Loans and the Allowance for Loan Losses (Details 11) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Allowance for loan losses:
Beginning balance	$ 42,289		$ 47,665
Charge-offs	(1,403)		(1,297)
Recoveries	341		230
Net (charge-offs) recoveries	(1,062)		(1,067)
Provision for loan losses	732		1,415
Benefit attributable to FDIC loss-share agreements	(126)		(132)
Recoveries payable to FDIC	469		167
Provision for loan losses charged to operations	1,075		1,450
Ending balance	42,302		48,048
Period-End Amount Allocated to:
Individually evaluated for impairment	6,520		15,262
Collectively evaluated for impairment	33,193		29,807
Acquired with deteriorated credit quality	2,589		2,979
Ending balance	42,302		48,048
Commercial, financial, agricultural
Allowance for loan losses:
Beginning balance	3,305		3,090
Charge-offs	(235)		(119)
Recoveries	35		37
Net (charge-offs) recoveries	(200)		(82)
Provision for loan losses	1,027		183
Benefit attributable to FDIC loss-share agreements	(25)		(68)
Recoveries payable to FDIC	2		5
Provision for loan losses charged to operations	1,004		120
Ending balance	4,109		3,128
Period-End Amount Allocated to:
Individually evaluated for impairment	0		253
Collectively evaluated for impairment	2,911		2,665
Acquired with deteriorated credit quality	1,198		210
Ending balance	4,109		3,128
Real estate – construction
Allowance for loan losses:
Beginning balance	1,415		1,091
Charge-offs	0		0
Recoveries	6		5
Net (charge-offs) recoveries	6		5
Provision for loan losses	(63)		13
Benefit attributable to FDIC loss-share agreements	0		0
Recoveries payable to FDIC	1		0
Provision for loan losses charged to operations	(62)		13
Ending balance	1,359		1,109
Period-End Amount Allocated to:
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	1,359		1,002
Acquired with deteriorated credit quality	0		107
Ending balance	1,359		1,109
Real estate – 1-4 family mortgage
Allowance for loan losses:
Beginning balance	13,549		18,629
Charge-offs	(485)		(887)
Recoveries	155		151
Net (charge-offs) recoveries	(330)		(736)
Provision for loan losses	618		496
Benefit attributable to FDIC loss-share agreements	0		(69)
Recoveries payable to FDIC	208		158
Provision for loan losses charged to operations	826		585
Ending balance	14,045		18,478
Period-End Amount Allocated to:
Individually evaluated for impairment	4,227		7,285
Collectively evaluated for impairment	9,541		10,823
Acquired with deteriorated credit quality	277		370
Ending balance	14,045		18,478
Real estate – commercial mortgage
Allowance for loan losses:
Beginning balance	22,759		23,688
Charge-offs	(633)		(60)
Recoveries	112		30
Net (charge-offs) recoveries	(521)		(30)
Provision for loan losses	(887)		480
Benefit attributable to FDIC loss-share agreements	(101)		5
Recoveries payable to FDIC	258		4
Provision for loan losses charged to operations	(730)		489
Ending balance	21,508		24,147
Period-End Amount Allocated to:
Individually evaluated for impairment	2,293		7,724
Collectively evaluated for impairment	18,102		14,133
Acquired with deteriorated credit quality	1,113		2,290
Ending balance	21,508		24,147
Installment loans to individuals
Allowance for loan losses:
Beginning balance	1,261	[1]	1,167	[1]
Charge-offs	(50)	[1]	(231)	[1]
Recoveries	33	[1]	7	[1]
Net (charge-offs) recoveries	(17)	[1]	(224)	[1]
Provision for loan losses	37	[1]	243	[1]
Benefit attributable to FDIC loss-share agreements	0	[1]	0	[1]
Recoveries payable to FDIC	0	[1]	0	[1]
Provision for loan losses charged to operations	37	[1]	243	[1]
Ending balance	1,281	[1]	1,186	[1]
Period-End Amount Allocated to:
Individually evaluated for impairment	0	[1]	0	[1]
Collectively evaluated for impairment	1,280	[1]	1,184	[1]
Acquired with deteriorated credit quality	1	[1]	2	[1]
Ending balance	$ 1,281	[1]	$ 1,186	[1]

[1] Includes lease financing receivables.