Loans (Impaired Loans Disclosure) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, recorded investment	$ 56,985	$ 62,282
With an allowance recorded, recorded investment	16,097	15,312
Impaired Financing Receivable, Recorded Investment	73,082	77,594
With no related allowance recorded, unpaid principal balance	74,277	80,510
With an allowance recorded, unpaid principal balance	19,357	18,904
Impaired Financing Receivable, Unpaid Principal Balance	93,634	99,414
Related allowance	3,129	1,737
Purchased impaired loans with subsequent deterioration	176,048	192,115
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance	178,265	196,617
Purchased impaired loans with subsequent deterioration, related allowance	5,373	5,373
Commercial and agricultural [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, recorded investment	875	1,755
With an allowance recorded, recorded investment	917	579
Impaired Financing Receivable, Recorded Investment	1,792	2,334
With no related allowance recorded, unpaid principal balance	1,413	2,608
With an allowance recorded, unpaid principal balance	917	602
Impaired Financing Receivable, Unpaid Principal Balance	2,330	3,210
Related allowance	227	282
Purchased impaired loans with subsequent deterioration	9,930	11,533
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance	9,800	11,728
Purchased impaired loans with subsequent deterioration, related allowance	545	524
Real estate - construction [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, recorded investment	8,953	11,875
With an allowance recorded, recorded investment	2,080	1,658
Impaired Financing Receivable, Recorded Investment	11,033	13,533
With no related allowance recorded, unpaid principal balance	14,910	18,553
With an allowance recorded, unpaid principal balance	2,159	1,843
Impaired Financing Receivable, Unpaid Principal Balance	17,069	20,396
Related allowance	501	82
Purchased impaired loans with subsequent deterioration	1,986	2,285
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance	1,924	2,236
Purchased impaired loans with subsequent deterioration, related allowance	197	200
Real estate - mortgage, 1-4 family residential [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, recorded investment	14,310	16,437
With an allowance recorded, recorded investment	4,599	1,681
Impaired Financing Receivable, Recorded Investment	18,909	18,118
With no related allowance recorded, unpaid principal balance	17,861	20,764
With an allowance recorded, unpaid principal balance	5,360	1,745
Impaired Financing Receivable, Unpaid Principal Balance	23,221	22,509
Related allowance	1,317	607
Purchased impaired loans with subsequent deterioration	33,174	34,961
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance	33,776	35,802
Purchased impaired loans with subsequent deterioration, related allowance	730	711
Real estate - mortgage, commercial [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, recorded investment	32,847	32,215
With an allowance recorded, recorded investment	8,501	11,394
Impaired Financing Receivable, Recorded Investment	41,348	43,609
With no related allowance recorded, unpaid principal balance	40,093	38,585
With an allowance recorded, unpaid principal balance	10,921	14,714
Impaired Financing Receivable, Unpaid Principal Balance	51,014	53,299
Related allowance	1,084	766
Purchased impaired loans with subsequent deterioration	129,655	141,974
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance	131,753	145,704
Purchased impaired loans with subsequent deterioration, related allowance	3,351	3,388
Consumer [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, recorded investment	0	0
With an allowance recorded, recorded investment	0	0
Impaired Financing Receivable, Recorded Investment	0	0
With no related allowance recorded, unpaid principal balance	0	0
With an allowance recorded, unpaid principal balance	0	0
Impaired Financing Receivable, Unpaid Principal Balance	0	0
Related allowance	0	0
Purchased impaired loans with subsequent deterioration	1,303	1,362
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance	1,012	1,147
Purchased impaired loans with subsequent deterioration, related allowance	$ 550	$ 550