Loans (Summary of Impaired Loans by Classes of Loans) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	$ 34,519	$ 42,961	$ 55,058
Unpaid Principal Balance	35,272	43,751	56,741
Related Valuation Allowance	6,184	8,108	9,887
Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	89,979	86,002	83,516
Unpaid Principal Balance	112,891	106,354	110,501
Related Valuation Allowance	0	0	0
Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	124,498	128,963	138,574
Unpaid Principal Balance	148,163	150,105	167,242
Related Valuation Allowance	6,184	8,108	9,887
Commercial [Member] | Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	4,347	6,368	7,039
Unpaid Principal Balance	4,931	6,818	7,980
Related Valuation Allowance	1,629	1,966	1,936
Commercial [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	21,565	23,230	19,832
Unpaid Principal Balance	26,737	27,959	28,011
Related Valuation Allowance	0	0	0
Commercial [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	25,912	29,598	26,871
Unpaid Principal Balance	31,668	34,777	35,991
Related Valuation Allowance	1,629	1,966	1,936
Real estate commercial [Member] | Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	12,876	17,267	22,714
Unpaid Principal Balance	13,045	17,607	23,450
Related Valuation Allowance	3,893	5,359	6,913
Real estate commercial [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	42,852	37,223	38,884
Unpaid Principal Balance	56,259	48,531	52,659
Related Valuation Allowance	0	0	0
Real estate commercial [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	55,728	54,490	61,598
Unpaid Principal Balance	69,304	66,138	76,109
Related Valuation Allowance	3,893	5,359	6,913
Real estate construction [Member] | Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment		171
Unpaid Principal Balance		171
Related Valuation Allowance		75
Real estate construction [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	372	1,046	61
Unpaid Principal Balance	442	1,116	61
Related Valuation Allowance	0	0	0
Real estate construction [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	372	1,217	61
Unpaid Principal Balance	442	1,287	61
Related Valuation Allowance	0	75	0
Land development [Member] | Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment		254	1,158
Unpaid Principal Balance		254	1,164
Related Valuation Allowance		50	328
Land development [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	11,247	10,867	7,708
Unpaid Principal Balance	15,510	15,112	12,739
Related Valuation Allowance	0	0	0
Land development [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	11,247	11,121	8,866
Unpaid Principal Balance	15,510	15,366	13,903
Related Valuation Allowance	0	50	328
Real estate residential [Member] | Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	17,296	18,901	24,147
Unpaid Principal Balance	17,296	18,901	24,147
Related Valuation Allowance	662	658	710
Real estate residential [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	10,407	10,164	12,687
Unpaid Principal Balance	10,407	10,164	12,687
Related Valuation Allowance	0	0	0
Real estate residential [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	27,703	29,065	36,834
Unpaid Principal Balance	27,703	29,065	36,834
Related Valuation Allowance	662	658	710
Consumer installment [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	699	739	1,278
Unpaid Principal Balance	699	739	1,278
Related Valuation Allowance	0	0	0
Consumer installment [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	699	739	1,278
Unpaid Principal Balance	699	739	1,278
Related Valuation Allowance	0	0	0
Home equity [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	2,837	2,733	3,066
Unpaid Principal Balance	2,837	2,733	3,066
Related Valuation Allowance	0	0	0
Home equity [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	2,837	2,733	3,066
Unpaid Principal Balance	2,837	2,733	3,066
Related Valuation Allowance	$ 0	$ 0	$ 0