Acquired Loans (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	$ 525,783	$ 769,990
Less allowance for loan losses, acquired loans	10,541	7,249
Net acquired loans	515,242	762,741
Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	23,626	34,216
Less allowance for loan losses, acquired loans	1,518	2,387
Net acquired loans	22,108	31,829
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	58,309	98,928
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	1,197	2,363
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	116,920	157,914
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	13,180	16,416
Real Estate Secured Financing Receivable [Member] | Nonfarm, Nonresidential Properties [Member] | Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	202,323	287,136
Real Estate Secured Financing Receivable [Member] | Nonfarm, Nonresidential Properties [Member] | Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	7,672	10,945
Real Estate Secured Financing Receivable [Member] | Other Real Estate Secured Financing Receivable [Member] | Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	27,813	33,948
Real Estate Secured Financing Receivable [Member] | Other Real Estate Secured Financing Receivable [Member] | Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	1,096	2,644
Commercial And Industrial Loans [Member] | Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	88,256	149,495
Commercial And Industrial Loans [Member] | Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	277	394
Consumer Loans Financing Receivable [Member] | Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	9,772	18,428
Consumer Loans Financing Receivable [Member] | Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	0	119
Other Loans Financing Receivable [Member] | Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	22,390	24,141
Other Loans Financing Receivable [Member] | Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	$ 204	$ 1,335