Loans (Details 4) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011
Schedule of Impaired loans by classes
Recorded Investment	$ 130,183	$ 140,221	$ 163,644
Unpaid Principal Balance	153,308	172,326	196,015
Related Valuation Allowance	8,138	9,286	11,621
Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	43,245	52,326	61,340
Unpaid Principal Balance	45,956	54,966	64,903
Related Valuation Allowance	8,138	9,286	11,621
Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	86,938	87,895	102,304
Unpaid Principal Balance	107,352	117,360	131,112
Related Valuation Allowance
Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	408
Unpaid Principal Balance	1,575
Commercial [Member]
Schedule of Impaired loans by classes
Recorded Investment	27,802	25,921	29,593
Unpaid Principal Balance	33,640	36,999	39,072
Related Valuation Allowance	1,423	1,480	2,127
Commercial [Member] | Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	4,112	6,362	7,278
Unpaid Principal Balance	4,183	7,650	9,096
Related Valuation Allowance	1,423	1,480	2,127
Commercial [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	23,690	19,559	22,315
Unpaid Principal Balance	28,827	29,349	29,976
Related Valuation Allowance
Real estate commercial [Member]
Schedule of Impaired loans by classes
Recorded Investment	58,528	61,003	72,939
Unpaid Principal Balance	72,563	75,619	89,097
Related Valuation Allowance	5,750	6,775	8,227
Real estate commercial [Member] | Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	19,581	20,050	29,681
Unpaid Principal Balance	21,555	21,370	31,417
Related Valuation Allowance	5,750	6,775	8,227
Real estate commercial [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	38,947	40,953	43,258
Unpaid Principal Balance	51,008	54,249	57,680
Related Valuation Allowance
Real estate construction [Member]
Schedule of Impaired loans by classes
Recorded Investment	181	156	152
Unpaid Principal Balance	181	934	1,124
Related Valuation Allowance	134
Real estate construction [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	227	156	152
Unpaid Principal Balance	1,394	934	1,124
Related Valuation Allowance
Land development [Member]
Schedule of Impaired loans by classes
Recorded Investment	8,439	11,089	14,097
Unpaid Principal Balance	10,524	16,722	19,859
Related Valuation Allowance	154	327	522
Land development [Member] | Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	972	902	2,225
Unpaid Principal Balance	1,008	934	2,234
Related Valuation Allowance	154	327	522
Land development [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	7,467	10,187	11,872
Unpaid Principal Balance	9,516	15,788	17,625
Related Valuation Allowance
Real estate residential [Member]
Schedule of Impaired loans by classes
Recorded Investment	31,012	37,585	39,965
Unpaid Principal Balance	31,012	37,585	39,965
Related Valuation Allowance	677	704	745
Real estate residential [Member] | Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	18,399	25,012	22,156
Unpaid Principal Balance	18,399	25,012	22,156
Related Valuation Allowance	677	704	745
Real estate residential [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	12,613	12,573	17,809
Unpaid Principal Balance	12,613	12,573	17,809
Related Valuation Allowance
Consumer installment [Member]
Schedule of Impaired loans by classes
Recorded Investment	1,182	1,707	3,205
Unpaid Principal Balance	1,182	1,707	3,205
Related Valuation Allowance	0
Consumer installment [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	1,182	1,707	3,205
Unpaid Principal Balance	1,182	1,707	3,205
Related Valuation Allowance
Home equity [Member]
Schedule of Impaired loans by classes
Recorded Investment	2,812	2,760	3,693
Unpaid Principal Balance	2,812	2,760	3,693
Related Valuation Allowance	0
Home equity [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	2,812	2,760	3,693
Unpaid Principal Balance	2,812	2,760	3,693
Related Valuation Allowance