Loans (Allowance for Loan Losses, by Segment Portfolio) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	$ 29,314	$ 39,360
Charge-offs	(3,010)	(4,015)
Recoveries	3,227	1,383
Provision for losses charged to continuing operations	110	3,067
Balance, end of period	29,641	39,795
Commercial and agricultural [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	3,238	5,776
Charge-offs	(319)	(694)
Recoveries	278	254
Provision for losses charged to continuing operations	176	669
Balance, end of period	3,373	6,005
Real estate - construction [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	4,987	11,995
Charge-offs	(344)	(1,775)
Recoveries	796	601
Provision for losses charged to continuing operations	155	91
Balance, end of period	5,594	10,912
Real estate - mortgage, 1-4 family residential [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	8,701	8,885
Charge-offs	(632)	(705)
Recoveries	185	133
Provision for losses charged to continuing operations	549	3,790
Balance, end of period	8,803	12,103
Real estate - mortgage, commercial [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	9,627	11,063
Charge-offs	(891)	(38)
Recoveries	932	74
Provision for losses charged to continuing operations	(377)	(2,300)
Balance, end of period	9,291	8,799
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	2,761	1,641
Charge-offs	(824)	(803)
Recoveries	1,036	321
Provision for losses charged to continuing operations	(393)	817
Balance, end of period	$ 2,580	$ 1,976