ALLOWANCE FOR LOAN LOSSES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016
Allowance for loan losses:
Beginning balance	$ 26,364	$ 32,947
Provision	14,360	64,700	$ 17,864
Charge-offs	(10,522)	(72,585)
Recoveries	1,018	1,302
Ending balance	31,220	26,364	32,947
Loans evaluated for impairment
Collectively evaluated for impairment				$ 3,104,089	$ 2,979,708
Individually evaluated for impairment				70,431	93,324
Purchased credit impaired				15,965	25,188
Total loans held for investment				3,190,485	3,098,220
Allowance for loan losses evaluated
Collectively evaluated for impairment				25,478	24,467
Individually evaluated for impairment				5,667	1,775
Purchased credit impaired				75	122
Total allowance for loan losses	26,364	32,947	32,947	31,220	26,364
Commercial & industrial
Loans evaluated for impairment
Total loans held for investment				1,286,496	1,053,925
Owner occupied commercial real estate
Loans evaluated for impairment
Total loans held for investment				415,230	394,210
Commercial real estate
Loans evaluated for impairment
Total loans held for investment				1,067,779	1,143,751
Construction, land & land development
Loans evaluated for impairment
Total loans held for investment				164,952	249,704
Residential mortgage
Loans evaluated for impairment
Total loans held for investment				238,580	245,191
Consumer and other
Loans evaluated for impairment
Total loans held for investment				17,448	11,439
Originated Loans
Allowance for loan losses:
Beginning balance	23,855	32,722
Provision	14,222	55,981
Charge-offs	(8,872)	(65,820)
Recoveries	773	972
Ending balance	29,978	23,855	32,722
Loans evaluated for impairment
Collectively evaluated for impairment				2,620,375	2,256,897
Individually evaluated for impairment				56,116	45,031
Total loans held for investment				2,676,491	2,301,928
Allowance for loan losses evaluated
Collectively evaluated for impairment				24,315	23,342
Individually evaluated for impairment				5,663	513
Total allowance for loan losses	23,855	32,722	32,722	29,978	23,855
Originated Loans | Commercial & industrial
Allowance for loan losses:
Beginning balance	9,491	23,084
Provision	15,291	51,189
Charge-offs	(8,726)	(65,684)
Recoveries	598	902
Ending balance	16,654	9,491	23,084
Loans evaluated for impairment
Collectively evaluated for impairment				1,173,371	867,924
Individually evaluated for impairment				49,656	36,407
Total loans held for investment				1,223,027	904,331
Allowance for loan losses evaluated
Collectively evaluated for impairment				11,245	9,097
Individually evaluated for impairment				5,409	394
Total allowance for loan losses	9,491	23,084	23,084	16,654	9,491
Originated Loans | Owner occupied commercial real estate
Allowance for loan losses:
Beginning balance	2,609	1,675
Provision	139	934
Ending balance	2,748	2,609	1,675
Loans evaluated for impairment
Collectively evaluated for impairment				327,906	264,876
Total loans held for investment				327,906	264,876
Allowance for loan losses evaluated
Collectively evaluated for impairment				2,748	2,609
Total allowance for loan losses	2,609	1,675	1,675	2,748	2,609
Originated Loans | Commercial real estate
Allowance for loan losses:
Beginning balance	8,576	4,525
Provision	(838)	4,077
Charge-offs		(26)
Ending balance	7,738	8,576	4,525
Loans evaluated for impairment
Collectively evaluated for impairment				823,361	808,874
Individually evaluated for impairment					7,155
Total loans held for investment				823,361	816,029
Allowance for loan losses evaluated
Collectively evaluated for impairment				7,738	8,576
Total allowance for loan losses	8,576	4,525	4,525	7,738	8,576
Originated Loans | Construction, land & land development
Allowance for loan losses:
Beginning balance	1,852	2,337
Provision	(371)	(485)
Ending balance	1,481	1,852	2,337
Loans evaluated for impairment
Collectively evaluated for impairment				133,711	179,999
Individually evaluated for impairment				3,287
Total loans held for investment				136,998	179,999
Allowance for loan losses evaluated
Collectively evaluated for impairment				1,257	1,852
Individually evaluated for impairment				224
Total allowance for loan losses	1,852	2,337	2,337	1,481	1,852
Originated Loans | Residential mortgage
Allowance for loan losses:
Beginning balance	1,134	815
Provision	(51)	271
Recoveries	53	48
Ending balance	1,136	1,134	815
Loans evaluated for impairment
Collectively evaluated for impairment				145,910	126,190
Individually evaluated for impairment				3,111	1,255
Total loans held for investment				149,021	127,445
Allowance for loan losses evaluated
Collectively evaluated for impairment				1,136	1,134
Total allowance for loan losses	1,134	815	815	1,136	1,134
Originated Loans | Consumer and other
Allowance for loan losses:
Beginning balance	193	286
Provision	52	(5)
Charge-offs	(146)	(110)
Recoveries	122	22
Ending balance	221	193	286
Loans evaluated for impairment
Collectively evaluated for impairment				16,116	9,034
Individually evaluated for impairment				62	214
Total loans held for investment				16,178	9,248
Allowance for loan losses evaluated
Collectively evaluated for impairment				191	74
Individually evaluated for impairment				30	119
Total allowance for loan losses	193	286	286	221	193
Acquired Loans
Allowance for loan losses:
Beginning balance	2,509	225
Provision	138	8,719
Charge-offs	(1,650)	(6,765)
Recoveries	245	330
Ending balance	1,242	2,509	225
Loans evaluated for impairment
Collectively evaluated for impairment				483,714	722,811
Individually evaluated for impairment				14,315	48,293
Purchased credit impaired				15,965	25,188
Total loans held for investment				513,994	796,292
Allowance for loan losses evaluated
Collectively evaluated for impairment				1,163	1,125
Individually evaluated for impairment				4	1,262
Purchased credit impaired				75	122
Total allowance for loan losses	2,509	225	225	1,242	2,509
Acquired Loans | Commercial & industrial
Allowance for loan losses:
Beginning balance	1,260	46
Provision	(964)	3,816
Charge-offs	(339)	(2,700)
Recoveries	78	98
Ending balance	35	1,260	46
Loans evaluated for impairment
Collectively evaluated for impairment				49,494	110,413
Individually evaluated for impairment				10,738	34,675
Purchased credit impaired				3,237	4,506
Total loans held for investment				63,469	149,594
Allowance for loan losses evaluated
Collectively evaluated for impairment				35
Individually evaluated for impairment					1,260
Total allowance for loan losses	1,260	46	46	35	1,260
Acquired Loans | Owner occupied commercial real estate
Allowance for loan losses:
Beginning balance		4
Provision	1,083	1,384
Charge-offs	(1,087)	(1,405)
Recoveries	4	17
Ending balance			4
Loans evaluated for impairment
Collectively evaluated for impairment				81,376	115,053
Individually evaluated for impairment				1,886	8,942
Purchased credit impaired				4,062	5,339
Total loans held for investment				87,324	129,334
Allowance for loan losses evaluated
Total allowance for loan losses		4	4
Acquired Loans | Commercial real estate
Allowance for loan losses:
Beginning balance	437	166
Provision	213	737
Charge-offs		(466)
Recoveries	8	0
Ending balance	658	437	166
Loans evaluated for impairment
Collectively evaluated for impairment				237,669	314,913
Individually evaluated for impairment				312	2,002
Purchased credit impaired				6,437	10,807
Total loans held for investment				244,418	327,722
Allowance for loan losses evaluated
Collectively evaluated for impairment				658	429
Purchased credit impaired					8
Total allowance for loan losses	437	166	166	658	437
Acquired Loans | Construction, land & land development
Allowance for loan losses:
Beginning balance	115	8
Provision	(97)	1,654
Charge-offs	(95)	(1,631)
Recoveries	77	84
Ending balance		115	8
Loans evaluated for impairment
Collectively evaluated for impairment				27,240	66,908
Individually evaluated for impairment				714	978
Purchased credit impaired					1,819
Total loans held for investment				27,954	69,705
Allowance for loan losses evaluated
Collectively evaluated for impairment					14
Purchased credit impaired					101
Total allowance for loan losses	115	8	8		115
Acquired Loans | Residential mortgage
Allowance for loan losses:
Beginning balance	685	1
Provision	(192)	1,125
Charge-offs	(19)	(548)
Recoveries	68	107
Ending balance	542	685	1
Loans evaluated for impairment
Collectively evaluated for impairment				86,876	113,338
Individually evaluated for impairment				454	1,691
Purchased credit impaired				2,229	2,717
Total loans held for investment				89,559	117,746
Allowance for loan losses evaluated
Collectively evaluated for impairment				467	672
Purchased credit impaired				75	13
Total allowance for loan losses	685	1	$ 1	542	685
Acquired Loans | Consumer and other
Allowance for loan losses:
Beginning balance	12
Provision	95	3
Charge-offs	(110)	(15)
Recoveries	10	24
Ending balance	7	12
Loans evaluated for impairment
Collectively evaluated for impairment				1,059	2,186
Individually evaluated for impairment				211	5
Total loans held for investment				1,270	2,191
Allowance for loan losses evaluated
Collectively evaluated for impairment				3	10
Individually evaluated for impairment				4	2
Total allowance for loan losses	$ 12	$ 12		$ 7	$ 12