Loans and Allowance for Loan Losses (Details) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 alternative	Jun. 30, 2013	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for Loan and Lease Losses	$ 128,000	$ 252,000	$ 451,000	$ 732,000	$ 2,193,000
Gross loans	1,021,599,000		1,021,599,000		982,710,000
Less [Abstract]
Net deferred loan fees, premiums and discounts	277,000		277,000		420,000
Allowance for loan losses	13,681,000	12,131,000	13,681,000	12,131,000	13,249,000
Net loans	1,007,641,000		1,007,641,000		969,041,000
Loans held for sale	929,000		929,000		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	13,603,000	11,984,000	13,249,000	11,776,000	11,776,000
Losses charged off	(102,000)	(168,000)	(182,000)	(550,000)	(1,128,000)
Recoveries	52,000	63,000	163,000	173,000	408,000
Balance, end of period	13,681,000	12,131,000	13,681,000	12,131,000	13,249,000
Ending Balance [Abstract]
Individually evaluated for impairment	322,000	439,000	322,000	439,000	604,000
Collectively evaluated for impairment	13,359,000	11,692,000	13,359,000	11,692,000	12,645,000
Loans [Abstract]
Ending balance	1,022,251,000	915,813,000	1,022,251,000	915,813,000	982,804,000
Ending Balance [Abstract]
Individually evaluated for impairment	3,648,000	5,544,000	3,648,000	5,544,000	5,145,000
Collectively evaluated for impairment	1,018,603,000	910,269,000	1,018,603,000	910,269,000	977,659,000
Construction and land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	18,945,000		18,945,000		25,321,000
Agricultural real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	109,577,000		109,577,000		109,376,000
1-4 Family residential properties
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	181,778,000		181,778,000		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	53,295,000		53,295,000		50,174,000
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	379,245,000		379,245,000		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	742,840,000		742,840,000		726,755,000
Agricultural loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	55,578,000		55,578,000		64,055,000
Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	200,077,000		200,077,000		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	27,000	(15,000)	36,000	14,000	57,000
Gross loans	14,052,000		14,052,000		14,579,000
Less [Abstract]
Allowance for loan losses	368,000	397,000	368,000	397,000	377,000
Allowance for Loan Losses [Abstract]
Balance, beginning of period	372,000	422,000	377,000	403,000	403,000
Losses charged off	(60,000)	(51,000)	(105,000)	(97,000)	(223,000)
Recoveries	29,000	41,000	60,000	77,000	140,000
Balance, end of period	368,000	397,000	368,000	397,000	377,000
Ending Balance [Abstract]
Individually evaluated for impairment	0	0	0	0	0
Collectively evaluated for impairment	368,000	397,000	368,000	397,000	377,000
Loans [Abstract]
Ending balance	14,304,000	15,814,000	14,304,000	15,814,000	14,967,000
Ending Balance [Abstract]
Individually evaluated for impairment	0	0	0	0	0
Collectively evaluated for impairment	14,304,000	15,814,000	14,304,000	15,814,000	14,967,000
All other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	9,052,000		9,052,000		9,094,000
Agricultural and Farm Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	165,200,000		165,200,000		173,400,000
Less [Abstract]
Decrease in loans receivable			(8,200,000)
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	136,600,000		136,600,000		147,100,000
Less [Abstract]
Decrease in loans receivable			(10,500,000)
Motels and Hotels Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	51,200,000		51,200,000
Non-residential Buildings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	104,900,000		104,900,000
Residential Buildings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	64,000,000		64,000,000
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	200,000	40,000	75,000	284,000	1,861,000
Less [Abstract]
Allowance for loan losses	10,771,000	9,304,000	10,771,000	9,304,000	10,646,000
Allowance for Loan Losses [Abstract]
Balance, beginning of period	10,581,000	9,341,000	10,646,000	9,301,000	9,301,000
Losses charged off	(28,000)	(98,000)	(32,000)	(367,000)	(764,000)
Recoveries	18,000	21,000	82,000	86,000	248,000
Balance, end of period	10,771,000	9,304,000	10,771,000	9,304,000	10,646,000
Ending Balance [Abstract]
Individually evaluated for impairment	322,000	439,000	322,000	439,000	604,000
Collectively evaluated for impairment	10,449,000	8,865,000	10,449,000	8,865,000	10,042,000
Loans [Abstract]
Ending balance	657,352,000	564,526,000	657,352,000	564,526,000	607,062,000
Ending Balance [Abstract]
Individually evaluated for impairment	3,648,000	5,232,000	3,648,000	5,232,000	5,145,000
Collectively evaluated for impairment	653,704,000	559,294,000	653,704,000	559,294,000	601,917,000
Agricultural/ Agricultural Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for Loan and Lease Losses	21,000	(3,000)	(10,000)	(145,000)	(30,000)
Less [Abstract]
Allowance for loan losses	524,000	414,000	524,000	414,000	533,000
Allowance for Loan Losses [Abstract]
Balance, beginning of period	503,000	417,000	533,000	558,000	558,000
Losses charged off	0	0	0	0	0
Recoveries	0	0	1,000	1,000	5,000
Balance, end of period	524,000	414,000	524,000	414,000	533,000
Ending Balance [Abstract]
Individually evaluated for impairment	0	0	0	0	0
Collectively evaluated for impairment	524,000	414,000	524,000	414,000	533,000
Loans [Abstract]
Ending balance	164,841,000	147,218,000	164,841,000	147,218,000	172,979,000
Ending Balance [Abstract]
Individually evaluated for impairment	0	312,000	0	312,000	0
Collectively evaluated for impairment	164,841,000	146,906,000	164,841,000	146,906,000	172,979,000
Residential Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for Loan and Lease Losses	6,000	92,000	11,000	144,000	171,000
Less [Abstract]
Allowance for loan losses	757,000	793,000	757,000	793,000	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	760,000	719,000	771,000	726,000	726,000
Losses charged off	(14,000)	(19,000)	(45,000)	(86,000)	(141,000)
Recoveries	5,000	1,000	20,000	9,000	15,000
Balance, end of period	757,000	793,000	757,000	793,000	771,000
Ending Balance [Abstract]
Individually evaluated for impairment	0	0	0	0	0
Collectively evaluated for impairment	757,000	793,000	757,000	793,000	771,000
Loans [Abstract]
Ending balance	185,754,000	188,255,000	185,754,000	188,255,000	187,796,000
Ending Balance [Abstract]
Individually evaluated for impairment	0	0	0	0	0
Collectively evaluated for impairment	185,754,000	188,255,000	185,754,000	188,255,000	187,796,000
Unallocated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for Loan and Lease Losses	(126,000)	138,000	339,000	435,000	134,000
Less [Abstract]
Allowance for loan losses	1,261,000	1,223,000	1,261,000	1,223,000	922,000
Allowance for Loan Losses [Abstract]
Balance, beginning of period	1,387,000	1,085,000	922,000	788,000	788,000
Losses charged off	0	0	0	0	0
Recoveries	0	0	0	0	0
Balance, end of period	1,261,000	1,223,000	1,261,000	1,223,000	922,000
Ending Balance [Abstract]
Individually evaluated for impairment	0	0	0	0	0
Collectively evaluated for impairment	1,261,000	1,223,000	1,261,000	1,223,000	922,000
Loans [Abstract]
Ending balance	0	0	0	0	0
Ending Balance [Abstract]
Individually evaluated for impairment	0	0	0	0	0
Collectively evaluated for impairment	$ 0	$ 0	$ 0	$ 0	$ 0