Loans and the Allowance for Loan Losses - (Details 11) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Allowance for loan losses:
Beginning balance		$ 42,859	$ 42,302	$ 42,437	$ 42,289
Charge-offs		(813)	(2,298)	(2,767)	(3,701)
Recoveries		622	709	1,198	1,050
Net (charge-offs) recoveries		(191)	(1,589)	(1,569)	(2,651)
Provision for loan losses		1,164	839	2,943	1,571
Benefit attributable to FDIC loss-share agreements		54	(458)	(116)	(584)
Recoveries payable to FDIC		212	794	403	1,263
Provision for loan losses charged to operations		1,430	1,175	3,230	2,250
Ending balance		44,098	41,888	44,098	41,888
Period-End Amount Allocated to:
Individually evaluated for impairment						$ 7,619	$ 5,902
Collectively evaluated for impairment						34,307	34,574
Acquired with deteriorated credit quality		42,859	42,302	42,437	42,289	44,098	41,888
Commercial, financial, agricultural
Allowance for loan losses:
Beginning balance		4,171	4,109	4,186	3,305
Charge-offs		(48)	(123)	(705)	(358)
Recoveries		105	104	158	139
Net (charge-offs) recoveries		57	(19)	(547)	(219)
Provision for loan losses		265	(96)	866	931
Benefit attributable to FDIC loss-share agreements		15	(30)	0	(55)
Recoveries payable to FDIC		4	7	7	9
Provision for loan losses charged to operations		284	(119)	873	885
Ending balance		4,512	3,971	4,512	3,971
Period-End Amount Allocated to:
Individually evaluated for impairment						164	0
Collectively evaluated for impairment						3,947	3,609
Acquired with deteriorated credit quality		4,171	4,109	4,186	3,305	4,512	3,971
Real estate – construction
Allowance for loan losses:
Beginning balance		1,943	1,359	1,852	1,415
Charge-offs		0	(26)	0	(26)
Recoveries		5	7	11	13
Net (charge-offs) recoveries		5	(19)	11	(13)
Provision for loan losses		315	(43)	400	(106)
Benefit attributable to FDIC loss-share agreements		0	0	0	0
Recoveries payable to FDIC		6	0	6	1
Provision for loan losses charged to operations		321	(43)	406	(105)
Ending balance		2,269	1,297	2,269	1,297
Period-End Amount Allocated to:
Individually evaluated for impairment						0	0
Collectively evaluated for impairment						2,269	1,297
Acquired with deteriorated credit quality		1,943	1,359	1,852	1,415	2,269	1,297
Real estate – 1-4 family mortgage
Allowance for loan losses:
Beginning balance		14,542	14,045	13,908	13,549
Charge-offs		(387)	(869)	(503)	(1,354)
Recoveries		170	215	565	370
Net (charge-offs) recoveries		(217)	(654)	62	(984)
Provision for loan losses		(186)	(130)	179	488
Benefit attributable to FDIC loss-share agreements		(78)	(43)	(115)	(43)
Recoveries payable to FDIC		158	574	185	782
Provision for loan losses charged to operations		(106)	401	249	1,227
Ending balance		14,219	13,792	14,219	13,792
Period-End Amount Allocated to:
Individually evaluated for impairment						4,924	4,125
Collectively evaluated for impairment						8,951	9,478
Acquired with deteriorated credit quality		14,542	14,045	13,908	13,549	14,219	13,792
Real estate – commercial mortgage
Allowance for loan losses:
Beginning balance		20,775	21,508	21,111	22,759
Charge-offs		(186)	(1,224)	(1,187)	(1,857)
Recoveries		309	357	401	469
Net (charge-offs) recoveries		123	(867)	(786)	(1,388)
Provision for loan losses		624	1,078	1,154	191
Benefit attributable to FDIC loss-share agreements		117	(385)	(1)	(486)
Recoveries payable to FDIC		44	213	205	471
Provision for loan losses charged to operations		785	906	1,358	176
Ending balance		21,683	21,547	21,683	21,547
Period-End Amount Allocated to:
Individually evaluated for impairment						2,531	1,566
Collectively evaluated for impairment						17,726	19,121
Acquired with deteriorated credit quality		20,775	21,508	21,111	22,759	21,683	21,547
Installment and other
Allowance for loan losses:
Beginning balance	[1]	1,428	1,281	1,380	1,261
Charge-offs	[1]	(192)	(56)	(372)	(106)
Recoveries	[1]	33	26	63	59
Net (charge-offs) recoveries	[1]	(159)	(30)	(309)	(47)
Provision for loan losses	[1]	146	30	344	67
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]	146	30	344	67
Ending balance	[1]	1,415	1,281	1,415	1,281
Period-End Amount Allocated to:
Individually evaluated for impairment	[1]					0	211
Collectively evaluated for impairment	[1]					1,414	1,069
Acquired with deteriorated credit quality	[1]	1,428	1,281	1,380	1,261	1,415	1,281
Receivables Acquired with Deteriorated Credit Quality
Allowance for loan losses:
Ending balance		2,172	1,412	2,172	1,412
Period-End Amount Allocated to:
Acquired with deteriorated credit quality		2,172	1,412	2,172	1,412	2,172	1,412
Receivables Acquired with Deteriorated Credit Quality | Commercial, financial, agricultural
Allowance for loan losses:
Ending balance		401	362	401	362
Period-End Amount Allocated to:
Acquired with deteriorated credit quality		401	362	401	362	401	362
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		344	189	344	189
Period-End Amount Allocated to:
Acquired with deteriorated credit quality		344	189	344	189	344	189
Receivables Acquired with Deteriorated Credit Quality | Real estate – commercial mortgage
Allowance for loan losses:
Ending balance		1,426	860	1,426	860
Period-End Amount Allocated to:
Acquired with deteriorated credit quality		1,426	860	1,426	860	1,426	860
Receivables Acquired with Deteriorated Credit Quality | Installment and other
Allowance for loan losses:
Ending balance	[1]	1	1	1	1
Period-End Amount Allocated to:
Acquired with deteriorated credit quality	[1]	$ 1	$ 1	$ 1	$ 1	$ 1	$ 1

[1] Includes lease financing receivables.