LOANS AND ALLOWANCE FOR LOAN LOSSES (Details 4) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Dec. 31, 2015
Allowance for loan losses
Beginning balance	$ 10,231	$ 8,284	$ 9,769	$ 7,817
Charge-offs	(1,012)	(1,225)	(2,645)	(1,990)
Recoveries	116	305	336	576
Provision for loan losses	2,298	994	4,173	1,955
Ending balance	11,633	8,358	11,633	8,358
Ending balance:
Individually evaluated for impairment					$ 450	$ 487
Collectively evaluated for impairment					10,414	7,960
Total	10,231	8,284	9,769	7,817	11,633	9,769
Ending balance:
Individually evaluated for impairment					19,979	15,553
Collectively evaluated for impairment					5,047,402	2,920,061
Purchased credit-impaired					202,572	142,042
Total					5,269,953	3,077,656
Receivables Acquired with Deteriorated Credit Quality
Allowance for loan losses
Beginning balance			1,322
Ending balance	769		769
Ending balance:
Total	769		1,322		769	1,322
Commercial real estate
Allowance for loan losses
Beginning balance	3,457	2,954	3,682	2,796
Charge-offs	(10)	(157)	(91)	(256)
Recoveries	2	7	6	12
Provision for loan losses	1,076	333	928	585
Ending balance	4,525	3,137	4,525	3,137
Ending balance:
Individually evaluated for impairment					390	314
Collectively evaluated for impairment					3,766	2,976
Total	3,457	2,954	3,682	2,796	4,525	3,682
Ending balance:
Individually evaluated for impairment					14,847	8,449
Collectively evaluated for impairment					2,387,256	1,354,977
Purchased credit-impaired					88,621	87,750
Total					2,490,724	1,451,176
Commercial real estate | Receivables Acquired with Deteriorated Credit Quality
Allowance for loan losses
Beginning balance			392
Ending balance	369		369
Ending balance:
Total	369		392		369	392
Commercial and industrial
Allowance for loan losses
Beginning balance	3,272	1,336	2,431	1,274
Charge-offs	(474)	(602)	(1,435)	(971)
Recoveries	73	114	77	250
Provision for loan losses	186	1,112	1,984	1,407
Ending balance	3,057	1,960	3,057	1,960
Ending balance:
Individually evaluated for impairment					0	106
Collectively evaluated for impairment					2,857	2,309
Total	3,272	1,336	2,431	1,274	3,057	2,431
Ending balance:
Individually evaluated for impairment					3,253	2,623
Collectively evaluated for impairment					758,840	540,685
Purchased credit-impaired					13,391	9,813
Total					775,484	553,121
Commercial and industrial | Receivables Acquired with Deteriorated Credit Quality
Allowance for loan losses
Beginning balance			16
Ending balance	200		200
Ending balance:
Total	200		16		200	16
Construction and development
Allowance for loan losses
Beginning balance	793	1,732	866	1,691
Charge-offs	(98)	(51)	(115)	(67)
Recoveries	17	5	28	10
Provision for loan losses	570	(1,021)	503	(969)
Ending balance	1,282	665	1,282	665
Ending balance:
Individually evaluated for impairment					0	0
Collectively evaluated for impairment					1,280	704
Total	793	1,732	866	1,691	1,282	866
Ending balance:
Individually evaluated for impairment					886	177
Collectively evaluated for impairment					400,257	330,714
Purchased credit-impaired					18,196	14,413
Total					419,339	345,304
Construction and development | Receivables Acquired with Deteriorated Credit Quality
Allowance for loan losses
Beginning balance			162
Ending balance	2		2
Ending balance:
Total	2		162		2	162
Residential real estate
Allowance for loan losses
Beginning balance	991	1,251	1,257	1,237
Charge-offs	(57)	(120)	(217)	(130)
Recoveries	11	28	193	52
Provision for loan losses	40	168	(248)	168
Ending balance	985	1,327	985	1,327
Ending balance:
Individually evaluated for impairment					60	0
Collectively evaluated for impairment					854	837
Total	991	1,251	1,257	1,237	985	1,257
Ending balance:
Individually evaluated for impairment					993	3,550
Collectively evaluated for impairment					623,382	315,030
Purchased credit-impaired					61,749	25,068
Total					686,124	343,648
Residential real estate | Receivables Acquired with Deteriorated Credit Quality
Allowance for loan losses
Beginning balance			420
Ending balance	71		71
Ending balance:
Total	71		420		71	420
Construction and development
Allowance for loan losses
Beginning balance	256	213	237	194
Charge-offs	0	0	0	0
Recoveries	0	0	0	27
Provision for loan losses	33	56	52	48
Ending balance	289	269	289	269
Ending balance:
Individually evaluated for impairment					0	0
Collectively evaluated for impairment					289	233
Total	256	213	237	194	289	237
Ending balance:
Individually evaluated for impairment					0	417
Collectively evaluated for impairment					297,663	44,630
Purchased credit-impaired					2,232	1,216
Total					299,895	46,263
Construction and development | Receivables Acquired with Deteriorated Credit Quality
Allowance for loan losses
Beginning balance			4
Ending balance	0		0
Ending balance:
Total	0		4		0	4
Home equity
Allowance for loan losses
Beginning balance	1,019	706	883	546
Charge-offs	(145)	(183)	(342)	(318)
Recoveries	2	113	2	154
Provision for loan losses	243	139	576	393
Ending balance	1,119	775	1,119	775
Ending balance:
Individually evaluated for impairment					0	67
Collectively evaluated for impairment					997	542
Total	1,019	706	883	546	1,119	883
Ending balance:
Individually evaluated for impairment					0	337
Collectively evaluated for impairment					513,195	274,042
Purchased credit-impaired					17,784	3,521
Total					530,979	277,900
Home equity | Receivables Acquired with Deteriorated Credit Quality
Allowance for loan losses
Beginning balance			274
Ending balance	122		122
Ending balance:
Total	122		274		122	274
Other consumer
Allowance for loan losses
Beginning balance	443	92	413	79
Charge-offs	(228)	(112)	(445)	(248)
Recoveries	11	38	30	71
Provision for loan losses	150	207	378	323
Ending balance	376	225	376	225
Ending balance:
Individually evaluated for impairment					0	0
Collectively evaluated for impairment					371	359
Total	443	$ 92	413	$ 79	376	413
Ending balance:
Individually evaluated for impairment					0	0
Collectively evaluated for impairment					66,809	59,983
Purchased credit-impaired					599	261
Total					67,408	60,244
Other consumer | Receivables Acquired with Deteriorated Credit Quality
Allowance for loan losses
Beginning balance			54
Ending balance	5		5
Ending balance:
Total	$ 5		$ 54		$ 5	$ 54