Acquired Loans (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	$ 37,250	$ 52,041
Less allowance for loan losses, acquired loans	2,326	4,190
Net acquired loans	34,924	47,851
Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	837,875	81,523
Less allowance for loan losses, acquired loans	3,007	1,885
Net acquired loans	834,868	79,638
Real Estate Secured Financing Receivable [Member] | Construction Land Development And Other Financing Receivable [Member] | Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	2,585	3,924
Real Estate Secured Financing Receivable [Member] | Construction Land Development And Other Financing Receivable [Member] | Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	106,655	10,056
Real Estate Secured Financing Receivable [Member] | Secured by 1-4 Family Residential Properties [Member] | Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	17,785	23,990
Real Estate Secured Financing Receivable [Member] | Secured by 1-4 Family Residential Properties [Member] | Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	168,573	19,404
Real Estate Secured Financing Receivable [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	12,120	18,407
Real Estate Secured Financing Receivable [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	301,686	45,649
Real Estate Secured Financing Receivable [Member] | Other Loans Secured by Real Estate [Member] | Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	2,817	3,567
Real Estate Secured Financing Receivable [Member] | Other Loans Secured by Real Estate [Member] | Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	35,051	669
Commercial and Industrial Loans [Member] | Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	478	747
Commercial and Industrial Loans [Member] | Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	186,649	3,035
Consumer Loans Financing Receivable [Member] | Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	151	177
Consumer Loans Financing Receivable [Member] | Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	22,251	2,610
Other Loans Financing Receivable [Member] | Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	1,314	1,229
Other Loans Financing Receivable [Member] | Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	$ 17,010	$ 100