Loans and Asset Quality Information (Details 9) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Provisions	$ 5,591	$ 6,467	$ 16,740	$ 28,022
Non-covered
Beginning balance	44,761	46,455	41,643	35,610	35,610
Charge-offs	(4,546)	(4,482)	(9,341)	(12,737)	(66,545)
Recoveries	558	357	2,700	900	2,585
Provisions	4,043	5,193	9,814	23,750	69,993
Ending balance	44,816	47,523	44,816	47,523	41,643
Ending balances: Allowance for loan losses
Individually evaluated for impairment	1,636	8,242	1,636	8,242	1,007
Collectively evaluated for impairment	43,180	39,281	43,180	39,281	40,636
Loans acquired with deteriorated credit quality
Loans receivable:
Ending balance - total	2,189,415	2,113,530	2,189,415	2,113,530	2,092,819
Ending balances: Loans
Individually evaluated for impairment	23,667	57,626	23,667	57,626	21,021
Collectively evaluated for impairment	2,165,748	2,055,904	2,165,748	2,055,904	2,071,798
Loans acquired with deteriorated credit quality
Commercial, financial and agricultural
Beginning balance	4,949	4,954	4,687	3,780	3,780
Charge-offs	(560)	(744)	(1,384)	(2,062)	(4,912)
Recoveries	214	18	233	34	354
Provisions	1,357	833	2,424	3,309	5,465
Ending balance	5,960	5,061	5,960	5,061	4,687
Ending balances: Allowance for loan losses
Individually evaluated for impairment	901	869	901	869
Collectively evaluated for impairment	5,059	4,192	5,059	4,192	4,687
Loans acquired with deteriorated credit quality
Loans receivable:
Ending balance - total	176,662	173,676	176,662	173,676	170,741
Ending balances: Loans
Individually evaluated for impairment	1,911	1,009	1,911	1,009
Collectively evaluated for impairment	174,751	172,667	174,751	172,667	170,741
Loans acquired with deteriorated credit quality
Real Estate construction, land development and other land loans
Beginning balance	14,857	16,419	12,856	11,306	11,306
Charge-offs	(394)	(174)	(1,217)	(2,852)	(19,312)
Recoveries	24	126	617	314	986
Provisions	106	1,448	2,337	9,051	19,876
Ending balance	14,593	17,819	14,593	17,819	12,856
Ending balances: Allowance for loan losses
Individually evaluated for impairment		4,819		4,819
Collectively evaluated for impairment	14,593	13,000	14,593	13,000	12,856
Loans acquired with deteriorated credit quality
Loans receivable:
Ending balance - total	232,352	244,723	232,352	244,723	218,108
Ending balances: Loans
Individually evaluated for impairment	5,977	23,860	5,977	23,860	4,276
Collectively evaluated for impairment	226,375	220,863	226,375	220,863	213,832
Loans acquired with deteriorated credit quality
Real estate residential, farmland and mutli-family
Beginning balance	15,285	15,369	14,082	13,532	13,532
Charge-offs	(858)	(2,144)	(1,655)	(4,235)	(20,879)
Recoveries	117	60	663	254	430
Provisions	417	1,674	1,871	5,408	20,999
Ending balance	14,961	14,959	14,961	14,959	14,082
Ending balances: Allowance for loan losses
Individually evaluated for impairment	52	635	52	635	50
Collectively evaluated for impairment	14,909	14,324	14,909	14,324	14,032
Loans acquired with deteriorated credit quality
Loans receivable:
Ending balance - total	850,060	810,106	850,060	810,106	819,439
Ending balances: Loans
Individually evaluated for impairment	1,739	9,508	1,739	9,508	1,705
Collectively evaluated for impairment	848,321	800,598	848,321	800,598	817,734
Loans acquired with deteriorated credit quality
Real estate home equity lines of credit
Beginning balance	2,040	2,132	1,884	1,690	1,690
Charge-offs	(265)	(281)	(889)	(732)	(3,287)
Recoveries	4	85	62	119	209
Provisions	282	210	1,004	1,069	3,272
Ending balance	2,061	2,146	2,061	2,146	1,884
Ending balances: Allowance for loan losses
Individually evaluated for impairment		439		439
Collectively evaluated for impairment	2,061	1,707	2,061	1,707	1,884
Loans acquired with deteriorated credit quality
Loans receivable:
Ending balance - total	198,281	207,686	198,281	207,686	220,880
Ending balances: Loans
Individually evaluated for impairment		1,331		1,331
Collectively evaluated for impairment	198,281	206,355	198,281	206,355	200,880
Loans acquired with deteriorated credit quality
Real estate mortgage commercial and other
Beginning balance	5,714	5,737	5,247	3,414	3,414
Charge-offs	(1,907)	(805)	(2,447)	(2,170)	(16,616)
Recoveries	93	6	882	47	333
Provisions	1,339	781	1,557	4,428	18,116
Ending balance	5,239	5,719	5,239	5,719	5,247
Ending balances: Allowance for loan losses
Individually evaluated for impairment	683	1,480	683	1,480	957
Collectively evaluated for impairment	4,556	4,239	4,556	4,239	4,290
Loans acquired with deteriorated credit quality
Loans receivable:
Ending balance - total	680,607	622,508	680,607	622,508	627,940
Ending balances: Loans
Individually evaluated for impairment	14,040	21,918	14,040	21,918	15,040
Collectively evaluated for impairment	666,567	600,590	666,567	600,590	612,900
Loans acquired with deteriorated credit quality
Consumer
Beginning balance	1,791	1,826	1,939	1,872	1,872
Charge-offs	(562)	(334)	(1,090)	(686)	(1,539)
Recoveries	106	62	243	132	273
Provisions	368	237	611	473	1,333
Ending balance	1,703	1,791	1,703	1,791	1,939
Ending balances: Allowance for loan losses
Individually evaluated for impairment
Collectively evaluated for impairment	1,703	1,791	1,703	1,791	1,939
Loans acquired with deteriorated credit quality
Loans receivable:
Ending balance - total	51,453	54,831	51,453	54,831	55,711
Ending balances: Loans
Individually evaluated for impairment
Collectively evaluated for impairment	51,453	54,831	51,453	54,831	55,711
Loans acquired with deteriorated credit quality
Unallocated
Beginning balance	125	18	948	16	16
Charge-offs			(659)
Recoveries
Provisions	174	10	10	12	932
Ending balance	299	28	299	28	948
Ending balances: Allowance for loan losses
Individually evaluated for impairment
Collectively evaluated for impairment	299	28	299	28	948
Loans acquired with deteriorated credit quality
Ending balances: Loans
Individually evaluated for impairment
Collectively evaluated for impairment
Loans acquired with deteriorated credit quality