Loans and Allowance for Loan Losses Schedule of Allowance for Loan Loss Activity (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Loans, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance	$ 15,959		$ 15,373		$ 15,529		$ 16,778
Allowance for loan losses, charge-offs	(356)		(159)		(591)		(1,839)
Allowance for loan losses, recoveries of bad debts	138		123		653		398
Provision for loan losses	(1,000)	[1]	300	[1]	(850)	[1]	300	[1]
Allowance for loan losses, ending balance	14,741		15,637		14,741		15,637
Commercial loan [Member]
Loans, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance	4,108		3,996		4,116		4,409
Allowance for loan losses, charge-offs	(315)		(27)		(514)		(27)
Allowance for loan losses, recoveries of bad debts	34		36		254		271
Provision for loan losses	369	[1]	(648)	[1]	340	[1]	(1,296)	[1]
Allowance for loan losses, ending balance	4,196		3,357		4,196		3,357
Construction, land, and land development [Member]
Loans, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance	3,933		3,066		4,616		3,572
Allowance for loan losses, charge-offs	0		0		0		(1,508)
Allowance for loan losses, recoveries of bad debts	0		0		42		0
Provision for loan losses	(158)	[1]	1,390	[1]	(883)	[1]	2,392	[1]
Allowance for loan losses, ending balance	3,775		4,456		3,775		4,456
1-4 family residential first mortgages [Member]
Loans, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance	663		1,090		637		1,215
Allowance for loan losses, charge-offs	(10)		(120)		(40)		(184)
Allowance for loan losses, recoveries of bad debts	3		77		121		92
Provision for loan losses	(38)	[1]	(150)	[1]	(100)	[1]	(226)	[1]
Allowance for loan losses, ending balance	618		897		618		897
Home equity loan [Member]
Loans, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance	441		596		568		832
Allowance for loan losses, charge-offs	0		(10)		(5)		(105)
Allowance for loan losses, recoveries of bad debts	99		10		212		18
Provision for loan losses	(171)	[1]	24	[1]	(406)	[1]	(125)	[1]
Allowance for loan losses, ending balance	369		620		369		620
Commercial real estate [Member]
Loans, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance	6,780		6,561		5,564		6,667
Allowance for loan losses, charge-offs	0		(2)		0		(3)
Allowance for loan losses, recoveries of bad debts	0		0		2		0
Provision for loan losses	(1,032)	[1]	(308)	[1]	182	[1]	(413)	[1]
Allowance for loan losses, ending balance	5,748		6,251		5,748		6,251
Consumer and other loans [Member]
Loans, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance	34		64		28		83
Allowance for loan losses, charge-offs	(31)		0		(32)		(12)
Allowance for loan losses, recoveries of bad debts	2		0		22		17
Provision for loan losses	30	[1]	(8)	[1]	17	[1]	(32)	[1]
Allowance for loan losses, ending balance	$ 35		$ 56		$ 35		$ 56

[1] The negative provisions for the various segments are either related to the decline in each of those portfolio segments during the time periods disclosed or improvement in the credit quality factors related to those portfolio segments.