Loans and the Allowance for Loan Losses - (Details 11) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Allowance for loan losses:
Beginning balance		$ 42,302	$ 48,048	$ 42,289	$ 47,665
Charge-offs		(2,298)	(2,529)	(3,701)	(3,826)
Recoveries		709	335	1,050	565
Net charge-offs		(1,589)	(2,194)	(2,651)	(3,261)
Provision for loan losses		839	2,451	1,571	3,866
Benefit attributable to FDIC loss-share agreements		(458)	(1,542)	(584)	(1,674)
Recoveries payable to FDIC		794	541	1,263	708
Provision for loan losses charged to operations		1,175	1,450	2,250	2,900
Ending balance		41,888	47,304	41,888	47,304
Period-End Amount Allocated to:
Individually evaluated for impairment						$ 5,902	$ 10,891
Collectively evaluated for impairment						34,574	36,413
Acquired with deteriorated credit quality		42,302	48,048	42,289	47,665	41,888	47,304
Commercial, financial, agricultural
Allowance for loan losses:
Beginning balance		4,109	3,128	3,305	3,090
Charge-offs		(123)	0	(358)	(119)
Recoveries		104	75	139	112
Net charge-offs		(19)	75	(219)	(7)
Provision for loan losses		(96)	(95)	931	88
Benefit attributable to FDIC loss-share agreements		(30)	0	(55)	(68)
Recoveries payable to FDIC		7	156	9	161
Provision for loan losses charged to operations		(119)	61	885	181
Ending balance		3,971	3,264	3,971	3,264
Period-End Amount Allocated to:
Individually evaluated for impairment						0	245
Collectively evaluated for impairment						3,609	3,019
Acquired with deteriorated credit quality		4,109	3,128	3,305	3,090	3,971	3,264
Real estate – construction
Allowance for loan losses:
Beginning balance		1,359	1,109	1,415	1,091
Charge-offs		(26)	0	(26)	0
Recoveries		7	3	13	8
Net charge-offs		(19)	3	(13)	8
Provision for loan losses		(43)	154	(106)	167
Benefit attributable to FDIC loss-share agreements		0	0	0	0
Recoveries payable to FDIC		0	1	1	1
Provision for loan losses charged to operations		(43)	155	(105)	168
Ending balance		1,297	1,267	1,297	1,267
Period-End Amount Allocated to:
Individually evaluated for impairment						0	0
Collectively evaluated for impairment						1,297	1,267
Acquired with deteriorated credit quality		1,359	1,109	1,415	1,091	1,297	1,267
Real estate – 1-4 family mortgage
Allowance for loan losses:
Beginning balance		14,045	18,478	13,549	18,629
Charge-offs		(869)	(1,985)	(1,354)	(2,872)
Recoveries		215	206	370	357
Net charge-offs		(654)	(1,779)	(984)	(2,515)
Provision for loan losses		(130)	(5,187)	488	(4,691)
Benefit attributable to FDIC loss-share agreements		(43)	(66)	(43)	(135)
Recoveries payable to FDIC		574	351	782	509
Provision for loan losses charged to operations		401	(4,902)	1,227	(4,317)
Ending balance		13,792	11,797	13,792	11,797
Period-End Amount Allocated to:
Individually evaluated for impairment						4,125	2,062
Collectively evaluated for impairment						9,478	9,735
Acquired with deteriorated credit quality		14,045	18,478	13,549	18,629	13,792	11,797
Real estate – commercial mortgage
Allowance for loan losses:
Beginning balance		21,508	24,147	22,759	23,688
Charge-offs		(1,224)	(483)	(1,857)	(543)
Recoveries		357	28	469	58
Net charge-offs		(867)	(455)	(1,388)	(485)
Provision for loan losses		1,078	7,522	191	8,002
Benefit attributable to FDIC loss-share agreements		(385)	(1,476)	(486)	(1,471)
Recoveries payable to FDIC		213	33	471	37
Provision for loan losses charged to operations		906	6,079	176	6,568
Ending balance		21,547	29,771	21,547	29,771
Period-End Amount Allocated to:
Individually evaluated for impairment						1,566	8,584
Collectively evaluated for impairment						19,121	21,187
Acquired with deteriorated credit quality		21,508	24,147	22,759	23,688	21,547	29,771
Installment loans to individuals
Allowance for loan losses:
Beginning balance	[1]	1,281	1,186	1,261	1,167
Charge-offs	[1]	(56)	(61)	(106)	(292)
Recoveries	[1]	26	23	59	30
Net charge-offs	[1]	(30)	(38)	(47)	(262)
Provision for loan losses	[1]	30	57	67	300
Benefit attributable to FDIC loss-share agreements	[1]	0	0	0	0
Recoveries payable to FDIC	[1]	0	0	0	0
Provision for loan losses charged to operations	[1]	30	57	67	300
Ending balance	[1]	1,281	1,205	1,281	1,205
Period-End Amount Allocated to:
Individually evaluated for impairment	[1]					211	0
Collectively evaluated for impairment	[1]					1,069	1,205
Acquired with deteriorated credit quality	[1]	1,281	1,186	1,261	1,167	1,281	1,205
Receivables Acquired with Deteriorated Credit Quality
Allowance for loan losses:
Ending balance		1,412	0	1,412	0
Period-End Amount Allocated to:
Acquired with deteriorated credit quality		1,412	0	1,412	0	1,412	0
Receivables Acquired with Deteriorated Credit Quality | Commercial, financial, agricultural
Allowance for loan losses:
Ending balance		362	0	362	0
Period-End Amount Allocated to:
Acquired with deteriorated credit quality		362	0	362	0	362	0
Receivables Acquired with Deteriorated Credit Quality | Real estate – construction
Allowance for loan losses:
Ending balance		0	0	0	0
Period-End Amount Allocated to:
Acquired with deteriorated credit quality		0	0	0	0	0	0
Receivables Acquired with Deteriorated Credit Quality | Real estate – 1-4 family mortgage
Allowance for loan losses:
Ending balance		189	0	189	0
Period-End Amount Allocated to:
Acquired with deteriorated credit quality		189	0	189	0	189	0
Receivables Acquired with Deteriorated Credit Quality | Real estate – commercial mortgage
Allowance for loan losses:
Ending balance		860	0	860	0
Period-End Amount Allocated to:
Acquired with deteriorated credit quality		860	0	860	0	860	0
Receivables Acquired with Deteriorated Credit Quality | Installment loans to individuals
Allowance for loan losses:
Ending balance	[1]	1	0	1	0
Period-End Amount Allocated to:
Acquired with deteriorated credit quality	[1]	$ 1	$ 0	$ 1	$ 0	$ 1	$ 0

[1] Includes lease financing receivables.