Loans and Allowance for Loan Losses, Part II (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Minimum Balance Of Loans For Which Credit Quality Analysis Is Performed	$ 100,000		$ 100,000
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	2,473,000		2,473,000		1,511,000
60-89 days Past Due	746,000		746,000		1,338,000
90 Days or More Past Due	319,000		319,000		582,000
Total Past Due	3,538,000		3,538,000		3,431,000
Current	1,018,713,000		1,018,713,000		979,373,000
Total Loans Receivable	1,022,251,000		1,022,251,000		982,804,000
Total Loans 90 days & Accruing	0		0		0
Number of days past due when interest is not accrued			ninety days
Period of satisfactory performance before returning to accrual status			not less than six months
Loans with a specific allowance [Abstract]
Recorded Balance	1,549,000		1,549,000		1,985,000
Unpaid Principal Balance	2,400,000		2,400,000		1,985,000
Specific Allowance	322,000		322,000		604,000
Loans without a specific allowance [Abstract]
Recorded Balance	3,283,000		3,283,000		4,484,000
Unpaid Principal Balance	4,005,000		4,005,000		6,173,000
Total Loans [Abstract]
Recorded Balance	4,832,000		4,832,000		6,469,000
Unpaid Principal Balance	6,405,000		6,405,000		8,158,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	5,142,000	6,993,000	5,196,000	7,259,000
Interest income recognized	5,000	2,000	8,000	3,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	4,468,000		4,468,000		6,121,000
Interest Lost on Nonaccrual Loans			32,000	72,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	3,009,000		3,009,000		3,200,000
Troubled Debt Restructuring, Allowance	265,000		265,000		431,000
Financing Receivable Modifications Performing Recorded Investment	364,000		364,000		348,000
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number			3	5
Financing Receivables, Modifications during Period, Balance			708,000	162,000
Subsequent Default, Number of Days Past Due			90 days
Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	989,773,000		989,773,000		944,340,000
Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	20,189,000		20,189,000		22,574,000
Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	12,289,000		12,289,000		15,890,000
Doubtful
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0		0
Construction and land development
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	371,000		371,000		0
60-89 days Past Due	0		0		0
90 Days or More Past Due	0		0		0
Total Past Due	371,000		371,000		0
Current	18,574,000		18,574,000		25,321,000
Total Loans Receivable	18,945,000		18,945,000		25,321,000
Total Loans 90 days & Accruing	0		0		0
Loans with a specific allowance [Abstract]
Recorded Balance	844,000		844,000		614,000
Unpaid Principal Balance	1,695,000		1,695,000		614,000
Specific Allowance	60,000		60,000		76,000
Loans without a specific allowance [Abstract]
Recorded Balance	0		0		869,000
Unpaid Principal Balance	0		0		1,727,000
Total Loans [Abstract]
Recorded Balance	844,000		844,000		1,483,000
Unpaid Principal Balance	1,695,000		1,695,000		2,341,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	1,112,000	1,425,000	1,126,000	1,445,000
Interest income recognized	0	0	0	0
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	844,000		844,000		1,483,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	844,000		844,000		1,482,000
Construction and land development | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	18,101,000		18,101,000		23,839,000
Construction and land development | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0		0
Construction and land development | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	844,000		844,000		1,482,000
Construction and land development | Doubtful
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0		0
Agricultural real estate
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	32,000		32,000		299,000
60-89 days Past Due	122,000		122,000		0
90 Days or More Past Due	0		0		0
Total Past Due	154,000		154,000		299,000
Current	109,456,000		109,456,000		109,106,000
Total Loans Receivable	109,610,000		109,610,000		109,405,000
Total Loans 90 days & Accruing	0		0		0
Loans with a specific allowance [Abstract]
Recorded Balance	0		0		0
Unpaid Principal Balance	0		0		0
Specific Allowance	0		0		0
Loans without a specific allowance [Abstract]
Recorded Balance	36,000		36,000		105,000
Unpaid Principal Balance	43,000		43,000		113,000
Total Loans [Abstract]
Recorded Balance	36,000		36,000		105,000
Unpaid Principal Balance	43,000		43,000		113,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	36,000	216,000	36,000	217,000
Interest income recognized	0	0	0	0
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	36,000		36,000		105,000
Agricultural real estate | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	107,840,000		107,840,000		108,262,000
Agricultural real estate | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	294,000		294,000		231,000
Agricultural real estate | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	1,476,000		1,476,000		912,000
Agricultural real estate | Doubtful
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0		0
1-4 Family residential properties
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	650,000		650,000		326,000
60-89 days Past Due	97,000		97,000		146,000
90 Days or More Past Due	236,000		236,000		371,000
Total Past Due	983,000		983,000		843,000
Current	181,812,000		181,812,000		183,918,000
Total Loans Receivable	182,795,000		182,795,000		184,761,000
Total Loans 90 days & Accruing	0		0		0
Loans with a specific allowance [Abstract]
Recorded Balance	178,000		178,000		0
Unpaid Principal Balance	178,000		178,000		0
Specific Allowance	1,000		1,000		0
Loans without a specific allowance [Abstract]
Recorded Balance	873,000		873,000		1,110,000
Unpaid Principal Balance	1,241,000		1,241,000		1,558,000
Total Loans [Abstract]
Recorded Balance	1,051,000		1,051,000		1,110,000
Unpaid Principal Balance	1,419,000		1,419,000		1,558,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	1,058,000	1,283,000	1,067,000	1,414,000
Interest income recognized	4,000	1,000	6,000	2,000
Loans Receivable, Modifications, Still Accruing Interest	305,000	103,000	305,000	103,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	746,000		746,000		1,009,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	489,000		489,000		306,000
Financing Receivable Modifications Performing Recorded Investment	305,000		305,000		101,000
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number			2	3
Financing Receivables, Modifications during Period, Balance			207,000	98,000
1-4 Family residential properties | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	180,594,000		180,594,000		182,593,000
1-4 Family residential properties | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	718,000		718,000		637,000
1-4 Family residential properties | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	1,483,000		1,483,000		1,531,000
1-4 Family residential properties | Doubtful
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0		0
Multifamily residential properties
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	289,000		289,000		0
60-89 days Past Due	0		0		0
90 Days or More Past Due	0		0		0
Total Past Due	289,000		289,000		0
Current	53,006,000		53,006,000		50,174,000
Total Loans Receivable	53,295,000		53,295,000		50,174,000
Total Loans 90 days & Accruing	0		0		0
Loans with a specific allowance [Abstract]
Recorded Balance	0		0		0
Unpaid Principal Balance	0		0		0
Specific Allowance	0		0		0
Loans without a specific allowance [Abstract]
Recorded Balance	0		0		0
Unpaid Principal Balance	0		0		0
Total Loans [Abstract]
Recorded Balance	0		0		0
Unpaid Principal Balance	0		0		0
Multifamily residential properties | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	53,295,000		53,295,000		50,174,000
Multifamily residential properties | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0		0
Multifamily residential properties | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0		0
Multifamily residential properties | Doubtful
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0		0
Commercial real estate
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	598,000		598,000		568,000
60-89 days Past Due	465,000		465,000		1,030,000
90 Days or More Past Due	0		0		145,000
Total Past Due	1,063,000		1,063,000		1,743,000
Current	377,568,000		377,568,000		355,256,000
Total Loans Receivable	378,631,000		378,631,000		356,999,000
Total Loans 90 days & Accruing	0		0		0
Loans with a specific allowance [Abstract]
Recorded Balance	439,000		439,000		1,096,000
Unpaid Principal Balance	439,000		439,000		1,096,000
Specific Allowance	172,000		172,000		301,000
Loans without a specific allowance [Abstract]
Recorded Balance	1,842,000		1,842,000		1,750,000
Unpaid Principal Balance	1,868,000		1,868,000		1,778,000
Total Loans [Abstract]
Recorded Balance	2,281,000		2,281,000		2,846,000
Unpaid Principal Balance	2,307,000		2,307,000		2,874,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	2,293,000	2,353,000	2,303,000	2,389,000
Interest income recognized	1,000	0	1,000	0
Loans Receivable, Modifications, Still Accruing Interest	39,000		39,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	2,242,000		2,242,000		2,807,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	1,364,000		1,364,000		899,000
Financing Receivable Modifications Performing Recorded Investment	39,000		39,000		39,000
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number			1	0
Financing Receivables, Modifications during Period, Balance			501,000	0
Commercial real estate | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	359,723,000		359,723,000		335,284,000
Commercial real estate | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	16,095,000		16,095,000		17,998,000
Commercial real estate | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	2,813,000		2,813,000		3,717,000
Commercial real estate | Doubtful
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0		0
Agricultural loans
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	181,000		181,000		122,000
60-89 days Past Due	8,000		8,000		49,000
90 Days or More Past Due	0		0		0
Total Past Due	189,000		189,000		171,000
Current	55,471,000		55,471,000		63,957,000
Total Loans Receivable	55,660,000		55,660,000		64,128,000
Total Loans 90 days & Accruing	0		0		0
Loans with a specific allowance [Abstract]
Recorded Balance	0		0		0
Unpaid Principal Balance	0		0		0
Specific Allowance	0		0		0
Loans without a specific allowance [Abstract]
Recorded Balance	0		0		0
Unpaid Principal Balance	0		0		0
Total Loans [Abstract]
Recorded Balance	0		0		0
Unpaid Principal Balance	0		0		0
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	0	229,000	0	253,000
Interest income recognized	0	0	0	0
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	0		0		0
Agricultural loans | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	54,539,000		54,539,000		62,439,000
Agricultural loans | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0		193,000
Agricultural loans | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	1,121,000		1,121,000		1,496,000
Agricultural loans | Doubtful
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0		0
Commercial and industrial loans
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	259,000		259,000		113,000
60-89 days Past Due	5,000		5,000		88,000
90 Days or More Past Due	75,000		75,000		62,000
Total Past Due	339,000		339,000		263,000
Current	199,880,000		199,880,000		168,090,000
Total Loans Receivable	200,219,000		200,219,000		168,353,000
Total Loans 90 days & Accruing	0		0		0
Loans with a specific allowance [Abstract]
Recorded Balance	88,000		88,000		275,000
Unpaid Principal Balance	88,000		88,000		275,000
Specific Allowance	89,000		89,000		227,000
Loans without a specific allowance [Abstract]
Recorded Balance	499,000		499,000		613,000
Unpaid Principal Balance	810,000		810,000		946,000
Total Loans [Abstract]
Recorded Balance	587,000		587,000		888,000
Unpaid Principal Balance	898,000		898,000		1,221,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	608,000	1,430,000	627,000	1,482,000
Interest income recognized	0	0	0	0
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	587,000		587,000		706,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	292,000		292,000		487,000
Financing Receivable Modifications Performing Recorded Investment	0		0		182,000
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number			0	1
Financing Receivables, Modifications during Period, Balance			0	56,000
Commercial and industrial loans | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	192,603,000		192,603,000		158,107,000
Commercial and industrial loans | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	3,071,000		3,071,000		3,515,000
Commercial and industrial loans | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	4,545,000		4,545,000		6,731,000
Commercial and industrial loans | Doubtful
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0		0
Consumer loans
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	93,000		93,000		83,000
60-89 days Past Due	49,000		49,000		25,000
90 Days or More Past Due	8,000		8,000		4,000
Total Past Due	150,000		150,000		112,000
Current	13,902,000		13,902,000		14,467,000
Total Loans Receivable	14,052,000		14,052,000		14,579,000
Total Loans 90 days & Accruing	0		0		0
Loans with a specific allowance [Abstract]
Recorded Balance	0		0		0
Unpaid Principal Balance	0		0		0
Specific Allowance	0		0		0
Loans without a specific allowance [Abstract]
Recorded Balance	33,000		33,000		37,000
Unpaid Principal Balance	43,000		43,000		51,000
Total Loans [Abstract]
Recorded Balance	33,000		33,000		37,000
Unpaid Principal Balance	43,000		43,000		51,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	35,000	57,000	37,000	59,000
Interest income recognized	0	1,000	1,000	1,000
Loans Receivable, Modifications, Still Accruing Interest	20,000	22,000	20,000	22,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	13,000		13,000		11,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	20,000		20,000		26,000
Financing Receivable Modifications Performing Recorded Investment	20,000		20,000		26,000
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number			0	1
Financing Receivables, Modifications during Period, Balance			0	8,000
Consumer loans | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	14,034,000		14,034,000		14,558,000
Consumer loans | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	11,000		11,000		0
Consumer loans | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	7,000		7,000		21,000
Consumer loans | Doubtful
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0		0
All other loans
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	0		0		0
60-89 days Past Due	0		0		0
90 Days or More Past Due	0		0		0
Total Past Due	0		0		0
Current	9,044,000		9,044,000		9,084,000
Total Loans Receivable	9,044,000		9,044,000		9,084,000
Total Loans 90 days & Accruing	0		0		0
Loans with a specific allowance [Abstract]
Recorded Balance	0		0		0
Unpaid Principal Balance	0		0		0
Specific Allowance	0		0		0
Loans without a specific allowance [Abstract]
Recorded Balance	0		0		0
Unpaid Principal Balance	0		0		0
Total Loans [Abstract]
Recorded Balance	0		0		0
Unpaid Principal Balance	0		0		0
All other loans | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	9,044,000		9,044,000		9,084,000
All other loans | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0		0
All other loans | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0		0
All other loans | Doubtful
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0		0
Loans secured by real estate
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	1,940,000		1,940,000		1,193,000
60-89 days Past Due	684,000		684,000		1,176,000
90 Days or More Past Due	236,000		236,000		516,000
Total Past Due	2,860,000		2,860,000		2,885,000
Current	740,416,000		740,416,000		723,775,000
Total Loans Receivable	743,276,000		743,276,000		726,660,000
Total Loans 90 days & Accruing	0		0		0
Loans with a specific allowance [Abstract]
Recorded Balance	1,461,000		1,461,000		1,710,000
Unpaid Principal Balance	2,312,000		2,312,000		1,710,000
Specific Allowance	233,000		233,000		377,000
Loans without a specific allowance [Abstract]
Recorded Balance	2,751,000		2,751,000		3,834,000
Unpaid Principal Balance	3,152,000		3,152,000		5,176,000
Total Loans [Abstract]
Recorded Balance	4,212,000		4,212,000		5,544,000
Unpaid Principal Balance	5,464,000		5,464,000		6,886,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	4,499,000	5,277,000	4,532,000	5,465,000
Interest income recognized	5,000	1,000	7,000	2,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	3,868,000		3,868,000		5,404,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	2,697,000		2,697,000		2,687,000
Financing Receivable Modifications Performing Recorded Investment	344,000		344,000		140,000
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number			3	3
Financing Receivables, Modifications during Period, Balance			$ 708,000	$ 98,000