Credit Quality and Related Allowance for Loan Losses (Details 5) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013 component class	Jun. 30, 2012	Jun. 30, 2013 quarter component class	Jun. 30, 2012	Dec. 31, 2012
Credit Quality and Related Allowance for Loan Losses
Period considered for quarter moving average which is a factor to calculate historical charge-off			12
The total number of components that represents the allowance for loan losses	2		2
The number of classes that groups of loans are collectively evaluated for impairment	2		2
Changes in allowance
Balance at the beginning of the period	$ 8,830,000	$ 7,745,000	$ 7,617,000	$ 7,154,000
Charge-offs	(31,000)	(925,000)	(190,000)	(957,000)
Recoveries	30,000	18,000	902,000	41,000
Provision	575,000	600,000	1,075,000	1,200,000
Balance at the end of the period	9,404,000	7,438,000	9,404,000	7,438,000
Allowance for Loan Losses:
Individually evaluated for impairment	3,027,000		3,027,000		2,535,000
Collectively evaluated for impairment	6,377,000		6,377,000		5,082,000
Total ending allowance balance	9,404,000	7,438,000	9,404,000	7,438,000
Loans
Individually evaluated for impairment	11,623,000		11,623,000		16,970,000
Loans acquired with deteriorated credit quality	882,000		882,000
Collectively evaluated for impairment	775,417,000		775,417,000		496,384,000
Total	787,922,000		787,922,000		513,354,000
Commercial and Agricultural
Changes in allowance
Balance at the beginning of the period	568,000	396,000	361,000	418,000
Recoveries	11,000	5,000	13,000	6,000
Provision	(39,000)	(46,000)	166,000	(69,000)
Balance at the end of the period	540,000	355,000	540,000	355,000
Allowance for Loan Losses:
Individually evaluated for impairment	319,000		319,000		46,000
Collectively evaluated for impairment	221,000		221,000		315,000
Total ending allowance balance	540,000	355,000	540,000	355,000
Loans
Individually evaluated for impairment	556,000		556,000		485,000
Loans acquired with deteriorated credit quality	303,000		303,000
Collectively evaluated for impairment	118,094,000		118,094,000		47,970,000
Total	118,953,000		118,953,000		48,455,000
Residential Real Estate Mortgages
Changes in allowance
Balance at the beginning of the period	2,772,000	882,000	1,954,000	939,000
Charge-offs		(11,000)	(134,000)	(11,000)
Recoveries	4,000	1,000	5,000	3,000
Provision	269,000	88,000	1,220,000	29,000
Balance at the end of the period	3,045,000	960,000	3,045,000	960,000
Allowance for Loan Losses:
Individually evaluated for impairment	302,000		302,000		237,000
Collectively evaluated for impairment	2,743,000		2,743,000		1,717,000
Total ending allowance balance	3,045,000	960,000	3,045,000	960,000
Loans
Individually evaluated for impairment	1,558,000		1,558,000		1,556,000
Loans acquired with deteriorated credit quality	320,000		320,000
Collectively evaluated for impairment	339,098,000		339,098,000		250,586,000
Total	340,976,000		340,976,000		252,142,000
Residential Real Estate Mortgages | Financing receivable | Owners of rental properties
Changes in allowance
Concentration of loans (as a percent)			14.71%	13.52%
Commercial Real Estate Mortgage
Changes in allowance
Balance at the beginning of the period	3,759,000	3,276,000	3,831,000	2,651,000
Charge-offs	(6,000)	(18,000)	(6,000)	(18,000)
Recoveries	5,000	1,000	6,000	2,000
Provision	230,000	(95,000)	157,000	529,000
Balance at the end of the period	3,988,000	3,164,000	3,988,000	3,164,000
Allowance for Loan Losses:
Individually evaluated for impairment	2,139,000		2,139,000		2,018,000
Collectively evaluated for impairment	1,849,000		1,849,000		1,813,000
Total ending allowance balance	3,988,000	3,164,000	3,988,000	3,164,000
Loans
Individually evaluated for impairment	8,332,000		8,332,000		8,839,000
Loans acquired with deteriorated credit quality	259,000		259,000
Collectively evaluated for impairment	287,938,000		287,938,000		173,192,000
Total	296,529,000		296,529,000		182,031,000
Commercial Real Estate Mortgage | Financing receivable | Owners of rental properties
Changes in allowance
Concentration of loans (as a percent)			14.15%	15.25%
Construction Real Estate Mortgage
Changes in allowance
Balance at the beginning of the period	814,000	2,719,000	950,000	2,775,000
Charge-offs		(877,000)		(877,000)
Recoveries		1,000	850,000	4,000
Provision	29,000	296,000	(957,000)	237,000
Balance at the end of the period	843,000	2,139,000	843,000	2,139,000
Allowance for Loan Losses:
Individually evaluated for impairment	267,000		267,000		234,000
Collectively evaluated for impairment	576,000		576,000		716,000
Total ending allowance balance	843,000	2,139,000	843,000	2,139,000
Loans
Individually evaluated for impairment	1,177,000		1,177,000		6,090,000
Collectively evaluated for impairment	15,182,000		15,182,000		13,977,000
Total	16,359,000		16,359,000		20,067,000
Installment Loans to Individuals
Changes in allowance
Balance at the beginning of the period	144,000	175,000	144,000	190,000
Charge-offs	(25,000)	(19,000)	(50,000)	(51,000)
Recoveries	10,000	10,000	28,000	26,000
Provision	12,000	3,000	19,000	4,000
Balance at the end of the period	141,000	169,000	141,000	169,000
Allowance for Loan Losses:
Collectively evaluated for impairment	141,000		141,000		144,000
Total ending allowance balance	141,000	169,000	141,000	169,000
Loans
Collectively evaluated for impairment	15,105,000		15,105,000		10,659,000
Total	15,105,000		15,105,000		10,659,000
Unallocated
Changes in allowance
Balance at the beginning of the period	773,000	297,000	377,000	181,000
Provision	74,000	354,000	470,000	470,000
Balance at the end of the period	847,000	651,000	847,000	651,000
Allowance for Loan Losses:
Collectively evaluated for impairment	847,000		847,000		377,000
Total ending allowance balance	$ 847,000	$ 651,000	$ 847,000	$ 651,000