Loans and Allowance for Loan Losses (Impaired Loans Disclosure) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, recorded investment	$ 49,357	$ 62,282
With an allowance recorded, recorded investment	2,963	15,312
Impaired Financing Receivable, Recorded Investment	52,320	77,594
With no related allowance recorded, unpaid principal balance	63,186	80,510
With an allowance recorded, unpaid principal balance	3,503	18,904
Impaired Financing Receivable, Unpaid Principal Balance	66,689	99,414
Related allowance	486	1,737
Purchased impaired loans with subsequent deterioration	147,852	192,115
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance	152,166	196,617
Purchased impaired loans with subsequent deterioration, related allowance	4,066	5,373
Commercial and agricultural [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, recorded investment	416	1,755
With an allowance recorded, recorded investment	0	579
Impaired Financing Receivable, Recorded Investment	416	2,334
With no related allowance recorded, unpaid principal balance	776	2,608
With an allowance recorded, unpaid principal balance	0	602
Impaired Financing Receivable, Unpaid Principal Balance	776	3,210
Related allowance	0	282
Purchased impaired loans with subsequent deterioration	8,821	11,533
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance	9,042	11,728
Purchased impaired loans with subsequent deterioration, related allowance	34	524
Real estate - construction [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, recorded investment	9,900	11,875
With an allowance recorded, recorded investment	97	1,658
Impaired Financing Receivable, Recorded Investment	9,997	13,533
With no related allowance recorded, unpaid principal balance	14,246	18,553
With an allowance recorded, unpaid principal balance	112	1,843
Impaired Financing Receivable, Unpaid Principal Balance	14,358	20,396
Related allowance	1	82
Purchased impaired loans with subsequent deterioration	8,258	2,285
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance	8,897	2,236
Purchased impaired loans with subsequent deterioration, related allowance	747	200
Real estate - mortgage, 1-4 family residential [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, recorded investment	10,465	16,437
With an allowance recorded, recorded investment	2,595	1,681
Impaired Financing Receivable, Recorded Investment	13,060	18,118
With no related allowance recorded, unpaid principal balance	13,416	20,764
With an allowance recorded, unpaid principal balance	2,994	1,745
Impaired Financing Receivable, Unpaid Principal Balance	16,410	22,509
Related allowance	446	607
Purchased impaired loans with subsequent deterioration	26,661	34,961
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance	27,130	35,802
Purchased impaired loans with subsequent deterioration, related allowance	527	711
Real estate - mortgage, commercial [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, recorded investment	28,576	32,215
With an allowance recorded, recorded investment	271	11,394
Impaired Financing Receivable, Recorded Investment	28,847	43,609
With no related allowance recorded, unpaid principal balance	34,748	38,585
With an allowance recorded, unpaid principal balance	397	14,714
Impaired Financing Receivable, Unpaid Principal Balance	35,145	53,299
Related allowance	39	766
Purchased impaired loans with subsequent deterioration	103,028	141,974
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance	106,249	145,704
Purchased impaired loans with subsequent deterioration, related allowance	2,567	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	1,084	1,362
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance	848	1,147
Purchased impaired loans with subsequent deterioration, related allowance	$ 191	$ 550