LOANS AND ALLOWANCE FOR LOAN LOSSES - Risk Categories of Loans by Class of Loans - (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Risk category of loans
Loans	$ 2,159,997	$ 2,155,392
Pass
Risk category of loans
Loans	1,185,478	1,181,671
Special Mention
Risk category of loans
Loans	11,796	19,019
Substandard
Risk category of loans
Loans	15,116	7,157
Substandard Commercial
Risk category of loans
Loans		1,117
Non-accrual
Risk category of loans
Loans	3,482	4,787
Performing
Risk category of loans
Loans		157,628
Watch
Risk category of loans
Loans		169
Minimum
Risk category of loans
Credit relationships with an outstanding balance	$ 1,000
Minimum | Substandard
Risk category of loans
Period of loans past due	90 days
Minimum | Watch
Risk category of loans
Period of loans past due	60 days
Minimum | Loss
Risk category of loans
Period of loans past due	119 days
Maximum | Watch
Risk category of loans
Period of loans past due	89 days
Consumer loans not secured by 1-4 family residential real estate | Minimum | Substandard
Risk category of loans
Period of loans past due	60 days
Consumer loans not secured by 1-4 family residential real estate | Maximum | Substandard
Risk category of loans
Period of loans past due	119 days
Commercial
Risk category of loans
Loans	$ 440,437	445,664
Commercial | Maximum
Risk category of loans
Loans classified by delinquency	250
Commercial | Commercial and industrial
Risk category of loans
Loans	375,427	380,960
Commercial | Commercial and industrial | Pass
Risk category of loans
Loans	331,350	338,436
Commercial | Commercial and industrial | Special Mention
Risk category of loans
Loans	3,617	8,324
Commercial | Commercial and industrial | Substandard
Risk category of loans
Loans	6,550	636
Commercial | Commercial and industrial | Substandard Commercial
Risk category of loans
Loans	46	99
Commercial | Commercial and industrial | Non-accrual
Risk category of loans
Loans	579	555
Commercial | Commercial and industrial | Performing
Risk category of loans
Loans	33,272	32,910
Commercial | Commercial and industrial | Watch
Risk category of loans
Loans	13
Commercial | Agricultural
Risk category of loans
Loans	65,010	64,704
Commercial | Agricultural | Pass
Risk category of loans
Loans	58,598	58,253
Commercial | Agricultural | Substandard
Risk category of loans
Loans		7
Commercial | Agricultural | Substandard Commercial
Risk category of loans
Loans	7
Commercial | Agricultural | Performing
Risk category of loans
Loans	6,405	6,444
Commercial Real Estate
Risk category of loans
Loans	934,917	925,884
Commercial Real Estate | Substandard Commercial
Risk category of loans
Loans	1,054
Commercial Real Estate | Performing
Risk category of loans
Loans	158,284
Commercial Real Estate | Watch
Risk category of loans
Loans	144
Commercial Real Estate | Maximum
Risk category of loans
Loans classified by delinquency	250
Commercial Real Estate | Farm
Risk category of loans
Loans	106,825	97,916
Commercial Real Estate | Farm | Pass
Risk category of loans
Loans	86,009	75,924
Commercial Real Estate | Farm | Special Mention
Risk category of loans
Loans	241	328
Commercial Real Estate | Farm | Substandard
Risk category of loans
Loans	700	713
Commercial Real Estate | Farm | Non-accrual
Risk category of loans
Loans	295	308
Commercial Real Estate | Farm | Performing
Risk category of loans
Loans	19,574	20,643
Commercial Real Estate | Farm | Watch
Risk category of loans
Loans	6
Commercial Real Estate | Hotel
Risk category of loans
Loans	76,898	72,193
Commercial Real Estate | Hotel | Pass
Risk category of loans
Loans	76,607	72,193
Commercial Real Estate | Hotel | Substandard
Risk category of loans
Loans	291
Commercial Real Estate | Construction and development
Risk category of loans
Loans	58,076	77,394
Commercial Real Estate | Construction and development | Pass
Risk category of loans
Loans	40,003	60,246
Commercial Real Estate | Construction and development | Substandard
Risk category of loans
Loans	2,182	2,499
Commercial Real Estate | Construction and development | Substandard Commercial
Risk category of loans
Loans	30	31
Commercial Real Estate | Construction and development | Non-accrual
Risk category of loans
Loans	113	113
Commercial Real Estate | Construction and development | Performing
Risk category of loans
Loans	15,748	14,438
Commercial Real Estate | Construction and development | Watch
Risk category of loans
Loans		67
Commercial Real Estate | Other
Risk category of loans
Loans	693,118	678,381
Commercial Real Estate | Other | Pass
Risk category of loans
Loans	592,911	576,619
Commercial Real Estate | Other | Special Mention
Risk category of loans
Loans	7,938	10,367
Commercial Real Estate | Other | Substandard
Risk category of loans
Loans	5,393	3,309
Commercial Real Estate | Other | Substandard Commercial
Risk category of loans
Loans	971	980
Commercial Real Estate | Other | Non-accrual
Risk category of loans
Loans	2,495	3,811
Commercial Real Estate | Other | Performing
Risk category of loans
Loans	83,285	83,193
Commercial Real Estate | Other | Watch
Risk category of loans
Loans	125	102
Residential
Risk category of loans
Loans	726,426	727,073
Residential | Substandard
Risk category of loans
Loans	3,658	2,350
Residential | Performing
Risk category of loans
Loans	722,211	720,819
Residential | Watch
Risk category of loans
Loans	557
Residential | Loss
Risk category of loans
Loans		3,904
Residential | 1-4 family
Risk category of loans
Loans	441,446	438,808
Residential | 1-4 family | Substandard
Risk category of loans
Loans	2,564	1,904
Residential | 1-4 family | Performing
Risk category of loans
Loans	438,497	434,133
Residential | 1-4 family | Watch
Risk category of loans
Loans	385
Residential | 1-4 family | Loss
Risk category of loans
Loans		2,771
Residential | Home equity
Risk category of loans
Loans	284,980	288,265
Residential | Home equity | Substandard
Risk category of loans
Loans	1,094	446
Residential | Home equity | Performing
Risk category of loans
Loans	283,714	286,686
Residential | Home equity | Watch
Risk category of loans
Loans	172
Residential | Home equity | Loss
Risk category of loans
Loans		1,133
Consumer
Risk category of loans
Loans	58,217	56,771
Consumer | Substandard
Risk category of loans
Loans	30	101
Consumer | Performing
Risk category of loans
Loans	58,173	56,638
Consumer | Loss
Risk category of loans
Loans	14	32
Consumer | Direct
Risk category of loans
Loans	57,779	56,312
Consumer | Direct | Substandard
Risk category of loans
Loans	30	101
Consumer | Direct | Performing
Risk category of loans
Loans	57,737	56,179
Consumer | Direct | Loss
Risk category of loans
Loans	12	32
Consumer | Indirect
Risk category of loans
Loans	438	459
Consumer | Indirect | Performing
Risk category of loans
Loans	436	$ 459
Consumer | Indirect | Loss
Risk category of loans
Loans	$ 2