Loans and Asset Quality Information (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Covered loans:
Impaired Purchased Loans - Carrying Value	$ 4,825	$ 7,864
Impaired Purchased Loans - Unpaid Principal Balance	8,815	17,032
Nonimpaired Purchased Loans - Carrying Value	277,489	335,370
Nonimpaired Purchased Loans - Unpaid Principal Balance	370,862	472,943
Total Covered Loans - Carrying Value	282,314	361,234
Total Covered Loans - Unpaid Principal Balance	379,677	489,975
Commercial, financial and agricultural
Covered loans:
Impaired Purchased Loans - Carrying Value	71	69
Impaired Purchased Loans - Unpaid Principal Balance	148	319
Nonimpaired Purchased Loans - Carrying Value	5,446	9,403
Nonimpaired Purchased Loans - Unpaid Principal Balance	7,009	11,736
Total Covered Loans - Carrying Value	5,517	9,472
Total Covered Loans - Unpaid Principal Balance	7,157	12,055
Real Estate construction, land development and other land loans
Covered loans:
Impaired Purchased Loans - Carrying Value	1,575	3,865
Impaired Purchased Loans - Unpaid Principal Balance	2,594	8,505
Nonimpaired Purchased Loans - Carrying Value	45,314	68,231
Nonimpaired Purchased Loans - Unpaid Principal Balance	82,676	115,489
Total Covered Loans - Carrying Value	46,889	72,096
Total Covered Loans - Unpaid Principal Balance	85,270	123,994
Real estate mortgage residential (1-4 family) first mortgages
Covered loans:
Impaired Purchased Loans - Carrying Value	794	1,214
Impaired Purchased Loans - Unpaid Principal Balance	1,902	2,639
Nonimpaired Purchased Loans - Carrying Value	135,086	157,712
Nonimpaired Purchased Loans - Unpaid Principal Balance	161,416	189,436
Total Covered Loans - Carrying Value	135,880	158,926
Total Covered Loans - Unpaid Principal Balance	163,318	192,075
Real estate mortgage home equity loans/lines of credit
Covered loans:
Impaired Purchased Loans - Carrying Value	16	127
Impaired Purchased Loans - Unpaid Principal Balance	56	577
Nonimpaired Purchased Loans - Carrying Value	19,466	23,211
Nonimpaired Purchased Loans - Unpaid Principal Balance	24,431	29,249
Total Covered Loans - Carrying Value	19,482	23,338
Total Covered Loans - Unpaid Principal Balance	24,487	29,826
Real estate mortgage commercial and other
Covered loans:
Impaired Purchased Loans - Carrying Value	2,369	2,585
Impaired Purchased Loans - Unpaid Principal Balance	4,115	4,986
Nonimpaired Purchased Loans - Carrying Value	71,404	93,428
Nonimpaired Purchased Loans - Unpaid Principal Balance	94,502	125,450
Total Covered Loans - Carrying Value	73,773	96,013
Total Covered Loans - Unpaid Principal Balance	98,617	130,436
Installment loans to individual
Covered loans:
Impaired Purchased Loans - Carrying Value		4
Impaired Purchased Loans - Unpaid Principal Balance		6
Nonimpaired Purchased Loans - Carrying Value	773	1,385
Nonimpaired Purchased Loans - Unpaid Principal Balance	828	1,583
Total Covered Loans - Carrying Value	773	1,389
Total Covered Loans - Unpaid Principal Balance	$ 828	$ 1,589