Loans and the Allowance for Loan Losses (Details 1) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Past due and nonaccrual loans
Total Loans	$ 2,800,163	$ 2,581,084
Unearned income	(7)	(15)
Commercial, financial, agricultural [Member]
Past due and nonaccrual loans
Total Loans	311,056	278,091
Lease financing [Member]
Past due and nonaccrual loans
Total Loans	224	343
Real estate - construction [Member]
Past due and nonaccrual loans
Total Loans	105,454	81,235
Real estate - 1-4 family mortgage [Member]
Past due and nonaccrual loans
Total Loans	883,396	824,627
Real estate - commercial mortgage [Member]
Past due and nonaccrual loans
Total Loans	1,440,880	1,336,635
Installment loans to individuals [Member]
Past due and nonaccrual loans
Total Loans	59,160	60,168
Accruing Loans [Member]
Past due and nonaccrual loans
30-89 Days Past Due	20,250	21,242
90 Days or More Past Due	2,358	4,894
Current Loans	2,683,798	2,435,760
Total Loans	2,706,406	2,461,896
Unearned income, Current Loans	(7)	(15)
Unearned income	(7)	(15)
Accruing Loans [Member] | Commercial, financial, agricultural [Member]
Past due and nonaccrual loans
30-89 Days Past Due	287	2,071
90 Days or More Past Due	18	165
Current Loans	306,897	269,078
Total Loans	307,202	271,314
Accruing Loans [Member] | Lease financing [Member]
Past due and nonaccrual loans
30-89 Days Past Due
90 Days or More Past Due
Current Loans	224	343
Total Loans	224	343
Accruing Loans [Member] | Real estate - construction [Member]
Past due and nonaccrual loans
30-89 Days Past Due
90 Days or More Past Due		41
Current Loans	103,522	73,670
Total Loans	103,522	73,711
Accruing Loans [Member] | Real estate - 1-4 family mortgage [Member]
Past due and nonaccrual loans
30-89 Days Past Due	11,915	11,949
90 Days or More Past Due	1,325	2,481
Current Loans	840,363	771,596
Total Loans	853,603	786,026
Accruing Loans [Member] | Real estate - commercial mortgage [Member]
Past due and nonaccrual loans
30-89 Days Past Due	7,787	6,749
90 Days or More Past Due	961	2,044
Current Loans	1,374,260	1,262,068
Total Loans	1,383,008	1,270,861
Accruing Loans [Member] | Installment loans to individuals [Member]
Past due and nonaccrual loans
30-89 Days Past Due	261	473
90 Days or More Past Due	54	163
Current Loans	58,539	59,020
Total Loans	58,854	59,656
Accruing Loans [Member] | Unearned income [Member]
Past due and nonaccrual loans
30-89 Days Past Due
90 Days or More Past Due
Non Accruing Loans [Member]
Past due and nonaccrual loans
30-89 Days Past Due	3,282	4,072
90 Days or More Past Due	70,456	107,789
Current Loans	20,019	7,327
Total Loans	93,757	119,188
Unearned income, Current Loans
Unearned income
Non Accruing Loans [Member] | Commercial, financial, agricultural [Member]
Past due and nonaccrual loans
30-89 Days Past Due	5	511
90 Days or More Past Due	3,615	5,474
Current Loans	234	792
Total Loans	3,854	6,777
Non Accruing Loans [Member] | Lease financing [Member]
Past due and nonaccrual loans
30-89 Days Past Due
90 Days or More Past Due
Current Loans
Total Loans
Non Accruing Loans [Member] | Real estate - construction [Member]
Past due and nonaccrual loans
30-89 Days Past Due
90 Days or More Past Due	1,932	7,524
Current Loans
Total Loans	1,932	7,524
Non Accruing Loans [Member] | Real estate - 1-4 family mortgage [Member]
Past due and nonaccrual loans
30-89 Days Past Due	2,627	1,140
90 Days or More Past Due	13,697	31,457
Current Loans	13,469	6,004
Total Loans	29,793	38,601
Non Accruing Loans [Member] | Real estate - commercial mortgage [Member]
Past due and nonaccrual loans
30-89 Days Past Due	645	2,411
90 Days or More Past Due	50,936	62,854
Current Loans	6,291	509
Total Loans	57,872	65,774
Non Accruing Loans [Member] | Installment loans to individuals [Member]
Past due and nonaccrual loans
30-89 Days Past Due	5	10
90 Days or More Past Due	276	480
Current Loans	25	22
Total Loans	$ 306	$ 512