Loans and Allowance for Loan Losses, Part II (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 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
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	2,084,000		1,511,000
60-89 days Past Due	1,167,000		1,338,000
90 Days or More Past Due	274,000		582,000
Total Past Due	3,525,000		3,431,000
Current	988,206,000		979,373,000
Total Loans Receivable	991,731,000		982,804,000
Total Loans 90 days & Accruing	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	2,024,000		1,985,000
Unpaid Principal Balance	2,874,000		1,985,000
Specific Allowance	359,000		604,000
Loans without a specific allowance [Abstract]
Recorded Balance	3,461,000		4,484,000
Unpaid Principal Balance	4,152,000		6,173,000
Total Loans [Abstract]
Recorded Balance	5,485,000		6,469,000
Unpaid Principal Balance	7,026,000		8,158,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	5,523,000	8,483,000
Interest income recognized	5,000	1,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	5,116,000		6,121,000
Interest Lost on Nonaccrual Loans	37,000	56,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	3,145,000		3,200,000
Troubled Debt Restructuring, Allowance	359,000		431,000
Financing Receivable Modifications Performing Recorded Investment	369,000		348,000
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number	2	3
Financing Receivables, Modifications during Period, Balance	207,000	82,000
Subsequent Default, Number of Days Past Due	90 days
Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	956,125,000		944,340,000
Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	21,885,000		22,574,000
Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	13,721,000		15,890,000
Doubtful
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0
Construction and land development
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	0		0
60-89 days Past Due	0		0
90 Days or More Past Due	0		0
Total Past Due	0		0
Current	28,260,000		25,321,000
Total Loans Receivable	28,260,000		25,321,000
Total Loans 90 days & Accruing	0		0
Loans with a specific allowance [Abstract]
Recorded Balance	1,440,000		614,000
Unpaid Principal Balance	2,290,000		614,000
Specific Allowance	145,000		76,000
Loans without a specific allowance [Abstract]
Recorded Balance	0		869,000
Unpaid Principal Balance	0		1,727,000
Total Loans [Abstract]
Recorded Balance	1,440,000		1,483,000
Unpaid Principal Balance	2,290,000		2,341,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	1,446,000	1,477,000
Interest income recognized	0	0
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	1,440,000		1,483,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	1,440,000		1,482,000
Construction and land development | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	26,820,000		23,839,000
Construction and land development | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0
Construction and land development | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	1,440,000		1,482,000
Construction and land development | Doubtful
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0
Agricultural real estate
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	685,000		299,000
60-89 days Past Due	0		0
90 Days or More Past Due	0		0
Total Past Due	685,000		299,000
Current	107,458,000		109,106,000
Total Loans Receivable	108,143,000		109,405,000
Total Loans 90 days & Accruing	0		0
Loans with a specific allowance [Abstract]
Recorded Balance	0		0
Unpaid Principal Balance	0		0
Specific Allowance	0		0
Loans without a specific allowance [Abstract]
Recorded Balance	101,000		105,000
Unpaid Principal Balance	108,000		113,000
Total Loans [Abstract]
Recorded Balance	101,000		105,000
Unpaid Principal Balance	108,000		113,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	101,000	519,000
Interest income recognized	0	0
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	101,000		105,000
Agricultural real estate | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	106,875,000		108,262,000
Agricultural real estate | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	231,000		231,000
Agricultural real estate | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	1,037,000		912,000
Agricultural real estate | Doubtful
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0
1-4 Family residential properties
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	453,000		326,000
60-89 days Past Due	125,000		146,000
90 Days or More Past Due	175,000		371,000
Total Past Due	753,000		843,000
Current	184,256,000		183,918,000
Total Loans Receivable	185,009,000		184,761,000
Total Loans 90 days & Accruing	0		0
Loans with a specific allowance [Abstract]
Recorded Balance	178,000		0
Unpaid Principal Balance	178,000		0
Specific Allowance	1,000		0
Loans without a specific allowance [Abstract]
Recorded Balance	900,000		1,110,000
Unpaid Principal Balance	1,231,000		1,558,000
Total Loans [Abstract]
Recorded Balance	1,078,000		1,110,000
Unpaid Principal Balance	1,409,000		1,558,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	1,083,000	1,817,000
Interest income recognized	2,000	1,000
Loans Receivable, Modifications, Still Accruing Interest	307,000	79,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	771,000		1,009,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	501,000		306,000
Financing Receivable Modifications Performing Recorded Investment	307,000		101,000
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number	2	2
Financing Receivables, Modifications during Period, Balance	207,000	73,000
1-4 Family residential properties | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	182,913,000		182,593,000
1-4 Family residential properties | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	628,000		637,000
1-4 Family residential properties | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	1,468,000		1,531,000
1-4 Family residential properties | Doubtful
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0
Multifamily residential properties
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	0		0
60-89 days Past Due	0		0
90 Days or More Past Due	0		0
Total Past Due	0		0
Current	49,986,000		50,174,000
Total Loans Receivable	49,986,000		50,174,000
Total Loans 90 days & Accruing	0		0
Loans with a specific allowance [Abstract]
Recorded Balance	0		0
Unpaid Principal Balance	0		0
Specific Allowance	0		0
Loans without a specific allowance [Abstract]
Recorded Balance	0		0
Unpaid Principal Balance	0		0
Total Loans [Abstract]
Recorded Balance	0		0
Unpaid Principal Balance	0		0
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	0	0
Interest income recognized	0	0
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	0		0
Multifamily residential properties | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	49,986,000		50,174,000
Multifamily residential properties | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0
Multifamily residential properties | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0
Multifamily residential properties | Doubtful
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0
Commercial real estate
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	647,000		568,000
60-89 days Past Due	1,013,000		1,030,000
90 Days or More Past Due	0		145,000
Total Past Due	1,660,000		1,743,000
Current	357,134,000		355,256,000
Total Loans Receivable	358,794,000		356,999,000
Total Loans 90 days & Accruing	0		0
Loans with a specific allowance [Abstract]
Recorded Balance	316,000		1,096,000
Unpaid Principal Balance	316,000		1,096,000
Specific Allowance	122,000		301,000
Loans without a specific allowance [Abstract]
Recorded Balance	1,859,000		1,750,000
Unpaid Principal Balance	1,886,000		1,778,000
Total Loans [Abstract]
Recorded Balance	2,175,000		2,846,000
Unpaid Principal Balance	2,202,000		2,874,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	2,185,000	2,435,000
Interest income recognized	1,000	0
Loans Receivable, Modifications, Still Accruing Interest	39,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	2,136,000		2,807,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	883,000		899,000
Financing Receivable Modifications Performing Recorded Investment	39,000		39,000
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number	0	0
Financing Receivables, Modifications during Period, Balance	0	0
Commercial real estate | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	338,229,000		335,284,000
Commercial real estate | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	17,815,000		17,998,000
Commercial real estate | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	2,750,000		3,717,000
Commercial real estate | Doubtful
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0
Agricultural loans
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	97,000		122,000
60-89 days Past Due	0		49,000
90 Days or More Past Due	0		0
Total Past Due	97,000		171,000
Current	50,161,000		63,957,000
Total Loans Receivable	50,258,000		64,128,000
Total Loans 90 days & Accruing	0		0
Loans with a specific allowance [Abstract]
Recorded Balance	0		0
Unpaid Principal Balance	0		0
Specific Allowance	0		0
Loans without a specific allowance [Abstract]
Recorded Balance	0		0
Unpaid Principal Balance	0		0
Total Loans [Abstract]
Recorded Balance	0		0
Unpaid Principal Balance	0		0
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	0	798,000
Interest income recognized	0	0
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	0		0
Agricultural loans | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	48,743,000		62,439,000
Agricultural loans | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		193,000
Agricultural loans | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	1,515,000		1,496,000
Agricultural loans | Doubtful
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0
Commercial and industrial loans
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	144,000		113,000
60-89 days Past Due	21,000		88,000
90 Days or More Past Due	96,000		62,000
Total Past Due	261,000		263,000
Current	187,675,000		168,090,000
Total Loans Receivable	187,936,000		168,353,000
Total Loans 90 days & Accruing	0		0
Loans with a specific allowance [Abstract]
Recorded Balance	90,000		275,000
Unpaid Principal Balance	90,000		275,000
Specific Allowance	91,000		227,000
Loans without a specific allowance [Abstract]
Recorded Balance	569,000		613,000
Unpaid Principal Balance	885,000		946,000
Total Loans [Abstract]
Recorded Balance	659,000		888,000
Unpaid Principal Balance	975,000		1,221,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	674,000	1,366,000
Interest income recognized	2,000	0
Loans Receivable, Modifications, Still Accruing Interest		9,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	659,000		706,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	298,000		487,000
Financing Receivable Modifications Performing Recorded Investment	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	9,000
Commercial and industrial loans | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	179,234,000		158,107,000
Commercial and industrial loans | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	3,211,000		3,515,000
Commercial and industrial loans | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	5,491,000		6,731,000
Commercial and industrial loans | Doubtful
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0
Consumer loans
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	58,000		83,000
60-89 days Past Due	8,000		25,000
90 Days or More Past Due	3,000		4,000
Total Past Due	69,000		112,000
Current	14,250,000		14,467,000
Total Loans Receivable	14,319,000		14,579,000
Total Loans 90 days & Accruing	0		0
Loans with a specific allowance [Abstract]
Recorded Balance	0		0
Unpaid Principal Balance	0		0
Specific Allowance	0		0
Loans without a specific allowance [Abstract]
Recorded Balance	32,000		37,000
Unpaid Principal Balance	42,000		51,000
Total Loans [Abstract]
Recorded Balance	32,000		37,000
Unpaid Principal Balance	42,000		51,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	34,000	71,000
Interest income recognized	0	0
Loans Receivable, Modifications, Still Accruing Interest	23,000	13,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	9,000		11,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	23,000		26,000
Financing Receivable Modifications Performing Recorded Investment	23,000		26,000
Consumer loans | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	14,299,000		14,558,000
Consumer loans | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0
Consumer loans | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	20,000		21,000
Consumer loans | Doubtful
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0
All other loans
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	0		0
60-89 days Past Due	0		0
90 Days or More Past Due	0		0
Total Past Due	0		0
Current	9,026,000		9,084,000
Total Loans Receivable	9,026,000		9,084,000
Total Loans 90 days & Accruing	0		0
Loans with a specific allowance [Abstract]
Recorded Balance	0		0
Unpaid Principal Balance	0		0
Specific Allowance	0		0
Loans without a specific allowance [Abstract]
Recorded Balance	0		0
Unpaid Principal Balance	0		0
Total Loans [Abstract]
Recorded Balance	0		0
Unpaid Principal Balance	0		0
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	0	0
Interest income recognized	0	0
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	0		0
All other loans | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	9,026,000		9,084,000
All other loans | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0
All other loans | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0
All other loans | Doubtful
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0
Loans secured by real estate
Loans Receivable Aging Analysis [Abstract]
30-59 days Past Due	1,785,000		1,193,000
60-89 days Past Due	1,138,000		1,176,000
90 Days or More Past Due	175,000		516,000
Total Past Due	3,098,000		2,885,000
Current	727,094,000		723,775,000
Total Loans Receivable	730,192,000		726,660,000
Total Loans 90 days & Accruing	0		0
Loans with a specific allowance [Abstract]
Recorded Balance	1,934,000		1,710,000
Unpaid Principal Balance	2,784,000		1,710,000
Specific Allowance	268,000		377,000
Loans without a specific allowance [Abstract]
Recorded Balance	2,860,000		3,834,000
Unpaid Principal Balance	3,225,000		5,176,000
Total Loans [Abstract]
Recorded Balance	4,794,000		5,544,000
Unpaid Principal Balance	6,009,000		6,886,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	4,815,000	6,248,000
Interest income recognized	3,000	1,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	4,448,000		5,404,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	2,824,000		2,687,000
Financing Receivable Modifications Performing Recorded Investment	346,000		140,000
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number	2	2
Financing Receivables, Modifications during Period, Balance	$ 207,000	$ 73,000