Loans and Asset Quality Information (Details 2) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Covered loans:
Impaired Purchased Loans - Carrying Value	$ 4,726	$ 4,825
Impaired Purchased Loans - Unpaid Principal Balance	8,774	8,815
Nonimpaired Purchased Loans - Carrying Value	258,742	277,489
Nonimpaired Purchased Loans - Unpaid Principal Balance	349,140	370,862
Total Covered Loans - Carrying Value	263,468	282,314	342,100
Total Covered Loans - Unpaid Principal Balance	357,914	379,677
Commercial, financial and agricultural
Covered loans:
Impaired Purchased Loans - Carrying Value	70	71
Impaired Purchased Loans - Unpaid Principal Balance	144	148
Nonimpaired Purchased Loans - Carrying Value	4,769	5,446
Nonimpaired Purchased Loans - Unpaid Principal Balance	6,782	7,009
Total Covered Loans - Carrying Value	4,839	5,517
Total Covered Loans - Unpaid Principal Balance	6,926	7,157
Real Estate construction, land development and other land loans
Covered loans:
Impaired Purchased Loans - Carrying Value	1,571	1,575
Impaired Purchased Loans - Unpaid Principal Balance	2,587	2,594
Nonimpaired Purchased Loans - Carrying Value	39,072	45,314
Nonimpaired Purchased Loans - Unpaid Principal Balance	75,283	82,676
Total Covered Loans - Carrying Value	40,643	46,889
Total Covered Loans - Unpaid Principal Balance	77,870	85,270
Real estate mortgage residential (1-4 family) first mortgages
Covered loans:
Impaired Purchased Loans - Carrying Value	773	794
Impaired Purchased Loans - Unpaid Principal Balance	1,895	1,902
Nonimpaired Purchased Loans - Carrying Value	130,265	135,086
Nonimpaired Purchased Loans - Unpaid Principal Balance	155,901	161,416
Total Covered Loans - Carrying Value	131,038	135,880
Total Covered Loans - Unpaid Principal Balance	157,796	163,318
Real estate mortgage home equity loans/lines of credit
Covered loans:
Impaired Purchased Loans - Carrying Value	16	16
Impaired Purchased Loans - Unpaid Principal Balance	55	56
Nonimpaired Purchased Loans - Carrying Value	18,639	19,466
Nonimpaired Purchased Loans - Unpaid Principal Balance	23,289	24,431
Total Covered Loans - Carrying Value	18,655	19,482
Total Covered Loans - Unpaid Principal Balance	23,344	24,487
Real estate mortgage commercial and other
Covered loans:
Impaired Purchased Loans - Carrying Value	2,296	2,369
Impaired Purchased Loans - Unpaid Principal Balance	4,093	4,115
Nonimpaired Purchased Loans - Carrying Value	65,265	71,404
Nonimpaired Purchased Loans - Unpaid Principal Balance	87,109	94,502
Total Covered Loans - Carrying Value	67,561	73,773
Total Covered Loans - Unpaid Principal Balance	91,202	98,617
Installment loans to individual
Covered loans:
Impaired Purchased Loans - Carrying Value
Impaired Purchased Loans - Unpaid Principal Balance
Nonimpaired Purchased Loans - Carrying Value	732	773
Nonimpaired Purchased Loans - Unpaid Principal Balance	776	828
Total Covered Loans - Carrying Value	732	773
Total Covered Loans - Unpaid Principal Balance	$ 776	$ 828