Loans (Details 4) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011
Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	$ 45,322	$ 52,326	$ 48,590
Unpaid Principal Balance	48,835	54,966	51,383
Related Valuation Allowance	8,659	9,286	9,326
Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	83,254	87,895	104,065
Unpaid Principal Balance	103,145	117,360	132,798
Related Valuation Allowance	0	0	0
Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	128,576	140,221	152,655
Unpaid Principal Balance	151,980	172,326	184,181
Related Valuation Allowance	8,659	9,286	9,326
Commercial [Member] | Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	6,743	6,362	5,342
Unpaid Principal Balance	7,357	7,650	6,965
Related Valuation Allowance	2,240	1,480	1,562
Commercial [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	19,768	19,559	24,454
Unpaid Principal Balance	24,517	29,349	32,108
Related Valuation Allowance	0	0	0
Commercial [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	26,511	25,921	29,796
Unpaid Principal Balance	31,874	36,999	39,073
Related Valuation Allowance	2,240	1,480	1,562
Real estate commercial [Member] | Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	19,694	20,050	20,084
Unpaid Principal Balance	22,593	21,370	21,245
Related Valuation Allowance	5,344	6,775	6,759
Real estate commercial [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	36,225	40,953	44,844
Unpaid Principal Balance	48,187	54,249	58,929
Related Valuation Allowance	0	0	0
Real estate commercial [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	55,919	61,003	64,928
Unpaid Principal Balance	70,780	75,619	80,174
Related Valuation Allowance	5,344	6,775	6,759
Real estate construction [Member] | Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	127
Unpaid Principal Balance	127
Related Valuation Allowance	43
Real estate construction [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	806	156	143
Unpaid Principal Balance	806	934	1,115
Related Valuation Allowance	0	0	0
Real estate construction [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	933	156	143
Unpaid Principal Balance	933	934	1,115
Related Valuation Allowance	43	0	0
Land development [Member] | Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	2,800	902	1,748
Unpaid Principal Balance	2,800	934	1,757
Related Valuation Allowance	383	327	387
Land development [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	7,723	10,187	11,047
Unpaid Principal Balance	10,903	15,788	17,069
Related Valuation Allowance	0	0	0
Land development [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	10,523	11,089	12,795
Unpaid Principal Balance	13,703	16,722	18,826
Related Valuation Allowance	383	327	387
Real estate residential [Member] | Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	15,958	25,012	21,416
Unpaid Principal Balance	15,958	25,012	21,416
Related Valuation Allowance	649	704	618
Real estate residential [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	14,907	12,573	17,544
Unpaid Principal Balance	14,907	12,573	17,544
Related Valuation Allowance	0	0	0
Real estate residential [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	30,865	37,585	38,960
Unpaid Principal Balance	30,865	37,585	38,960
Related Valuation Allowance	649	704	618
Consumer installment [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	876	1,707	2,931
Unpaid Principal Balance	876	1,707	2,931
Related Valuation Allowance	0	0	0
Consumer installment [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	876	1,707	2,931
Unpaid Principal Balance	876	1,707	2,931
Related Valuation Allowance	0	0	0
Home equity [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	2,949	2,760	3,102
Unpaid Principal Balance	2,949	2,760	3,102
Related Valuation Allowance	0	0	0
Home equity [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	2,949	2,760	3,102
Unpaid Principal Balance	2,949	2,760	3,102
Related Valuation Allowance	$ 0	$ 0	$ 0