Loans and Allowance for Loan Losses (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2014 alternative	Mar. 31, 2013	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for Loan and Lease Losses	$ 323,000	$ 480,000	$ 2,193,000
Gross loans	990,651,000		982,710,000
Less [Abstract]
Net deferred loan fees, premiums and discounts	348,000		420,000
Allowance for loan losses	13,603,000	11,984,000	13,249,000
Net loans	976,700,000		969,041,000
Loans held for sale	1,428,000		514,000
Impaired Loans [Abstract]
Minimum value of loans individually measured for impairment	100,000
Number of alternatives for measuring impaired loans receivable	3
Adversely Classified Loans [Abstract]
Minimum balance of adversely classified loan in which a detailed analysis is performed	100,000
Non-classified and Watch Loans [Abstract]
Time period used a a base for loss estimations	five-year
Allowance for Loan Losses [Abstract]
Balance, beginning of period	13,249,000	11,776,000	11,776,000
Losses charged off	(80,000)	(382,000)	(1,128,000)
Recoveries	111,000	110,000	408,000
Balance, end of period	13,603,000	11,984,000	13,249,000
Ending Balance [Abstract]
Individually evaluated for impairment	359,000	578,000	604,000
Collectively evaluated for impairment	13,244,000	11,406,000	12,645,000
Loans [Abstract]
Ending balance	991,731,000	902,965,000	982,804,000
Ending Balance [Abstract]
Individually evaluated for impairment	4,357,000	6,983,000	5,145,000
Collectively evaluated for impairment	987,374,000	895,982,000	977,659,000
Construction and land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	28,260,000		25,321,000
Agricultural real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	108,112,000		109,376,000
1-4 Family residential properties
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	183,495,000		184,158,000
Ending Balance [Abstract]
Period When Loans are Charged-down	180 days
Multifamily residential properties
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	49,986,000		50,174,000
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	359,467,000		357,726,000
Loans Receivable Additional Information [Abstract]
Debt coverage ratio	1.20x
Amortization period of loans	twenty years
Commercial real estate | Minimum [Member]
Loans Receivable Additional Information [Abstract]
Maximum Loan-to-value Ratio (in hundredths)	65.00%
Commercial real estate | Maximum [Member]
Loans Receivable Additional Information [Abstract]
Maximum Loan-to-value Ratio (in hundredths)	80.00%
Loans secured by real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	729,320,000		726,755,000
Agricultural loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	50,181,000		64,055,000
Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	187,796,000		168,227,000
Loans Receivable Additional Information [Abstract]
Maximum Loan-to-value Ratio (in hundredths)	80.00%
Amortization period of loans	seven years
Loans Receivable, Time Period	one year
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for Loan and Lease Losses	9,000	29,000	57,000
Gross loans	14,319,000		14,579,000
Less [Abstract]
Allowance for loan losses	372,000	422,000	377,000
Allowance for Loan Losses [Abstract]
Balance, beginning of period	377,000	403,000	403,000
Losses charged off	(45,000)	(46,000)	(223,000)
Recoveries	31,000	36,000	140,000
Balance, end of period	372,000	422,000	377,000
Ending Balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	372,000	422,000	377,000
Loans [Abstract]
Ending balance	14,500,000	15,539,000	14,967,000
Ending Balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	14,500,000	15,539,000	14,967,000
All other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	9,035,000		9,094,000
Agricultural and Farm Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	158,400,000		173,400,000
Less [Abstract]
Decrease in loans receivable	(15,000,000)
Loans Receivable Additional Information [Abstract]
Maximum Loan-to-value Ratio (in hundredths)	65.00%
Amortization period of loans	twenty five years
Loans Receivable, Time Period	one year
Other Grain Farming [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	133,400,000		147,100,000
Less [Abstract]
Decrease in loans receivable	(13,700,000)
Motels and Hotels Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	50,900,000
Non-residential Buildings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	97,200,000
Residential Buildings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	60,800,000
Unsecured Open-end Loans [Member]
Ending Balance [Abstract]
Period When Loans are Charged-down	180 days
Other Secured Loans [Member]
Ending Balance [Abstract]
Period When Loans are Charged-down	120 days
Commercial/ Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for Loan and Lease Losses	(125,000)	244,000	1,861,000
Less [Abstract]
Allowance for loan losses	10,581,000	9,341,000	10,646,000
Allowance for Loan Losses [Abstract]
Balance, beginning of period	10,646,000	9,301,000	9,301,000
Losses charged off	(4,000)	(269,000)	(764,000)
Recoveries	64,000	65,000	248,000
Balance, end of period	10,581,000	9,341,000	10,646,000
Ending Balance [Abstract]
Individually evaluated for impairment	359,000	569,000	604,000
Collectively evaluated for impairment	10,222,000	8,772,000	10,042,000
Loans [Abstract]
Ending balance	631,172,000	561,523,000	607,062,000
Ending Balance [Abstract]
Individually evaluated for impairment	4,357,000	5,873,000	5,145,000
Collectively evaluated for impairment	626,815,000	555,650,000	601,917,000
Agricultural/ Agricultural Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for Loan and Lease Losses	(31,000)	(142,000)	(30,000)
Less [Abstract]
Allowance for loan losses	503,000	417,000	533,000
Allowance for Loan Losses [Abstract]
Balance, beginning of period	533,000	558,000	558,000
Losses charged off	0	0	0
Recoveries	1,000	1,000	5,000
Balance, end of period	503,000	417,000	533,000
Ending Balance [Abstract]
Individually evaluated for impairment	0	9,000	0
Collectively evaluated for impairment	503,000	408,000	533,000
Loans [Abstract]
Ending balance	158,052,000	138,252,000	172,979,000
Ending Balance [Abstract]
Individually evaluated for impairment	0	1,110,000	0
Collectively evaluated for impairment	158,052,000	137,142,000	172,979,000
Residential Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for Loan and Lease Losses	5,000	52,000	171,000
Less [Abstract]
Allowance for loan losses	760,000	719,000	771,000
Loans Receivable Additional Information [Abstract]
Maximum Loan-to-value Ratio (in hundredths)	80.00%
Amortization period of loans	twenty five years
Balloon period	five years
Allowance for Loan Losses [Abstract]
Balance, beginning of period	771,000	726,000	726,000
Losses charged off	(31,000)	(67,000)	(141,000)
Recoveries	15,000	8,000	15,000
Balance, end of period	760,000	719,000	771,000
Ending Balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	760,000	719,000	771,000
Loans [Abstract]
Ending balance	188,007,000	187,651,000	187,796,000
Ending Balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	188,007,000	187,651,000	187,796,000
Unallocated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for Loan and Lease Losses	465,000	297,000	134,000
Less [Abstract]
Allowance for loan losses	1,387,000	1,085,000	922,000
Allowance for Loan Losses [Abstract]
Balance, beginning of period	922,000	788,000	788,000
Losses charged off	0	0	0
Recoveries	0	0	0
Balance, end of period	1,387,000	1,085,000	922,000
Ending Balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	1,387,000	1,085,000	922,000
Loans [Abstract]
Ending balance	0	0	0
Ending Balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	$ 0	$ 0	$ 0