Loans and Allowance for Loan Losses, Part II (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 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	1,138,000		1,138,000		1,511,000
60-89 days Past Due	1,698,000		1,698,000		1,338,000
90 Days or More Past Due	350,000		350,000		582,000
Total Past Due	3,186,000		3,186,000		3,431,000
Current	1,037,822,000		1,037,822,000		979,373,000
Total Loans Receivable	1,041,008,000		1,041,008,000		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	1,606,000		1,606,000		1,985,000
Unpaid Principal Balance	2,457,000		2,457,000		1,985,000
Specific Allowance	307,000		307,000		604,000
Loans without a specific allowance [Abstract]
Recorded Balance	3,214,000		3,214,000		4,484,000
Unpaid Principal Balance	3,947,000		3,947,000		6,173,000
Total Loans [Abstract]
Recorded Balance	4,820,000		4,820,000		6,469,000
Unpaid Principal Balance	6,404,000		6,404,000		8,158,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	5,017,000	7,129,000	5,309,000	7,659,000
Interest income recognized	6,000	3,000	15,000	6,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	4,424,000		4,424,000		6,121,000
Interest Lost on Nonaccrual Loans			44,000	109,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	2,977,000		2,977,000		3,200,000
Troubled Debt Restructuring, Allowance	260,000		260,000		431,000
Financing Receivable Modifications Performing Recorded Investment	395,000		395,000		348,000
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number			4	9
Financing Receivables, Modifications during Period, Balance			749,000	603,000
Subsequent Default, Number of Days Past Due			90 days
Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	1,009,062,000		1,009,062,000		944,340,000
Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	22,469,000		22,469,000		22,574,000
Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	9,477,000		9,477,000		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	26,000		26,000		0
60-89 days Past Due	0		0		0
90 Days or More Past Due	0		0		0
Total Past Due	26,000		26,000		0
Current	23,087,000		23,087,000		25,321,000
Total Loans Receivable	23,113,000		23,113,000		25,321,000
Total Loans 90 days & Accruing	0		0		0
Loans with a specific allowance [Abstract]
Recorded Balance	817,000		817,000		614,000
Unpaid Principal Balance	1,668,000		1,668,000		614,000
Specific Allowance	52,000		52,000		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	817,000		817,000		1,483,000
Unpaid Principal Balance	1,668,000		1,668,000		2,341,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	817,000	1,753,000	1,004,000	1,775,000
Interest income recognized	0	0	0	0
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	817,000		817,000		1,483,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	817,000		817,000		1,482,000
Construction and land development | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	22,296,000		22,296,000		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	817,000		817,000		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	81,000		81,000		299,000
60-89 days Past Due	0		0		0
90 Days or More Past Due	0		0		0
Total Past Due	81,000		81,000		299,000
Current	109,647,000		109,647,000		109,106,000
Total Loans Receivable	109,728,000		109,728,000		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	34,000		34,000		105,000
Unpaid Principal Balance	41,000		41,000		113,000
Total Loans [Abstract]
Recorded Balance	34,000		34,000		105,000
Unpaid Principal Balance	41,000		41,000		113,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	34,000	238,000	35,000	238,000
Interest income recognized	0	0	0	0
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	34,000		34,000		105,000
Agricultural real estate | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	108,111,000		108,111,000		108,262,000
Agricultural real estate | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	431,000		431,000		231,000
Agricultural real estate | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	1,186,000		1,186,000		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	564,000		564,000		326,000
60-89 days Past Due	160,000		160,000		146,000
90 Days or More Past Due	212,000		212,000		371,000
Total Past Due	936,000		936,000		843,000
Current	184,438,000		184,438,000		183,918,000
Total Loans Receivable	185,374,000		185,374,000		184,761,000
Total Loans 90 days & Accruing	0		0		0
Loans with a specific allowance [Abstract]
Recorded Balance	171,000		171,000		0
Unpaid Principal Balance	171,000		171,000		0
Specific Allowance	14,000		14,000		0
Loans without a specific allowance [Abstract]
Recorded Balance	867,000		867,000		1,110,000
Unpaid Principal Balance	1,240,000		1,240,000		1,558,000
Total Loans [Abstract]
Recorded Balance	1,038,000		1,038,000		1,110,000
Unpaid Principal Balance	1,411,000		1,411,000		1,558,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	1,129,000	1,007,000	1,156,000	1,172,000
Interest income recognized	5,000	2,000	12,000	4,000
Loans Receivable, Modifications, Still Accruing Interest	345,000	102,000	345,000	102,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	693,000		693,000		1,009,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	511,000		511,000		306,000
Financing Receivable Modifications Performing Recorded Investment	345,000		345,000		101,000
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number			3	1
Financing Receivables, Modifications during Period, Balance			248,000	357,000
1-4 Family residential properties | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	181,577,000		181,577,000		182,593,000
1-4 Family residential properties | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	818,000		818,000		637,000
1-4 Family residential properties | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	2,979,000		2,979,000		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	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	53,186,000		53,186,000		50,174,000
Total Loans Receivable	53,186,000		53,186,000		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	53,186,000		53,186,000		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	0		0		568,000
60-89 days Past Due	1,285,000		1,285,000		1,030,000
90 Days or More Past Due	49,000		49,000		145,000
Total Past Due	1,334,000		1,334,000		1,743,000
Current	373,358,000		373,358,000		355,256,000
Total Loans Receivable	374,692,000		374,692,000		356,999,000
Total Loans 90 days & Accruing	0		0		0
Loans with a specific allowance [Abstract]
Recorded Balance	518,000		518,000		1,096,000
Unpaid Principal Balance	518,000		518,000		1,096,000
Specific Allowance	141,000		141,000		301,000
Loans without a specific allowance [Abstract]
Recorded Balance	1,770,000		1,770,000		1,750,000
Unpaid Principal Balance	1,794,000		1,794,000		1,778,000
Total Loans [Abstract]
Recorded Balance	2,288,000		2,288,000		2,846,000
Unpaid Principal Balance	2,312,000		2,312,000		2,874,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	2,349,000	2,939,000	2,379,000	2,985,000
Interest income recognized	1,000	0	2,000	0
Loans Receivable, Modifications, Still Accruing Interest	38,000		38,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	2,250,000		2,250,000		2,807,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	1,345,000		1,345,000		899,000
Financing Receivable Modifications Performing Recorded Investment	38,000		38,000		39,000
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number			1	4
Financing Receivables, Modifications during Period, Balance			501,000	176,000
Commercial real estate | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	355,902,000		355,902,000		335,284,000
Commercial real estate | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	15,877,000		15,877,000		17,998,000
Commercial real estate | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	2,913,000		2,913,000		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	328,000		328,000		122,000
60-89 days Past Due	184,000		184,000		49,000
90 Days or More Past Due	0		0		0
Total Past Due	512,000		512,000		171,000
Current	59,709,000		59,709,000		63,957,000
Total Loans Receivable	60,221,000		60,221,000		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	209,000	0	238,000
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	58,601,000		58,601,000		62,439,000
Agricultural loans | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	734,000		734,000		193,000
Agricultural loans | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	886,000		886,000		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	88,000		88,000		113,000
60-89 days Past Due	69,000		69,000		88,000
90 Days or More Past Due	72,000		72,000		62,000
Total Past Due	229,000		229,000		263,000
Current	211,135,000		211,135,000		168,090,000
Total Loans Receivable	211,364,000		211,364,000		168,353,000
Total Loans 90 days & Accruing	0		0		0
Loans with a specific allowance [Abstract]
Recorded Balance	100,000		100,000		275,000
Unpaid Principal Balance	100,000		100,000		275,000
Specific Allowance	100,000		100,000		227,000
Loans without a specific allowance [Abstract]
Recorded Balance	510,000		510,000		613,000
Unpaid Principal Balance	830,000		830,000		946,000
Total Loans [Abstract]
Recorded Balance	610,000		610,000		888,000
Unpaid Principal Balance	930,000		930,000		1,221,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	653,000	905,000	696,000	1,169,000
Interest income recognized	0	0	0	0
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	610,000		610,000		706,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	286,000		286,000		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	54,000
Commercial and industrial loans | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	206,074,000		206,074,000		158,107,000
Commercial and industrial loans | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	4,599,000		4,599,000		3,515,000
Commercial and industrial loans | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	691,000		691,000		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	51,000		51,000		83,000
60-89 days Past Due	0		0		25,000
90 Days or More Past Due	17,000		17,000		4,000
Total Past Due	68,000		68,000		112,000
Current	14,986,000		14,986,000		14,467,000
Total Loans Receivable	15,054,000		15,054,000		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	42,000		42,000		51,000
Total Loans [Abstract]
Recorded Balance	33,000		33,000		37,000
Unpaid Principal Balance	42,000		42,000		51,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	35,000	78,000	39,000	82,000
Interest income recognized	0	1,000	1,000	2,000
Loans Receivable, Modifications, Still Accruing Interest	12,000	29,000	12,000	29,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	20,000		20,000		11,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	18,000		18,000		26,000
Financing Receivable Modifications Performing Recorded Investment	12,000		12,000		26,000
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number			0	3
Financing Receivables, Modifications during Period, Balance			0	16,000
Consumer loans | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	15,039,000		15,039,000		14,558,000
Consumer loans | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	10,000		10,000		0
Consumer loans | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	5,000		5,000		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	8,276,000		8,276,000		9,084,000
Total Loans Receivable	8,276,000		8,276,000		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	8,276,000		8,276,000		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	671,000		671,000		1,193,000
60-89 days Past Due	1,445,000		1,445,000		1,176,000
90 Days or More Past Due	261,000		261,000		516,000
Total Past Due	2,377,000		2,377,000		2,885,000
Current	743,716,000		743,716,000		723,775,000
Total Loans Receivable	746,093,000		746,093,000		726,660,000
Total Loans 90 days & Accruing	0		0		0
Loans with a specific allowance [Abstract]
Recorded Balance	1,506,000		1,506,000		1,710,000
Unpaid Principal Balance	2,357,000		2,357,000		1,710,000
Specific Allowance	207,000		207,000		377,000
Loans without a specific allowance [Abstract]
Recorded Balance	2,671,000		2,671,000		3,834,000
Unpaid Principal Balance	3,075,000		3,075,000		5,176,000
Total Loans [Abstract]
Recorded Balance	4,177,000		4,177,000		5,544,000
Unpaid Principal Balance	5,432,000		5,432,000		6,886,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	4,329,000	5,937,000	4,574,000	6,170,000
Interest income recognized	6,000	2,000	14,000	4,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	3,794,000		3,794,000		5,404,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	2,673,000		2,673,000		2,687,000
Financing Receivable Modifications Performing Recorded Investment	383,000		383,000		140,000
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number			4	5
Financing Receivables, Modifications during Period, Balance			$ 749,000	$ 533,000