LOANS AND ALLOWANCE FOR LOAN LOSSES - Risk Categories of Loans by Class of Loans - (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Risk category of loans
Loans	$ 2,548,803	$ 2,155,392
Pass
Risk category of loans
Loans	1,343,105	1,181,671
Special Mention
Risk category of loans
Loans	18,088	19,019
Substandard
Risk category of loans
Loans	22,239	7,157
Substandard Commercial
Risk category of loans
Loans	1,323	1,117
Non-accrual
Risk category of loans
Loans	6,315	4,787
Performing
Risk category of loans
Loans	176,626	157,628
Watch
Risk category of loans
Loans	129	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	$ 474,165	445,664
Commercial | Maximum
Risk category of loans
Loans classified by delinquency	250
Commercial | Commercial and industrial
Risk category of loans
Loans	407,519	380,960
Commercial | Commercial and industrial | Pass
Risk category of loans
Loans	361,795	338,436
Commercial | Commercial and industrial | Special Mention
Risk category of loans
Loans	1,625	8,324
Commercial | Commercial and industrial | Substandard
Risk category of loans
Loans	5,076	636
Commercial | Commercial and industrial | Substandard Commercial
Risk category of loans
Loans	79	99
Commercial | Commercial and industrial | Non-accrual
Risk category of loans
Loans	546	555
Commercial | Commercial and industrial | Performing
Risk category of loans
Loans	38,397	32,910
Commercial | Agricultural
Risk category of loans
Loans	66,646	64,704
Commercial | Agricultural | Pass
Risk category of loans
Loans	55,416	58,253
Commercial | Agricultural | Special Mention
Risk category of loans
Loans	2,306
Commercial | Agricultural | Substandard
Risk category of loans
Loans		7
Commercial | Agricultural | Substandard Commercial
Risk category of loans
Loans	108
Commercial | Agricultural | Non-accrual
Risk category of loans
Loans	1,450
Commercial | Agricultural | Performing
Risk category of loans
Loans	7,366	6,444
Commercial Real Estate
Risk category of loans
Loans	1,093,659	925,884
Commercial Real Estate | Maximum
Risk category of loans
Loans classified by delinquency	250
Commercial Real Estate | Farm
Risk category of loans
Loans	110,843	97,916
Commercial Real Estate | Farm | Pass
Risk category of loans
Loans	87,892	75,924
Commercial Real Estate | Farm | Special Mention
Risk category of loans
Loans	1,997	328
Commercial Real Estate | Farm | Substandard
Risk category of loans
Loans	721	713
Commercial Real Estate | Farm | Non-accrual
Risk category of loans
Loans	1,363	308
Commercial Real Estate | Farm | Performing
Risk category of loans
Loans	18,870	20,643
Commercial Real Estate | Hotel
Risk category of loans
Loans	87,720	72,193
Commercial Real Estate | Hotel | Pass
Risk category of loans
Loans	84,756	72,193
Commercial Real Estate | Hotel | Substandard
Risk category of loans
Loans	2,964
Commercial Real Estate | Construction and development
Risk category of loans
Loans	82,550	77,394
Commercial Real Estate | Construction and development | Pass
Risk category of loans
Loans	56,211	60,246
Commercial Real Estate | Construction and development | Special Mention
Risk category of loans
Loans	911
Commercial Real Estate | Construction and development | Substandard
Risk category of loans
Loans	5,022	2,499
Commercial Real Estate | Construction and development | Substandard Commercial
Risk category of loans
Loans	27	31
Commercial Real Estate | Construction and development | Non-accrual
Risk category of loans
Loans	97	113
Commercial Real Estate | Construction and development | Performing
Risk category of loans
Loans	20,283	14,438
Commercial Real Estate | Construction and development | Watch
Risk category of loans
Loans		67
Commercial Real Estate | Other
Risk category of loans
Loans	812,546	678,381
Commercial Real Estate | Other | Pass
Risk category of loans
Loans	697,035	576,619
Commercial Real Estate | Other | Special Mention
Risk category of loans
Loans	11,249	10,367
Commercial Real Estate | Other | Substandard
Risk category of loans
Loans	8,456	3,309
Commercial Real Estate | Other | Substandard Commercial
Risk category of loans
Loans	1,109	980
Commercial Real Estate | Other | Non-accrual
Risk category of loans
Loans	2,859	3,811
Commercial Real Estate | Other | Performing
Risk category of loans
Loans	91,710	83,193
Commercial Real Estate | Other | Watch
Risk category of loans
Loans	129	102
Residential
Risk category of loans
Loans	919,640	727,073
Residential | Substandard
Risk category of loans
Loans	4,480	3,904
Residential | Performing
Risk category of loans
Loans	912,952	720,819
Residential | Watch
Risk category of loans
Loans	2,208	2,350
Residential | 1-4 family
Risk category of loans
Loans	632,522	438,808
Residential | 1-4 family | Substandard
Risk category of loans
Loans	3,678	2,771
Residential | 1-4 family | Performing
Risk category of loans
Loans	626,972	434,133
Residential | 1-4 family | Watch
Risk category of loans
Loans	1,872	1,904
Residential | Home equity
Risk category of loans
Loans	287,118	288,265
Residential | Home equity | Substandard
Risk category of loans
Loans	802	1,133
Residential | Home equity | Performing
Risk category of loans
Loans	285,980	286,686
Residential | Home equity | Watch
Risk category of loans
Loans	336	446
Consumer
Risk category of loans
Loans	61,339	56,771
Consumer | Substandard
Risk category of loans
Loans	13	101
Consumer | Performing
Risk category of loans
Loans	61,248	56,638
Consumer | Loss
Risk category of loans
Loans	78	32
Consumer | Direct
Risk category of loans
Loans	60,948	56,312
Consumer | Direct | Substandard
Risk category of loans
Loans	13	101
Consumer | Direct | Performing
Risk category of loans
Loans	60,857	56,179
Consumer | Direct | Loss
Risk category of loans
Loans	78	32
Consumer | Indirect
Risk category of loans
Loans	391	459
Consumer | Indirect | Performing
Risk category of loans
Loans	$ 391	$ 459