Loans and Allowance for Loan Losses (Allowance for Loan Losses, by Segment Portfolio) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	$ 39,360	$ 93,687
Charge-offs	(30,968)	(128,424)
Recoveries	6,873	6,735
Provision for losses charged to continuing operations	14,049	67,362
Balance, end of period	29,314	39,360
Commercial and agricultural [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	5,776	11,144
Charge-offs	(3,494)	(10,832)
Recoveries	991	855
Provision for losses charged to continuing operations	(35)	4,609
Balance, end of period	3,238	5,776
Real estate - construction [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	11,995	46,792
Charge-offs	(11,084)	(65,526)
Recoveries	3,237	2,637
Provision for losses charged to continuing operations	839	28,092
Balance, end of period	4,987	11,995
Real estate - mortgage, 1-4 family residential [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	8,885	7,742
Charge-offs	(6,422)	(11,384)
Recoveries	573	831
Provision for losses charged to continuing operations	5,665	11,696
Balance, end of period	8,701	8,885
Real estate - mortgage, commercial [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	11,063	26,851
Charge-offs	(5,510)	(36,998)
Recoveries	852	891
Provision for losses charged to continuing operations	3,222	20,319
Balance, end of period	9,627	11,063
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	1,641	1,158
Charge-offs	(4,458)	(3,684)
Recoveries	1,220	1,521
Provision for losses charged to continuing operations	4,358	2,646
Balance, end of period	$ 2,761	$ 1,641