losses evaluated:
Collectively evaluated for impairment					290	658	487
Individually evaluated for impairment					0	0	0
Purchased credit impaired					0	0	0
Total allowance for loan losses	574	340	658	437	290	658	487
Acquired | Construction, land & land development
Allowance for loan losses:
Beginning balance	20	9	0	115
Provision	18	(6)	38	(91)
Charge-offs	0	0	0	(95)
Recoveries	0	0	0	74
Ending balance	38	3	38	3
Loans evaluated for impairment:
Collectively evaluated for impairment					23,907	27,240	46,984
Individually evaluated for impairment					700	714	1,468
Purchased credit impaired					0	0	18
Total loans held for investment					24,607	27,954	48,470
Allowance for loans losses evaluated:
Collectively evaluated for impairment					38	0	3
Individually evaluated for impairment					0	0	0
Purchased credit impaired					0	0	0
Total allowance for loan losses	20	9	0	115	38	0	3
Acquired | Residential mortgage
Allowance for loan losses:
Beginning balance	539	611	542	685
Provision	(396)	(20)	(412)	(126)
Charge-offs	0	0	0	0
Recoveries	287	7	300	39
Ending balance	430	598	430	598
Loans evaluated for impairment:
Collectively evaluated for impairment					74,555	86,876	99,052
Individually evaluated for impairment					104	454	402
Purchased credit impaired					2,002	2,229	2,462
Total loans held for investment					76,661	89,559	101,916
Allowance for loans losses evaluated:
Collectively evaluated for impairment					320	467	561
Individually evaluated for impairment					0	0	20
Purchased credit impaired					110	75	17
Total allowance for loan losses	539	611	542	685	430	542	598
Acquired | Consumer and other
Allowance for loan losses:
Beginning balance	10	215	7	12
Provision	(2)	0	14	199
Charge-offs	(6)	0	(20)	0
Recoveries	2	2	3	6
Ending balance	4	217	4	217
Loans evaluated for impairment:
Collectively evaluated for impairment					677	1,059	1,323
Individually evaluated for impairment					202	211	215
Purchased credit impaired					0	0	0
Total loans held for investment					879	1,270	1,538
Allowance for loans losses evaluated:
Collectively evaluated for impairment					1	3	5
Individually evaluated for impairment					3	4	212
Purchased credit impaired					0	0	0
Total allowance for loan losses	$ 10	$ 215	$ 7	$ 12	$ 4	$ 7	$ 217