Loans and Allowance for Loan Losses (Impaired Loans Disclosure) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, recorded investment	$ 62,282	$ 53,884
With an allowance recorded, recorded investment	15,312	42,357
Impaired Financing Receivable, Recorded Investment	77,594	96,241
With no related allowance recorded, unpaid principal balance	80,510	76,783
With an allowance recorded, unpaid principal balance	18,904	44,208
Impaired Financing Receivable, Unpaid Principal Balance	99,414	120,991
Related allowance	1,737	11,090
Financing Receivable, Acquired with Deteriorated Credit Quality	192,115	0
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance	196,617
Financing Receivable, Allowance for Credit Losses, Acquired with Deteriorated Credit Quality	5,373	0
Commercial and agricultural [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, recorded investment	1,755	2,354
With an allowance recorded, recorded investment	579	1,536
Impaired Financing Receivable, Recorded Investment	2,334	3,890
With no related allowance recorded, unpaid principal balance	2,608	4,346
With an allowance recorded, unpaid principal balance	602	2,047
Impaired Financing Receivable, Unpaid Principal Balance	3,210	6,393
Related allowance	282	1,506
Financing Receivable, Acquired with Deteriorated Credit Quality	11,533	0
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance	11,728
Financing Receivable, Allowance for Credit Losses, Acquired with Deteriorated Credit Quality	524	0
Real estate - construction [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, recorded investment	11,875	16,351
With an allowance recorded, recorded investment	1,658	14,109
Impaired Financing Receivable, Recorded Investment	13,533	30,460
With no related allowance recorded, unpaid principal balance	18,553	25,714
With an allowance recorded, unpaid principal balance	1,843	14,718
Impaired Financing Receivable, Unpaid Principal Balance	20,396	40,432
Related allowance	82	4,899
Financing Receivable, Acquired with Deteriorated Credit Quality	2,285	0
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance	2,236
Financing Receivable, Allowance for Credit Losses, Acquired with Deteriorated Credit Quality	200	0
Real estate - mortgage, 1-4 family residential [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, recorded investment	16,437	13,003
With an allowance recorded, recorded investment	1,681	11,883
Impaired Financing Receivable, Recorded Investment	18,118	24,886
With no related allowance recorded, unpaid principal balance	20,764	19,657
With an allowance recorded, unpaid principal balance	1,745	12,328
Impaired Financing Receivable, Unpaid Principal Balance	22,509	31,985
Related allowance	607	2,140
Financing Receivable, Acquired with Deteriorated Credit Quality	34,961	0
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance	35,802
Financing Receivable, Allowance for Credit Losses, Acquired with Deteriorated Credit Quality	711	0
Real estate - mortgage, commercial [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, recorded investment	32,215	22,176
With an allowance recorded, recorded investment	11,394	14,659
Impaired Financing Receivable, Recorded Investment	43,609	36,835
With no related allowance recorded, unpaid principal balance	38,585	26,964
With an allowance recorded, unpaid principal balance	14,714	14,943
Impaired Financing Receivable, Unpaid Principal Balance	53,299	41,907
Related allowance	766	2,415
Financing Receivable, Acquired with Deteriorated Credit Quality	141,974	0
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance	145,704
Financing Receivable, Allowance for Credit Losses, Acquired with Deteriorated Credit Quality	3,388	0
Consumer [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, recorded investment	0	0
With an allowance recorded, recorded investment	0	170
Impaired Financing Receivable, Recorded Investment	0	170
With no related allowance recorded, unpaid principal balance	0	102
With an allowance recorded, unpaid principal balance	0	172
Impaired Financing Receivable, Unpaid Principal Balance	0	274
Related allowance	0	130
Financing Receivable, Acquired with Deteriorated Credit Quality	1,362	0
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance	1,147
Financing Receivable, Allowance for Credit Losses, Acquired with Deteriorated Credit Quality	$ 550	$ 0