Loans and Allowance for Loan Losses, Part II (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
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	1,144,000		1,144,000		$ 1,133,000
60-89 days Past Due	355,000		355,000		321,000
90 Days or More Past Due	727,000		727,000		1,433,000
Total Past Due	2,226,000		2,226,000		2,887,000
Current	1,056,877,000		1,056,877,000		1,059,519,000
Total Loans Receivable	1,059,103,000		1,059,103,000		1,062,406,000
Total Loans 90 days & Accruing	0		$ 0		0
Number of days past due when interest is not accrued
Period of satisfactory performance before returning to accrual status
Loans with a specific allowance [Abstract]
Recorded Balance	1,766,000		$ 1,766,000		1,407,000
Unpaid Principal Balance	2,537,000		2,537,000		4,261,000
Specific Allowance	537,000		537,000		263,000
Loans without a specific allowance [Abstract]
Recorded Balance	1,303,000		1,303,000		3,133,000
Unpaid Principal Balance	1,814,000		1,814,000		7,902,000
Total Loans [Abstract]
Recorded Balance	3,069,000		3,069,000		4,540,000
Unpaid Principal Balance	4,351,000		4,351,000		12,163,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	3,097,000	$ 5,142,000	3,137,000	$ 5,196,000
Interest income recognized	6,000	5,000	10,000	8,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	2,468,000		2,468,000		4,105,000
Interest Lost on Nonaccrual Loans			39,000	$ 32,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	1,838,000		1,838,000		2,860,000
Troubled Debt Restructuring, Allowance	508,000		508,000		234,000
Financing Receivable Modifications Performing Recorded Investment	601,000		$ 601,000		435,000
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number			10	3
Financing Receivables, Modifications during Period, Balance			$ 768,000	$ 708,000
Subsequent Default, Number of Days Past Due
Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	1,022,453,000		$ 1,022,453,000		1,026,901,000
Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	29,415,000		29,415,000		25,696,000
Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	7,235,000		7,235,000		9,809,000
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	0		0		297,000
60-89 days Past Due	0		0		25,000
90 Days or More Past Due	0		0		0
Total Past Due	0		0		322,000
Current	27,420,000		27,420,000		21,305,000
Total Loans Receivable	27,420,000		27,420,000		21,627,000
Total Loans 90 days & Accruing	0		0		0
Loans with a specific allowance [Abstract]
Recorded Balance	154,000		154,000		785,000
Unpaid Principal Balance	719,000		719,000		2,960,000
Specific Allowance	26,000		26,000		43,000
Loans without a specific allowance [Abstract]
Recorded Balance	0		0		0
Unpaid Principal Balance	0		0		0
Total Loans [Abstract]
Recorded Balance	154,000		154,000		785,000
Unpaid Principal Balance	719,000		719,000		2,960,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	154,000	1,112,000	154,000	1,126,000
Interest income recognized	0	0	0	0
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	154,000		154,000		785,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	153,000		153,000		785,000
Construction and land development | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	27,266,000		27,266,000		20,842,000
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	154,000		154,000		785,000
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	147,000		147,000		0
60-89 days Past Due	0		0		0
90 Days or More Past Due	0		0		0
Total Past Due	147,000		147,000		0
Current	112,155,000		112,155,000		110,193,000
Total Loans Receivable	112,302,000		112,302,000		110,193,000
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	93,000		93,000		73,000
Unpaid Principal Balance	98,000		98,000		235,000
Total Loans [Abstract]
Recorded Balance	93,000		93,000		73,000
Unpaid Principal Balance	98,000		98,000		235,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	93,000	36,000	94,000	36,000
Interest income recognized	1,000	0	2,000	0
Loans Receivable, Modifications, Still Accruing Interest	67,000		67,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	26,000		26,000		29,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	67,000		67,000		44,000
Financing Receivable Modifications Performing Recorded Investment	67,000		$ 67,000		44,000
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number			1
Financing Receivables, Modifications during Period, Balance			$ 23,000
Agricultural real estate | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	109,463,000		109,463,000		107,976,000
Agricultural real estate | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	1,767,000		1,767,000		1,036,000
Agricultural real estate | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	1,072,000		1,072,000		1,181,000
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	398,000		398,000		201,000
60-89 days Past Due	176,000		176,000		224,000
90 Days or More Past Due	182,000		182,000		385,000
Total Past Due	756,000		756,000		810,000
Current	172,596,000		172,596,000		181,111,000
Total Loans Receivable	173,352,000		173,352,000		181,921,000
Total Loans 90 days & Accruing	0		0		0
Loans with a specific allowance [Abstract]
Recorded Balance	416,000		416,000		67,000
Unpaid Principal Balance	416,000		416,000		134,000
Specific Allowance	0		0		0
Loans without a specific allowance [Abstract]
Recorded Balance	734,000		734,000		1,156,000
Unpaid Principal Balance	1,073,000		1,073,000		2,866,000
Total Loans [Abstract]
Recorded Balance	1,150,000		1,150,000		1,223,000
Unpaid Principal Balance	1,489,000		1,489,000		3,000,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	1,163,000	1,058,000	1,188,000	1,067,000
Interest income recognized	2,000	4,000	3,000	6,000
Loans Receivable, Modifications, Still Accruing Interest	342,000	305,000	342,000	$ 305,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	808,000		808,000		878,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	481,000		481,000		503,000
Financing Receivable Modifications Performing Recorded Investment	342,000		$ 342,000		345,000
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number			4	2
Financing Receivables, Modifications during Period, Balance			$ 79,000	$ 207,000
1-4 Family residential properties | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	169,911,000		169,911,000		177,764,000
1-4 Family residential properties | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	925,000		925,000		1,187,000
1-4 Family residential properties | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	2,516,000		2,516,000		2,970,000
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	52,422,000		52,422,000		53,129,000
Total Loans Receivable	52,422,000		52,422,000		53,129,000
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	51,842,000		51,842,000		52,793,000
Multifamily residential properties | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	249,000		249,000		0
Multifamily residential properties | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	331,000		331,000		336,000
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	3,000		3,000		60,000
60-89 days Past Due	126,000		126,000		32,000
90 Days or More Past Due	395,000		395,000		945,000
Total Past Due	524,000		524,000		1,037,000
Current	371,228,000		371,228,000		378,567,000
Total Loans Receivable	371,752,000		371,752,000		379,604,000
Total Loans 90 days & Accruing	0		0		0
Loans with a specific allowance [Abstract]
Recorded Balance	536,000		536,000		472,000
Unpaid Principal Balance	607,000		607,000		986,000
Specific Allowance	29,000		29,000		136,000
Loans without a specific allowance [Abstract]
Recorded Balance	116,000		116,000		1,640,000
Unpaid Principal Balance	117,000		117,000		3,808,000
Total Loans [Abstract]
Recorded Balance	652,000		652,000		2,112,000
Unpaid Principal Balance	724,000		724,000		4,794,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	655,000	2,293,000	659,000	2,303,000
Interest income recognized	1,000	1,000	1,000	1,000
Loans Receivable, Modifications, Still Accruing Interest	36,000	39,000	36,000	$ 39,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	616,000		616,000		2,074,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	256,000		256,000		1,283,000
Financing Receivable Modifications Performing Recorded Investment	36,000		$ 36,000		37,000
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number			0	1
Financing Receivables, Modifications during Period, Balance			$ 0	$ 501,000
Commercial real estate | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	349,417,000		349,417,000		357,873,000
Commercial real estate | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	21,456,000		21,456,000		18,817,000
Commercial real estate | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	879,000		879,000		2,914,000
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	0		0		16,000
60-89 days Past Due	0		0		20,000
90 Days or More Past Due	0		0		0
Total Past Due	0		0		36,000
Current	59,719,000		59,719,000		68,262,000
Total Loans Receivable	59,719,000		59,719,000		68,298,000
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
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	0		0		0
Agricultural loans | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	58,798,000		58,798,000		67,619,000
Agricultural loans | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	228,000		228,000		0
Agricultural loans | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	693,000		693,000		679,000
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	559,000		559,000		228,000
60-89 days Past Due	35,000		35,000		10,000
90 Days or More Past Due	145,000		145,000		98,000
Total Past Due	739,000		739,000		336,000
Current	238,384,000		238,384,000		223,444,000
Total Loans Receivable	239,123,000		239,123,000		223,780,000
Total Loans 90 days & Accruing	0		0		0
Loans with a specific allowance [Abstract]
Recorded Balance	252,000		252,000		83,000
Unpaid Principal Balance	387,000		387,000		181,000
Specific Allowance	103,000		103,000		84,000
Loans without a specific allowance [Abstract]
Recorded Balance	321,000		321,000		249,000
Unpaid Principal Balance	478,000		478,000		933,000
Total Loans [Abstract]
Recorded Balance	573,000		573,000		332,000
Unpaid Principal Balance	865,000		865,000		1,114,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	584,000	608,000	594,000	627,000
Interest income recognized	1,000	0	3,000	$ 0
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	456,000		456,000		332,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	434,000		434,000		236,000
Financing Receivable Modifications Performing Recorded Investment	117,000		$ 117,000		0
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number			2	0
Financing Receivables, Modifications during Period, Balance			$ 227,000	$ 0
Commercial and industrial loans | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	233,151,000		233,151,000		218,193,000
Commercial and industrial loans | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	4,790,000		4,790,000		4,647,000
Commercial and industrial loans | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	1,182,000		1,182,000		940,000
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	37,000		37,000		331,000
60-89 days Past Due	18,000		18,000		10,000
90 Days or More Past Due	5,000		5,000		5,000
Total Past Due	60,000		60,000		346,000
Current	14,500,000		14,500,000		14,772,000
Total Loans Receivable	14,560,000		14,560,000		15,118,000
Total Loans 90 days & Accruing	0		0		0
Loans with a specific allowance [Abstract]
Recorded Balance	408,000		408,000		0
Unpaid Principal Balance	408,000		408,000		0
Specific Allowance	379,000		379,000		0
Loans without a specific allowance [Abstract]
Recorded Balance	39,000		39,000		15,000
Unpaid Principal Balance	48,000		48,000		60,000
Total Loans [Abstract]
Recorded Balance	447,000		447,000		15,000
Unpaid Principal Balance	456,000		456,000		60,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	448,000	35,000	448,000	37,000
Interest income recognized	1,000	0	1,000	1,000
Loans Receivable, Modifications, Still Accruing Interest	39,000	20,000	39,000	$ 20,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	408,000		408,000		7,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	447,000		447,000		9,000
Financing Receivable Modifications Performing Recorded Investment	39,000		$ 39,000		9,000
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number			3	0
Financing Receivables, Modifications during Period, Balance			$ 439,000	$ 0
Consumer loans | Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	14,152,000		14,152,000		15,105,000
Consumer loans | Watch
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	0		0		9,000
Consumer loans | Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	408,000		408,000		4,000
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	8,453,000		8,453,000		8,736,000
Total Loans Receivable	8,453,000		8,453,000		8,736,000
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	8,453,000		8,453,000		8,736,000
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	548,000		548,000		558,000
60-89 days Past Due	302,000		302,000		281,000
90 Days or More Past Due	577,000		577,000		1,330,000
Total Past Due	1,427,000		1,427,000		2,169,000
Current	735,821,000		735,821,000		744,305,000
Total Loans Receivable	737,248,000		737,248,000		746,474,000
Total Loans 90 days & Accruing	0		0		0
Loans with a specific allowance [Abstract]
Recorded Balance	1,106,000		1,106,000		1,324,000
Unpaid Principal Balance	1,742,000		1,742,000		4,080,000
Specific Allowance	55,000		55,000		179,000
Loans without a specific allowance [Abstract]
Recorded Balance	943,000		943,000		2,869,000
Unpaid Principal Balance	1,288,000		1,288,000		6,909,000
Total Loans [Abstract]
Recorded Balance	2,049,000		2,049,000		4,193,000
Unpaid Principal Balance	3,030,000		3,030,000		10,989,000
Average recorded investment and interest income recognized [Abstract]
Average investment in impaired loans	2,065,000	4,499,000	2,095,000	4,532,000
Interest income recognized	4,000	$ 5,000	6,000	$ 7,000
Balances of Nonaccrual Loans [Abstract]
Recorded balance of nonaccrual loans	1,604,000		1,604,000		3,766,000
Troubled Debt Restructuring [Abstract]
Troubled Debt Restructurings Balance	957,000		957,000		2,615,000
Financing Receivable Modifications Performing Recorded Investment	$ 445,000		$ 445,000		$ 426,000
Recorded Balance of Troubled Debt Restructurings [Abstract]
Financing Receivables, Modifications during Period, Number			5	3
Financing Receivables, Modifications during Period, Balance			$ 102,000	$ 708,000