Acquired Loans (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	$ 40,820	$ 52,041
Less allowance for loan losses, acquired loans	2,578	4,190
Net acquired loans	38,242	47,851
Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	922,453	81,523
Less allowance for loan losses, acquired loans	112	1,885
Net acquired loans	922,341	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	3,662	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	132,116	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	18,899	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	184,928	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	13,341	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	318,603	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	2,929	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	34,869	669
Commercial and Industrial Loans [Member] | Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	543	747
Commercial and Industrial Loans [Member] | Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	206,338	3,035
Consumer Loans Financing Receivable [Member] | Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	173	177
Consumer Loans Financing Receivable [Member] | Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	27,420	2,610
Other Loans Financing Receivable [Member] | Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	1,273	1,229
Other Loans Financing Receivable [Member] | Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	$ 18,179	$ 100