Loans and Asset Quality Information (Details 7) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Company's nonaccrual loans:
Nonaccrual loans	$ 90,138	$ 66,525
Commercial Unsecured
Company's nonaccrual loans:
Nonaccrual loans	215	457
Commercial Secured
Company's nonaccrual loans:
Nonaccrual loans	2,385	2,401
Secured by Inventory and Accounts Receivable
Company's nonaccrual loans:
Nonaccrual loans	262	76
Real Estate construction, land development and other land loans
Company's nonaccrual loans:
Nonaccrual loans	25,565	18,052
Real estate residential, farmland and mutli-family
Company's nonaccrual loans:
Nonaccrual loans	28,225	20,341
Real estate home equity lines of credit
Company's nonaccrual loans:
Nonaccrual loans	2,000	2,087
Real estate commercial
Company's nonaccrual loans:
Nonaccrual loans	30,512	20,227
Consumer
Company's nonaccrual loans:
Nonaccrual loans	974	2,884
Non-covered
Company's nonaccrual loans:
Nonaccrual loans	38,917	33,034
Non-covered | Commercial Unsecured
Company's nonaccrual loans:
Nonaccrual loans	26	307
Non-covered | Commercial Secured
Company's nonaccrual loans:
Nonaccrual loans	2,382	2,398
Non-covered | Secured by Inventory and Accounts Receivable
Company's nonaccrual loans:
Nonaccrual loans	23	17
Non-covered | Real Estate construction, land development and other land loans
Company's nonaccrual loans:
Nonaccrual loans	7,118	6,354
Non-covered | Real estate residential, farmland and mutli-family
Company's nonaccrual loans:
Nonaccrual loans	13,551	9,629
Non-covered | Real estate home equity lines of credit
Company's nonaccrual loans:
Nonaccrual loans	1,479	1,622
Non-covered | Real estate commercial
Company's nonaccrual loans:
Nonaccrual loans	13,428	9,885
Non-covered | Consumer
Company's nonaccrual loans:
Nonaccrual loans	910	2,822
Covered
Company's nonaccrual loans:
Nonaccrual loans	51,221	33,491
Covered | Commercial Unsecured
Company's nonaccrual loans:
Nonaccrual loans	189	150
Covered | Commercial Secured
Company's nonaccrual loans:
Nonaccrual loans	3	3
Covered | Secured by Inventory and Accounts Receivable
Company's nonaccrual loans:
Nonaccrual loans	239	59
Covered | Real Estate construction, land development and other land loans
Company's nonaccrual loans:
Nonaccrual loans	18,447	11,698
Covered | Real estate residential, farmland and mutli-family
Company's nonaccrual loans:
Nonaccrual loans	14,674	10,712
Covered | Real estate home equity lines of credit
Company's nonaccrual loans:
Nonaccrual loans	521	465
Covered | Real estate commercial
Company's nonaccrual loans:
Nonaccrual loans	17,084	10,342
Covered | Consumer
Company's nonaccrual loans:
Nonaccrual loans	$ 64	$ 62