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, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Loans, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance	$ 13,213		$ 15,959		$ 13,791		$ 15,529
Allowance for loan losses, charge-offs	(70)		(356)		(885)		(591)
Allowance for loan losses, recoveries of bad debts	102		138		189		653
Provision for loan losses	100	[1]	(1,000)	[1]	250	[1]	(850)	[1]
Allowance for loan losses, ending balance	13,345		14,741		13,345		14,741
Commercial loan [Member]
Loans, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance	3,898		4,108		4,199		4,116
Allowance for loan losses, charge-offs	0		(315)		(577)		(514)
Allowance for loan losses, recoveries of bad debts	35		34		87		254
Provision for loan losses	347		369		571		340
Allowance for loan losses, ending balance	4,280		4,196		4,280		4,196
Construction, land, and land development [Member]
Loans, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance	2,540		3,933		3,032		4,616
Allowance for loan losses, charge-offs	0		0		0		0
Allowance for loan losses, recoveries of bad debts	0		0		8		42
Provision for loan losses	(189)		(158)		(689)		(883)
Allowance for loan losses, ending balance	2,351		3,775		2,351		3,775
1-4 family residential first mortgages [Member]
Loans, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance	553		663		613		637
Allowance for loan losses, charge-offs	(10)		(10)		(73)		(40)
Allowance for loan losses, recoveries of bad debts	2		3		4		121
Provision for loan losses	66		(38)		67		(100)
Allowance for loan losses, ending balance	611		618		611		618
Home equity [Member]
Loans, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance	563		441		403		568
Allowance for loan losses, charge-offs	(60)		0		(123)		(5)
Allowance for loan losses, recoveries of bad debts	56		99		80		212
Provision for loan losses	(18)		(171)		181		(406)
Allowance for loan losses, ending balance	541		369		541		369
Commercial real estate [Member]
Loans, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance	5,609		6,780		5,485		5,564
Allowance for loan losses, charge-offs	0		0		(112)		0
Allowance for loan losses, recoveries of bad debts	7		0		7		2
Provision for loan losses	(107)		(1,032)		129		182
Allowance for loan losses, ending balance	5,509		5,748		5,509		5,748
Consumer and other loans [Member]
Loans, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance	50		34		59		28
Allowance for loan losses, charge-offs	0		(31)		0		(32)
Allowance for loan losses, recoveries of bad debts	2		2		3		22
Provision for loan losses	1		30		(9)		17
Allowance for loan losses, ending balance	$ 53		$ 35		$ 53		$ 35

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