Loans and Allowance for Credit Losses (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Recorded investment and unpaid principal balance for impaired loans with the associated allowance
Recorded Investment	$ 84,943		$ 84,943		$ 98,752
Unpaid Principal Balance	115,972		115,972		130,627
Related Allowance	11,734		11,734		13,236
Average Recorded Investment	82,037	143,855	82,098	135,270
Interest Income Recognized	38	251	105	282
Commercial, Financial, Agricultural and Other with No Related Allowance [Member]
Recorded investment and unpaid principal balance for impaired loans with the associated allowance
Recorded Investment	6,003		6,003		2,010
Unpaid Principal Balance	7,034		7,034		3,418
Related Allowance	0		0		0
Average Recorded Investment	7,735	2,297	10,291	3,167
Interest Income Recognized	3	2	21	5
Real Estate Construction with No Related Allowance [Member]
Recorded investment and unpaid principal balance for impaired loans with the associated allowance
Recorded Investment	4,132		4,132		10,814
Unpaid Principal Balance	10,281		10,281		20,161
Related Allowance	0		0		0
Average Recorded Investment	10,118	10,204	7,268	12,727
Interest Income Recognized	0	2	0	2
Residential Real Estate with No Related Allowance [Member]
Recorded investment and unpaid principal balance for impaired loans with the associated allowance
Recorded Investment	3,050		3,050		3,125
Unpaid Principal Balance	3,498		3,498		3,513
Related Allowance	0		0		0
Average Recorded Investment	15,082	1,987	9,219	2,005
Interest Income Recognized	6	1	11	2
Commercial Real Estate with No Related Allowance [Member]
Recorded investment and unpaid principal balance for impaired loans with the associated allowance
Recorded Investment	30,303		30,303		36,777
Unpaid Principal Balance	31,888		31,888		41,974
Related Allowance	0		0		0
Average Recorded Investment	25,696	26,255	26,529	29,407
Interest Income Recognized	19	7	53	18
Loans to Individuals with No Related Allowance [Member]
Recorded investment and unpaid principal balance for impaired loans with the associated allowance
Recorded Investment	0		0		0
Unpaid Principal Balance	0		0		0
Related Allowance	0		0		0
Average Recorded Investment	0	7	0	16
Interest Income Recognized	0	0	0	0
Subtotal with No Related Allowance [Member]
Recorded investment and unpaid principal balance for impaired loans with the associated allowance
Recorded Investment	43,488		43,488		52,726
Unpaid Principal Balance	52,701		52,701		69,066
Related Allowance	0		0		0
Average Recorded Investment	58,631	40,750	53,307	47,322
Interest Income Recognized	28	12	85	27
Commercial, Financial, Agricultural and Other With Related Allowance [Member]
Recorded investment and unpaid principal balance for impaired loans with the associated allowance
Recorded Investment	25,972		25,972		34,056
Unpaid Principal Balance	26,685		26,685		34,341
Related Allowance	8,046		8,046		9,069
Average Recorded Investment	17,441	30,770	19,101	27,026
Interest Income Recognized	3	74	6	76
Real Estate Construction With Related Allowance [Member]
Recorded investment and unpaid principal balance for impaired loans with the associated allowance
Recorded Investment	10,928		10,928		6,298
Unpaid Principal Balance	31,827		31,827		21,402
Related Allowance	2,747		2,747		2,960
Average Recorded Investment	4,068	31,701	6,865	31,124
Interest Income Recognized	0	1	0	2
Residential Real Estate With Related Allowance [Member]
Recorded investment and unpaid principal balance for impaired loans with the associated allowance
Recorded Investment	1,820		1,820		955
Unpaid Principal Balance	1,820		1,820		955
Related Allowance	431		431		93
Average Recorded Investment	644	722	797	506
Interest Income Recognized	7	0	14	0
Commercial Real Estate With Related Allowance [Member]
Recorded investment and unpaid principal balance for impaired loans with the associated allowance
Recorded Investment	2,735		2,735		4,717
Unpaid Principal Balance	2,939		2,939		4,863
Related Allowance	510		510		1,114
Average Recorded Investment	1,253	39,912	2,028	29,292
Interest Income Recognized	0	164	0	177
Loans to Individuals with Related Allowance [Member]
Recorded investment and unpaid principal balance for impaired loans with the associated allowance
Recorded Investment	0		0		0
Unpaid Principal Balance	0		0		0
Related Allowance	0		0		0
Average Recorded Investment	0	0	0	0
Interest Income Recognized	0	0	0	0
Subtotal With Related Allowance [Member]
Recorded investment and unpaid principal balance for impaired loans with the associated allowance
Recorded Investment	41,455		41,455		46,026
Unpaid Principal Balance	63,271		63,271		61,561
Related Allowance	11,734		11,734		13,236
Average Recorded Investment	23,406	103,105	28,791	87,948
Interest Income Recognized	$ 10	$ 239	$ 20	$ 255