LOANS AND ALLOWANCE FOR LOAN LOSSES - Risk Categories of Loans by Class of Loans - (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Risk category of loans
Loans	$ 2,651,673	$ 2,155,392
Pass
Risk category of loans
Loans	1,481,038	1,181,671
Special Mention
Risk category of loans
Loans	20,526	19,019
Substandard
Risk category of loans
Loans	18,626	7,157
Substandard Commercial
Risk category of loans
Loans	1,421	1,117
Non-accrual
Risk category of loans
Loans	5,844	4,787
Performing
Risk category of loans
Loans	169,710	157,628
Watch
Risk category of loans
Loans	$ 90	169
Minimum | Substandard
Risk category of loans
Period of loans past due	90 days
Minimum | Non-accrual
Risk category of loans
Period for which principal and interest has been in default	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	$ 534,559	445,664
Commercial | Commercial and industrial
Risk category of loans
Loans	461,092	380,960
Commercial | Commercial and industrial | Pass
Risk category of loans
Loans	415,064	338,436
Commercial | Commercial and industrial | Special Mention
Risk category of loans
Loans	3,347	8,324
Commercial | Commercial and industrial | Substandard
Risk category of loans
Loans	5,297	636
Commercial | Commercial and industrial | Substandard Commercial
Risk category of loans
Loans	55	99
Commercial | Commercial and industrial | Non-accrual
Risk category of loans
Loans	827	555
Commercial | Commercial and industrial | Performing
Risk category of loans
Loans	36,502	32,910
Commercial | Agricultural
Risk category of loans
Loans	73,467	64,704
Commercial | Agricultural | Pass
Risk category of loans
Loans	61,637	58,253
Commercial | Agricultural | Special Mention
Risk category of loans
Loans	2,283
Commercial | Agricultural | Substandard Commercial
Risk category of loans
Loans	190	7
Commercial | Agricultural | Non-accrual
Risk category of loans
Loans	1,441
Commercial | Agricultural | Performing
Risk category of loans
Loans	7,916	6,444
Commercial Real Estate
Risk category of loans
Loans	1,162,696	925,884
Commercial Real Estate | Farm
Risk category of loans
Loans	111,807	97,916
Commercial Real Estate | Farm | Pass
Risk category of loans
Loans	89,297	75,924
Commercial Real Estate | Farm | Special Mention
Risk category of loans
Loans	2,209	328
Commercial Real Estate | Farm | Substandard
Risk category of loans
Loans	694	713
Commercial Real Estate | Farm | Substandard Commercial
Risk category of loans
Loans	7
Commercial Real Estate | Farm | Non-accrual
Risk category of loans
Loans	1,340	308
Commercial Real Estate | Farm | Performing
Risk category of loans
Loans	18,260	20,643
Commercial Real Estate | Hotel
Risk category of loans
Loans	91,213	72,193
Commercial Real Estate | Hotel | Pass
Risk category of loans
Loans	88,166	72,193
Commercial Real Estate | Hotel | Substandard
Risk category of loans
Loans	2,983
Commercial Real Estate | Hotel | Non-accrual
Risk category of loans
Loans	64
Commercial Real Estate | Construction and development
Risk category of loans
Loans	102,598	77,394
Commercial Real Estate | Construction and development | Pass
Risk category of loans
Loans	74,811	60,246
Commercial Real Estate | Construction and development | Special Mention
Risk category of loans
Loans	3,600
Commercial Real Estate | Construction and development | Substandard
Risk category of loans
Loans	2,287	2,499
Commercial Real Estate | Construction and development | Substandard Commercial
Risk category of loans
Loans	91	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	21,778	14,438
Commercial Real Estate | Construction and development | Watch
Risk category of loans
Loans		67
Commercial Real Estate | Other
Risk category of loans
Loans	857,078	678,381
Commercial Real Estate | Other | Pass
Risk category of loans
Loans	752,063	576,619
Commercial Real Estate | Other | Special Mention
Risk category of loans
Loans	9,087	10,367
Commercial Real Estate | Other | Substandard
Risk category of loans
Loans	7,365	3,309
Commercial Real Estate | Other | Substandard Commercial
Risk category of loans
Loans	1,078	980
Commercial Real Estate | Other | Non-accrual
Risk category of loans
Loans	2,141	3,811
Commercial Real Estate | Other | Performing
Risk category of loans
Loans	85,254	83,193
Commercial Real Estate | Other | Watch
Risk category of loans
Loans	90	102
Residential
Risk category of loans
Loans	892,513	727,073
Residential | Substandard
Risk category of loans
Loans	4,176	3,904
Residential | Performing
Risk category of loans
Loans	886,198	720,819
Residential | Watch
Risk category of loans
Loans	2,139	2,350
Residential | 1-4 family
Risk category of loans
Loans	608,366	438,808
Residential | 1-4 family | Substandard
Risk category of loans
Loans	3,262	2,771
Residential | 1-4 family | Performing
Risk category of loans
Loans	603,102	434,133
Residential | 1-4 family | Watch
Risk category of loans
Loans	2,002	1,904
Residential | Home equity
Risk category of loans
Loans	284,147	288,265
Residential | Home equity | Substandard
Risk category of loans
Loans	914	1,133
Residential | Home equity | Performing
Risk category of loans
Loans	283,096	286,686
Residential | Home equity | Watch
Risk category of loans
Loans	137	446
Consumer
Risk category of loans
Loans	61,905	56,771
Consumer | Substandard
Risk category of loans
Loans	4	101
Consumer | Performing
Risk category of loans
Loans	61,839	56,638
Consumer | Loss
Risk category of loans
Loans	62	32
Consumer | Direct
Risk category of loans
Loans	61,574	56,312
Consumer | Direct | Substandard
Risk category of loans
Loans	4	101
Consumer | Direct | Performing
Risk category of loans
Loans	61,508	56,179
Consumer | Direct | Loss
Risk category of loans
Loans	62	32
Consumer | Indirect
Risk category of loans
Loans	331	459
Consumer | Indirect | Performing
Risk category of loans
Loans	$ 331	$ 459