LOANS AND ALLOWANCE FOR LOAN LOSSES - Risk Categories of Loans by Class of Loans - (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Risk category of loans
Loans	$ 2,584,907	$ 2,155,392
Pass
Risk category of loans
Loans	1,397,432	1,181,671
Special Mention
Risk category of loans
Loans	20,050	19,019
Substandard
Risk category of loans
Loans	19,805	7,157
Substandard Commercial
Risk category of loans
Loans	1,038	1,117
Non-accrual
Risk category of loans
Loans	5,757	4,787
Performing
Risk category of loans
Loans	171,772	157,628
Watch
Risk category of loans
Loans	501	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	$ 490,359	445,664
Commercial | Maximum
Risk category of loans
Loans classified by delinquency	250
Commercial | Commercial and industrial
Risk category of loans
Loans	422,614	380,960
Commercial | Commercial and industrial | Pass
Risk category of loans
Loans	376,585	338,436
Commercial | Commercial and industrial | Special Mention
Risk category of loans
Loans	2,526	8,324
Commercial | Commercial and industrial | Substandard
Risk category of loans
Loans	5,845	636
Commercial | Commercial and industrial | Substandard Commercial
Risk category of loans
Loans	62	99
Commercial | Commercial and industrial | Non-accrual
Risk category of loans
Loans	507	555
Commercial | Commercial and industrial | Performing
Risk category of loans
Loans	37,072	32,910
Commercial | Commercial and industrial | Watch
Risk category of loans
Loans	17
Commercial | Agricultural
Risk category of loans
Loans	67,745	64,704
Commercial | Agricultural | Pass
Risk category of loans
Loans	55,797	58,253
Commercial | Agricultural | Special Mention
Risk category of loans
Loans	2,461
Commercial | Agricultural | Substandard
Risk category of loans
Loans		7
Commercial | Agricultural | Substandard Commercial
Risk category of loans
Loans	98
Commercial | Agricultural | Non-accrual
Risk category of loans
Loans	1,450
Commercial | Agricultural | Performing
Risk category of loans
Loans	7,929	6,444
Commercial | Agricultural | Watch
Risk category of loans
Loans	10
Commercial Real Estate
Risk category of loans
Loans	1,125,996	925,884
Commercial Real Estate | Maximum
Risk category of loans
Loans classified by delinquency	250
Commercial Real Estate | Farm
Risk category of loans
Loans	109,507	97,916
Commercial Real Estate | Farm | Pass
Risk category of loans
Loans	86,685	75,924
Commercial Real Estate | Farm | Special Mention
Risk category of loans
Loans	2,238	328
Commercial Real Estate | Farm | Substandard
Risk category of loans
Loans	696	713
Commercial Real Estate | Farm | Non-accrual
Risk category of loans
Loans	1,352	308
Commercial Real Estate | Farm | Performing
Risk category of loans
Loans	18,536	20,643
Commercial Real Estate | Hotel
Risk category of loans
Loans	90,929	72,193
Commercial Real Estate | Hotel | Pass
Risk category of loans
Loans	87,883	72,193
Commercial Real Estate | Hotel | Substandard
Risk category of loans
Loans	2,983
Commercial Real Estate | Construction and development
Risk category of loans
Loans	87,722	77,394
Commercial Real Estate | Construction and development | Pass
Risk category of loans
Loans	61,333	60,246
Commercial Real Estate | Construction and development | Special Mention
Risk category of loans
Loans	3,596
Commercial Real Estate | Construction and development | Substandard
Risk category of loans
Loans	2,344	2,499
Commercial Real Estate | Construction and development | Substandard Commercial
Risk category of loans
Loans	13	31
Commercial Real Estate | Construction and development | Non-accrual
Risk category of loans
Loans	31	113
Commercial Real Estate | Construction and development | Performing
Risk category of loans
Loans	20,391	14,438
Commercial Real Estate | Construction and development | Watch
Risk category of loans
Loans	14	67
Commercial Real Estate | Other
Risk category of loans
Loans	837,838	678,381
Commercial Real Estate | Other | Pass
Risk category of loans
Loans	729,149	576,619
Commercial Real Estate | Other | Special Mention
Risk category of loans
Loans	9,229	10,367
Commercial Real Estate | Other | Substandard
Risk category of loans
Loans	7,937	3,309
Commercial Real Estate | Other | Substandard Commercial
Risk category of loans
Loans	802	980
Commercial Real Estate | Other | Non-accrual
Risk category of loans
Loans	2,417	3,811
Commercial Real Estate | Other | Performing
Risk category of loans
Loans	87,844	83,193
Commercial Real Estate | Other | Watch
Risk category of loans
Loans	460	102
Residential
Risk category of loans
Loans	907,525	727,073
Residential | Substandard
Risk category of loans
Loans	4,801	3,904
Residential | Performing
Risk category of loans
Loans	900,752	720,819
Residential | Watch
Risk category of loans
Loans	1,972	2,350
Residential | 1-4 family
Risk category of loans
Loans	621,259	438,808
Residential | 1-4 family | Substandard
Risk category of loans
Loans	4,039	2,771
Residential | 1-4 family | Performing
Risk category of loans
Loans	615,454	434,133
Residential | 1-4 family | Watch
Risk category of loans
Loans	1,766	1,904
Residential | Home equity
Risk category of loans
Loans	286,266	288,265
Residential | Home equity | Substandard
Risk category of loans
Loans	762	1,133
Residential | Home equity | Performing
Risk category of loans
Loans	285,298	286,686
Residential | Home equity | Watch
Risk category of loans
Loans	206	446
Consumer
Risk category of loans
Loans	61,027	56,771
Consumer | Substandard
Risk category of loans
Loans	20	101
Consumer | Performing
Risk category of loans
Loans	60,940	56,638
Consumer | Loss
Risk category of loans
Loans	67	32
Consumer | Direct
Risk category of loans
Loans	60,675	56,312
Consumer | Direct | Substandard
Risk category of loans
Loans	20	101
Consumer | Direct | Performing
Risk category of loans
Loans	60,588	56,179
Consumer | Direct | Loss
Risk category of loans
Loans	67	32
Consumer | Indirect
Risk category of loans
Loans	352	459
Consumer | Indirect | Performing
Risk category of loans
Loans	$ 352	$ 459