Allowance for Loan Losses (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010
Allowance for loan losses:
Ending balance (total allowance)	$ 29,227	$ 40,008	$ 39,958	$ 49,911	$ 47,539	$ 28,419
Ending balance: individually evaluated for impairment	5,019		10,626
Ending balance: collectively evaluated for impairment	24,208		29,332
Loan balances:
Ending balance (loan portfolio) (1)	847,797		969,111
Ending balance: individually evaluated for impairment	84,689		135,100
Ending balance: collectively evaluated for impairment	763,108		834,011
Commercial, financial and agricultural [Member]
Allowance for loan losses:
Ending balance (total allowance)	16,319		25,080
Ending balance: individually evaluated for impairment	3,336		7,477
Ending balance: collectively evaluated for impairment	12,983		17,603
Loan balances:
Ending balance (loan portfolio) (1)	200,093		206,652
Ending balance: individually evaluated for impairment	24,379		36,559
Ending balance: collectively evaluated for impairment	175,714		170,093
Commercial real estate [Member]
Allowance for loan losses:
Ending balance (total allowance)	8,851		11,029
Ending balance: individually evaluated for impairment	281		3,092
Ending balance: collectively evaluated for impairment	8,570		7,937
Loan balances:
Ending balance (loan portfolio) (1)	364,317		428,646
Ending balance: individually evaluated for impairment	31,636		66,402
Ending balance: collectively evaluated for impairment	332,681		362,244
Real estate construction loans [Member]
Allowance for loan losses:
Ending balance (total allowance)	176		623
Ending balance: individually evaluated for impairment			57
Ending balance: collectively evaluated for impairment	176		566
Loan balances:
Ending balance (loan portfolio) (1)	43,632		49,704
Ending balance: individually evaluated for impairment	17,111		19,251
Ending balance: collectively evaluated for impairment	26,521		30,453
Residential mortgages (1st and 2nd liens) [Member]
Allowance for loan losses:
Ending balance (total allowance)	2,286		2,401
Ending balance: individually evaluated for impairment	930
Ending balance: collectively evaluated for impairment	1,356		2,401
Loan balances:
Ending balance (loan portfolio) (1)	146,642		160,619
Ending balance: individually evaluated for impairment	7,501		8,345
Ending balance: collectively evaluated for impairment	139,141		152,274
Home equity loans [Member]
Allowance for loan losses:
Ending balance (total allowance)	1,406		512
Ending balance: individually evaluated for impairment	468
Ending balance: collectively evaluated for impairment	938		512
Loan balances:
Ending balance (loan portfolio) (1)	75,223		79,684
Ending balance: individually evaluated for impairment	3,560		3,897
Ending balance: collectively evaluated for impairment	71,663		75,787
Consumer loans [Member]
Allowance for loan losses:
Ending balance (total allowance)	189		313
Ending balance: individually evaluated for impairment	4
Ending balance: collectively evaluated for impairment	185		313
Loan balances:
Ending balance (loan portfolio) (1)	17,890		43,806
Ending balance: individually evaluated for impairment	502		646
Ending balance: collectively evaluated for impairment	$ 17,388		$ 43,160