LOANS AND ALLOWANCE FOR LOAN LOSSES (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Allowance for loan losses
Beginning balance	$ 7,817	$ 7,043
Charge-offs	(765)	(1,159)
Recoveries	271	39
Provision for loan losses	961	1,290
Ending balance	8,284	7,213
Ending balance:
Individually evaluated for impairment	174		390
Collectively evaluated for impairment	6,733		6,129
Purchased credit-impaired	1,377		1,298
Total	8,284	7,213
Ending balance:
Individually evaluated for impairment	16,205		9,985
Collectively evaluated for impairment	2,708,680		2,682,925
Purchased credit-impaired	189,617		206,127
Total	2,914,502		2,899,037
Commercial real estate
Allowance for loan losses
Beginning balance	2,796	2,419
Charge-offs	(99)	(242)
Recoveries	5	4
Provision for loan losses	252	99
Ending balance	2,954	2,280
Ending balance:
Individually evaluated for impairment	52		158
Collectively evaluated for impairment	2,369		2,177
Purchased credit-impaired	533		461
Total	2,954	2,280
Ending balance:
Individually evaluated for impairment	10,745		5,398
Collectively evaluated for impairment	1,253,631		1,227,597
Purchased credit-impaired	111,395		122,541
Total	1,375,771		1,355,536
Commercial and industrial
Allowance for loan losses
Beginning balance	1,274	805
Charge-offs	(369)	(241)
Recoveries	136	5
Provision for loan losses	295	213
Ending balance	1,336	782
Ending balance:
Individually evaluated for impairment	60		229
Collectively evaluated for impairment	1,232		952
Purchased credit-impaired	44		93
Total	1,336	782
Ending balance:
Individually evaluated for impairment	2,884		2,343
Collectively evaluated for impairment	445,372		452,487
Purchased credit-impaired	10,865		14,018
Total	459,121		468,848
Construction and development
Allowance for loan losses
Beginning balance	1,691	1,400
Charge-offs	(16)	(196)
Recoveries	5	0
Provision for loan losses	52	406
Ending balance	1,732	1,610
Ending balance:
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	1,687		1,590
Purchased credit-impaired	45		101
Total	1,732	1,610
Ending balance:
Individually evaluated for impairment	867		910
Collectively evaluated for impairment	350,939		337,540
Purchased credit-impaired	32,404		32,357
Total	384,210		370,807
Residential real estate
Allowance for loan losses
Beginning balance	1,237	1,673
Charge-offs	(10)	(196)
Recoveries	24	11
Provision for loan losses	0	238
Ending balance	1,251	1,726
Ending balance:
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	698		681
Purchased credit-impaired	553		556
Total	1,251	1,726
Ending balance:
Individually evaluated for impairment	1,336		928
Collectively evaluated for impairment	324,258		328,693
Purchased credit-impaired	28,768		30,628
Total	354,362		360,249
Construction and development
Allowance for loan losses
Beginning balance	194	187
Charge-offs	0	0
Recoveries	27	0
Provision for loan losses	(8)	27
Ending balance	213	214
Ending balance:
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	213		194
Purchased credit-impaired	0		0
Total	213	214
Ending balance:
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	28,706		28,436
Purchased credit-impaired	1,471		1,625
Total	30,177		30,061
Home equity
Allowance for loan losses
Beginning balance	546	476
Charge-offs	(135)	(188)
Recoveries	41	12
Provision for loan losses	254	203
Ending balance	706	503
Ending balance:
Individually evaluated for impairment	62		3
Collectively evaluated for impairment	448		456
Purchased credit-impaired	196		87
Total	706	503
Ending balance:
Individually evaluated for impairment	373		406
Collectively evaluated for impairment	270,560		271,928
Purchased credit-impaired	4,157		4,328
Total	275,090		276,662
Other consumer
Allowance for loan losses
Beginning balance	79	83
Charge-offs	(136)	(96)
Recoveries	33	7
Provision for loan losses	116	104
Ending balance	92	98
Ending balance:
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	86		79
Purchased credit-impaired	6		0
Total	92	98
Ending balance:
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	35,214		36,244
Purchased credit-impaired	557		630
Total	$ 35,771		$ 36,874