ALLOWANCE FOR LOAN LOSSES (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Dec. 31, 2011
Allowance for loan losses:
Beginning Balance	$ 17,299	$ 20,865	$ 20,865
Charge-offs	(1,587)	(2,832)	(12,015)
Recoveries	687	198	1,099
Provision	1,500	2,250	7,350
Ending balance	17,899	20,481	17,299
Ending balance individually evaluated for impairment	7,689	8,737	7,338
Ending balance collectively evaluated for impairment	10,210	11,744	9,961
Ending balance	17,899	20,481	17,299
Loans:
Ending balance individually evaluated for impairment	65,812	69,771	67,249
Ending balance collectively evaluated for impairment	548,946	596,882	560,000
Ending balance	614,758	666,653	627,249
Agriculture and Agricultural Real Estate [Member]
Allowance for loan losses:
Beginning Balance	76	64	64
Charge-offs	0	0	(97)
Recoveries	0	0	0
Provision	(6)	5	109
Ending balance	70	69	76
Ending balance individually evaluated for impairment	0	69	0	69
Ending balance collectively evaluated for impairment	70	0	76	0
Ending balance	70	69	76
Loans:
Ending balance individually evaluated for impairment	420	1,051	409	1,051
Ending balance collectively evaluated for impairment	11,815	14,042	11,595	14,042
Ending balance	12,235	15,093	12,004	58,983
Commercial [Member]
Allowance for loan losses:
Beginning Balance	2,224	2,184	2,184
Charge-offs	(202)	(96)	(499)
Recoveries	236	66	347
Provision	(105)	586	192
Ending balance	2,153	2,740	2,224
Ending balance individually evaluated for impairment	1,330	1,477	1,316
Ending balance collectively evaluated for impairment	823	1,263	908
Ending balance	2,153	2,740	2,224
Loans:
Ending balance individually evaluated for impairment	4,193	3,975	4,519
Ending balance collectively evaluated for impairment	56,873	60,632	53,675
Ending balance	61,066	64,607	58,194
Commercial Real Estate [Member]
Allowance for loan losses:
Beginning Balance	7,551	9,351	9,351
Charge-offs	(813)	(1,573)	(8,156)
Recoveries	64	9	80
Provision	1,106	1,519	6,276
Ending balance	7,908	9,306	7,551
Ending balance individually evaluated for impairment	2,312	3,408	2,084
Ending balance collectively evaluated for impairment	5,596	5,898	5,467
Ending balance	7,908	9,306	7,551
Loans:
Ending balance individually evaluated for impairment	35,960	36,492	36,471
Ending balance collectively evaluated for impairment	238,580	265,417	246,543
Ending balance	274,540	293,270	283,014
Construction Real Estate [Member]
Allowance for loan losses:
Beginning Balance	2,401	2,632	2,632
Charge-offs	(18)	(462)	(1,036)
Recoveries	274	37	240
Provision	(188)	113	565
Ending balance	2,469	2,320	2,401
Ending balance individually evaluated for impairment	1,863	1,257	1,820
Ending balance collectively evaluated for impairment	606	1,063	581
Ending balance	2,469	2,320	2,401
Loans:
Ending balance individually evaluated for impairment	6,225	8,449	7,410
Ending balance collectively evaluated for impairment	10,853	13,492	11,009
Ending balance	17,078	18,499	18,419
Residential Real Estate [Member]
Allowance for loan losses:
Beginning Balance	4,715	6,227	6,227
Charge-offs	(433)	(654)	(2,031)
Recoveries	80	50	274
Provision	746	7	245
Ending balance	5,108	5,630	4,715
Ending balance individually evaluated for impairment	2,084	2,453	1,994
Ending balance collectively evaluated for impairment	3,024	3,177	2,721
Ending balance	5,108	5,630	4,715
Loans:
Ending balance individually evaluated for impairment	18,668	19,568	18,051
Ending balance collectively evaluated for impairment	216,655	230,415	222,281
Ending balance	235,323	248,155	240,332
Consumer and Other [Member]
Allowance for loan losses:
Beginning Balance	332	407	407
Charge-offs	(121)	(47)	(196)
Recoveries	33	36	158
Provision	(53)	20	(37)
Ending balance	191	416	332
Ending balance individually evaluated for impairment	100	73	124
Ending balance collectively evaluated for impairment	91	343	208
Ending balance	191	416	332
Loans:
Ending balance individually evaluated for impairment	346	236	389
Ending balance collectively evaluated for impairment	14,170	12,884	14,897
Ending balance	$ 14,516	$ 16,060	$ 15,286