Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI (3) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Financing Receivable, Modifications [Line Items]
Nonaccrual	$ 73,381	$ 82,363
Troubled Debt Restructurings [Member]
Financing Receivable, Modifications [Line Items]
Accruing	1,482	1,513
Nonaccrual	15,360	22,760
Total	16,842	24,273
Troubled Debt Restructurings [Member] | Construction Land Development and Other Land Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing	227	233
Nonaccrual	7,304	12,073
Total	7,531	12,306
Troubled Debt Restructurings [Member] | Secured by 1-4 Family Residential Properties [Member]
Financing Receivable, Modifications [Line Items]
Accruing	1,255	1,280
Nonaccrual	4,965	5,908
Total	6,220	7,188
Troubled Debt Restructurings [Member] | Secured by Nonfarm, Nonresidential Properties [Member]
Financing Receivable, Modifications [Line Items]
Accruing	0	0
Nonaccrual	2,349	4,582
Total	2,349	4,582
Troubled Debt Restructurings [Member] | Other Loans Secured by Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Accruing	0	0
Nonaccrual	174	197
Total	174	197
Troubled Debt Restructurings [Member] | Commercial and Industrial Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing	0
Nonaccrual	568
Total	$ 568