Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI (2) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 Contract	Dec. 31, 2013 Contract	Dec. 31, 2012 Contract
Troubled Debt Restructurings [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts	17	14	64
Pre-Modification Outstanding Recorded Investment	$ 1,248	$ 4,884	$ 11,048
Post-Modification Outstanding Recorded Investment	1,234	4,820	10,884
Troubled Debt Restructurings [Member] | Construction, Land Development and Other Land [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts			12
Pre-Modification Outstanding Recorded Investment			4,092
Post-Modification Outstanding Recorded Investment			4,092
Troubled Debt Restructurings [Member] | Secured by 1-4 Family Residential Properties [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts	17	10	48
Pre-Modification Outstanding Recorded Investment	1,248	498	5,399
Post-Modification Outstanding Recorded Investment	1,234	441	5,383
Troubled Debt Restructurings [Member] | Loans 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 Secured by Real Estate [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts			1
Pre-Modification Outstanding Recorded Investment			199
Post-Modification Outstanding Recorded Investment			199
Troubled Debt Restructurings [Member] | Commercial and Industrial [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts		2	1
Pre-Modification Outstanding Recorded Investment		944	148
Post-Modification Outstanding Recorded Investment		937	0
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 that Subsequently Defaulted [Member]
Troubled Debt Restructurings that Subsequently Defaulted [Abstract]
Number of Contracts	1	5	24
Recorded Investment	103	345	4,212
Troubled Debt Restructurings that Subsequently Defaulted [Member] | Construction, Land Development and Other Land [Member]
Troubled Debt Restructurings that Subsequently Defaulted [Abstract]
Number of Contracts	0	0	7
Recorded Investment	0	0	1,881
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	1	5	16
Recorded Investment	103	345	1,469
Troubled Debt Restructurings that Subsequently Defaulted [Member] | Loans secured by Nonfarm, Nonresidential Properties [Member]
Troubled Debt Restructurings that Subsequently Defaulted [Abstract]
Number of Contracts	0	0	1
Recorded Investment	$ 0	$ 0	$ 862