Loans and Asset Quality Information (Details 8) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011
30-59 Days Past Due	$ 22,722	$ 22,901
60-89 Days Past Due	8,976	11,385
Nonaccrual loans	107,032	115,038	108,627
Current	2,300,863	2,279,782
Total non-covered loans	2,137,074	2,069,152	2,058,724
[UnamortizedNetDeferredLoanCosts]	1,478	1,280	1,295
Total Covered Loans - Carrying Value	303,997	361,234	373,824
Loans	2,441,071	2,430,386	2,432,548
Commercial Unsecured
Nonaccrual loans	293	452
Commercial Secured
Nonaccrual loans	3,389	2,548
Secured by Inventory and Accounts Receivable
Nonaccrual loans	732	690
Real Estate construction, land development and other land loans
Nonaccrual loans	34,890	43,976
Total non-covered loans	236,960	246,805	254,361
Real estate residential, farmland and mutli-family
Nonaccrual loans	30,993	36,480
Total non-covered loans	826,953	795,655	785,412
Real estate home equity lines of credit
Nonaccrual loans	3,937	4,229
Total non-covered loans	203,154	207,436	211,999
Real estate commercial
Nonaccrual loans	29,910	23,662
Total non-covered loans	640,578	587,183	576,459
Consumer
Nonaccrual loans	2,888	3,001
Total non-covered loans	56,235	58,436	59,653
Non-covered
30-59 Days Past Due		16,390	17,604
60-89 Days Past Due		7,997	6,393
Nonaccrual loans	69,413	73,566	69,413
Current		1,969,919	2,042,186
Total non-covered loans	2,135,596	2,067,872	2,135,596
Non-covered | Commercial Unsecured
30-59 Days Past Due	289	67
60-89 Days Past Due	61	591
Nonaccrual loans	104	452
Current	36,379	37,668
Total non-covered loans	36,833	38,778
Non-covered | Commercial Secured
30-59 Days Past Due	930	672
60-89 Days Past Due	336	207
Nonaccrual loans	3,386	2,190
Current	108,956	108,682
Total non-covered loans	113,608	111,751
Non-covered | Secured by Inventory and Accounts Receivable
30-59 Days Past Due	32	247
60-89 Days Past Due
Nonaccrual loans	701	588
Current	20,542	20,993
Total non-covered loans	21,275	21,828
Non-covered | Real Estate construction, land development and other land loans
30-59 Days Past Due	2,021	1,250
60-89 Days Past Due	1,690	1,411
Nonaccrual loans	16,858	22,772
Current	216,391	221,372
Total non-covered loans	236,960	246,805
Non-covered | Real estate residential, farmland and mutli-family
30-59 Days Past Due	8,532	9,751
60-89 Days Past Due	2,997	4,259
Nonaccrual loans	21,980	25,430
Current	793,444	756,215
Total non-covered loans	826,953	795,655
Non-covered | Real estate home equity lines of credit
30-59 Days Past Due	1,337	1,126
60-89 Days Past Due	315	237
Nonaccrual loans	3,211	3,161
Current	198,291	202,912
Total non-covered loans	203,154	207,436
Non-covered | Real estate commercial
30-59 Days Past Due	3,925	2,620
60-89 Days Past Due	756	1,006
Nonaccrual loans	20,354	16,203
Current	615,543	567,354
Total non-covered loans	640,578	587,183
Non-covered | Consumer
30-59 Days Past Due	538	657
60-89 Days Past Due	238	286
Nonaccrual loans	2,819	2,770
Current	52,640	54,723
Total non-covered loans	56,235	58,436
Covered
30-59 Days Past Due	5,118	6,511
60-89 Days Past Due	2,583	3,388
Nonaccrual loans	37,619	41,472
Current	258,677	309,863
Total non-covered loans	303,997	361,234	373,824
Covered | Commercial Unsecured
Nonaccrual loans	189
Covered | Commercial Secured
Nonaccrual loans	3	358
Covered | Secured by Inventory and Accounts Receivable
Nonaccrual loans	31	102
Covered | Real Estate construction, land development and other land loans
Nonaccrual loans	18,032	21,204
Covered | Real estate residential, farmland and mutli-family
Nonaccrual loans	9,013	11,050
Covered | Real estate home equity lines of credit
Nonaccrual loans	726	1,068
Covered | Real estate commercial
Nonaccrual loans	9,556	7,459
Covered | Consumer
Nonaccrual loans	$ 69	$ 231