LOANS AND ALLOWANCE FOR LOAN LOSSES (Allowance for Loan Loss Activity, by Portfolio Segment, Balances for Allowance for Credit Losses, and Loans Based on Impairment Methodology) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Dec. 31, 2017
Allowance for loan losses
Balance, beginning of the year	$ 38,208	$ 37,192
Recoveries credited to allowance	4,082	2,559
Loans charged off	(10,099)	(9,949)
Provision charged to operations	9,103	7,360
Balance, end of period	41,294	37,162
Total Loans
Loans individually evaluated for impairment			$ 56,272	$ 53,481
ALL individually evaluated for impairment			1,596	503
Loans collectively evaluated for impairment			9,260,580	7,049,050
ALL collectively evaluated for impairment			39,698	37,705
Total Loans			9,411,598	7,141,552
Total ALL	38,208	37,192	41,294	38,208
Purchased Impaired
Allowance for loan losses
Balance, beginning of the year	0
Balance, end of period	0
Total Loans
Total Loans			94,746	39,021
Total ALL	0		0	0
Construction and Land Development
Allowance for loan losses
Balance, beginning of the year	9,709	10,055
Recoveries credited to allowance	400	193
Loans charged off	(703)	(2,115)
Provision charged to operations	(1,218)	535
Balance, end of period	8,188	8,668
Total Loans
Loans individually evaluated for impairment			11,748	17,571
ALL individually evaluated for impairment			139	122
Loans collectively evaluated for impairment			1,161,264	928,382
ALL collectively evaluated for impairment			8,049	9,587
Total Loans			1,178,054	948,791
Total ALL	9,709	10,055	8,188	9,709
Construction and Land Development | Purchased Impaired
Allowance for loan losses
Balance, beginning of the year	0
Balance, end of period	0
Total Loans
Total Loans			5,042	2,838
Total ALL	0		0	0
Commercial Real Estate - Owner Occupied
Allowance for loan losses
Balance, beginning of the year	2,931	3,801
Recoveries credited to allowance	488	84
Loans charged off	(174)	(46)
Provision charged to operations	(300)	(620)
Balance, end of period	2,945	3,219
Total Loans
Loans individually evaluated for impairment			11,809	6,588
ALL individually evaluated for impairment			149	94
Loans collectively evaluated for impairment			1,245,420	922,555
ALL collectively evaluated for impairment			2,796	2,837
Total Loans			1,283,125	943,933
Total ALL	2,931	3,801	2,945	2,931
Commercial Real Estate - Owner Occupied | Purchased Impaired
Allowance for loan losses
Balance, beginning of the year	0
Balance, end of period	0
Total Loans
Total Loans			25,896	14,790
Total ALL	0		0	0
Commercial Real Estate - Non-Owner Occupied
Allowance for loan losses
Balance, beginning of the year	7,544	6,622
Recoveries credited to allowance	82	2
Loans charged off	(94)	(1,181)
Provision charged to operations	806	1,825
Balance, end of period	8,338	7,268
Total Loans
Loans individually evaluated for impairment			6,922	6,017
ALL individually evaluated for impairment			0	0
Loans collectively evaluated for impairment			2,398,754	1,701,032
ALL collectively evaluated for impairment			8,338	7,544
Total Loans			2,427,251	1,713,659
Total ALL	7,544	6,622	8,338	7,544
Commercial Real Estate - Non-Owner Occupied | Purchased Impaired
Allowance for loan losses
Balance, beginning of the year	0
Balance, end of period	0
Total Loans
Total Loans			21,575	6,610
Total ALL	0		0	0
Multifamily Real Estate
Allowance for loan losses
Balance, beginning of the year	1,092	1,236
Recoveries credited to allowance	5	0
Loans charged off	0	0
Provision charged to operations	525	(136)
Balance, end of period	1,622	1,100
Total Loans
Loans individually evaluated for impairment			0	0
ALL individually evaluated for impairment			0	0
Loans collectively evaluated for impairment			542,576	356,999
ALL collectively evaluated for impairment			1,622	1,092
Total Loans			542,662	357,079
Total ALL	1,092	1,236	1,622	1,092
Multifamily Real Estate | Purchased Impaired
Allowance for loan losses
Balance, beginning of the year	0
Balance, end of period	0
Total Loans
Total Loans			86	80
Total ALL	0		0	0
Commercial & Industrial
Allowance for loan losses
Balance, beginning of the year	4,552	4,627
Recoveries credited to allowance	413	451
Loans charged off	(692)	(1,241)
Provision charged to operations	2,429	1,526
Balance, end of period	6,702	5,363
Total Loans
Loans individually evaluated for impairment			2,538	2,976
ALL individually evaluated for impairment			317	128
Loans collectively evaluated for impairment			1,149,746	608,639
ALL collectively evaluated for impairment			6,385	4,424
Total Loans			1,154,583	612,023
Total ALL	4,552	4,627	6,702	4,552
Commercial & Industrial | Purchased Impaired
Allowance for loan losses
Balance, beginning of the year	0
Balance, end of period	0
Total Loans
Total Loans			2,299	408
Total ALL	0		0	0
Residential 1-4 Family - Commercial
Allowance for loan losses
Balance, beginning of the year	4,437	3,698
Recoveries credited to allowance	306	249
Loans charged off	(137)	(451)
Provision charged to operations	(2,147)	55
Balance, end of period	2,459	3,551
Total Loans
Loans individually evaluated for impairment			6,051	5,160
ALL individually evaluated for impairment			227	35
Loans collectively evaluated for impairment			697,674	597,821
ALL collectively evaluated for impairment			2,232	4,402
Total Loans			719,798	612,395
Total ALL	4,437	3,698	2,459	4,437
Residential 1-4 Family - Commercial | Purchased Impaired
Allowance for loan losses
Balance, beginning of the year	0
Balance, end of period	0
Total Loans
Total Loans			16,073	9,414
Total ALL	0		0	0
Residential 1-4 Family - Mortgage
Allowance for loan losses
Balance, beginning of the year	1,524	2,701
Recoveries credited to allowance	235	83
Loans charged off	(640)	(364)
Provision charged to operations	405	(90)
Balance, end of period	1,524	2,330
Total Loans
Loans individually evaluated for impairment			14,326	11,465
ALL individually evaluated for impairment			301	36
Loans collectively evaluated for impairment			580,641	470,492
ALL collectively evaluated for impairment			1,223	1,488
Total Loans			611,728	485,690
Total ALL	1,524	2,701	1,524	1,524
Residential 1-4 Family - Mortgage | Purchased Impaired
Allowance for loan losses
Balance, beginning of the year	0
Balance, end of period	0
Total Loans
Total Loans			16,761	3,733
Total ALL	0		0	0
Auto
Allowance for loan losses
Balance, beginning of the year	975	946
Recoveries credited to allowance	365	352
Loans charged off	(759)	(761)
Provision charged to operations	760	398
Balance, end of period	1,341	935
Total Loans
Loans individually evaluated for impairment			525	413
ALL individually evaluated for impairment			215	2
Loans collectively evaluated for impairment			305,662	282,061
ALL collectively evaluated for impairment			1,126	973
Total Loans			306,196	282,474
Total ALL	975	946	1,341	975
Auto | Purchased Impaired
Allowance for loan losses
Balance, beginning of the year	0
Balance, end of period	0
Total Loans
Total Loans			9	0
Total ALL	0		0	0
HELOC
Allowance for loan losses
Balance, beginning of the year	1,360	1,328
Recoveries credited to allowance	554	240
Loans charged off	(488)	(861)
Provision charged to operations	(70)	675
Balance, end of period	1,356	1,382
Total Loans
Loans individually evaluated for impairment			1,674	2,520
ALL individually evaluated for impairment			173	51
Loans collectively evaluated for impairment			604,263	534,051
ALL collectively evaluated for impairment			1,183	1,309
Total Loans			612,116	537,521
Total ALL	1,360	1,328	1,356	1,360
HELOC | Purchased Impaired
Allowance for loan losses
Balance, beginning of the year	0
Balance, end of period	0
Total Loans
Total Loans			6,179	950
Total ALL	0		0	0
Consumer and all other
Allowance for loan losses
Balance, beginning of the year	4,084	2,178
Recoveries credited to allowance	1,234	905
Loans charged off	(6,412)	(2,929)
Provision charged to operations	7,913	3,192
Balance, end of period	6,819	3,346
Total Loans
Loans individually evaluated for impairment			679	771
ALL individually evaluated for impairment			75	35
Loans collectively evaluated for impairment			574,580	647,018
ALL collectively evaluated for impairment			6,744	4,049
Total Loans			576,085	647,987
Total ALL	4,084	$ 2,178	6,819	4,084
Consumer and all other | Purchased Impaired
Allowance for loan losses
Balance, beginning of the year	0
Balance, end of period	0
Total Loans
Total Loans			826	198
Total ALL	$ 0		$ 0	$ 0