Loans and the Allowance for Loan Losses (Details 11) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Allowance for loan losses:
Beginning balance	$ 48,048		$ 46,505		$ 47,665		$ 44,347
Charge-offs	(2,529)		(3,513)		(3,826)		(5,018)
Recoveries	335		1,042		565		1,655
Net (charge-offs) recoveries	(2,194)		(2,471)		(3,261)		(3,363)
Provision for loan losses	2,451		3,425		3,866		6,884
Benefit attributable to FDIC loss-share agreements	(1,542)		(502)		(1,674)		(1,671)
Recoveries payable to FDIC	541		77		708		837
Provision for loan losses charged to operations	1,450		3,000		2,900		6,050
Ending balance	47,304		47,034		47,304		47,034
Period-End Amount Allocated to:
Individually evaluated for impairment	10,891		15,944		10,891		15,944
Collectively evaluated for impairment	36,413		31,090		36,413		31,090
Acquired with deteriorated credit quality	0		0		0		0
Ending balance	47,304		47,034		47,304		47,034
Commercial, financial, agricultural
Allowance for loan losses:
Beginning balance	3,128		2,942		3,090		3,307
Charge-offs	0		(46)		(119)		(280)
Recoveries	75		90		112		247
Net (charge-offs) recoveries	75		44		(7)		(33)
Provision for loan losses	(95)		563		88		510
Benefit attributable to FDIC loss-share agreements	0		(83)		(68)		(330)
Recoveries payable to FDIC	156		12		161		24
Provision for loan losses charged to operations	61		492		181		204
Ending balance	3,264		3,478		3,264		3,478
Period-End Amount Allocated to:
Individually evaluated for impairment	245		834		245		834
Collectively evaluated for impairment	3,019		2,644		3,019		2,644
Acquired with deteriorated credit quality	0		0		0		0
Ending balance	3,264		3,478		3,264		3,478
Real estate – construction
Allowance for loan losses:
Beginning balance	1,109		676		1,091		711
Charge-offs	0		0		0		0
Recoveries	3		47		8		63
Net (charge-offs) recoveries	3		47		8		63
Provision for loan losses	154		140		167		88
Benefit attributable to FDIC loss-share agreements	0		0		0		0
Recoveries payable to FDIC	1		0		1		1
Provision for loan losses charged to operations	155		140		168		89
Ending balance	1,267		863		1,267		863
Period-End Amount Allocated to:
Individually evaluated for impairment	0		0		0		0
Collectively evaluated for impairment	1,267		863		1,267		863
Acquired with deteriorated credit quality	0		0		0		0
Ending balance	1,267		863		1,267		863
Real estate – 1-4 family mortgage
Allowance for loan losses:
Beginning balance	18,478		19,737		18,629		18,347
Charge-offs	(1,985)		(652)		(2,872)		(1,266)
Recoveries	206		132		357		471
Net (charge-offs) recoveries	(1,779)		(520)		(2,515)		(795)
Provision for loan losses	(5,187)		521		(4,691)		1,718
Benefit attributable to FDIC loss-share agreements	(66)		(369)		(135)		(630)
Recoveries payable to FDIC	351		63		509		792
Provision for loan losses charged to operations	(4,902)		215		(4,317)		1,880
Ending balance	11,797		19,432		11,797		19,432
Period-End Amount Allocated to:
Individually evaluated for impairment	2,062		7,843		2,062		7,843
Collectively evaluated for impairment	9,735		11,589		9,735		11,589
Acquired with deteriorated credit quality	0		0		0		0
Ending balance	11,797		19,432		11,797		19,432
Real estate – commercial mortgage
Allowance for loan losses:
Beginning balance	24,147		22,096		23,688		21,416
Charge-offs	(483)		(2,527)		(543)		(3,120)
Recoveries	28		756		58		847
Net (charge-offs) recoveries	(455)		(1,771)		(485)		(2,273)
Provision for loan losses	7,522		1,962		8,002		3,787
Benefit attributable to FDIC loss-share agreements	(1,476)		(50)		(1,471)		(711)
Recoveries payable to FDIC	33		2		37		20
Provision for loan losses charged to operations	6,079		1,914		6,568		3,096
Ending balance	29,771		22,239		29,771		22,239
Period-End Amount Allocated to:
Individually evaluated for impairment	8,584		7,267		8,584		7,267
Collectively evaluated for impairment	21,187		14,972		21,187		14,972
Acquired with deteriorated credit quality	0		0		0		0
Ending balance	29,771		22,239		29,771		22,239
Installment loans to individuals
Allowance for loan losses:
Beginning balance	1,186	[1]	1,054	[1]	1,167	[1]	566	[1]
Charge-offs	(61)	[1]	(288)	[1]	(292)	[1]	(352)	[1]
Recoveries	23	[1]	17	[1]	30	[1]	27	[1]
Net (charge-offs) recoveries	(38)	[1]	(271)	[1]	(262)	[1]	(325)	[1]
Provision for loan losses	57	[1]	239	[1]	300	[1]	781	[1]
Benefit attributable to FDIC loss-share agreements	0	[1]	0	[1]	0	[1]	0	[1]
Recoveries payable to FDIC	0	[1]	0	[1]	0	[1]	0	[1]
Provision for loan losses charged to operations	57	[1]	239	[1]	300	[1]	781	[1]
Ending balance	1,205	[1]	1,022	[1]	1,205	[1]	1,022	[1]
Period-End Amount Allocated to:
Individually evaluated for impairment	0	[1]	0	[1]	0	[1]	0	[1]
Collectively evaluated for impairment	1,205	[1]	1,022	[1]	1,205	[1]	1,022	[1]
Acquired with deteriorated credit quality	0	[1]	0	[1]	0	[1]	0	[1]
Ending balance	$ 1,205	[1]	$ 1,022	[1]	$ 1,205	[1]	$ 1,022	[1]

[1] Includes lease financing receivables.