Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI (2) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013 Contract	Mar. 31, 2012 Contract
Troubled Debt Restructurings [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts	6	12
Pre-Modification Outstanding Recorded Investment	$ 4,635	$ 5,830
Post-Modification Outstanding Recorded Investment	4,572	5,830
Troubled Debt Restructurings [Member] | Construction Land Development And Other Financing Receivable [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts		8
Pre-Modification Outstanding Recorded Investment		3,611
Post-Modification Outstanding Recorded Investment		3,611
Troubled Debt Restructurings [Member] | Secured by 1-4 Family Residential Properties [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts	2	2
Pre-Modification Outstanding Recorded Investment	249	1,009
Post-Modification Outstanding Recorded Investment	193	1,009
Troubled Debt Restructurings [Member] | Secured by Nonfarm, Nonresidential Properties [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts	1	2
Pre-Modification Outstanding Recorded Investment	952	1,210
Post-Modification Outstanding Recorded Investment	952	1,210
Troubled Debt Restructurings [Member] | Other Loans [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts	1
Pre-Modification Outstanding Recorded Investment	2,490
Post-Modification Outstanding Recorded Investment	2,490
Troubled Debt Restructurings [Member] | Commercial and Industrial [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts	2
Pre-Modification Outstanding Recorded Investment	944
Post-Modification Outstanding Recorded Investment	937
Troubled Debt Restructurings that Subsequently Defaulted [Member]
Troubled Debt Restructurings that Subsequently Defaulted [Abstract]
Number of Contracts	23	4
Recorded Investment	1,742	1,681
Troubled Debt Restructurings that Subsequently Defaulted [Member] | Construction Land Development And Other Financing Receivable [Member]
Troubled Debt Restructurings that Subsequently Defaulted [Abstract]
Number of Contracts	4	1
Recorded Investment	236	299
Troubled Debt Restructurings that Subsequently Defaulted [Member] | Secured by 1-4 Family Residential Properties [Member]
Troubled Debt Restructurings that Subsequently Defaulted [Abstract]
Number of Contracts	19	3
Recorded Investment	$ 1,506	$ 1,382