Loans and Allowance for Loan Losses (Impaired Loans, Average Recorded Investment and Interest Income Recognized) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Financing Receivable, Impaired [Line Items]
With no related alowance recorded, average recorded investment	$ 48,800	$ 75,948	$ 50,485	$ 81,445
With no related allowance recorded, interest income recognized	7	812	102	2,188
With an allowance recorded, average recorded investment	2,975	15,301	6,109	15,790
With an allowance recorded, interest income recognized	0	84	11	378
Impaired Financing Receivable, Average Recorded Investment	51,775	91,249	56,594	97,235
Impaired Financing Receivable, Interest Income, Cash Basis Method	7	896	113	2,566
Commercial and agricultural [Member]
Financing Receivable, Impaired [Line Items]
With no related alowance recorded, average recorded investment	434	1,557	455	1,879
With no related allowance recorded, interest income recognized	0	56	7	152
With an allowance recorded, average recorded investment	0	1,274	107	1,266
With an allowance recorded, interest income recognized	0	6	0	36
Impaired Financing Receivable, Average Recorded Investment	434	2,831	562	3,145
Impaired Financing Receivable, Interest Income, Cash Basis Method	0	62	7	188
Real estate - construction [Member]
Financing Receivable, Impaired [Line Items]
With no related alowance recorded, average recorded investment	10,006	15,484	10,300	18,140
With no related allowance recorded, interest income recognized	3	104	23	350
With an allowance recorded, average recorded investment	97	2,802	220	2,873
With an allowance recorded, interest income recognized	0	9	6	32
Impaired Financing Receivable, Average Recorded Investment	10,103	18,286	10,520	21,013
Impaired Financing Receivable, Interest Income, Cash Basis Method	3	113	29	382
Real estate - mortgage, 1-4 family residential [Member]
Financing Receivable, Impaired [Line Items]
With no related alowance recorded, average recorded investment	10,516	14,265	10,442	15,096
With no related allowance recorded, interest income recognized	0	81	14	292
With an allowance recorded, average recorded investment	2,605	6,436	1,682	6,869
With an allowance recorded, interest income recognized	0	41	4	163
Impaired Financing Receivable, Average Recorded Investment	13,121	20,701	12,124	21,965
Impaired Financing Receivable, Interest Income, Cash Basis Method	0	122	18	455
Real estate - mortgage, commercial [Member]
Financing Receivable, Impaired [Line Items]
With no related alowance recorded, average recorded investment	27,844	44,480	29,288	46,051
With no related allowance recorded, interest income recognized	4	567	58	1,388
With an allowance recorded, average recorded investment	273	4,689	3,933	4,687
With an allowance recorded, interest income recognized	0	27	0	145
Impaired Financing Receivable, Average Recorded Investment	28,117	49,169	33,221	50,738
Impaired Financing Receivable, Interest Income, Cash Basis Method	4	594	58	1,533
Consumer [Member]
Financing Receivable, Impaired [Line Items]
With no related alowance recorded, average recorded investment	0	162	0	279
With no related allowance recorded, interest income recognized	0	4	0	6
With an allowance recorded, average recorded investment	0	100	167	95
With an allowance recorded, interest income recognized	0	1	1	2
Impaired Financing Receivable, Average Recorded Investment	0	262	167	374
Impaired Financing Receivable, Interest Income, Cash Basis Method	$ 0	$ 5	$ 1	$ 8