LHFI and Allowance for Loan Losses, LHFI - Change in Allowance for Loan Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	$ 67,619
Provision for loan losses, LHFI	10,957	$ 8,375	$ 1,211
Balance at end of period	71,265	67,619
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Total	71,265	67,619		$ 71,265	$ 67,619
Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	67,619	69,616	66,448
Loans charged-off	(18,930)	(22,469)	(13,226)
Recoveries	11,619	12,097	15,183
Net (charge-offs) recoveries	(7,311)	(10,372)	1,957
Provision for loan losses, LHFI	10,957	8,375	1,211
Balance at end of period	71,265	67,619	69,616
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually				5,544	8,988
Collectively				65,721	58,631
Total	67,619	67,619	69,616	71,265	67,619
Allowance for Loan Losses, LHFI [Member] | Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	11,587	13,073
Loans charged-off	(311)	(2,435)
Recoveries	1,380	1,773
Provision for loan losses, LHFI	(3,571)	(824)
Balance at end of period	9,085	11,587	13,073
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually				616	909
Collectively				8,469	10,678
Total	11,587	11,587	13,073	9,085	11,587
Allowance for Loan Losses, LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	10,678	9,677
Loans charged-off	(1,319)	(2,473)
Recoveries	1,122	920
Provision for loan losses, LHFI	(134)	2,554
Balance at end of period	10,347	10,678	9,677
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually				1,420	1,230
Collectively				8,927	9,448
Total	10,678	10,678	9,677	10,347	10,678
Allowance for Loan Losses, LHFI [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	21,563	18,523
Loans charged-off	(3,067)	(1,439)
Recoveries	976	605
Provision for loan losses, LHFI	1,495	3,874
Balance at end of period	20,967	21,563	18,523
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually				851	3,402
Collectively				20,116	18,161
Total	21,563	21,563	18,523	20,967	21,563
Allowance for Loan Losses, LHFI [Member] | Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	2,467	2,141
Loans charged-off	(27)	(24)
Recoveries	7	136
Provision for loan losses, LHFI	(184)	214
Balance at end of period	2,263	2,467	2,141
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually				118	15
Collectively				2,145	2,452
Total	2,467	2,467	2,141	2,263	2,467
Allowance for Loan Losses, LHFI [Member] | Commercial and Industrial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	15,815	19,917
Loans charged-off	(6,602)	(8,081)
Recoveries	732	1,761
Provision for loan losses, LHFI	12,066	2,218
Balance at end of period	22,011	15,815	19,917
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually				2,425	3,304
Collectively				19,586	12,511
Total	15,815	15,815	19,917	22,011	15,815
Allowance for Loan Losses, LHFI [Member] | Consumer Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	2,879	2,149
Loans charged-off	(1,864)	(2,171)
Recoveries	4,007	3,289
Provision for loan losses, LHFI	(1,781)	(388)
Balance at end of period	3,241	2,879	2,149
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually				3
Collectively				3,238	2,879
Total	2,879	2,879	2,149	3,241	2,879
Allowance for Loan Losses, LHFI [Member] | State and Other Political Subdivision Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	809	1,314
Provision for loan losses, LHFI	50	(505)
Balance at end of period	859	809	1,314
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Collectively				859	809
Total	809	809	1,314	859	809
Allowance for Loan Losses, LHFI [Member] | Other Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	1,821	2,822
Loans charged-off	(5,740)	(5,846)
Recoveries	3,395	3,613
Provision for loan losses, LHFI	3,016	1,232
Balance at end of period	2,492	1,821	2,822
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually				111	128
Collectively				2,381	1,693
Total	$ 1,821	$ 1,821	$ 2,822	$ 2,492	$ 1,821